ER alpha genotypes and breast cancer recurrence

501 Background: Pharmacogenomic studies have documented the importance of CYP2D6 in the metabolism of tamoxifen (TAM) and the resulting clinical outcomes. However, there is no data relating polymorphisms within the estrogen receptor to disease recurrence in patients receiving adjuvant TAM. Methods: Blood samples and clinical data were collected at baseline. Assessment of clinical data was conducted yearly to evaluate disease recurrence. A Taqman Allelic Discrimination assay was utilized for genotyping the ER alpha Pvu II polymorphism. Fisher's exact tests were used to test relationships of genotypes and disease recurrence. Cox regression analysis was used to assess time to disease recurrence and was adjusted for lymph node status, histologic grade, and tumor size. Results: Within our cohort of 301 women receiving adjuvant TAM therapy, 291 women were eligible for analysis. With a median follow-up time of 5.2 years, 5% have developed recurrent disease. Patients with the ER alpha Pvu II PP genotype had a hig...