Almost four out of 10 cancer cases in Germany are attributable to environmental and lifestyle factors. These include mainly smoking, low physical activity, overweight and infections. In the current year, it is estimated that 85 072 cancer cases were caused by smoking. This corresponds to 19% of all new cases. In men, the proportion of lung tumors due to tobacco consumption is 89% and in women 83%. Hermann Brenner and his group of authors of the German Center for Cancer Research (DKFZ) report on how these risk factors influence the number of cancer cases in Germany in concrete terms, in this thematic issue of Deutsches Ärzteblatt International. In their series of articles, the authors determined the proportion of new cancer cases in a particular segment of the population among all the new tumors expected for 2018. The calculation is based on demographic projections, on the relative risks published and on the incidence of cancer and exposure data for the range 35-84 years in Germany.
Overweight and lack of physical activity / exercise account for 7% and 6% of the expected cancer load, respectively, and are the main risk for uterine and kidney cancers. The estimated numbers (percentages) of attributable tumors were 30 567 (7%) for excess weight, 27 081 (6%) for low physical activity, 14 474 (3%) for low intake of dietary fiber, 9447 (2% ) for low fruit and vegetable consumption, 9454 (2%) and 1687 (0.4%) for processed meat and high consumption of red meat, respectively, and 1204 (0.3%) for the intake of high salt. Excess weight contributed substantially to endometrial, renal and liver carcinoma (fraction attributable to the population, PAF = 24 to 35%). Low physical activity contributed to uterine, renal and pulmonary carcinoma (PAF = 15 to 19%) and dietary factors mainly contributed to colorectal, breast and lung cancer (PAF = 9 to 16%). In overweight people the risk of liver cancer also increases, while the lack of exercise also contributes to lung cancer.
For 2018, it is estimated that over 17 600 cancer cases (4.0% of all incident cancers) are attributable to infections. The major contributions come from Helicobacter pylori infections (n = 8764) and human papillomavirus (n = 7669). It was estimated that hepatitis B and C infection, human HIV virus and herpesvirus 8 caused 983 cases, 144 cases and 116 cases respectively. More than 5400 cancer cases (1.2% of all incident tumors) have been attributed to selected environmental factors, of which the largest contributor is indoor radon (n = 3185), followed by particles (n = 1049), use of the sunbed (n = 892) and passive smoke (n = 309). A lower but still important proportion of new malignancies is due to high consumption of alcohol, high consumption of processed meat or low levels of dietary fiber intake, fruit and vegetables. Additional risk factors include internal radon, particulate matter or use of the sunbed.
The burden of cancer attributable to high alcohol consumption was estimated in 9588 cases (men 8117, women 1471, 2% of all incident tumors). The highest PAF were observed for oral cavity and pharyngeal cancer (men 34%, women 6%) and carcinoma of the esophagus (men 30%, women 5%). Of about 440 000 cancer cases predictable in Germany in 2018, it is estimated that approximately 85,000 and 9500 cases are attributable to the consumption of alcohol and smoking, respectively, corresponding to 19% and 2% of all cancer cases. Given the still significant prevalence of smoking and alcohol consumption in this country, there is enormous potential for cancer prevention. The authors make an appeal for more stringent prevention measures in terms of smoking, alcohol, overweight, unhealthy diet and lack of exercise. They also require targeted preventive measures regarding infections and environmental factors. But they underline that further research is needed to identify and quantify environmental risks more comprehensively.
The study concerned Germany, but given that the “Western” lifestyle is inclusive of Europe, the Americas and other parts of continents and nations with the same tendency, it is easy to sense that the proportions could comfortably be reflected in them. Italy included.
- edited by Dr. GIanfrancesco Cormaci, PhD, specialist in Clinical Biochemistry.
Gredner T et al. Dtsch Arztebl Int. 2018 Sep 3;115(35-36):586-593.
Behrens G et al. Dtsch Arztebl Int. 2018 Sep 3;115(35-36):578-585.
Mons U et al. Dtsch Arztebl Int. 2018 Sep 3; 115(35-36):571-577.