Effect of fertility concerns on tamoxifen use in young survivors of breast cancer.

Abstract

572 Background: For premenopausal patients with ER+ breast cancer, a 5-year course of tamoxifen results in a 47% reduction in annual recurrence risk and a 26% reduction in annual mortality. Despite these benefits, adherence rates for tamoxifen are low, particularly among younger women. We hypothesize that fertility concerns are causally related to the poor tamoxifen adherence rates observed among young breast cancer survivors. Methods: With IRB approval, a retrospective analysis of 535 women with breast cancer between 2000-2012 was undertaken. Patients were younger than age 46, premenopausal and had ER+ breast cancer. 138 patients did not complete a 5-year course. Patient and provider factors that influenced tamoxifen initiation and adherence were reviewed: (1) evidence of referral to a fertility specialist; (2) documentation of discussion about tamoxifen-related fertility concerns; (3) agreement to take tamoxifen; (4) duration of tamoxifen use. Phone interviews conducted with 27 patients focused on lack of initiation or early discontinuation. The Log-rank (Mantel-Cox) test was used to compare Kaplan-Meier curves and generate hazard ratios. Results: Of the 138 patients who did not complete 5 years of therapy, 38 (27.5%) failed to initiate or discontinued tamoxifen secondary to fertility concerns. Only 114 (21.3%) charts documented referral to a fertility specialist. Patients who expressed a desire to maintain fertility or to have children in the future (115 patients, 21.5%) were more likely to discontinue tamoxifen treatment (HR=2.7, p=0.001). Other critical factors included being unmarried (HR=1.9, p=0.011) and lack of college education (HR=2.5, p=0.0008). Major themes from phone interviews: (1) patients felt they were not adequately informed about fertility preservation and had to pursue information independently; (2) patients did not initiate/resume tamoxifen postpartum because of inadequate physician guidance. Conclusions: Concerns about fertility have a significant negative impact on the initiation and adherence to tamoxifen for young breast cancer patients. Efforts to improve tamoxifen adherence among young cancer patients should include prioritization of fertility preservation as part of the treatment plan.