Research into the causes of cancer has produced information on genetic mutations along with viral causes, but studies on possible cancer bacteria also point to certain bacterial origins of the disease. An example is the presence of Helicobacter pylori in the stomach, which is known to cause stomach ulcers, but also seems to increase the chance of developing stomach cancer. Scientists investigating possible bacteria-cancer connections find clues to the possible link when unexpected amounts of certain bacteria appear in cancerous tissue.
Viral causes of cancers are commonly known, and vaccines are even available for some. An example of a virus that can be addressed with a vaccine is the human papillomavirus (HPV), which is sexually transmitted and can cause cervical cancer later in life. Hepatitis C virus is also known as a cause of cirrhosis and liver cancer. However, cancerous bacteria are part of a completely different group of organisms than viruses, since bacteria are cells and viruses are mere strings of genetic material wrapped in protective proteins.
Genetic mutations are a significant field of interest in cancer research, where many types of tumors have been associated with specific mutations in the affected person's genes. Many mechanisms by which mutations affect the development of cancers have also been clarified, but in the case of tumors caused or potentially caused by microbes such as viruses and bacteria, these mechanisms are, as of 2012, still unknown. . Sometimes the only reason a cancerous bacterium is proposed is because researchers have noted its presence in cancerous tissue, where it was not expected to be found.
For example, in 2011, researchers at the British Columbia Cancer Agency tested colon cancer tissue and found that a certain type of bacteria, called Fusobacterium , was present in the cancer at much higher levels than in other parts of the body, and that bacteria were also present. it is more likely to occur in cancers that have spread. Although this does not prove that the bacteria caused the cancer in the first place, it does provide a starting point for future research on the interaction between the bacteria and cancer cells. It is believed that Helicobacter pylori , which is associated with stomach cancer, helps trigger cancer through constant irritation and cell turnover from the original ulcers it causes. Another possible type of cancer bacteria through indirect, or even direct, mechanisms is Chlamydia trachomatis a sexually transmitted disease that appears to work with HPV to cause cervical cancer.