The risk of recurrence in breast cancer patients treated with tamoxifen: polymorphisms of CYP2D6 and ABCB1.

CYP2D6 plays a major role in the metabolism of tamoxifen, and polymorphism of P-glycoprotein has been associated with resistance of many drug therapies. This study investigates the clinical impact of genetic variants of CYP2D6 and ABCB1 in breast cancer patients treated with tamoxifen. Blood samples from 95 breast cancer patients treated with tamoxifen were collected and genotyped for CYP2D6 and ABCB1 variants using allele-specific PCR method.

Identification of different subtypes of breast cancer using tissue microarray.

Breast cancer may be classified into luminal A, luminal B, HER2+/ER-, basal-like and normal-like subtypes based on gene expression profiling or immunohistochemical (IHC) characteristics. The main aim of the present study was to classify breast cancer into molecular subtypes based on immunohistochemistry findings and correlate the subtypes with clinicopathological factors. Two hundred and seventeen primary breast carcinomas tumor tissues were immunostained for ER, PR, HER2, CK5/6, EGFR, CK8/18, p53 and Ki67 using tissue microarray technique.