Chapter 078. Prevention and Early Detection of Cancer (Part 3) Cancer Chemoprevention Chemoprevention involves the use of specific natural or synthetic chemical agents to reverse, suppress, or prevent carcinogenesis before the development of invasive malignancy. Cancer develops through an accumulation of genetic and epigenetic changes that are potential points of intervention to prevent cancer. The initial changes are termed initiation. The alteration can be inherited or acquired through the action of physical, infectious, or chemical carcinogens. Like most human diseases, cancer arises from an interaction between genetics and environmental exposures (Table 78-1). Influences that cause the initiated cell to progress through the carcinogenic process and change phenotypically are termed promoters. Promoters include hormones such as androgens, linked to prostate cancer, and estrogen, linked to breast and endometrial cancer. The distinction between an initiator and promoter is sometimes arbitrary; some components of cigarette smoke are "complete carcinogens," acting as both initiators and promoters. Cancer can be prevented or controlled through interference with the factors that cause cancer initiation, promotion, or progression. Compounds of interest in chemoprevention often have antimutagenic, antioxidant, anti-inflammatory, antiproliferative, or pro-apoptotic activity (or a combination). Table 78-1 Suspected Carcinogens Carcinogens a Associated Cancer or Neoplasm Alkylating agents Acute myeloid leukemia, bladder cancer Androgens Prostate cancer Aromatic amines (dyes) Bladder cancer Arsenic Cancer of the lung, skin Asbestos Cancer of the lung, pleura, peritoneum Benzene Acute myelocytic leukemia Chromium Lung cancer Diethylstilbestrol (prenatal) Vaginal cancer (clear cell) Epstein-Barr virus Burkitt's lymphoma, nasal T cell lymphoma Estrogens Cancer of the endometrium, liver, breast Ethyl alcohol Cancer of the liver, esophagus, head and neck Helicobacter pylori Gastric cancer, gastric MALT lymphoma Hepatitis B or C virus Liver cancer Human immunodeficiency virus Non- Hodgkin's lymphoma, Kaposi's sarcoma, squamous cell carcinomas (especially of the urogenital tract) Human papilloma virus Cervix cancer, head and neck cancer Human T cell lymphot ropic virus type I (HTLV-I) Adult T cell leukemia/lymphoma Immunosuppressive agents (azathioprine, cyclosporine, glucocorticoids) Non-Hodgkin's lymphoma Nitrogen mustard gas Cancer of the lung, head and neck, nasal sinuses Nickel dust Cancer of the lung, nasal sinuses Phenacetin Cancer of the renal pelvis and bladder Polycyclic hydrocarbons Cancer of the lung, skin (especially squamous cell carcinoma of scrotal skin) Schistosomiasis Bladder cancer (squamous cell) Sunlight (ultraviolet) Skin cancer ( squamous cell and melanoma) Tobacco (including smokeless) Cancer of the upper aerodigestive tract, bladder Vinyl chloride Liver cancer (angiosarcoma) a Agents that are thought to act as cancer initiators and/or promoters. . Chapter 078. Prevention and Early Detection of Cancer (Part 3) Cancer Chemoprevention Chemoprevention involves the use of specific natural or synthetic. gas Cancer of the lung, head and neck, nasal sinuses Nickel dust Cancer of the lung, nasal sinuses Phenacetin Cancer of the renal pelvis and bladder Polycyclic hydrocarbons Cancer of the. Cancer or Neoplasm Alkylating agents Acute myeloid leukemia, bladder cancer Androgens Prostate cancer Aromatic amines (dyes) Bladder cancer Arsenic Cancer of the lung, skin Asbestos Cancer