Helicobacter pylori Estimates place the worldwide risk of<unk> s from<unk>  causes at 16.1%. Viral<unk>  are risk factors for cervical<unk> , 80% of liver<unk> s, and 15–20% of the other<unk> s. This proportion varies in different regions of the world from a high of 32.7% in Sub-Saharan Africa to 3.3% in Australia and New Zealand. Helicobacter pylori is associated with stomach<unk> , and Mycobacterium, some other bacteria and parasites also have an effect. A virus that can cause<unk>  is called an oncovirus or tumor virus. These include the human papillomavirus, which is associated with cervical carcinoma and nasopharyngeal carcinoma; Epstein-Barr virus, which is associated with a variety of Epstein-Barr virus associated lymphoproliferative lymphomas; Kaposi's sarcoma herpesvirus, which is associated with Kaposi's sarcoma and primary effusion lymphoma; hepatitis B and hepatitis C viruses which are associated with hepatocellular carcinoma; human T-cell leukemia virus-1, which is associated with adult T-cell leukemia/lymphoma; and bovine leukemia virus, which is associated with breast<unk> (reviewed in International Journal of Environment and Public Health, authors = Buehring GC, Sans HM / Title: Breast<unk>  gone viral? Review of bovine leukemia virus role in causation, and related opportunities for<unk>  prevention. Bacterial infection may also increase the risk of<unk> , as seen in Helicobacter pylori-induced stomach<unk> . Parasitic<unk>  strongly associated with<unk>  include Schistosoma haematobium (squamous cell carcinoma of the bladder) and the liver flukes, Opisthorchis viverrini and Clonorchis sinensis (cholangiocarcinoma).
Infectious causes of cancer
Cancer signs and symptoms
Risk factors for breast cancer
Soft tissue pathology
Immune-mediated inflammatory diseases
Causes of cancer
Psychogenic
Infectious diseases 