Abstract: OcjectiVe To observe the association of uridine diphosphate glucuronosyl transferase 1 A1( UGT1 A1 ) gene polymorphism with the toXicity and toXicity of irinotecan( CPT-11 ) chemotherapy in Chinese patients with small cell lung cancer( SCLC ). Methods In 34 patients with SCLC who had received first-line treatment with irinotecan plus cisplatin,genomic DNA samples were eXtracted,leukocytes in the peripheral blood,and the geno types were determined by analyzing the sequence of the UGT1A1 gene. The influence of the UGT1A1* 28 polymorphism on the short-term efficacy and toXicity of irinotecan was analyzed. Results The UGT1A1 genotypes in 34 consecutive patients were as follows:UGT1A1*28 homozygous wild-type TA6/6( 26 cases,76. 5%),heterozygous mutant-type TA6/7( 6 cases,17. 6%),homozygous mutant-type TA7/7( 2 cases,5. 9%). Marked increases in diarrhea were observed in patients who had the TA 6/7 or TA 7/7 geno type( p<0 . 05 ). Conclusion The polymorphism of UGTIAl*28 in Chinese SCLC patients was lower,TA6/7 orTA7/7 increased the risk of developing grade or more severe diarrhea for the patients after receiving irinotecan treatment but had no influence on efficacy of chemotherapy.

Key words: small cell lung carcinoma, irinotecan, polymorphism, genetic