Preventing cancer through modifiable risk factors
Cancer, a leading cause of death worldwide, is significantly influenced by modifiable lifestyle and environmental factors, with estimates suggesting that 30-50% of cases are preventable. Key risk factors include alcohol use, tobacco consumption, poor diet, lack of physical activity, and excess body weight, all of which have been linked to an increased risk of various cancer types. Targeting these modifiable behaviors through prevention efforts and public awareness can substantially reduce the global burden of cancer, underscoring the importance of individual lifestyle choices in cancer prevention.
​Between 30–50% of all cancer cases are preventable.
Cancer is one of the leading causes of death worldwide, responsible for nearly 10 million deaths in 2020, according to the World Health Organization (WHO). However, a significant portion of cancers are preventable through modifications to lifestyle and environmental factors. Recent research estimates that 30-50% of cancers are linked to behaviours and exposures that can be avoided. Reducing modifiable risk factors presents an enormous opportunity to lower the cancer burden globally.
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One of the most important preventable risk factors for cancer is alcohol use. According to the American Cancer Society (ACS), alcohol use accounts for about 6% of all cancers and 4% of cancer deaths in the United States each year (ACS, 2022). Alcohol has been directly linked to an increased risk of several types of cancer, including cancers of the mouth, throat, larynx, oesophagus, liver, colon, rectum and breast (ACS, 2022). For each of these cancer types, the risk rises with greater alcohol intake. Even moderate drinking can raise breast cancer risk in women.
The European Code Against Cancer echoes guidelines from the World Health Organization and other public health organizations in recommending limiting alcohol consumption to reduce cancer risk. Alcohol is classified as a Group 1 carcinogen by the International Agency for Research on Cancer based on sufficient evidence that it causes cancer in humans. The Code's sixth recommendation specifically addresses alcohol, stating, "If you drink alcohol of any type, limit your intake. Not drinking alcohol is better for cancer prevention." This aligns with research finding that the risk of developing an alcohol-attributable cancer increases with the amount of alcohol consumed. While low levels of drinking may still carry some risk, avoiding alcohol altogether removes this risk factor. For individuals who choose to drink, the Code provides a clear message to keep consumption well below recommended limits to help lower cancer risk.
In addition to alcohol, other modifiable behaviours that significantly impact cancer risk include tobacco use, excess body weight, poor diet and lack of physical activity. A 2017 study from the ACS found that over 40% of cancers and cancer deaths in the US were attributable to these factors (ACS, 2017). Specifically, cigarette smoking accounted for nearly 30% of cancer deaths, while excess weight, poor diet and physical inactivity collectively contributed to about 16% of cancer mortality.
Reducing exposure to known carcinogens like tobacco, optimizing nutrition, maintaining a healthy weight and being physically active could prevent hundreds of thousands of cancers each year, according to the research. Comprehensive lifestyle changes offer a powerful yet underutilized strategy for cancer control. With further efforts to raise public awareness of modifiable risks and support healthy behaviours, it may be possible to lower cancer rates substantially in the coming decades.
In conclusion, between 30-50% of cancers have identifiable links to lifestyle and environmental exposures under our control. Targeting modifiable risk factors through prevention efforts presents a significant opportunity to reduce the cancer burden worldwide. Individual choices around behaviours like alcohol use, diet, physical activity and tobacco avoidance can make a meaningful difference in cancer risk.
