Smoking and drinking cessation and risk of esophageal cancer (Spain)

Objectives: To explore the effectiveness of alcohol drinking and tobacco sm oking cessation in reducing esophageal cancer risk, taking into account the key characteristics of each habit and the simultaneous exposure to both ha bits. Methods: Data from a series of five hospital-based case-control studies of incident squamous-cell carcinoma of the esophagus conducted by the Internat ional Agency for Research on Cancer (IARC, Lyon, France) in high-risk areas in South America were combined and analyzed by multivariate logistic regre ssion procedures. A total of 2063 men (655 case patients and 1408 control s ubjects) were included in the pooled analysis. Results: For either habit, the risk of esophageal cancer decreased rapidly, strongly and significantly with longer periods of abstention. The risk red uction was statistically significant regardless of the intensity and durati on of each habit and the type of tobacco or alcoholic drink consumed. For s ubjects exposed to both risk factors, the protective effect of quitting bot h habits appeared to be synergistic, reaching, after only five to nine year s of simultaneous cessation of both exposures, a 70% risk reduction, a redu ction that clearly overlapped with the risk intervals of both never-smokers and never-drinkers. The risk benefit of merely quitting alcohol drinking w as delayed (> 10 years of cessation) unless it was also accompanied by a fe w years of smoking cessation. Conclusions: Our findings solidly demonstrate for the first time the effect iveness of smoking and drinking cessation in reducing esophageal cancer ris k. For the large proportion of subjects in the general population exposed t o both risk factors, our results further emphasize the importance of smokin g cessation to effectively reduce cancer risk.