Objective: The main objective of this study was to further elucidate the effect of consuming various foods on the development of squamous cell carcinoma (SCC) in three different sections of the esophagus.
Methods: A total of 343 patients with SCC of the esophagus and 755 cancer-free control subjects were recruited for this study from 1996 to 2005.
Results: We found that intake of vegetables, raw onions/garlic, and fruits are significantly protective against esophageal SSC risk, whereas intake of hot foods can significantly increase its risk. There was a significant inverse relation between the frequency of tea consumption and esophageal SCC risk (P for trend = 0.005), with a 0.5-fold lower risk associated with the intake of unfermented tea (green tea, oolong tea, or jasmine tea). The effects of dietary factors on esophageal SCC were similar in all subsites, with the exception of consumption of coffee. Coffee consumption was more pronounced in having a protective effect in the middle third section compared with the lower third section of the esophagus (adjusted odds ratio 0.4, 95% confidence interval 0.2-0.9), although this protective effect was marginally significant (adjusted odds ratio 0.6, 95% confidence interval 0.4-1.0) against esophageal SCC in all subsites. Our data also suggest that discomfort when eating hot foods may exert a carcinogenic effect by direct contact with the esophageal mucosa and tend to have more harmful effects in the upper than in the lower esophagus. In contrast, vegetables, fruits, and tea with components that are thought to inhibit carcinogenesis by absorbed components affected all subsites similarly.
Conclusion: Our results add additional information that certain dietary components may affect carcinogenesis locally and systemically.