Clinicopathologic characteristics and survival for adult renal sarcoma: A population-based study.

Introduction: To analyze the association of clinicopathologic characteristics and treatment modality with survival among adult patients with renal sarcoma.

Methods: We identified 489 adults diagnosed with renal sarcoma from the Surveillance, Epidemiology and End Results registry between 1973 and 2011. Cancer-specific survival was estimated using the Kaplan-Meier method and was compared between groups with log rank and Cox models.

Results: Median age at diagnosis was 61 years, while median tumor size was 11 cm. Tumor histology was leiomyosarcoma in 175, liposarcoma in 100, other subtypes in 129, and unknown in 85 cases. Tumor stage at diagnosis was nonmetastatic in 322 (67%) and metastatic in 167 (33%) cases. Treatment of nonmetastatic disease was surgical resection in 171 patients, radiation in 24, both in 35, neither in 18, and unknown in 74 cases. Treatment of metastatic disease was surgery in 39 patients, radiation in 27, both in 11, neither in 42, and unknown in 48. For nonmetastatic and metastatic disease, 5-year cancer-specific survival rates were 58% and 16%, respectively. On multivariable analysis, surgery was associated with decreased cancer-specific mortality among both patients with nonmetastatic disease (hazard ratio = 0.34; 95% CI: 0.14-0.85) and those with metastatic disease (hazard ratio = 0.38; 95% CI: 0.18-0.77). Age, race, tumor size, and tumor grade were independently associated with cancer death in nonmetastatic disease, whereas race and tumor histology remained associated with mortality in metastatic disease (all P < 0.05).

Conclusion: Although metastatic renal sarcoma has an ominous prognosis, durable survival may be achieved for localized tumors. Although we recognize the potential for selection bias, our results suggest an association between surgical resection and decreased mortality for both nonmetastatic and metastatic renal sarcoma.