The effect analysis of CYP2D6 gene polymorphism in the toremifene and tamoxifen treatment in patient with breast cancer.

The purpose of the present research work was to study the CYP2D6 gene polymorphism survival outcome after breast cancer patient received the toremifene and tamoxifen treatment. Seventy-eight patients who received radical mastectomy and toremifene and tamoxifen treatment after operation were divided into three groups: CYP2D6*1/*1 group (13 cases), CYP2D6*1/*10 group (28cases) and CYP2D6*10/*10 group (35 cases), according to the gene polymorphism of blood serum CYP2D6. The results of treatment of three groups were compared. After operation the content of blood serum CA125, CA153, VEGF, IGF-1 were all lower than before. The content of CYP2D6*10/*10 group was higher than those of CYP2D6*1/*1 group and CYP2D6*1/*10 group. The content of CYP2D6*1/*1 group had no difference with that of CYP2D6*1/*10 group. All patients were followed up for a median duration of 30.5 months. Progression-free survival (PFS) of CYP2D6*10/*10 was shortened. The recurrence rate increased and the survival rate reduced. There were no obvious differences between CYP2D6*1/*1group and CYP2D6*1/*10 group. In summary, CYP2D6 gene polymorphism relates with the effect of toremifene and tamoxifen treatment in patient with ER positive breast cancer and null allele homozygote CYP2D6*10/*10 can lead to a poor prognosis.