Low risk of hip fracture among elderly breast cancer survivors.

PURPOSE: Prior research has shown that women with either osteoporotic fracture or low bone density are at a decreased risk of breast cancer. Little prior work has evaluated whether women with breast cancer are at a decreased risk of osteoporotic fracture.
METHODS: We used data from the National Cancer Institute's Surveillance Epidemiology and End Results (SEER)-Medicare program to study the risk of hip fracture among elderly female Medicare beneficiaries with and without histories of breast cancer. Using the SEER file, we identified elderly women survivors of stage 0, I, or II breast cancer (N=5980) diagnosed between the ages of 55 and 64 years; using the Medicare 5% file, we identified elderly women without histories of cancer (N=23,165) from SEER regions. Using Medicare claims from 1993 through 1998, we followed women for hospitalization for hip fracture or death until December 31, 1998.
RESULTS: We found the rate ratio of hospitalization for hip fracture for breast cancer survivors relative to comparison patients was 0.63 (95% CI: 0.43-0.94) after adjusting for age, race, socioeconomic status, geographic location, cohort entry year, and medical comorbidity.
CONCLUSIONS: We conclude that survivors of early stage post-menopausal breast cancer are at significantly lower risk of hip fracture than women who do not have histories of breast cancer.