Cancers Attributable to Smoking and Obesity in Turkey: a population-based study

Objective: Cancers are the second most common cause of mortality following cardiovascular diseases in Turkey. Tobacco and obesity are the two major etiological factors for cancer progression, which are highly prevalent in Turkey. This study aimed to evaluate the new cancer cases in Turkey attributable to these two main risk factors. Material and methods: The tobacco-related cancers based on the International Agency for Research on Cancer (IARC) monographs were esophagus, oral cavity, gastric, pancreatic, larynx, lung, renal, and bladder cancers, and the obesity-related cancers based on the IARC's and World Cancer Research Fund (WCRF)/American Institute for Cancer Research (AICR) Continuous Update Project's reports were esophagus, colon, rectum, gallbladder, pancreas, kidney, ovary, endometrium, and breast cancers. The cancer incidences were obtained from the national cancer statistics. A lag time of at least 10 years was regarded adequate to observe the effects of past exposures on the new cancer cases. Prevalence of tobacco smoking was based on Peto-Lopez approach, and the obesity prevalence was obtained from the National Burden of Disease and Cost-Effectiveness Project Household Survey, 2003 Report in Turkey. Using these incidence and prevalence data, we estimated the population-attributable fractions (PAF) of cancers attributable to smoking and obesity in Turkey. Results: For tobacco-related cancers, the highest PAFs were found in lung cancer (89.8%), larynx cancer (86%), oral cavity and pharynx cancer (77.2%) in males, and larynx cancer (46.5%), lung cancer (43%), and esophagus cancer (31.4%) in females. For obesity-related cancers, the highest PAFs were found in esophagus adenocarcinoma (31.4%), kidney cancer (19.8%), gallbladder cancer (15.1%) in males, and esophagus adenocarcinoma (33.9%), endometrium cancer (32.8%), and postmenopausal breast cancer (22.8%) in females. When all tobacco-related cancers were considered, 41283 cases in males and 3853 cases in females were attributable to tobacco smoking, and when all obesity-related cancer types were considered, the number of attributable cancer cases to obesity was 2653 in men and 7387 in women Conclusion: The current situation of avoidable cancer burden in Turkey shows that eliminating the tobacco smoking and obesity may result with preventing more than 50000 cancer cases in Turkey.