COLORECTAL-CANCER IN PATIENTS WITH ESOPHAGEAL ADENOCARCINOMA

The incidence of adenocarcinoma of the esophagus and gastric cardia ha s been rising rapidly in Western Europe and the United States, especia lly among white males. Previous reports, based on case series, have su ggested an association between colonic neoplasia and Barrett's esophag us, a metaplastic condition of the lower esophagus that can lead to ad enocarcinoma. We analyzed cancer incidence data from 1973 to 1989 from the nine population-based registries of the Surveillance, Epidemiolog y, and End Results program of the United States National Cancer Instit ute to investigate this association, using malignancies as an outcome. Using a case-control design, we measured the odds of being diagnosed with colorectal adenocarcinoma some time in life among persons diagnos ed with adenocarcinomas of the esophagus or gastric cardia relative to persons diagnosed with squamous cell carcinomas of the esophagus. Amo ng white males the odds ratio was 1.44 (95% confidence interval, 1.03- 2.02). This association appeared to be independent of which cancer occ urred first. In contrast, white females with adenocarcinomas were less likely to be diagnosed with colorectal cancer than those with squamou s cell carcinomas (odds ratio, 0.39; 95% confidence interval, 0.19-0.7 8). These associations appeared to be specific for colorectal tissue b ecause there was no relationship between histological type of esophage al cancer and prostate cancer in men or breast cancer in women. We con clude that men with esophageal adenocarcinoma may be more likely to be diagnosed with colorectal cancer in their lifetime than expected; the opposite association may exist for women. These data provide addition al evidence that some colorectal and esophageal adenocarcinomas share a common etiology. Prospective studies of both men and women with mali gnant and premalignant lesions of the colon and esophagus are needed t o establish the clinical significance of these findings while taking i nto account gender, and to identify underlying mechanisms.