ObjectiveTo investigate the distribution of uridine diphosphate-glucuronosyltransferase 1A1 (UGT1A1) gene polymorphisms in esophageal carcinoma (EC) patients, and their relationship with adverse effects (delayed diarrhea and neutropenia) of Irinotecan. MethodsForty-eight patients with esophageal squamous carcinoma who were admitted to Sichuan Provincial People's Hospital between January and October 2012 were recruited in the study. There were 37 male and 11 female patients with their age of 56 (25-38) years. Formalin-fixed, paraffin-embedded samples were collected from those EC patients and genomic DNA was extracted. UGT1A1 polymorphisms were detected by PCR and DNA sequencing. Three genetic loci were investigated including UGT1A1* 28 (TA6 > TA7), UGT1A1* 6 (211G > A) and UGT1A1* 93 (-3156G > A). Adverse effects (delayed diarrhea and neutropenia) of patients with different UGT1A1 polymorphisms after Irinotecan treatment were recorded. The relationship between UGT1A1 polymorphisms and Irinotecan-induced adverse effects was analyzed. ResultsUGT1A1 polymorphisms were detected in 10 out of 48 (20.8%) EC patients. UGT1A1* 93 (-3156G > A)polymorphisms were most common with the polymorphism rate of 16.7% (8/48), followed by GT1A1* 6 (211G > A) polymorphisms with the polymorphism rate of 4.2% (2/48). The incidences of grade 3~4 diarrhea and grade 3~4 neutropenia after Irinotecan treatment in the patients with UGT1A1 polymorphisms were 60.0% and 40.0% respectively, which were significantly higher than those of the patients with wild type UGT1A1 (21.1% and 15.8% respectively, P < 0.05). UGT1A1 polymorphism rates were 45.5% (5/11) in female patients and 13.5% (5/37) in male patients, which were significantly different (P < 0.05). ConclusionsIn EC patients, 2 polymorphism loci including UGT1A1* 93 (-3156G > A) and GT1A1* 6 (211G > A) can effectively predict adverse effects caused by Irinotecan treatment. UGT1A1 polymorphism rate of male patients is significantly lower than that of female patients.