Sex differences in the proportion of esophageal squamous cell carcinoma cases attributable to tobacco smoking and alcohol consumption

Objective: Alcohol and tobacco are the two major established environmental factors associated with squamous cell carcinoma of the esophagus (ESCC). However, the prevalence of these exposures differs substantially between men and women. Moreover, the prevalence of smoking has declined in recent years, whereas per capita consumption of alcohol has remained steady in both sexes. Quantifying the burden of ESCC attributable to these causal factors is necessary to inform potential preventive strategies. Methods: We estimated the population attributable fraction (PAF) of ESCC due to smoking and alcohol, using data from an Australian population based case–control study (305 ESCC cases, 1554 controls). Results: Estimated PAF for ESCC were 49% (95% CI: 38–60) and 32% (95% CI: 25–40) due to smoking and heavy alcohol consumption respectively. More than 75% of the ESCC burden in men could be attributed to smokers with heavy alcohol consumption. The highest burden was among ≥30 pack years smokers who also consumed alcohol heavily (>17 drinks/week); this differed significantly between men (PAF 36%, 95% CI 29–44) and women (PAF 5%, 95% CI 2–10). Among women only, low intakes of fruit and vegetables accounted for about 9% of the ESCC burden. Conclusion: The burden of ESCC attributable to smoking combined with heavy alcohol consumption is remarkably high in men. In women, the burden of ESCC due to these factors is lower, and poor nutrition may also play a role.