A risk factor is something that gives you a higher chance (risk) of getting a certain disease.
Risk factors for cancer include:
Carcinogens are things that sometimes cause cancer. Usually, your risk of cancer is higher if you're exposed to more of a carcinogen or you're exposed for a longer time.
Each of your body's cells contains genes. Genes are the instructions that tell each of your cells what to do. Genes tell cells when to grow, when to stop growing, and what substances to make. For example, certain genes tell cells in your stomach to make stomach acid.
Sometimes one of your genes can go bad in ways that make a cell turn cancerous. A gene can go bad if:
Less likely, you inherited a cancer gene from one of your parents. Sometimes people in a family are more likely to have a certain cancer. A cancer-causing gene could run in that family. One cancer-causing gene called BRCA increases the risk of breast cancer.
Being around certain things can raise your chances of cancer, including:
Asbestos (a mineral fiber used for insulation and other building materials): Lung cancer and mesothelioma (cancer in the tissues that line your lungs)
Sunlight: Skin cancer
X-rays: Leukemia and cancer in the organ exposed to radiation
Radon (a radioactive gas that comes from the ground and can build up to harmful levels in basements): Lung cancer
Some chemicals used at work (such as benzene, chromates, nickel, certain pesticides, and vinyl chloride) can cause cancer.
Geography (where you live) can affect your chances of getting cancer. One reason is that people in different areas may be exposed to different amounts of carcinogens. Another reason is that people in different areas may have different genetic risk factors.
Just being overweight or obese can raise your risk of breast, uterus, colon, kidney, and esophagus cancer.
Estrogen and diethylstilbestrol (DES): Breast cancer
Some drugs to treat cancer actually increase your risk of developing another cancer later on
Radiation exposure, either on purpose for medical reasons or accidentally:
From medical tests (x-rays, CT scan) or radiation therapy
Accidental exposure to radioactive material or nuclear radiation from a power plant accident
Infections with certain viruses and bacteria:
Helicobacter pylori bacteria : Stomach cancer
Inflammatory disorders (long-term inflammation of certain organs) may increase risk of cancer: