Demographic Patterns and Clinicopathological Analysis of Sarcomatoid Renal Cell Carcinoma in US Population

Background: Sarcomatoid renal cell carcinoma (RCC) is defined by the presence of any amount of sarcomatoid components admixed with other RCC histologic subtypes. Our investigation utilizes a large, diverse set of sarcomatoid RCC patients to summarize clinical, demographic, and pathological factors along with demographic disparities that may affect the prognosis and survival of sarcomatoid RCC patients. Methods: The Surveillance, Epidemiology, and End Results (SEER) database was employed to compile data from 2000 to 2018 from 2695 patients diagnosed with sarcomatoid RCC. Results: The mean age for sarcomatoid RCC diagnosis is 62.8 years. Males (68.2%) and White patients (82.6%) were more likely to be diagnosed with sarcomatoid RCC. Among the 64.4% of tumors with known size, 35.4% were less than 7 cm, 27.6% were 7.1 to 10 cm, and 36.4% were larger than 10 cm. Among the 95.8% of patients with known stage, 15.3% were localized, 28.9% were regionalized, and 55.8% were found in distant sites. Among the 44.2% of cases with known metastases site, lung was found to be the most common metastatic site.. Surgery was the most common treatment (70.9%). While the overall 5-year survival was 18.1%, it was 27.1% among patients who underwent surgery. Independent risk factors for mortality include age > 60 years, distant stage, and tumor size > 10 cm, per our multivariate analysis. Conclusion: Sarcomatoid RCC most commonly affects White males in their seventh decade. Increased age, distant stage, and size > 10 cm tumor size have associations with unfavorable prognosis. Surgery is associated with better survival outcomes in localized disease and multimodal therapy (surgery with adjuvant chemoradiation was associated with better survival.)