BackgroundAromatase inhibitor therapy induces bone loss and risk of fracture in postmenopausal breast cancer survivors (PBCS). Targetable patient-level factors to mitigate osteoporosis risk in this population are underreported. Here, we assessed the association between osteoporosis knowledge and beliefs, receipt of bone mineral density, and osteoporosis preventive behaviors among PBCS. MethodsIn this cross-sectional study, early stage PBCS with diabetes mellitus (ages 55-86 years) completed the Facts on Osteoporosis Quiz, Osteoporosis Health Beliefs Scale, and Osteoporosis Preventive Behaviors cross-sectional questionnaires. Multivariate logistic regression assessed factors associated with engagement in strength-training exercise.ResultsMean age was 66.1 years with 20% self-reporting as non-Hispanic White, 40% non-Hispanic Black, 27% Hispanic, and 13% other. Osteoporosis knowledge (10.5±3.4), seriousness (14.9±3.8), and susceptibility (14.0±3.5) mean scores were low. Most (75%) PBCS were adherent to calcium and vitamin D supplements, but only 47% reported engagement in strength-training exercises. Married/partnered, higher osteoporosis knowledge and health motivation scores were associated with exercise. After adjustment of marital status and osteoporosis knowledge, only health motivation was associated with exercise (OR 5.56, 95% CI 1.35-22.93). ConclusionsPBCS are motivated to keep a healthy lifestyle despite limited osteoporosis knowledge, perceived risk, and susceptibility. However, <50% participated in strength-training exercise. Oncologic care should include osteoporosis and fracture prevention strategies, directed at encouraging cancer survivors to increase engagement in strength-training exercises and calcium intake.