Time pattern of reduction in risk of oesophageal cancer following alcohol cessation-a meta-analysis

Aim To establish the current level of knowledge of the effect of drinking cessation on the risk of developing oesophageal cancer. Method A meta-analysis was conducted based on relevant studies identified through a systematic literature review. A generalized least squares model for trend estimation of summarized doseresponse data were utilized in order to estimate the effect of years since drinking cessation on risk of oesophageal cancer. Result Seventeen studies that estimate the risk reduction after quantified drinking cessation were identified in the systematic literature review. Nine of these were appropriate for inclusion in the meta-analysis. A large degree of heterogeneity existed between the studies, but this was explainable and the increased risk of oesophageal cancer caused by alcohol consumption was found to be reversible, with a common trend between studies. A required time-period of 16.5 years (95% confidence interval 12.723.7) was estimated until no risk from former drinking remained, although this might have been an overestimation due to sample characteristics. The doseresponse relationship was found to have an exponential decay. This means that about half the reduction in alcohol-related risk occurred after just a third of the time-period required to eliminate the additional risk. Conclusion The alcohol-related increased risk of oesophageal cancer is reversible following drinking cessation. It is most likely that about 16 years are required until all elevated risk has disappeared. Due to lack of research and data, more research is urgently required to increase the robustness of the estimates and to approach study limitations.