Globally, more than 15% of human cancer cases occurring in 2008 could be ascribed to infectious agents classified as carcinogenic according to the international agency for research on cancer iarc. In the present work, causation criteria for viruses and cancer will be described, as well as the viral agents that comply with these criteria in human tumors, their epidemiological and biological characteristics, the molecular mechanisms by which they induce cellular transformation and their associated cancers. The first question was whether there was any evidence of human exposure, and, indeed, people do have antibodies to these cancercausing chicken viruses in their bloodstream. Principles of transformation and pathogenesis by john nicholas 2008 english pdf. Some viruses lead to inflammation or tissue damage that triggers increased cell divisionwhich leads to a greater chance that mutations will take place, eventually leading to cancer. Epsteinbarr virus, human papilloma virus, hepatitis b virus, and human herpes virus8 are the four dna viruses that are capable of causing the development of human cancers. Other factors may increase the chance of cancer including immune system complications, cell mutations, exposure to cancer causing agents and hereditary susceptibility. Vaccines have been developed against some cancer viruses including hepatitis b and human papillomaviruses hpv 16 and 18. Human papillomavirus 175 11 human papillomavirus hpv is the most common sexually transmitted infection in the united states. Immunology and vaccinepreventable diseases pink book.
Table 431association of viruses with human cancersa. Printer friendly version pdf icon pdf common human coronaviruses, including types 229e, nl63, oc43, and hku1, usually cause mild to moderate upperrespiratory tract illnesses, like the common cold. A number of different viruses have been associated. Important human cancer viruses human tcell leukemia virus is a member of the retrovirus family rna genome epsteinbarr virus and kaposis sarcoma virus are members of the herpesvirus family dna genome human papilloma virus is a member of the papillomavirusfamily dna genome. Accordingly, hormoneresponsive viruses have become major suspects as etiological agents for human breast cancer. This excludes viruses and cancer sites for which evidence of carcinogenicity is weaker. Although many viruses can cause various tumors in animals, only seven of them are associated with human cancers and are currently considered oncogenic viruses. To date, seven viruses ebv, kshv, highrisk hpv, mcpv, hbv, hcv and htlv1 have been consistently linked to different types of human cancer, and infections are estimated to account for up to 20% of all. In addition to the above viruses and cancers, there also exist a number of other cancers that may have an infectious etiology. Several factors increase the risk of developing cancers such as smoking for lung cancer or sun exposure for melanoma. Whether you or someone you love has cancer, knowing what to expect can help you cope.
Viruses and human cancer presents a general overview of all viral infections now known to be linked with human cancers. Cervical cancer is the second most common cancer in women worldwide, and there is now unequivocal evidence implicating certain types of human papillomavirus hpv as the primary cause of cervical cancer and its. Scribd is the worlds largest social reading and publishing site. Papillomaviruses are dna viruses that exhibit species specificity and induce hyperplastic epithelial lesions as a result of infection. The first identification of a tumorcausing virus, rous sarcoma virus, occurred almost 100 years ago, but it was not until the 1970s that the genetic basis for oncogenesis by this and other acutely. With the letters rna removed, it now refers to any virus with a dna or rna genome causing cancer and is synonymous with tumor virus or cancer virus. Breast cancer is currently the most common neoplasm diagnosed in women globally. Oncogenic viruses fact sheet morgridge institute for. There is a growing body of evidence to suggest that human papillomavirus hpv infection may play a key role in invasiveness of breast cancer. It will also be of great value to practicing physicians, residents and clinical fellows in these specialties. The year 2011 marks the centenary of francis peyton rouss landmark experiments on an avian cancer virus. Cancer causing viruses and the role of laboratory medicine scielo. For example, the human papillomavirus hpv can cause cervical and several other cancers. The first identification of a tumorcausing virus, rous sarcoma virus, occurred.
Most people get infected with one or more of these viruses at some point in their lives. Both dna and rna viruses have been shown to be capable of causing cancer in humans. The new england journal of medicine 312 n engl j med 360. The eight known human tumour viruses contribute to nearly 1015% of the cancers worldwide. Researchers know that there are several viruses that can lead to cancer. Three of these cancers kaposi sarcoma, non hodgkin lymphoma, and cervical cancer are considered aidsdeining cancers. As obligatory intracellular parasites, viruses encode proteins that reprogram host. Since then, seven human viruses have been found to cause 1015% of human cancers worldwide.
Infection by viruses is the second leading cause of cancers. Human t lymphotrophic virus type 1 and hepatitis c viruses are the two rna viruses that contribute to human cancers. Multiple treatments are required and in the case of hpv 16 and 18, the vaccine does not protect against other forms of the virus. Human papillomavirus hpv human papillomavirus, or hpv, is the most common sexually transmitted infection sti in the united states. Chapters are written by internationally recognized experts, and all are generously illustrated with tables, diagrams, and photographic images. Some cancer registries exclude nonmelanoma skin cancers, or attribute deaths to hiv rather than. This term originated from studies of acutely transforming retroviruses in the 195060s, when the term oncornaviruses was used to denote their rna virus origin. The viruses that have been strongly associated with human cancers are listed in table 431. Research on oncogenic viruses and related human cancers has advanced rapidly in the past decade. Viruses may contribute to the development of human tumors by different mechanisms. A cancer treatment in which high energy beams are used to kill cancer cells.
In recent years, great leaps in genomic sciences have allowed researchers to detect viruses living in and on the human bodycollectively called the human virome. The relationship of cervical cancer and sexual behavior was suspected for more than 100 years and was established by epidemiologic studies in the 1960s. Recent genomic explorations of human samples have revealed dozens of previously unrecognized viruses resident in our gut, lung, skin, and blood. Close study of viruses and human cancer has led to optimism for the development of new strategies for the prevention of the preceding infection that can lead to. The first human tumor virus was discovered in the middle of the last century by anthony epstein, bert achong and yvonne barr in african pediatric patients with burkitts lymphoma. The genome of htlv1 has a characteristic retroviral organization, i. Inform yourself about the role viruses play in contributing to cancer. Concern has been raised about the potential infectivity of cancercausing farm animal viruses for decades. Viruses are the causes of approximately 25% of human cancers.
Pdf the first human tumor virus was discovered in the middle of the last century by anthony epstein, bert achong and yvonne barr in african. About 80 percent of women will get at least one type of hpv at some point in their lifetime. From basic information about cancer and its causes to indepth information on specific cancer types including risk factors, early detection, diagnosis, and treatment options youll find it here. Advancements in research on virusrelated cancers offer a. Read about cancer signs, stages, cells, symptoms, and types. Highthroughput sequencingbased investigation of viruses. To date, seven viruses ebv, kshv, highrisk hpv, mcpv, hbv, hcv and htlv1 have been consistently linked to different types of human cancer, and infections are estimated to. And hepatitis c can lead to liver cancer and nonhodgkins lymphoma studying viruses and cancer is helping researchers develop vaccines and other ways to reduce cancer risk. Upon entry, the virus uses components of the host cell to complete its life cycle. Viruses and human cancer from basic science to clinical prevention is designed to meet this need by providing an advanced overview on the basic and clinical aspects of oncogenic viruses and the human cancers that they cause. In general, each type of virus tends to infect only a certain type of cell in the body.
This book provides an uptodate overview of the 6 major viruses that cause human cancers hpv, hbv, hcv, ebv. Past, present and future i n 2008, cancer caused 7. A causal role for these viruses in human malignancies remains to be fully addressed. Viruses account for about 20% of total human cancer cases. Epsteinbarr virus, hepatitis b virus, human papillomavirus, human tcell lymphotropic virus, hepatitis c virus, kaposis sarcoma herpesvirus, and merkel cell polyomavirus. Human oncogenic viruses and their associated tumors.
Some viruses can cause or contribute to the development of cancer. Viruses and human cancer from basic science to clinical. Viruses and human tumours bacteriophage subviral agents isolation of virus diagnosis treatment and prevention of virus infections sub microscopic entity consisting of a single nucleic acid surrounded by a protein coat and capable of replication only within the living cells. Viruses associated with human cancer sciencedirect. Unlike other viruses, such as influenza viruses, that cause an acute infection, oncogenic viruses often cause longterm, persistent infections. Studies evaluating markers of a bodys weakened immune system, or immunosuppression, such as decreased cd4 t cells, also support the link between these human viruses and cancer. Oncogenic viruses virology online microbiology notes. The human cancers associated with viral infection are summarized in table 2. Most articles, however, focus on a specific oncogenic virus and cancer. There is consequently a need for a comprehensive, uptodate monograph that offers broad and integrated knowledge. Close study of viruses and human cancer has led to optimism for the development of new strategies for the prevention of the preceding infection that can lead to carcinogenesis. To date, seven viruses ebv, kshv, highrisk hpv, mcpv, hbv, hcv and htlv1 have been consistently linked to different types of human cancer. The viruses now known or suspected of being linked to cancer in humans include human papilloma viruses, the epsteinbarr virus, the hepatitis b and c viruses, the human herpes.
In 12% of cancers, seven different viruses have been causally linked to human oncogenesis. Five viruses are being added to the report on carcinogens. When the dna or rna affects the host cells genes, it can push the cell toward becoming cancer. Due to their importance in carcinogenesis, there is a desperate need for a book that discusses these viruses. Whenever cells divide, there is a risk that a genetic mutation will take place. It is estimated that viral infections contribute to 1520% of all human cancers. Since the discovery of the first human cancercausing virus, several others have been associated with neoplasias. They include human papillomaviruses hpvs, epsteinbarr virus ebv, human herpesvirus 8, hepatitis b virus, hepatitis c virus, and two human retroviruses plus. Tumor viruses and human malignancy about 20% of human cancerresults from tumor virus infection study of rna and dna tumor viruses has revolutionized modern concept of cancer development cancer is a disease of genes study of cancer using molecular biology and tumor viruses as tools concept of cancer as a transferable infectious disease. After a preliminary chapter about the general biological characteristics of. About a fifth of all human cancers worldwide are caused by infectious agents. National institute of environmental health sciences nihhhs cancercausing viruses. T cells, also support the link between these human viruses and cancer. It is usually spread through vaginal, oral, or anal sex.
This indicates that the virus is no stranger to our immune systems. Some viruses do this by inserting their own dna or rna into that of the host cell. The human tumour viruses induce malignancies after a prolonged latency and in conjunction with other environmental and host factors. Radiation can also cause genetic damage that can lead to cancer. These five viruses are more likely to lead to cancer in people that.
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