The Study Of Association Between CYP19Gene Polymorphism And Letrozole Treatment

Objective: To study the association between cyrochrome p45019(CYP19)rs10046polymorphism and postmenopausal breast cancerpostoperative Estrogen-Receptor positive patients receiving letrozole treatment.Method: Collecting the peripheral blood of56postmenopausal breast cancerpostoperative Estrogen-Receptor positive patients receiving letrozole treatmentmore than6months, testing CYP19rs10046polymorphism by using themethod of the polymerase chain reation-restricition fragment lengthpolymorphism(PCR-PFLR), taking a median follow-up of30months for thepatients and analyzing the association between CYP19rs10046polymorphismand the side reaction and DFS of patients receiving letrozole treatment. Result:1.The distribution of56patients’ three genotypes of CYP19rs10046was asfollows: TT genotype of31cases, accounting for55%; TC genotype of18cases, accounting for32%; CC genotype of7cases, accounting for13%;andthe distribution of each genotype is in good agreement with Hardy-Weinbergequilibrium.2.Doing the chi-square analysis of the side reactions among thegroups of three genotypes, only found the differences of the hot flashes and noside reactions among the groups (P=0.032, P=0.048), while there was nostatistical significance for the differences of the bone pain and other side reactions (P=0.862, P=0.543).3.Drawing the Kaplan Meier-survival curveline separately for the three genotypes of patients and the follow-up results,and carrying out parallel Long-rank tests, found no differences of the DFSamong the patients of genotype TT, genotype TC and genotype CC (P=0.547);Combining the groups of genotype TC and genotype CC into one group, thendrawing the Kaplan Meier-survival curve line and carrying out parallelLong-rank tests with the group of genotype TT, also found no differences ofthe DFS between the two groups（P=0.403）; Combining with the factors thatmay affect the prognosis of patients: gene polymorphism, TNM staging,preoperative chemotherapy, surgery, chemotherapy, radiotherapy afteroperation, postoperative lymph node metastasis number, immunohistochemicalER, PR, Her-2results and side reactions, using Cox proportional hazardregression analysis, found that DFS had no relation to genotype TT, genotypeTC and genotype CC（P=0.092）. However, Combining the groups of genotypeTC and genotype CC into one group and using Cox proportional hazardregression analysis with the group of genotype TT showed that the genepolymorphism was associated with DFS（OR=0.032，95%CI：0.004~0.263，P=0.01）. Conclusion:1.CYP19gene polymorphism has a dependency onletrozole treatment.2. Genotype TT can be used as an independent prognosticfactor.3. Letrozole individualized endocrine therapy can be guided accordingto CYP19genotype.