The objective of this study was to conduct a pooled analysis to evaluate the strength of the evidence available in the epidemiological literature on the association between alcohol drinking cessation and reduction in esophageal and head and neck cancer risks. A search using several electronic bibliographic databases was performed for relevant epidemiological literature between 1966 and 2006. A total of 13 unique studies including over 5,000 cases were found. Categorical and third order polynomial (cubic) regression models were fitted to estimate the temporal relationship between years of drinking cessation and risk of cancer. The risk of esophageal cancer significantly increased within the first 2 yr following cessation [odds ratios (ORs)(0-2 yr): 2.50, 95% confidence intervals (CI): 2.23-2.80], then decreased rapidly and significantly after longer periods of abstention (OR(15+ yr): 0.37, 95% CI: 0.33-0.41). An elevated risk, although not strong as for esophageal cancer, was observed for head and neck cancer up to 10 yr of quitting drinking (OR(5-10 yr): 1.26, 95% CI: 1.18-1.35). Such risk only reduced after 10 yr of cessation (OR(10-16 yr): 0.67, 95% CI: 0.63-0.73). After more than 20 yr of alcohol cessation, the risks for both cancers were no longer significantly different from the risk of never drinkers. Our findings demonstrate an important role of alcohol cessation on esophageal and head and neck carcinogenesis.
(c) 2007 Wiley-Liss, Inc.