What Causes Cancer? American Cancer Society

This screening test is very useful in places where access to medical care is limited. We have developed these areas based on user testing and user feedback. We strive to provide information that is accurate, complete and up-to-date.

Carriers of these mutations may then undergo enhanced surveillance, chemoprevention, or preventative surgery to reduce their subsequent risk. Unlike diagnostic efforts prompted by symptoms and medical signs, cancer screening involves efforts to detect cancer after it has formed, but before any noticeable symptoms appear. This may involve physical examination, blood or urine tests or medical imaging. Reduced expression of DNA repair genes disrupts DNA repair. This is shown in the figure at the 4th level from the top. Mutation rates increase substantially in cells defective in DNA mismatch repair or in homologous recombinational repair .

His contemporary Nicolaes Tulp believed that cancer was a poison that slowly spreads and concluded that it was contagious. Disruption of a single gene may also result from integration of genomic material from a DNA virus or retrovirus, leading to the expression of viral oncogenes in the affected cell and its descendants. Medical use of ionizing radiation is a small but growing source of radiation-induced cancers. Ionizing radiation may be used to treat other cancers, but this may, in some cases, induce a second form of cancer.

Inflammation can contribute to proliferation, survival, angiogenesis and migration of cancer cells by influencing the tumor microenvironment. Oncogenes build up an inflammatory pro-tumorigenic microenvironment. Tobacco is responsible for about one in five cancer deaths worldwide and about one in three in the developed world.

Radiation exposure such as ultraviolet radiation and radioactive material is a risk factor for cancer. Many non-melanoma skin cancers are due to ultraviolet radiation, mostly from sunlight. Sources of ionizing radiation include medical imaging and radon gas. Cancers comprise a large family of diseases that involve abnormal cell growth with the potential to invade or spread to other parts of the body. A neoplasm or tumor is a group of cells that have undergone unregulated growth and will often form a mass or lump, but may be distributed diffusely. The words “you have cancer” may be one of the hardest things anyone has to hear.

In the United States, an estimated 15.5 million people with a history of cancer were living as of January 1, 2016, according to a 2018 report from the American Cancer Society. Donate to the American Cancer Society today to ensure no cancer journey—from prevention to survivorship—has to be walked alone. Whether you want to learn about treatment options, get advice on coping with side effects, or have questions about health insurance, we’re here to help. Check with your doctor for guidance on the national recommendations regarding vaccinations, testing and screenings. Millions of lives could be saved each year by implementing resource appropriate strategies for prevention, early detection and treatment.


We read each email and regularly answer inside one business day.

Contact Details

Email: [email protected]

If the error control processes fail, then the mutations will survive and be passed along to daughter cells. Large-scale mutations involve the deletion or gain of a portion of a chromosome. Genomic amplification occurs when a cell gains copies of a small chromosomal locus, usually containing one or more oncogenes and adjacent genetic material. Translocation occurs when two separate chromosomal regions become abnormally fused, often at a characteristic location.

Survival rates are estimates based on the experiences of large groups of people who have different kinds of cancer. Like prognoses, cancer survival rates vary based on cancer type, stage and treatment. According to the most recent data from the National Cancer Institute, 68% of people with any kind of cancer were alive five years after their diagnosis. Having cancer screening tests at regular intervals is the single best way to protect against cancer. Not only can screening tests find cancers early when they’re most treatable, in the case of colon and cervical cancer they can actually help prevent the disease. Certain infections can either directly or indirectly cause changes that can lead to cancer.