Cancer prevention

[4] Greater than a reported 75% of cancer deaths could be prevented by avoiding risk factors including: tobacco, overweight / obesity, an insufficient diet, physical inactivity, alcohol, sexually transmitted infections, and air pollution.

[10][11] Dietary recommendations for reducing cancer risk typically include an emphasis on vegetables, fruit, whole grains, and fish, and an avoidance of processed and red meat (beef, pork, lamb), animal fats, and refined carbohydrates.

[15] Substituting processed foods, such as biscuits, cakes or white bread – which are high in fat, sugars and refined starches – with a plant-based diet may reduce the risk of cancer.

[12][13] The primary dietary factors that increase risk are obesity and alcohol consumption; with a diet low in fruits and vegetables and high in red meat being implicated but not confirmed.

[27] COX-2 inhibitors may decrease the rate of polyp formation in people with familial adenomatous polyposis however are associated with the same adverse effects as NSAIDs.

[36] A 2018 systematic review concluded that selenium has no beneficial effect in reducing the risk of cancer based on high quality evidence.

Many factors influence whether a person exposed to a carcinogen will develop cancer, including the amount and duration of the exposure and the individual's genetic background.

[2] All such vaccines incite adaptive immunity by enhancing cytotoxic T lymphocyte (CTL) recognition and activity against tumor-associated or tumor-specific antigens (TAA and TSAs).

[2][42] Screening procedures, commonly sought for more prevalent cancers, such as colon, breast, and cervical, have greatly improved in the past few decades from advances in biomarker identification and detection.

[2] For women older than the age of 65 and with no history of cervical cancer or abnormality, and with an appropriate precedence of negative Pap test results may cease regular screening.

[2] Mammograms are widely used to screen for breast cancer, and are recommended for women 50–74 years of age by the US Preventive Services Task Force (USPSTF).

For example, consumption of tobacco and alcohol, a medical history of genital warts and STDs, immunosuppression, unprotected sex, and early age of first sexual intercourse and pregnancy all may serve as risk factors for cervical cancer.

A 2013 review of more recent cancer prevention literature by Schottenfeld et al.,[51] summarizing studies reported between 2000 and 2010, points to most of the same avoidable factors identified by Doll and Peto.

*Included in diet †Carcinogenic infections include: for the uterine cervix (human papillomavirus [HPV]), liver (hepatitis B virus [HBV] and hepatitis C virus [HCV]), stomach (Helicobacter pylori [H pylori]), lymphoid tissues (Epstein-Barr virus [EBV]), nasopharynx (EBV), urinary bladder (Schistosoma hematobium), and biliary tract (Opisthorchis viverrini, Clonorchis sinensis) Cancer has been thought to be a preventable disease since the time of Roman physician Galen, who observed that an unhealthy diet was correlated with cancer incidence.

Further observation in the 18th century led to the discovery that certain chemicals, such as tobacco, soot and tar (leading to scrotal cancer in chimney sweeps, as reported by Percivall Pott in 1775), could serve as carcinogens for humans.

[62] In the early 20th century, physical and biological carcinogens, such as X-ray radiation or the Rous Sarcoma Virus discovered 1911, were identified.

[64] In the early 1990s, the European School of Oncology led a review of the code and added details about the scientific evidence behind each of the recommendations.