Summary: Dr. Rodvien describes the causes of cancer, discussing interactions of our genetic material that we inherited with the environment that surrounds us. More than one event is needed from each of these large groups in order to produce a cancer. Radiation, viruses and chemicals are the major environmental exposures, and amongst these exposures, tobacco is the single most important cause in part because it is commonly associated with several cancers, avoidable, and because even if it has been used in the past, avoidance now decreases the risk of subsequent cancers. Cancer of the lung is the most well-known of the cancers associated with tobacco but there are others as well. Asbestos is another known cancer-causing substance, and there are a number of viruses that can interact with our genetic material to cause still other cancers. Amongst these viruses, there are viruses that cause hepatitis in many of us and liver cancer in a few of us. There is also a virus we all associate with infectious mononucleosis, and that virus causes or is associated with lymphoma.
