Clinical Characteristics and Prognostic Factors of Renal Sarcoma: A Japanese National Cancer Registry Study

We analyzed survival rates and prognostic factors for renal sarcoma using Japan's National Cancer Registry data. We conducted a retrospective cohort study of patients diagnosed with renal sarcoma (2016-2019). Prognostic factors were evaluated using Cox regression analyses. Among 235 patients, female sex (HR, 0.43; 95% CI, 0.23-0.83; p = 0.012), older age (≥60 years: HR, 5.87; p < 0.001), histologic subtype (angiosarcoma: HR, 12.65; p < 0.001), and distant disease (HR, 6.32; p < 0.001) were significant independent prognostic factors. Surgical resection (HR, 0.41; p = 0.004) and radiation therapy (HR, 0.39; p = 0.010) were associated with improved survival. Histologic subtype is the most critical prognostic factor for renal sarcoma in Japan's aging population, with dramatic survival differences: clear cell sarcoma (94.4% 3-year survival) versus angiosarcoma (19.0%). This heterogeneity mandates histology-specific treatment protocols rather than organ-based approaches, with particular relevance for aging societies in Asia.