What are the causes of cancers?
A number of agents have been implicated in causing cancer. A large proportion of cancers are caused by living habits and environmental carcinogens: Tobacco: causes cancer of the mouth, throat (pharynx), voice box (larynx), food pipe (esophagus), lung, pancreas, kidney, urinary bladder, and uterine cervix. At least 90% of lung cancer deaths are due to smoking. Alcohol: Increases the risk of cancers of mouth, pharynx, larynx and esophagus by increasing the permeability of the mucosa to various carcinogens especially tobacco. Ionizing radiation: well established as an etiologic factor in the development of leukemia. Environmental exposure: Asbestos exposure can cause cancers of the lung, pleura and abdominal peritoneum. Excessive exposure to solar ultraviolet radiation dramatically increases the risk for skin cancers. Viruses and bacteria: Chronic carrier state of Hepatitis B virus increases significantly the risk of developing liver cancer. Viruses of the HPV & HSV family cause carcinoma
