Predictors of skeletal complications in patients with metastatic breast carcinoma

The high rate of incidence of skeletal complications in women with metastatic breast carcinoma appears to contribute significantly to their morbidity. Although recent trials have demonstrated the efficacy of bisphosphonates in preventing skeletal complications in selected patients, to the authors' knowledge the incidence rate of skeletal complications in an unselected population of women with metastatic breast carcinoma is unknown. The current study was designed to examine the incidence rate of skeletal complications in a large unselected group of women with metastatic breast carcinoma to determine predictors of these complications.

All women (n = 718) diagnosed with metastatic breast carcinoma between 1981-1991 at the study institution were studied retrospectively.

Greater than 50% of the women developed skeletal complications; among these women, 51% had > 1 complication. Approximately 80% of those with bone-limited disease at the time of diagnosis developed complications, as did 60% of those with bone and visceral disease and 21% of those with no bone disease. By univariate analysis, the site of initial metastatic disease, abnormal alkaline phosphatase, and a disease free interval of < 3 years were predictive of skeletal complications. Multivariate analysis revealed that bone involvement at the time of diagnosis was predictive of subsequent skeletal complications.

In this large retrospective study with extensive follow-up, skeletal complications were extremely common and repetitive, although complications predated patient death by >/= 1 year in the group of women presenting with any bone disease. The presence of bone disease at the time of initial presentation was predictive of skeletal complications. In this group of patients, the authors were unable to identify a subgroup with a low rate of skeletal complications.