The Outcomes Of Tamoxifen Therapy In Breast Cancer Patients And Genotypes Of Sult1a1 And Glucuronosyltransferase

Background: The CYP2D6 genotype has been shown in previous meta-analysis to influence both the mortality and recurrence in breast cancer patients treated with tamoxifen. However, the effect of other drug-metabolizing enzymes on tamoxifen pharmacokinetics is uncertain. We aimed to assess the association between SULT1A1 and glucuronosyltransferase (UGT) genotypes and the outcome of breast cancer patients with tamoxifen therapy. Method: We performed a systematic search of Pubmed and Embase (Ovid) databases, and outcomes of overall survival, relapse/recurrence-free survival and disease-free survival were extracted and analyzed. Statistical analysis was performed by Engauge Digitizer 4.1, Revman4.2 and STATA 10.0. Results: A total of 4339 breast cancer cases in 14 studies were identified for data analysis. The results suggested a decrease in relapse/recurrence-free survival of breast cancer in patients carrying variant alleles of SULT1A1, while no increase or decrease in survival was observed when analyzed in combination with data of overall survival and disease-free survival. No statistically significant result was shown in the pooled-analysis of UGT2B15 genotypes and UGT2B7 genotypes. Conclusions: This current meta-analysis suggested the variant allele SULT1A1*2 might be an outcome predictive factor to assess the clinical responses of breast cancer patients towards tamoxifen therapy. Future studies are needed to validate our findings.