Cancers attributable to modifiable risk factors: a road map for prevention

The implementation of primary and secondary preventive strategies is based on the evidence generated by cancer epidemiology, where the identification of risk factors and the description of their prevalence are fundamental to derive estimates on the burden of cancer from different etiologies, typically expressed as the population attributable fraction, which corresponds to the proportion of a cancer that may be prevented by controlling a given risk factor. However, even when cancer finds its etiology in modifiable factors, its prevention through the control of those factors is not always feasible, or it remains suboptimal despite the possibility of reducing the burden. We reviewed selected associations between modifiable risk factors and cancer, including tobacco smoking, occupational exposures, infections, air pollution, alcohol, and diet and obesity, and illustrated examples of both successes and failures in cancer control, underlying how current understanding of the avoidable causes of cancer is incomplete.