Bone-only versus visceral-only metastatic pattern in breast cancer: analysis of 150 patients. A GOCS study. Grupo Oncológico Cooperativo del Sur.

The medical records of 510 patients with metastatic breast cancer were retrospectively reviewed. Seventy-seven patients with metastases confined to skeleton and 73 patients bearing visceral-only disease were identified. All patients had a disease-free interval greater than or equal to 6 months and received systemic therapy with any of the following modalities: chemotherapy, hormonotherapy, or chemohormonotherapy. The clinical features, response to treatment, and survival were analyzed and compared for both groups. Median survival of patients with osseous metastases was 28 months, while it was 13 months for those patients with a visceral pattern (p less than 0.001). Response rates to first and second line systemic therapy for both metastatic patterns showed no significant differences, suggesting a similar degree of sensitivity or resistance in both groups. Objective regression to first therapy was 45% in the group with bony disease and 41% among patients with visceral involvement; median duration of response was 16 months and 13 months, respectively. In both groups progressive disease conserved the original metastatic pattern in most patients. We conclude that although a superiority in survival was evident for the osseous metastatic pattern, for these patients efforts should be made to select the least aggressive therapy in order to avoid excessive toxicity. Further studies are needed to confirm our findings.