Trial Information

The Pharmacogenomics of Breast Cancer Prevention: A Genome-Wide Association Study in Participants Experiencing Breast Cancer Events in High-Risk Postmenopausal Women Receiving Selective Estrogen Receptor Modulators on NSABP Trials P-1 and P-2

OBJECTIVES:

Primary

- To identify genes associated with breast events (i.e., the occurrence of invasive
breast cancer or ductal carcinoma in situ), in terms of single-nucleotide polymorphisms
(SNPs) in a genome-wide association study, in Caucasian women at high risk of
developing breast cancer who have received a selective estrogen receptor modulator
(SERM) (i.e., tamoxifen or raloxifene) on the NSABP-P-1 OR NSABP-P-2 breast cancer
prevention clinical trials.

- To determine the impact of CYP2D6 metabolizer status, which includes genotype and
status of concurrent use of CYP2D6 inhibitors, on breast cancer events in participants
receiving either tamoxifen or raloxifene.

Secondary

- To explore whether multiple SNPs within a region are independently associated with a
breast event.

- To explore whether there are interactions among SNPs that increase the risk for a
breast event.

- To explore whether there is interaction of any SNPs identified in the primary objective
with randomized treatment, in terms of the risk for a breast event.

OUTLINE: Samples are stratified according to CYP2D6 genotype and CYP2D6 metabolizer status.

DNA extracted from previously collected blood samples is analyzed in a genome-wide
association study and compared with 2 control samples from patients who did not experience a
breast event. DNA samples are used to identify and analyze single nucleotide polymorphisms.