[Long-term effect of treating patients with precancerous lesions of the esophagus].

OBJECTIVE To report long term therapeutic effect in patients with esophageal pre-cancerous lesions in high-risk area of esophageal cancer. METHODS The therapeutic trial enrolled 2,531 cases of severe dysplasia and 3,393 cases of mild dysplasia. A 2-arm randomized, placebo-controlled design was used in which the participants received Zeng Sheng Ping (ZSP, an herbal composite), retinamide or placebo for cases with severe dysplasia and riboflavin or placebo for those with mild dysplasia. RESULTS Treatment with ZSP and retinamide decreased malignant transformation rate of severe dysplasia by 52.2% and 43.2%, respectively after 5 years of treatment. When the treatment had been discontinued for 4 years, the rate of malignat transformation was decreased by 42.1% and 38.2% respectively, which remained significantly higher than that of the placebo-treated control. Riboflavin treatment was continued for 9 years. At the end of 5-year medication, the malignant transformation rate decreased by 34.8%, which was not significantly different from that of the placebo control. When the treatment was continued up to 9 years, the rate was further decreased to 37.0%, which became statistically significant. CONCLUSION ZSP, retinamide and riboflavin treatment can effectively prevent esophageal dysplasia from transforming into carcinoma.