Oncoviruses

After being infected with Oncoviruses the risk of developing certain types of cancer increases. Such cancer-causing viruses are the cause of about 10 to 20% of all cancers. Many oncoviruses are well known to science and well described.

What are oncoviruses?

Viruses are infectious particles that reproduce and are subject to the rules of evolution. However, they are not real living beings in the classical sense, as they do not have their own metabolic apparatus, but rely on that of the host cells. In doing so, they introduce new genetic material into the host cell's genetic material or change the host cell's genetic material. Such processes sometimes lead to the transformation of benign cells into tumor cells.

The viruses that have been shown to cause cancer in multicellular animals and humans are oncoviruses. Many different mechanisms play a role in the development of cancer, depending on the type of virus. Some viruses activate cancer-causing genes that are already present in the host cell. Other viruses build viral oncogenes into the host cell. There are oncoviruses among all virus groups, i.e. both retroviruses and DNA viruses.

Occurrence, Distribution & Properties

Hepatitis viruses are the most relevant oncoviruses for humans. Hepatitis B viruses and hepatitis C viruses drastically increase the likelihood of developing liver cancer with certain courses of infection.

Hepatitis C and hepatitis B are transmitted through blood transfusions, during sexual intercourse, and directly at birth. But there are also many hepatitis infections that have arisen in an unclear way, perhaps through the smallest skin damage. If the infection is chronic, i.e. if the immune system does not eliminate the virus from the organism, hepatocellular carcinoma can develop.

With biochemical evidence of antibodies and antigens, laboratory analyzes allow an exact diagnosis of hepatitis B and hepatitis C as well as the current infection status. Patients themselves, however, often do not notice creeping chronic hepatitis. Laboratory tests for the detection of hepatitis antigens and hepatitis antibodies are therefore part of the routine medical check-up. Anyone who has not yet had contact with the hepatitis B virus can get vaccinated. A hepatitis B vaccination prevents infection with this virus and thus also contributes to general cancer prophylaxis.

Human papillomavirus (HPV) are also responsible for a large proportion of the cancers caused by viruses. The main target organ for this virus is the cervix. Papillomaviruses are the viruses that make sexual intercourse a cancer risk because it is transmitted between the genitals or during oral sex. Cervical cancer is one of the most common cancers in women.

In addition to cervical cancer, HPV viruses also cause penile cancer or oral cancer in rare cases. An approved vaccine against certain HPV viruses has been available since 2006. The HPV vaccination is thus another vaccination that can be used for cancer prophylaxis.

The HTLV-1 virus is a retrovirus that sometimes causes leukemia, or blood cancer, in humans. As a retrovirus, it belongs to a group of viruses similar to the HI viruses. As with HIV, infection is permanent. However, HTLV-1 infections are rare and even more rarely lead to T-cell leukemia.

The Epstein-Barr virus is a herpes virus. Epstein-Barr viruses cause Pfeiffer glandular fever. The viruses are mostly harmless and infect almost 100% of all people. The host cells of these viruses are the B lymphocytes in the immune system. Epstein-Barr virus is thought to play a role in a rare but very severe form of lymph gland cancer, Hodgkin's disease. But how exactly this form of cancer develops, why most people survive an infection with the Epstein-Barr virus without consequences and why the cancer only occurs in very rare cases are questions of current research.

Illnesses & ailments

Viruses are a constant threat to the organism. Many ways of infection and the development of cancer are known. But many cancer-causing mechanisms and the role that viruses play in them have not yet been described. Many viruses, such as the hepatitis virus and the herpes virus, are not extremely infectious. However, once people become infected with them, they often struggle with long-term effects from these viruses, including causing cancer.

In the case of hepatitis viruses, many routes of infection are not entirely clear. Sexual intercourse is particularly intense body contact, which can also lead to infection by viruses that are otherwise very difficult to transmit. Condoms reduce the risk of viral infections during sexual intercourse.

Many cancers have multiple causes. Alcohol damages the liver and very quickly leads to liver destruction and liver cancer in hepatitis B patients. Tobacco smoke damages the mucous membranes in the mouth and, together with HPV viruses, can promote oral cancer. In addition to avoiding viral infections, avoiding other carcinogenic substances is therefore also important for overall prophylaxis. Regular visits to the doctor lead to a good diagnostic overview of what is going on in one's own body.