Abstract
PURPOSE: Endocrine therapy (ET) underuse puts women at increased risk for breast cancer (BC) recurrence. Our objective was to determine if health-related quality of life (HRQOL) subgroups were associated with underuse. METHODS: Data came from the third phase of the Carolina Breast Cancer Study. We included 1,599 women with hormone receptor-positive BC age 20 to 74 years. HRQOL was measured, on average, 5 months postdiagnosis. Subgroups were derived using latent profile (LP) analysis. Underuse was defined as not initiating or adhering to ET by 36 months postdiagnosis. Multivariable logistic regression models estimated adjusted odds ratios (ORs) between HRQOL LPs and underuse. The best HRQOL LP was the reference. Chemotherapy- and race-stratified models were estimated, separately. RESULTS: Initiation analyses included 953 women who had not begun ET by their 5-month survey. Of these, 154 never initiated ET. Adherence analyses included 1,114 ET initiators, of whom 211 were nonadherent. HRQOL was not significantly associated with noninitiation, except among nonchemotherapy users, with membership in the poorest LP associated with increased odds of noninitiation (adjusted OR, 5.5; 95% CI, 1.7 to 17.4). Membership in the poorest LPs was associated with nonadherence (LP1: adjusted OR, 2.2; 95% CI, 1.2 to 4.0 and LP2: adjusted OR,1.9; 95% CI, 1.1 to 3.6). Membership in the poorest LP was associated with nonadherence among nonchemotherapy users (adjusted OR, 2.1; 95% CI, 1.2 to 5.1). CONCLUSION: Our results suggest women with poor HRQOL during active treatment may be at increased risk for ET underuse. Focusing on HRQOL, a modifiable factor, may improve targeting of future interventions early in the BC continuum to improve ET initiation and adherence and prevent BC recurrence.