BACKGROUND:

Western breast cancer survivors have an increased risk of osteoporosis and bone fracture. Breast cancer occurs 10 to 20 years earlier in Asian women than in Western women. We investigated if younger Asian women with breast cancer also have increased risk of fracture.

METHODS:

We used the universal insurance claims data from 2000 to 2003 to identify 22,076 patients with breast cancer and 88,304 women without cancer, frequency matched with age and index date (the date for a health care visit). The incidence of fracture in both cohorts and the hazard ratios (HRs) of fracture in the cancer cohort were estimated by the end of 2009.

RESULTS:

The incidence of all types of fracture was higher in the breast cancer cohort than in the comparison cohort (46.72 vs. 42.52 per 10,000 person-years), with adjusted HRs (aHRs) of 1.18 (95% confidence intervals [CI], 1.03-1.35) for hip fractures, 1.12 (95% CI, 0.98-1.28) for forearm fractures and 1.24 (95% CI, 1.04-1.48) for vertebral fractures. The aHRs were significant in both non-traumatic fractures (1.29; 95% CI, 1.11-1.51) and traumatic fractures (1.12; 95% CI, 1.01-1.23). The age-specific aHR was higher for younger breast cancer patients, and was significant for <50 years old patients in both traumatic (aHR 1.35; 95% CI 1.08-1.68) and non-traumatic (aHR, 1.72; 95% CI, 1.21-2.44) fractures.

CONCLUSION:

This study suggests that Asian women with breast cancer might have an increased risk of fracture.