Top-level domain

A top-level domain (TLD) is one of the domains at the highest level in the hierarchical Domain Name System of the Internet. The top-level domain names are installed in the root zone of the name space. For all domains in lower levels, it is the last part of the domain name, that is, the last label of a fully qualified domain name. For example, in the domain name www.example.com, the top-level domain is .com, or .COM, as domain names are not case-sensitive. Management of most top-level domains is delegated to responsible organizations by the Internet Corporation for Assigned Names and Numbers (ICANN), which operates the Internet Assigned Numbers Authority (IANA) and is in charge of maintaining the DNS root zone.

Originally, the top-level domain space was organized into three main groups, Countries, Categories, and Multiorganizations. An additional temporary group consisted only of the initial DNS domain, arpa, intended for transitional purposes toward the stabilization of the domain name system.

Countries are designated in the Domain Name System by their two-letter ISO country code; there are exceptions, however (e.g., .uk). This group of domains is therefore commonly known as country-code top-level domains (ccTLD). Since 2009, countries with non-Latin based alphabets or scripting systems may apply for internationalized country code top-level domain names, which are displayed in end-user applications in their language-native script or alphabet, but use a Punycode-translated ASCII domain name in the Domain Name System.

The Categories group has become known as the generic top-level domains. Initially this group consisted of GOV, EDU, COM, MIL, ORG, and NET.

In the growth of the Internet, it became desirable to create additional generic top-level domains. Some of the initial domains' purposes were also generalized, modified, or assigned for maintenance to special organizations affiliated with the intended purpose.

As a result, IANA today distinguishes the following groups of top-level domains:

country-code top-level domains (ccTLD): Two letter domains established for countries or territories. With some historical exceptions, the code for any territory is the same as its two-letter ISO 3166 code.

internationalized country code top-level domains (IDN ccTLD).

generic top-level domains (gTLD): Top-level domains with three or more characters

unsponsored top-level domains: domains that operate directly under policies established by ICANN processes for the global Internet community.

sponsored top-level domains (sTLD): These domains are proposed and sponsored by private agencies or organizations that establish and enforce rules restricting the eligibility to use the TLD. Use is based on community theme concepts.

infrastructure top-level domain: This group consists of one domain, the Address and Routing Parameter Area (ARPA). It is managed by IANA on behalf of the Internet Engineering Task Force for various purposes specified in the Request for Comments publications.

In addition, a group of internationalized domain name (IDN) top-level domains has been installed under test for testing purposes in the IDN development process.

The authoritative list of currently existing TLDs in the root zone is published at the IANA website at http://www.iana.org/domains/root/db/.

Tags:  ICANN , Generic top-level domain ,  Domain name registration ,Domain name

ICANN

Internet Corporation for Assigned Names and Numbers (ICANN, /ˈaɪkæn/ eye-kan) is a non-profit corporation headquartered in Marina del Rey, California, United States, that was created on September 18, 1998, and incorporated on September 30, 1998 to oversee a number of Internet-related tasks previously performed directly on behalf of the U.S. government by other organizations, notably the Internet Assigned Numbers Authority (IANA).

ICANN is responsible for managing the Internet Protocol address spaces (IPv4 and IPv6) and assignment of address blocks to regional Internet registries, for maintaining registries of Internet protocol identifiers, and for the management of the top-level domain name space (DNS root zone), which includes the operation of root nameservers. Most visibly, much of its work has concerned the introduction of new generic top-level domains (TLDs). The technical work of ICANN is referred to as the "IANA function".

ICANN's primary principles of operation have been described as helping preserve the operational stability of the Internet; to promote competition; to achieve broad representation of global Internet community; and to develop policies appropriate to its mission through bottom-up, consensus-based processes.

On September 29, 2006, ICANN signed a new agreement with the United States Department of Commerce (DOC) that moves the private organization towards full management of the Internet's system of centrally coordinated identifiers through the multi-stakeholder model of consultation that ICANN represents.

Structure

At present, ICANN is formally organized as a non-profit corporation "for charitable and public purposes" under the California Nonprofit Public Benefit Corporation Law. It is managed by a Board of Directors, which is composed of six representatives of the Supporting Organizations, sub-groups that deal with specific sections of the policies under ICANN's purview; eight independent representatives of the general public interest, selected through a Nominating Committee in which all the constituencies of ICANN are represented; and the President and CEO, appointed by the rest of the Board.

There are currently three Supporting Organizations. The Generic Names Supporting Organization (GNSO) deals with policy making on generic top-level domains (gTLDs). The Country Code Names Supporting Organization (ccNSO) deals with policy making on country-code top-level domains (ccTLDs). The Address Supporting Organization (ASO) deals with policy making on IP addresses.

ICANN also relies on some advisory committees to receive advice on the interests and needs of stakeholders that do not directly participate in the Supporting Organizations. These include the Governmental Advisory Committee (GAC), which is composed of representatives of a large number of national governments from all over the world; the At-Large Advisory Committee (ALAC) which is composed of representatives of organizations of individual Internet users from around the world; the Root Server System Advisory Committee which provides advice on the operation of the DNS root server system; the Security and Stability Advisory Committee (SSAC) which is composed of Internet experts who study security issues pertaining to ICANN's mandate; and the Technical Liaison Group (TLG) which is composed of representatives of other international technical organizations that focus, at least in part, on the Internet.

Democratic input

In the Memorandum of Understanding that set up the relationship between ICANN and the U.S. government, ICANN was given a mandate requiring that it operate "in a bottom up, consensus driven, democratic manner." However, the attempts that ICANN have made to set up an organizational structure that would allow wide input from the global Internet community did not produce results amenable to the current Board. As a result, the At-Large constituency and direct election of board members by the global Internet community were soon abandoned.

ICANN holds periodic public meetings rotated between continents for the purpose of encouraging global participation in its processes. Critics who? argue that these public meetings are often held in countries with lower Internet usage and far away from locations that the majority of the Internet-using public can afford to reach. This makes public input or participation from traditional Internet users less likely. Supporters who? reply that ICANN has a worldwide presence, and a key part of its mission is to build Internet use where it is weak.

Resolutions of the ICANN Board, preliminary reports, and minutes of the meetings, are published on the ICANN website, sometimes in real time. However there are criticisms from ICANN constituencies including the Noncommercial Users Constituency (NCUC) and the At-Large Advisory Committee (ALAC) that there is not enough public disclosure and that too many discussions and decisions take place out of sight of the public.

In the early 2000s, there had been speculation that the United Nations might signal a takeover of ICANN, followed by a negative reaction from the US government and worries about a division of the Internet the World Summit on the Information Society in Tunisia in November 2005 agreed not to get involved in the day-to-day and technical operations of ICANN. However it also agreed to set up an international Internet Governance Forum, with a consultative role on the future governance of the Internet. ICANN's Government Advisory Committee is currently set up to provide advice to ICANN regarding public policy issues and has participation by many of the world's governments.

It is argued by whom? that ICANN was never given the authority to decide policy, e.g., choose new TLDs or shut out other interested parties who refuse to pay ICANN's US$185,000 fee, but was to be a technical caretaker. Critics who? suggest that ICANN should not be allowed to impose business rules on market participants, and that all TLDs should be added on a first-come-first-served basis and the market should be the arbiter of who succeeds and who does not.

A member of the European Parliament, William Newton-Dunn, has recently been addressing questions to the European Commission which asks whether ICANN is engaging in restraint of European free trade laws by imposing restrictions on who can operate a TLD and sell domain names. Some restrictions are considered insurmountable by many small business owners and individuals, such as the perhaps partially refundable $185,000 application fee.

Activities

One task that ICANN was asked to do was to address the issue of domain name ownership resolution for generic top-level domains (gTLDs). ICANN's attempt at such a policy was drafted in close cooperation with the World Intellectual Property Organization (WIPO), and the result has now become known as the Uniform Dispute Resolution Policy (UDRP). This policy essentially attempts to provide a mechanism for rapid, cheap and reasonable resolution of domain name conflicts, avoiding the traditional court system for disputes by allowing cases to be brought to one of a set of bodies that arbitrate domain name disputes. According to ICANN policy, a domain registrant must agree to be bound by the UDRP — they cannot get a domain name without agreeing to this.

A look at the UDRP decision patterns has led some to conclude that compulsory domain name arbitration is less likely to give a fair hearing to domain name owners asserting defenses under the First Amendment and other laws, compared to the federal courts of appeal in particular.

Notable events

On March 18, 2002, publicly elected At-Large Representative for North America board member Karl Auerbach sued ICANN in Superior Court in California to gain access to ICANN's accounting records without restriction. Auerbach won.

In September and October 2003, ICANN played a crucial role in the conflict over VeriSign's "wild card" DNS service Site Finder. After an open letter from ICANN issuing an ultimatum to VeriSign, later supported by the IAB, the company voluntarily shut down the service on October 4, 2003. Following this action, VeriSign filed a lawsuit against ICANN on February 27, 2004, claiming that ICANN had overstepped its authority. In this lawsuit, VeriSign sought to reduce ambiguity about ICANN's authority. The antitrust component of VeriSign's claim was dismissed in August 2004. VeriSign's broader challenge that ICANN overstepped its contractual rights is currently outstanding. A proposed settlement already approved by ICANN's board would resolve VeriSign's challenge to ICANN in exchange for the right to increase pricing on .com domains. At the meeting of ICANN in Rome which took place from March 2 to March 6, 2004, ICANN agreed to ask approval of the US Department of Commerce for the Waiting List Service of VeriSign.

On June 26, 2008, the ICANN Board started a new process of TLD naming policy to take a "significant step forward on the introduction of new generic top-level domains." This program envisions the availability of many new or already proposed domains, as well a new application and implementation process.

On October 1, 2008, ICANN issued Breach Notices against Joker and Beijing Innovative Linkage Technology Ltd. after further researching reports and complaints issued by KnujOn. These notices gave the Registrars 15 days to fix their Whois investigation efforts.

In 2010, ICANN approved a major review of its policies with respect to accountability, transparency, and public participation by the Berkman Center for Internet and Society at Harvard University. This external review was in support of the work of ICANN's Accountability and Transparency Review team.

On February 3rd, 2011, ICANN announced that it had distributed the last batch of its remaining IPv4 addresses to the world’s five Regional Internet Registries, the organizations that manage IP addresses in different regions. These Registries will begin assigning the final IPv4 addresses within their regions until they run out completely, which could come as soon as early 2012.

Expansion of allowed gTLDs

On June 20, 2011 ICANN's board voted to end most restrictions on the allowed generic top-level domain (gTLD) suffixes from the 22 currently available extensions (such as .com, .gov, .edu, etc).Companies and organizations will be able to choose essentially arbitrary suffixes for their internet domain names. The use of non-latin characters (such as Cyrillic, Arabic, Chinese, etc) will also be allowed in gTLDs. ICANN will begin accepting applications for new gTLDS on January 12, 2012. The initial price to apply for a new gTLD suffix will be $185,000.[32] It is anticipated that many corporations will apply for gTLDs based on their brands. ICANN expects that the first batch of new gTLDs will be operational by the end of 2012. ICANN expects the new rules to significantly change the face of the internet. Peter Thrush, chairman of ICANN's board of directors stated after the vote: "Today's decision will usher in a new internet age. We have provided a platform for the next generation of creativity and inspiration. Unless there is a good reason to restrain it, innovation should be allowed to run free.

History

Before the establishment of ICANN, the Government of the United States controlled the domain name system of the internet.

The original mandate for ICANN came from the United States government, spanning the presidential administrations of both Bill Clinton and George W. Bush. On January 30, 1998, the National Telecommunications and Information Administration (NTIA), an agency of the U.S. Department of Commerce, issued for comment, "A Proposal to Improve the Technical Management of Internet Names and Addresses." The proposed rule making, or "Green Paper", was published in the Federal Register on February 20, 1998, providing opportunity for public comment. NTIA received more than 650 comments as of March 23, 1998, when the comment period closed.

The Green Paper proposed certain actions designed to privatize the management of Internet names and addresses in a manner that allows for the development of robust competition and facilitates global participation in Internet management. The Green Paper proposed for discussion a variety of issues relating to DNS management including private sector creation of a new not-for-profit corporation (the "new corporation") managed by a globally and functionally representative Board of Directors. ICANN was formed in response to this policy. The IANA function currently exists under an agreement with the U.S. Department of Commerce.

ICANN was incorporated in California on September 30, 1998. It is qualified to do business in the District of Columbia. ICANN was established in California due to the presence of Jon Postel, who was a founder of ICANN and was set to be its first CTO prior to his unexpected death. ICANN remains in the same building where he worked, which is home to an office of the Information Sciences Institute at the University of Southern California.

On July 26, 2006, the United States government renewed the contract with ICANN for performance of the IANA function for an additional one to five years. The context of ICANN's relationship with the U.S. government was clarified on September 29, 2006 when ICANN signed a new Memorandum of Understanding with the United States Department of Commerce (DOC).

In July 2008, the U.S. Department of Commerce reiterated an earlier statement that it has "no plans to transition management of the authoritative root zone file to ICANN". The letter also stresses the separate roles of the IANA and VeriSign.
Tags: Top-level domain ,  Generic top-level domain ,  Domain name registration ,Domain name

Generic top-level domain

A generic top-level domain (gTLD) is one of the categories of top-level domains (TLDs) maintained by the Internet Assigned Numbers Authority (IANA) for use in the Domain Name System of the Internet.

Overall, IANA currently distinguishes the following groups of top-level domains:

infrastructure top-level domain (arpa)

country-code top-level domains (ccTLD)

internationalized top-level domains (IDNs)

internationalized country code top-level domains

testing top-level domains

generic top-level domains (gTLD)

The core group of generic top-level domains consists of the com, info, net, and org domains. In addition, the domains biz, name, and pro are also considered generic, however, these are designated as restricted, because registrations within them require proof of eligibility within the guidelines set for each.

Historically, the group of generic top-level domains included domains, created in the early development of the domain name system, that are now sponsored by designated agencies or organizations and are restricted to specific types of registrants. Thus, domains edu, gov, int, and mil are now considered sponsored top-level domains, much like the many newly created themed domain names (e.g., jobs). The entire group of domains that do not have a geographic or country designation (see country-code top-level domain) is still often referred to by the term generic TLDs.

Unrestricted gTLD

Unrestricted generic top-level domains are those domains that are available for registrations by any person or organization for any use. The prominent gTLDs in this group are com, net, org, and info. However, info was the only one of these, and the first, that was explicitly chartered as unrestricted. The others initially had a specific target audience. However, due to lack of enforcement, they acquired an unrestricted character, which was later grandfathered.

Sponsored gTLD

The term sponsored top-level domain is derived from the fact that these domains are based on theme concepts proposed by private agencies or organizations that establish and enforce rules restricting the eligibility of registrants to use the TLD. For example, the aero TLD is sponsored by the Société Internationale de Télécommunications Aéronautiques, which limits registrations to members of the air-transport industry.

Geographic gTLD

A geographic TLD (or GeoTLD) is a generic top-level domain using the name of or invoking an association with a geographical, geopolitical, ethnic, linguistic or cultural community. As of 2009, only two GeoTLDs existed: the sponsored domains .cat, for the Catalan language and culture, and .asia, but many others have been proposed (see also proposed top-level domain).

New top-level domains

The introduction of several generic top-level domains over the years has not stopped the demand for more gTLDs and ICANN has received many proposals for establishment of new top-level domains.[Proponents have argued for a variety of models ranging from adoption of policies for unrestricted gTLDs (see above) to chartered gTLDs for specialized uses by specialized organizations.

A new initiative started in 2008 foresees a stringent application process for new domains that adhere to a restricted naming policy for open gTLDs, community-based domains, and internationalized domain names (IDNs). According to a guidebook published by ICANN, a community-based gTLD is "a gTLD that is operated for the benefit of a defined community consisting of a restricted population." All other domains fall under the category open gTLD', which "is one that can be used for any purpose consistent with the requirements of the application and evaluation criteria, and with the registry agreement. An open gTLD may or may not have a formal relationship with an exclusive registrant or user population. It may or may not employ eligibility or use restrictions."

The establishment of new gTLDs under this program requires the operation of a domain registry and a demonstration of technical and financial capacity for such operations and the management of registrar relationships.

A fourth version of the draft applicant guidebook (DAG4) was published in May 2011.

June 20, 2011 vote on expansion of allowed gTLDs

On June 20, 2011 ICANN's board voted to end most restrictions on the allowed generic top-level domain (gTLD) suffixes from the 22 currently available extensions (such as .com, .gov, .edu, etc).Companies and organizations will be able to choose essentially arbitrary suffixes for their internet domain names. The use of non-latin characters (such as Cyrillic, Arabic, Chinese, etc) will also be allowed in gTLDs. ICANN will begin accepting applications for new gTLDS on January 12, 2012. The initial price to apply for a new gTLD suffix will be $185,000. It is anticipated that many corporations will apply for gTLDs based on their brands. ICANN expects that the first batch of new gTLDs will be operational by the end of 2012.ICANN expects the new rules to significantly change the face of the Internet. Peter Thrush, chairman of ICANN's board of directors stated after the vote: "Today's decision will usher in a new internet age. We have provided a platform for the next generation of creativity and inspiration. Unless there is a good reason to restrain it, innovation should be allowed to run free. Industry analysts predicted 500-1000 new gTLDs, mostly reflecting names of companies and products, but also cities as well as generic names like .bank and .sport. According to Theo Hnarakis, chief executive of Melbourne IT, the decision "will allow corporations to better take control of their brands. For example, .apple or .ipad would take customers right to those products.

Four lists that track new gTLD applicants include .Nxt, New TLDs.tv, Valideus and Registries.tel.

History

The initial set of top-level domains, defined by RFC 920 in October 1984, was a set of "general purpose domains": com, edu, gov, mil, org. The net domain was added with the first implementation of these domains. The com, net, and org TLDs, despite their originally specific goals, are now open for use for any purpose.

In November 1988, another TLD was introduced, int. This TLD was introduced in response to NATO's request for a domain name which adequately reflected its character as an international organization. It was also originally planned to be used for some Internet infrastructure databases, such as ip6.int, the IPv6 equivalent of in-addr.arpa. However, in May 2000, the Internet Architecture Board proposed to exclude infrastructure databases from the int domain. All new databases of this type would be created in arpa (a legacy domain from the conversion of ARPANET), and existing usage would move to arpa wherever feasible, which led to the use of ip6.arpa for IPv6 reverse lookups.

By the mid-1990s there was discussion of introduction of more TLDs. Jon Postel, as head of IANA, invited applications from interested parties. In early 1995, Postel created "Draft Postel", an Internet draft containing the procedures to create new domain name registries and new TLDs. Draft Postel created a number of small committees to approve the new TLDs. Because of the increasing interest, a number of large organizations took over the process under the Internet Society's umbrella. This second attempt involved setting up a temporary organization called the International Ad Hoc Committee (IAHC). On February 4, 1997, the IAHC issued a report ignoring the Draft Postel recommendations and instead recommended the introduction of seven new TLDs (arts, firm, info, nom, rec, store, and web). However, these proposals were abandoned after the U.S. government intervened.

In September 1998, the Internet Corporation for Assigned Names and Numbers (ICANN) was created to take over the task of managing domain names. After a call for proposals (August 15, 2000) and a brief period of public consultation, ICANN announced on November 16, 2000 its selection of the following seven new TLDs: aero, biz, coop, info, museum, name, pro.

Biz, info, and museum were activated in June 2001, name and coop in January 2002, pro in May 2002, and aero later in 2002. pro became a gTLD in May 2002, but did not become fully operational until June 2004. xxx was approved in March 2011 and is expected to go live before the end of 2011.

ICANN added further TLDs, starting with a set of sponsored top-level domains. The application period for these was from December 15, 2003 until March 16, 2004, and resulted in ten applications. Of these, ICANN has approved asia, cat, jobs, mobi, tel and travel, all of which are now in operation. xxx was finally approved in March 2011, one year after an independent review found ICANN had broken its own bylaws when it rejected its application in 2007. Of the remaining applications (post, mail and an alternative tel proposal), post are still under consideration.

On June 26, 2008, during the 32nd International Public ICANN Meeting in Paris, ICANN started a new process of TLD naming policy to take a "significant step forward on the introduction of new generic top-level domains." This program envisions the availability of many new or already proposed domains, as well a new application and implementation process. Observers believed that the new rules could result in hundreds of new gTLDs to be registered.

Tags: Top-level domain , ICANN , Domain name registration ,Domain name

Mesothelioma

Mesothelioma, more precisely malignant mesothelioma, is a rare form of cancer that develops from the protective lining that covers many of the body's internal organs, the mesothelium. It is usually caused by exposure to asbestos.

Its most common site is the pleura (outer lining of the lungs and internal chest wall), but it may also occur in the peritoneum (the lining of the abdominal cavity), the heart, the pericardium (a sac that surrounds the heart) or tunica vaginalis.

Most people who develop mesothelioma have worked on jobs where they inhaled asbestos particles, or they have been exposed to asbestos dust and fiber in other ways. It has also been suggested that washing the clothes of a family member who worked with asbestos can put a person at risk for developing mesothelioma. Unlike lung cancer, there is no association between mesothelioma and smoking, but smoking greatly increases the risk of other asbestos-induced cancers. Compensation via asbestos funds or lawsuits is an important issue in mesothelioma (see asbestos and the law).

The symptoms of mesothelioma include shortness of breath due to pleural effusion (fluid between the lung and the chest wall) or chest wall pain, and general symptoms such as weight loss. The diagnosis may be suspected with chest X-ray and CT scan, and is confirmed with a biopsy (tissue sample) and microscopic examination. A thoracoscopy (inserting a tube with a camera into the chest) can be used to take biopsies. It allows the introduction of substances such as talc to obliterate the pleural space (called pleurodesis), which prevents more fluid from accumulating and pressing on the lung. Despite treatment with chemotherapy, radiation therapy or sometimes surgery, the disease carries a poor prognosis. Research about screening tests for the early detection of mesothelioma is ongoing.

Signs and symptoms

Symptoms or signs of mesothelioma may not appear until 20 to 50 years (or more) after exposure to asbestos. Shortness of breath, cough, and pain in the chest due to an accumulation of fluid in the pleural space (pleural effusion) are often symptoms of pleural mesothelioma.

Symptoms of peritoneal mesothelioma include weight loss and cachexia, abdominal swelling and pain due to ascites (a buildup of fluid in the abdominal cavity). Other symptoms of Peritoneal Mesothelioma may include bowel obstruction, blood clotting abnormalities, anemia, and fever. If the cancer has spread beyond the mesothelium to other parts of the body, symptoms may include pain, trouble swallowing, or swelling of the neck or face.

These symptoms may be caused by mesothelioma or by other, less serious conditions.

Mesothelioma that affects the pleura can cause these signs and symptoms:

Chest wall pain

Pleural effusion, or fluid surrounding the lung

Shortness of breath

Fatigue or anemia

Wheezing, hoarseness, or cough

Blood in the sputum (fluid) coughed up (hemoptysis)

In severe cases, the person may have many tumor masses. The individual may develop a pneumothorax, or collapse of the lung. The disease may metastasize, or spread, to other parts of the body.

Tumors that affect the abdominal cavity often do not cause symptoms until they are at a late stage. Symptoms include:

Abdominal pain

Ascites, or an abnormal buildup of fluid in the abdomen

A mass in the abdomen

Problems with bowel function

Weight loss

In severe cases of the disease, the following signs and symptoms may be present:

Blood clots in the veins, which may cause thrombophlebitis

Disseminated intravascular coagulation, a disorder causing severe bleeding in many body organs

Jaundice, or yellowing of the eyes and skin

Low blood sugar level

Pleural effusion

Pulmonary emboli, or blood clots in the arteries of the lungs

Severe ascites

A mesothelioma does not usually spread to the bone, brain, or adrenal glands. Pleural tumors are usually found only on one side of the lungs.

Cause

Working with asbestos is the major risk factor for mesothelioma. In the United States, asbestos is the major cause of malignant mesothelioma and has been considered "indisputably" associated with the development of mesothelioma. Indeed, the relationship between asbestos and mesothelioma is so strong that many consider mesothelioma a “signal” or “sentinel” tumor. A history of asbestos exposure exists in most cases. However, mesothelioma has been reported in some individuals without any known exposure to asbestos. In rare cases, mesothelioma has also been associated with irradiation, intrapleural thorium dioxide (Thorotrast), and inhalation of other fibrous silicates, such as erionite. Some studies suggest that simian virus 40 (SV40) may act as a cofactor in the development of mesothelioma.

Asbestos was known in antiquity, but it wasn't mined and widely used commercially until the late 1800s. Its use greatly increased during World War II. Since the early 1940s, millions of American workers have been exposed to asbestos dust. Initially, the risks associated with asbestos exposure were not publicly known. However, an increased risk of developing mesothelioma was later found among shipyard workers, people who work in asbestos mines and mills, producers of asbestos products, workers in the heating and construction industries, and other tradespeople. Today, the official position of the U.S. Occupational Safety and Health Administration (OSHA) and the U.S. EPA is that protections and "permissible exposure limits" required by U.S. regulations, while adequate to prevent most asbestos-related non-malignant disease, they are not adequate to prevent or protect against asbestos-related cancers such as mesothelioma.Likewise, the British Government's Health and Safety Executive (HSE) states formally that any threshold for mesothelioma must be at a very low level and it is widely agreed that if any such threshold does exist at all, then it cannot currently be quantified. For practical purposes, therefore, HSE assumes that no such "safe" threshold exists. Others have noted as well that there is no evidence of a threshold level below which there is no risk of mesothelioma. There appears to be a linear, dose-response relationship, with increasing dose producing increasing disease. Nevertheless, mesothelioma may be related to brief, low level or indirect exposures to asbestos. The dose necessary for effect appears to be lower for asbestos-induced mesothelioma than for pulmonary asbestosis or lung cancer. Again, there is no known safe level of asbestos to asbestos as it relates to increased risk of mesothelioma.

The duration of exposure to asbestos causing mesothelioma can be short. For example, cases of mesothelioma have been documented with only 1–3 months of exposure. People who work with asbestos wear personal protective equipment to lower their risk of exposure.

Latency, the time from first exposure to manifestation of disease, is prolonged in the case of mesothelioma. It is virtually never less than fifteen years and peaks at 30–40 years. In a review of occupationally related mesothelioma cases, the median latency was 32 years.Based upon the data from Peto et al, the risk of mesothelioma appears to increase to the third or fourth power from first exposure.

Environmental exposures

Incidence of mesothelioma had been found to be higher in populations living near naturally occurring asbestos. For example, in central Cappadocia, Turkey, mesothelioma was causing 50% of all deaths in three small villages — Tuzköy, Karain and Sarıhıdır. Initially, this was attributed to erionite, a zeolite mineral with similar properties to asbestos, however, recently, detailed epidemiological investigation showed that erionite causes mesothelioma mostly in families with a genetic predisposition. The documented presence of asbestos fibers in water supplies and food products has fostered concerns about the possible impact of long-term and, as yet, unknown exposure of the general population to these fibers.

Occupational

Exposure to asbestos fibers has been recognized as an occupational health hazard since the early 1900s. Numerous epidemiological studies have associated occupational exposure to asbestos with the development of pleural plaques, diffuse pleural thickening, asbestosis, carcinoma of the lung and larynx, gastrointestinal tumors, and diffuse malignant mesothelioma of the pleura and peritoneum. Asbestos has been widely used in many industrial products, including cement, brake linings, gaskets, roof shingles, flooring products, textiles, and insulation.

Commercial asbestos mining at Wittenoom, Western Australia, occurred between 1945 and 1966. A cohort study of miners employed at the mine reported that while no deaths occurred within the first 10 years after crocidolite exposure, 85 deaths attributable to mesothelioma had occurred by 1985. By 1994, 539 reported deaths due to mesothelioma had been reported in Western Australia.

Tags:  Breast cancer , Lung cancer , War on Cancer , Cancer 

Breast cancer

Breast cancer malignant breast neoplasm is cancer originating from breast tissue, most commonly from the inner lining of milk ducts or the lobules that supply the ducts with milk. Cancers originating from ducts are known as ductal carcinomas; those originating from lobules are known as lobular carcinomas.

The size, stage, rate of growth, and other characteristics of the tumor determine the kinds of treatment. Treatment may include surgery, drugs (hormonal therapy and chemotherapy), radiation and/or immunotherapy. Surgical removal of the tumor provides the single largest benefit, with surgery alone being capable of producing a cure in many cases. To somewhat increase the likelihood of long-term disease-free survival, several chemotherapy regimens are commonly given in addition to surgery. Most forms of chemotherapy kill cells that are dividing rapidly anywhere in the body, and as a result cause temporary hair loss and digestive disturbances. Radiation may be added to kill any cancer cells in the breast that were missed by the surgery, which usually extends survival somewhat, although radiation exposure to the heart may cause heart failure in the future. Some breast cancers are sensitive to hormones such as estrogen and/or progesterone, which makes it possible to treat them by blocking the effects of these hormones.

Prognosis and survival rate varies greatly depending on cancer type and staging. With best treatment and dependent on staging, 5-year relative survival varies from 98% to 23, with an overall survival rate of 85%.

Worldwide, breast cancer comprises 22.9% of all non-melanoma skin cancers in women. In 2008, breast cancer caused 458,503 deaths worldwide (13.7% of cancer deaths in women). Breast cancer is more than 100 times more common in women than breast cancer in men, although males tend to have poorer outcomes due to delays in diagnosis.

Classification

Breast cancers can be classified by different schemata. Every aspect influences treatment response and prognosis. Description of a breast cancer would optimally include multiple classification aspects, as well as other findings, such as signs found on physical exam. Classification aspects include stage (TNM), pathology, grade, receptor status, and the presence or absence of genes as determined by DNA testing:

Stage. The TNM classification for breast cancer is based on the size of the tumor (T), whether or not the tumor has spread to the lymph nodes (N) in the armpits, and whether the tumor has metastasized (M) (i.e. spread to a more distant part of the body). Larger size, nodal spread, and metastasis have a larger stage number and a worse prognosis.

The main stages are:

Stage 0 is a pre-cancerous or marker condition, either ductal carcinoma in situ (DCIS) or lobular carcinoma in situ (LCIS).

Stages 1–3 are defined as 'early' cancer with a good prognosis.

Stage 4 is defined as 'advanced' and/or 'metastatic' cancer with a poor prognosis.

Histopathology. Breast cancer is usually classified primarily by its histological appearance. Most breast cancers are derived from the epithelium lining the ducts or lobules, and these cancers are classified as ductal or lobular carcinoma. Carcinoma in situ is growth of low grade cancerous or precancerous cells in particular tissue compartment such as the mammary duct without invasion of the surrounding tissue. In contrast, invasive carcinoma does not confine itself to the initial tissue compartment and invades the surrounding tissue.

Grade (Bloom-Richardson grade). When cells become differentiated, they take different shapes and forms to function as part of an organ. Cancerous cells lose that differentiation. In cancer grading, tumor cells are generally classified as well differentiated (low grade), moderately differentiated (intermediate grade), and poorly differentiated (high grade). Poorly differentiated cancers have a worse prognosis.

Receptor status. Cells have receptors on their surface and in their cytoplasm and nucleus. Chemical messengers such as hormones bind to these receptors, and this causes changes in the cell. Breast cancer cells may or may not have three important receptors: estrogen receptor (ER), progesterone receptor (PR), and HER2/neu.

ER+ cancer cells depend on estrogen for their growth, so they can be treated with drugs to block estrogen effects (e.g. tamoxifen), and generally have a better prognosis.

HER2+ breast cancer had a worse prognosis, but HER2+ cancer cells respond to drugs such as the monoclonal antibody, trastuzumab, (in combination with conventional chemotherapy) and this has improved the prognosis significantly. Cells with none of these receptors are called basal-like or triple negative.

DNA assays of various types including DNA microarrays have compared normal cells to breast cancer cells. The specific changes in a particular breast cancer can be used to classify the cancer in several ways, and may assist in choosing the most effective treatment for that DNA type.

Signs and symptoms

The first noticeable symptom of breast cancer is typically a lump that feels different from the rest of the breast tissue. More than 80% of breast cancer cases are discovered when the woman feels a lump.The earliest breast cancers are detected by a mammogram. Lumps found in lymph nodes located in the armpits can also indicate breast cancer.

Indications of breast cancer other than a lump may include changes in breast size or shape, skin dimpling, nipple inversion, or spontaneous single-nipple discharge. Pain ("mastodynia") is an unreliable tool in determining the presence or absence of breast cancer, but may be indicative of other breast health issues.

Inflammatory breast cancer is a special type of breast cancer which can pose a substantial diagnostic challenge. Symptoms may resemble a breast inflammation and may include pain, swelling, nipple inversion, warmth and redness throughout the breast, as well as an orange-peel texture to the skin referred to as peau d'orange.

Another reported symptom complex of breast cancer is Paget's disease of the breast. This syndrome presents as eczematoid skin changes such as redness and mild flaking of the nipple skin. As Paget's advances, symptoms may include tingling, itching, increased sensitivity, burning, and pain. There may also be discharge from the nipple. Approximately half of women diagnosed with Paget's also have a lump in the breast.

In rare cases, what initially appears as a fibroadenoma (hard movable lump) could in fact be a phyllodes tumor. Phyllodes tumors are formed within the stroma (connective tissue) of the breast and contain glandular as well as stromal tissue. Phyllodes tumors are not staged in the usual sense; they are classified on the basis of their appearance under the microscope as benign, borderline, or malignant.

Occasionally, breast cancer presents as metastatic disease, that is, cancer that has spread beyond the original organ. Metastatic breast cancer will cause symptoms that depend on the location of metastasis. Common sites of metastasis include bone, liver, lung and brain. Unexplained weight loss can occasionally herald an occult breast cancer, as can symptoms of fevers or chills. Bone or joint pains can sometimes be manifestations of metastatic breast cancer, as can jaundice or neurological symptoms. These symptoms are "non-specific", meaning they can also be manifestations of many other illnesses.

Most symptoms of breast disorder do not turn out to represent underlying breast cancer. Benign breast diseases such as mastitis and fibroadenoma of the breast are more common causes of breast disorder symptoms. The appearance of a new symptom should be taken seriously by both patients and their doctors, because of the possibility of an underlying breast cancer at almost any age.

Tags:  Mesothelioma ,  Lung cancer , War on Cancer , Cancer 

Lung cancer

Lung cancer is a disease that consists of uncontrolled cell growth in tissues of the lung. This growth may lead to metastasis, which is the invasion of adjacent tissue and infiltration beyond the lungs. The vast majority of primary lung cancers are carcinomas, derived from epithelial cells. Lung cancer, the most common cause of cancer-related death in men and women, is responsible for 1.3 million deaths worldwide annually, as of 2004. The most common symptoms are shortness of breath, coughing (including coughing up blood), and weight loss.

The main types of lung cancer are small-cell lung carcinoma and non-small-cell lung carcinoma. Non-small-cell lung carcinoma (NSCLC) is sometimes treated with surgery, while small-cell lung carcinoma (SCLC) usually responds better to chemotherapy and radiation. The most common cause of lung cancer is long-term exposure to tobacco smoke. Nonsmokers account for 15% of lung cancer cases, and these cases are often attributed to a combination of genetic factors, radon gas, asbestos, and air pollution including secondhand smoke.

Lung cancer may be seen on chest radiograph and computed tomography (CT scan). The diagnosis is confirmed with a biopsy. This is usually performed by bronchoscopy or CT-guided biopsy. Treatment and prognosis depend on the histological type of cancer, the stage (degree of spread), and the patient's performance status. Possible treatments include surgery, chemotherapy, and radiotherapy. Survival depends on stage, overall health, and other factors, but overall only 14% of people diagnosed with lung cancer survive five years after the diagnosis.

Signs and symptoms

Symptoms that may suggest lung cancer include:

dyspnea (shortness of breath)

hemoptysis (coughing up blood)

chronic coughing or change in regular coughing pattern

wheezing

chest pain or pain in the abdomen

cachexia (weight loss), fatigue, and loss of appetite

dysphonia (hoarse voice)

clubbing of the fingernails (uncommon)

dysphagia (difficulty swallowing).

If the cancer grows in the airway, it may obstruct airflow, causing breathing difficulties. The obstruction can lead to accumulation of secretions behind the blockage, and predispose to pneumonia. Many lung cancers have a rich blood supply. The surface of the cancer may be fragile, leading to bleeding from the cancer into the airway. This blood may subsequently be coughed up.

Depending on the type of tumor, so-called paraneoplastic phenomena may initially attract attention to the disease. In lung cancer, these phenomena may include Lambert-Eaton myasthenic syndrome (muscle weakness due to auto-antibodies), hypercalcemia, or syndrome of inappropriate antidiuretic hormone (SIADH). Tumors in the top (apex) of the lung, known as Pancoast tumors, may invade the local part of the sympathetic nervous system, leading to changed sweating patterns and eye muscle problems (a combination known as Horner's syndrome) as well as muscle weakness in the hands due to invasion of the brachial plexus.

Many of the symptoms of lung cancer (bone pain, fever, and weight loss) are nonspecific; in the elderly, these may be attributed to comorbid illness. In many patients, the cancer has already spread beyond the original site by the time they have symptoms and seek medical attention. Common sites of metastasis include the brain, bone, adrenal glands, contralateral (opposite) lung, liver, pericardium, and kidneys. About 10% of people with lung cancer do not have symptoms at diagnosis; these cancers are incidentally found on routine chest radiograph.

Causes

The main causes of any cancer include carcinogens (such as those in tobacco smoke), ionizing radiation, and viral infection. This exposure causes cumulative changes to the DNA in the tissue lining the bronchi of the lungs (the bronchial epithelium). As more tissue becomes damaged, eventually a cancer develops.

Smoking

NIH graph showing the correlation and time-lag between tobacco smoking and lung cancer rate in the U.S. male population.

Smoking, particularly of cigarettes, is by far the main contributor to lung cancer. Cigarette smoke contains over 60 known carcinogens, including radioisotopes from the radon decay sequence, nitrosamine, and benzopyrene. Additionally, nicotine appears to depress the immune response to malignant growths in exposed tissue. Across the developed world, 91% of lung cancer deaths in men during the year 2000 were attributed to smoking (71% for women). In the United States, smoking is estimated to account for 87% of lung cancer cases (90% in men and 85% in women). Among male smokers, the lifetime risk of developing lung cancer is 17.2%; among female smokers, the risk is 11.6%. This risk is significantly lower in nonsmokers: 1.3% in men and 1.4% in women.

Women who smoke (former smokers and current smokers) and take hormone therapy are at a much higher risk of dying of lung cancer. In a study by Chlebowski et al. published in 2009, the women taking hormones were about 60% more likely to die of lung cancer than the women taking a placebo. Not surprisingly, the risk was highest for current smokers, followed by past smokers, and lowest for those who have never smoked. Among the women who smoked (former or current smokers), 3.4% of those taking hormone therapy died of lung cancer compared to 2.3% for women taking the placebo.

Tags: Mesothelioma , Breast cancer ,  War on Cancer , Cancer 

War on Cancer

War on Cancer refers to the effort to find a cure for cancer by increased research to improve the understanding of cancer biology and the development of more effective cancer treatments, such as targeted drug therapies. The aim of such efforts is to eradicate cancer as a major cause of death. The signing of the National Cancer Act of 1971 by then U.S. President Richard Nixon is generally viewed as the beginning of the war on cancer, though it was not described as a "war" in the legislation itself.

Despite significant progress in the treatment of certain forms of cancer (such as childhood leukemia), cancer in general remains a major cause of death nearly 40 years after this war on cancer began, leading to a perceived lack of progress and to new legislation aimed at augmenting the original National Cancer Act of 1971. New research directions, in part based on the results of the Human Genome Project, hold promise for a better understanding of the genetic factors underlying cancer, and the development of new diagnostics, therapies, preventive measures, and early detection ability.

History

National Cancer Act of 1971

The war on cancer began with the National Cancer Act of 1971, a United States federal law. The act was intended "to amend the Public Health Service Act so as to strengthen the National Cancer Institute in order to more effectively carry out the national effort against cancer". It was signed into law by then U.S. President Richard Nixon on December 23, 1971.

NCI Director's Challenge

In 2003, Andrew von Eschenbach, the director of the National Cancer Institute issued a challenge "to eliminate the suffering and death from cancer, and to do so by 2015".This was supported by the American Association for Cancer Research in 2005 though some scientists felt this goal was impossible to reach and undermined von Eschenbach's credibility.

John E. Niederhuber, who succeeded Andrew von Eschenbach as NCI director, noted that cancer is a global health crisis, with 12.9 million new cases diagnosed in 2009 worldwide and that by 2030, this number could rise to 27 million including 17 million deaths "unless we take more pressing action."

Harold Varmus, former director of the NIH and current director of the NCI, held a town hall meeting in 2010 in which he outlined his priorities for improving the cancer research program, including the following:

reforming the clinical trials system,

improving utilization of the NIH clinical center (Mark O. Hatfield Clinical Research Center),

readjusting the drug approval and regulation processes,

improving cancer treatment and prevention, and

formulating new, more specific and science-based questions.

Renewed focus on cancer

Recent years have seen an increased perception of a lack of progress in the war on cancer, and renewed motivation to confront the disease. On July 15, 2008, the United States Senate Committee on Health, Education, Labor, and Pensions convened a panel discussion titled, Cancer: Challenges and Opportunities in the 21st Century. It included interviews with noted cancer survivors such as Arlen Specter, Elizabeth Edwards and Lance Armstrong, who came out of retirement in 2008, returning to competitive cycling "to raise awareness of the global cancer burden."

Lance Armstrong Foundation

The Lance Armstrong Foundation (LAF) created the LIVESTRONG Global Cancer Campaign to address the burden of cancer worldwide and encourage nations to make commitments to battle the disease and provide better access to care. In April 2009, the LAF announced that the Hashemite Kingdom of Jordan pledged $300 million to fund three important cancer control initiatives – building a cutting-edge cancer treatment and research facility, developing a national cancer control plan and creating an Office of Advocacy and Survivorship. The LAF encourages similar commitments from other nations to combat the disease.

LIVESTRONG Day is an annual event established by the LAF to serve as "a global day of action to raise awareness about the fight against cancer." Individuals from around the world are encouraged to host cancer-oriented events in their local communities and then register their events with the LAF website. In 2009, LIVESTRONG Day occurred on October 2.

21st Century Cancer Access to Life-Saving Early detection, Research and Treatment (ALERT) Act

The US Senate on 26 March 2009 issued a new bill (S. 717), the 21st Century Cancer Access to Life-Saving Early detection, Research and Treatment (ALERT) Act[24] intended to "overhaul the 1971 National Cancer Act. The bill aims to improve patient access to prevention and early detection by:

providing funding for research in early detection,

supplying grants for screening and referrals for treatment, and

increasing access to clinical trials and information.

Obama-Biden Plan to Combat Cancer

During their 2008 U.S. presidential campaign then Senators Barack Obama and Joe Biden published a plan to combat cancer that entailed doubling "federal funding for cancer research within 5 years, focusing on NIH and NCI" as well as working "with Congress to increase funding for the Food and Drug Administration. Their plan would provide additional funding for:

research on rare cancers and those without effective treatment options,

the study of health disparities and evaluation of possible interventions,

and efforts to better understand genetic factors that can impact cancer onset and outcomes.

President Obama's 2009 economic stimulus package includes $10 billion for the NIH, which funds much of the cancer research in the U.S., and he has pledged to increase federal funding for cancer research by a third for the next two years as part of a drive to find "a cure for cancer in our time. In a message published in the July 2009 issue of Harper's Bazaar, President Obama described his mother's battle with ovarian cancer and, noting the additional funding his administration has slated for cancer research, stated: "Now is the time to commit ourselves to waging a war against cancer as aggressive as the war cancer wages against us." On 30 September 2009, Obama announced that $1 billion of a $5 billion medical research spending plan would be earmarked for research into the genetic causes of cancer and targeted cancer treatments.

Cancer-related federal spending of money from the 2009 Recovery Act can be tracked online.

World Cancer Campaign

The International Union Against Cancer (UICC) has organized a World Cancer campaign in 2009 with the theme, "I love my healthy active childhood," to promote healthy habits in children and thereby reduce their lifestyle-based cancer risk as adults. The World Health Organization is also promoting this campaign and joins with the UICC in annually promoting World Cancer Day on 4 February.

Tags:  Mesothelioma , Breast cancer , Lung cancer  , Cancer