Frequency of CYP2D6*10 genotypes in Pakistani breast cancer patients taking adjuvant tamoxifen.

OBJECTIVE: To investigate the frequency of cytochrome P2D6*10 in breast cancer patients.

METHODS: This retrospective study was conducted at the Nuclear Medicine, Oncology and Radiotherapy Institute, Islamabad, and the Combined Military Hospital, Rawalpindi, Pakistan, and comprised medical records of breast cancer patients from January 2000 to September 2013. Pre- and post-menopausal women with diagnosed breast cancer who were advised 20mg/day of tamoxifen as adjuvant therapy were included. The frequency of the cytochrome was determined using polymerase chain reaction-restriction fragment length polymorphism analysis.

RESULTS: Of the 232 participants, 25(10.8%) had stage I disease, 127(54.7%) had stage II and 80(34.5%) had stage III disease. The overall mean age was 46.9±9.9 years. The allele frequency of cytochrome CYP2D6*1 was 431(93%) and that of CYP2D6*10 was 33(7 %). Pakistanis differed significantly from the Asian populations and other ethnic groups in the distribution of the allele cytochrome, but its frequency was comparable to South Indians.

CONCLUSIONS: The frequency of CYP2D6*10 allele in Pakistani breast cancer women was comparable to the South Indians, but was significantly lower than other populations.