The authors queried the Memorial Sloan Kettering Cancer Center kidney cancer database of 3,850 patients with RCC who underwent partial or radical nephrectomy from 2000-2017. Patients were divided into four groups for the analysis: pT1-2NxMx RCC without sarcomatoid features, pT1-2NxMx sarcomatoid RCC, pT3-4 sarcomatoid RCC, and pT3-4 RCC without sarcomatoid features. Clinicopathological outcomes including age, sex, race, primary histology, lymph node involvement and margin status were compared between groups using student t and Chi-squared 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. Among these 3,850 cases, 168 (4.4%) sarcomatoid RCC patients were identified of which 33 (19.6%) were pT1-2. The mean overall follow-up time was 59.9 months. When comparing cancer specific survival between groups, survival was poorer in patients with sarcomatoid features regardless of pT stage (p<0.0001). Of note, cancer specific survival was worse in sarcomatoid RCC pT1-2 patients than in non-sarcomatoid pT3-4 patients. Overall survival results were similar, with sarcomatoid tumors having worse estimates on survival analysis (p<0.0001).
In summary, patients with pT1-2 sarcomatoid RCC demonstrated worse cancer-specific outcomes when compared to pT3-T4 RCC without sarcomatoid features, regardless of primary histology. Sarcomatoid differentiation in low-stage disease may be a marker of poor oncologic outcomes requiring more vigilant surveillance and possible inclusion in adjuvant therapy trials. Future directions include combining the current data with other institutions in order to develop a larger cohort of sarcomatoid RCC patients.
Presented by: Kyle A. Blum MD, MSc¹
Co-Authors: Eden Axler ², Renzo G. DiNatale MD¹, Alejandro Sanchez MD¹, Nirmal T. John MD¹, Mazyar Ghanaat MD¹, Mahyar Kashan BSc¹, Maria Becerra MD¹, Paul Russo MD¹, Jonathan A. Coleman MD¹, Satish K. Tickoo MD¹ and A. Ari Hakimi MD¹
Affiliation: ¹Memorial Sloan Kettering Cancer Center, New York, NY; ²University of Michigan, Ann Arbor, MI
Written by: Zachary Klaassen, MD, Society of Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre @zklaassen_md at the 18th Annual Meeting of the Society of Urologic Oncology, November 20-December 1, 2017 – Washington, DC