Decreased risk of esophageal cancer owing to cigarette and alcohol cessation in smokers and drinkers: a systematic review and meta-analysis

Smoking cigarettes and drinking alcoholic beverages are considered very important risk factors for adverse health effects, such as many types of cancer and cardiovascular disease. In this study, we evaluated the influence of smoking and drinking cessation on risk of esophageal cancer, by means of meta-analysis. We extracted 205 studies by conducting a systematic literature search. Thirty-five studies that estimated risk reduction following smoking cessation and 18 studies conducted following drinking cessation were identified in the literature review. Former smokers had a significantly lower summary risk ratio (RR) than current smokers [RR 0.74, 95% confidence interval (CI) 0.68-0.80]. In subgroup analysis of Japanese smokers, squamous cell carcinoma, and adenocarcinoma, RRs for former smokers versus current smokers were 0.65 (95% CI 0.51-0.83), 0.60 (95% CI 0.50-0.72), and 0.93 (95% CI 0.84-1.03), respectively. The summary RR between former alcohol drinkers and current drinkers was not significant (RR 1.09, 95% CI 0.94-1.26). In our analysis of time since drinking cessation, drinkers who had stopped consuming alcohol for 5 years or more had a significantly lower summary RR than current drinkers (RR 0.78, 95% CI 0.66-0.93). Summary RR for drinkers who stopped for 10 years or more versus current drinkers was 0.65 (95% CI 0.57-0.74). Our investigation found that smoking cessation lowers esophageal cancer incidence. We also found that esophageal cancer incidence risk could be decreased in current drinkers by cessation of alcohol consumption for 5 years or more.