Disease-related causes
- Infections (approximately 15% of all causes of cancer).
- Viruses
- Hepatitis B (HBV) and C (HCV) [hepatocellular carcinoma]
- HPV (human papillomavirus) types 16 and 18 [mainly cervical carcinoma/cervical cancer]
- EBV (Epstein-Barr virus; also known as human herpesvirus (HHV-4)) [gastric cancer; lymphomas, such as Burkitt’s lymphoma, B-cell lymphoma, Hodgkin’s lymphoma]
- HHV-8 (herpes virus type 8) [Kaposi’s sarcoma (KS)]
- HTLV-1 (human T-lymphotropic virus type 1; retrovirus) [4-5% of infected individuals develop highly aggressive adult T-cell leukemia (ATL); survival: 8-10 months]
- Merkel cell polyoma virus (MCPyV or incorrectly MCV) [approximately 70%-80% of Merkel cell carcinomas are associated with MCPyV]
- Bacteria – Helicobacter pylori [gastric carcinoma]
- Parasites
- Clonorchis sinensis (Chinese liver fluke) [cholangiocarcinoma/biliary duct carcinoma]
- Opisthorchis viverrini (trematode affecting bile ducts) [cholangiocarcinoma]
- Schistosoma haematobium [bladder carcinoma]
- Unknown class of pathogens (exhibit homologies to the p4ABAYE plasmid of Acinetobacter, but also contain viral components of CRESS DNA viruses) from cow’s milk and beef: called BMMF for “Bovine Milk and Meat Factors” – may increase risk for colon carcinoma (colorectal cancer) and mammary carcinoma (breast cancer); the pathogen has been detected in blood serum and milk from Eurasian cattle. BMMF infection occurs in early infancy shortly after weaning, as soon as milk is fed. When the child’s immune system matures at about one year of age, the child is presumed to be immunocompetent and able to fight off the BMMF pathogen. It is thought that certain sugar compounds in breast milk may prevent infection with the pathogen.
- Viruses
- Subclinical inflammation (English “silent inflammation”) – permanent systemic inflammation (inflammation that affects the whole organism), which runs without clinical symptoms.
Note: IARC (International Agency for Research on Cancer) classifies the above 11 chronic infections as Group 1 carcinogens. Most cancers are caused by Helicobacter pylori. This is followed by the oncogenic (cancer-causing) HPV variants.
Further notes
- An analysis of insurance data was able to show that rising or frequent infections (gastroenteritis (gastrointestinal infection), hepatitis (liver inflammation), influenza (flu), pneumonia (pneumonia)) were significantly increased in the year before a cancer diagnosis. This was especially true for the incidence (frequency of new cases) of hepatitis and pneumonia, which was consistently low in the control group over the entire period, but increased significantly in the later cancer patients.