Abstract 5749: The association between physical health-related quality of life, physical functioning and risk of contralateral breast cancer

Abstract

Abstract Background: Physical limitations and disability among older cancer patients can lead to suboptimal treatment and surveillance for secondary cancers. Our objective was to evaluate the effects of poor physical health-related quality of life (PQOL) and physical functioning (PF) on contralateral breast cancer (CBC) risk among older women diagnosed with unilateral breast cancer (UBC). Methods: We performed a nested case-control study within a cohort from the Surveillance, Epidemiology and End Results Medicare Health Outcomes Survey (MHOS) database. Women were required to have first primary UBC without prophylactic contralateral mastectomy. Among 2,938 women ages 65 years and older with stages I-III UBC between 1997 and 2011, we identified 100 subsequent CBC cases and 915 controls using incidence density sampling without replacement matched on age, race, and quarter-year of diagnosis. PQOL and PF were determined from survey responses to the Medical Outcomes Trust Short Form 36 component scores. Conditional logistic regression models were used to estimate relative risks (RR) and 95% confidence intervals (CI) for metachronous CBC. Results: Cases and controls were similar with respect to comorbidities, stage, surgery and radiation treatments but differed by hormone receptor status (ER/PR-negative, cases 23% and controls 11%). Cases had lower mean PQOL (-1.8; 95% CI -4.3, 0.7) and PF (-2.2, 95% CI -4.9, 0.5) component scores, but these differences were not statistically significant. In multivariable models, estimates suggest increased CBC risk for women in the lowest quartile of PQOL compared to those in the upper quartile (RR=1.8; 95% CI 0.8, 4.3). Compared to women in the upper quartile of physical functioning scores, women in the lower three quartiles had a 2.6-fold (95% CI 1.2, 5.9) increased risk of CBC. Conclusions: Our findings indicate that low physical health-related quality of life is common among older women diagnosed with breast cancer, and poor physical functioning is related to risk of CBC. Efforts to understand and minimize declines in physical functioning post-breast cancer diagnosis may help optimize treatment strategies to reduce the risk of this adverse outcome. Citation Format: Nita Mukand, Nadia Nabulsi, Ali Alobaidi, Alemseged Asfaw, Brian C. Chiu, Naomi Y. Ko, Gregory S. Calip. The association between physical health-related quality of life, physical functioning and risk of contralateral breast cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5749.