Oesophageal cancer in never-smokers and never-drinkers.

Alcohol, tobacco and diet are the most important determinants of oesophageal cancer. Previous studies which examined smoking in non-drinkers and drinking in non-smokers did not report the main effects of dietary factors or the smoking and drinking effects adjusted for dietary factors. Data from a hospital-based case-control study in Hong Kong Chinese were used to examine the effects of dietary variables as well as tobacco and alcohol in never-drinkers and never-smokers. Among the 400 cases, there were 68 never-smokers and 53 never-drinkers; 540 were never-smokers and 407 were never-drinkers among 1598 controls. In never-smokers, alcohol drinking was strongly associated with risk. Use of green leafy vegetables and citrus fruits was protective. Among never-drinkers, smokers had increased risk, but the protective effect of vegetables and fruits did not reach statistical significance. In never-smokers and in never-drinkers alike, frequent consumption of pickled vegetables and being born in Teochew or Hokkien were associated with increased risks. This study provides further support for the independent effects of alcohol, tobacco and diet in oesophageal cancer.