Some estimates currently attribute 15% to 20% of all cancers to infectious pathogen causes. In future, this percentage may be revised upwards if the pathogens currently associated with cancers (such as those listed below) are proven to actually cause those cancers. (Note: for the sake of completeness, some infectious pathogens known to cause cancers are included in the list, in addition to the infectious pathogens associated with cancers.) Adrenal tumor is associated with BK virus and simian virus 40. Anal cancer is associated with human papillomaviruses. Bladder cancer can be caused by Schistosoma helminths. Brain tumor. Glioblastoma multiforme is associated with cytomegalovirus, BK virus, JC virus, and simian virus 40. Breast cancer is associated with mouse mammary tumor virus, Epstein-Barr virus, and human papillomaviruses. Carcinoid tumors are associated with enterovirus infections. Cervical cancer can be caused by human papillomaviruses. Colorectal cancer is associated with the bacteria Helicobacter pylori, Streptococcus bovis and Fusobacterium nucleatum, with human papillomaviruses, and with the helminth Schistosoma japonicum. JC virus may be a risk factor for colorectal cancer. Gallbladder cancer is associated with the bacterium Salmonella typhi. Hodgkin's lymphoma is associated with Epstein-Barr virus, hepatitis C virus, and HIV. Kaposi's Sarcoma can be caused by Kaposi's sarcoma herpesvirus and HIV. Liver cancer. Hepatocellular carcinoma can be caused by hepatitis B virus, hepatitis C virus, and by the helminth Schistosoma japonicum. Lung cancer is associated with the bacterium Chlamydia pneumoniae, with human papillomaviruses, and with Merkel cell polyomavirus. Leukemia. Adult T-cell leukemia can be caused by human T-cell leukemia virus-1. Mesothelioma is associated with simian virus 40, especially in conjunction with asbestos exposure. Nasopharyngeal carcinoma can be caused by Epstein-Barr virus. Non-Hodgkin lymphoma is associated with HIV and simian virus 40. Oropharyngeal cancer can be caused by human papillomaviruses. Ovarian cancer is associated with mumps virus. Pancreatic cancer is associated with hepatitis B virus and the bacterium Helicobacter pylori. Prostate cancer is associated with xenotropic murine leukemia virus-related virus and BK virus. Skin neoplasm is associated with human papillomaviruses. Squamous cell carcinoma is associated with human papillomaviruses. Stomach cancer is associated with the bacterium Helicobacter pylori. Thyroid cancer is associated with simian virus 40.
Chronic obstructive pulmonary disease (which includes both chronic bronchitis and emphysema) is associated with Chlamydia pneumoniae and Epstein-Barr virus.