Presentation Authors: Kyle Blum*, Renzo DiNatale, Alejandro Sanchez, Andrew Silagy, Julian Marcon, Roy Mano, Sounak Gupta, Satish Tickoo, Victor Reuter, Jonathan Coleman, Paul Russo, A. Ari Hakimi, New York, NY
Introduction: Sarcomatoid features (sRCC) are present in approximately 4% of renal cell carcinoma cases. This rare sub-variant is associated with extremely poor clinical outcomes. Due to its rarity, limited studies have evaluated the impact of sarcomatoid differentiation among patients, especially with lower stage pT1-2 disease. We herein report survival trends stage-for-stage between sRCC and non-sRCC patients who underwent nephrectomy.
Methods: After IRB approval, we queried our prospectively maintained database for patients who underwent partial or radical nephrectomy between 2000-2017. Patients were divided into four groups for analysis: non-sRCC pT1-2; non-sRCC pT3-4; sRCC pT1-2 and sRCC pT3-4. All patients included were NxMx. Clinicopathological outcomes including sex, race, age, primary histology, lymph node involvement and margin status were compared between groups using chiâˆ’squared and two-tailed t-tests. Overall survival rates were analyzed by constructing Kaplan Meier curves, p-values were calculated using log rank tests and fitting Cox proportional hazards models for adjusted analyses.
Results: In a total of 3,850 cases available for analysis, sRCC was identified in 168 (4.4%) patients. Mean overall follow-up for the entire cohort was 59.9 months (range 1-192). Lower stage (pT1-2) was present in 33 (19.6%) sRCC patients and in 2,644 (71.8%) non-sRCC patients. Cancer-Specific Survival (CCS) between groups was worse in patients with sarcomatoid features regardless of pT stage (p < 0.0001), figure 1. Of note, CSS was worse in lower stage sRCC pT1-2 patients than in higher stage non-sRCC pT3-4 patients. Overall survival (OS) results were similar, with sarcomatoid tumors yielding poorer estimates on survival analysis (p < 0.0001).
Conclusions: Patients with lower stage pT1-2 sRCC demonstrated worse CSS when compared to even higher stage pT3-T4 non-sRCC, regardless of primary histology. Our data suggests that the presence of sarcomatoid features, even at low stage, is a significant marker for poor oncologic outcomes. Based on this observed aggressiveness, sarcomatoid features in lower stage RCC may require more vigilant surveillance and early entry into adjuvant therapy trials.
Source of Funding: Supported in part through the NIH/NCI Cancer Center Support Grant P30 CA008748