Studies on medicamentous inhibitory therapy for esophageal precancerous lesions--3- and 5-year inhibitory effects of antitumor-B, retinamide and riboflavin.

Since 1983, we have been conducting inhibitory therapy for precancerous lesions of the esophagus in two regions of Henan Province considered high-risk areas of esophageal carcinoma. Our goal was to effect a 50% reduction in the canceration rate of marked esophageal dysplasia. By means of a cytological survey, 2531 cases of marked esophageal dysplasia and 3393 cases of mild esophageal dysplasia were selected. The former were randomly divided into 3 groups for antitumor-B (ATB, a mixture of Chinese herbs), retinamide (4-ethoxycarbophenylretinamide) and placebo treatment respectively, and the latter into 2 groups treated with riboflavin and placebo respectively. Treatment was continued for 3 or 5 years (administration rate greater than 90% in all groups) and esophageal cytology reexamined (reexamination rates were 94.1% and 92.5% respectively). Our results were as follows: 1) ATB 3- and 5-year subjects saw the canceration rate of marked esophageal dysplasia drop by 52.2% and 47.3% respectively as compared to control (P less than 0.01). 2) Retinamide lowered the canceration rate by 37.3% after a 3-year treatment period, with this reduction reaching 43.2% after an additional 2 years of treatment with increased dosages (P less than 0.05, P less than 0.01). 3) In the riboflavin group, the canceration rate of mild esophageal dysplasia was reduced by 22.2% and 34.8% after 3 and 5 years of treatment respectively, but these differences were not statistically significant. The above results verify the efficacy of medicamentous inhibitory therapy for esophageal precancerous lesions.(ABSTRACT TRUNCATED AT 250 WORDS)