Abstract
Abstract only
472
Background: Sarcomatoid differentiation is not a distinct histological entity and it can present in any of the subtypes of renal cell carcinoma (RCC). Although many studies were published in the literature about its aggressive clinical course, limited clinical data was available about its management and especially about the role of newer targeted therapies. At our institution, we looked at the prognostic factors in SRCC and the role of systemic therapy in its management. Methods: During the years of 1997 to 2012, we studied the records of over 400 patients diagnosed with RCC. Out of them, 43 were identified as having SRCC. Cox proportional hazards risk analysis was used to analyze the factors associated with the risk of mortality. Survival probability was estimated using Kaplan Meier method. Results: Median age at diagnosis was 58. Median tumor size was 9.75 cm. High Furhmans grades (III & IV) were seen in 67.44%. 68.29% patients presented with stage IV disease. 74.42 % patients had upfront nephrectomy. Of the systemic therapies given, 20.9% received cytokines, 16.2% received chemotherapy and 34.8% received target therapy. Probability of survival at 1 year was 50% (95% CI 33-65) and at 5 years was 24% (95% CI 10-41). Median time to progression was 13 months (95% CI 7 -23). Factors associated with risk of mortality were mainly the stage at diagnosis [HR 2.174, p = 0.0123, CI (1.184-3.992)], Nephrectomy [HR0.243, p = 0.0012, CI (0.104- 0.571)] and the use of target therapy [HR 0.313, p = 0.0070, CI (0.134-0.728)]. Conclusions: Our study confirmed that the SRCC is more aggressive than conventional RCC in its presentation and in its median time to progression. It responds poorly and unpredictably to systemic therapies. In our study, upfront nephrectomy and target therapy appeared to be independent predictors of survival. SRCC needs to be considered as a different disease entity and new treatment options need to be explored for this unfortunate subset of patients with kidney cancer.