Prognostic factors and impact of surgery in patients with metastatic soft tissue sarcoma at diagnosis: A population-based cohort study

Abstract

Background: Approximately 10% of the patients with soft tissue sarcoma show metastasis at initial diagnosis, and hence, poorer prognosis. However, the prognostic factors and whether definitive surgery for the primary lesion improves overall survival, especially when complete resection of metastasis is difficult, remain unclear. Methods: This retrospective analysis was based on the Bone and Soft Tissue Tumor Registry in Japan. Patients with soft tissue sarcoma having metastasis at diagnosis were enrolled, excluding those with Ewing's sarcoma, rhabdomyosarcoma and several other sarcomas with unique behavior and treatment strategies. Overall survival was estimated using the Kaplan-Meier method and compared among the common histologic subtypes. Multivariate analysis with the Cox regression model was used to identify the prognostic factors. Results: In total, 1184 patients were included, with a median follow-up duration of 10 months (range: 1-83). The median overall survival was 21 months (95% confidence interval: 18.2-23.8). The multivariate analyses indicated that tumor size, grade and histologic subtypes significantly correlated with overall survival. Moreover, surgery for the primary lesion, in addition to surgery for metastases and chemotherapy, showed significant association with better survival. Conclusions: The prognostic factors in patients with metastatic soft tissue sarcoma at diagnosis are generally similar to those in patients with localized disease. The overall survival in patients differed significantly according to histologic subtype. Surgical resection of primary lesions, especially those with a wide margin, may be an independent prognostic factor. Further studies are needed identify which subgroup of patients would benefit the most from primary lesion surgery.