Epidemiology and outcome of sarcomatoid renal cell cancer compared to clear cell renal cancer: A Surveillance, Epidemiology, and End Results (SEER) database review.

Abstract

504 Background: Sarcomatoid renal cell carcinoma (SRCCa) is a rare type of RCCa. Few case series in literature indicated its dismal prognosis. We studied the epidemiology and survival outcome of SRCCa compared to clear RCCa (CRCCa) by reviewing the SEER database. Methods: SEER database (8.1.2) was reviewed for patients (pts) with histologically confirmed SRCCa and CRCCa between 2004 -2007. Variables included were: age, race, gender, laterality, surgery of primary RCCa and AJCC stage. Primary outcome was 3 year Disease Specific Survival (DSS). Data was analyzed using Chi square, Kaplan Meier and Cox proportional hazard model. Results: A total of 7,653 pts with CRCCa and 540 with SRCCa were included between 2004 and 2007. Mean age in SRCCa was 61 compared to 62 yrs in CRCCa. White to black race ratio was 7.5:1 in both types. Left primary was 54% in SRCCa and 51% in CRCCa. Male to female ratio was 1.9:1 in SRCCa and 1.7:1 in CRCCa (Table). The main stage at presentation was stage IV (63%) in SRCCa and stage I (53%) in CRCCa. Surgery rate was higher in SRCCa in stage II and IV, same between two groups in stage II and higher in CRCCa in stage I. When we analyzed the effect of RCCa type on DSS for each stage separately, SRCCa had worse 3-year DSS in stage I, II, III and IV independent of age, sex, race, gender and surgery. The Hazard Ratio was 4.97 for stage I, 11.37 for stage II, 3.91 for stage III and 1.58 for stage IV (p <0.001). Conclusions: SRCCa have no statistical significant difference in age, race, gender and laterality compared to CRCCa. When compared stage to stage, SRCCa have worse outcome than RCCa even after adjusting for potential confounders including age, race, gender and surgery. The effect appears to be less prominent in higher stages than in lower stages of the disease. [Table: see text]