Assessing Outcomes for Breast Cancer Patients Treated with Tamoxifen

Reference #:

2005-305

Inventors/Contributors

Matthew M. Ames, Ph.D., Matthew P. Goetz, M.D., James N. Ingle, M.D.

Description

In the adjuvant treatment of estrogen receptor (ER) positive breast cancer, hormonal therapy reduces the risk of breast cancer recurrence and decreases mortality. CYP2D6 catalyzes the conversion of N-desmethyl tamoxifen to 4-OH N-desmethyltamoxifen (Endoxifen), which is the most important tamoxifen metabolite. We show that women receiving adjuvant tamoxifen who are homozygous for the CYP2D6*4 allele, the most common genetic polymorphism accounting for CYP2D6 poor metabolizers, have a nearly 2-fold higher risk of breast cancer recurrence compared with patients heterozygous or homozygous for the wild type allele. These results suggest that women who are CYP2D6 poor metabolizers may benefit from alternative and or additional therapies besides tamoxifen monotherapy.

Patent Status

Pending