Objectives: Sarcomatoid metastatic renal cell carcinoma (mRCC) represents an aggressive subset of disease, and a definitive therapeutic strategy is lacking. We seek to define outcomes associated with systemic therapy (including immunotherapy, cytotoxic therapy, and targeted agents) for sarcomatoid mRCC, with attention to novel prognostic schema.
Materials and methods: From an institutional database including 270 patients with mRCC, we identified 34 patients with documented sarcomatoid features. Within this cohort, we assessed 21 patients who received systemic therapy. Survival was assessed in the overall cohort and in subgroups divided by clinicopathologic characteristics, including the extent of sarcomatoid features, Memorial Sloan-Kettering Cancer Center (MSKCC) risk criteria, Heng criteria, and the nature of systemic therapy rendered.
Results: Of the 21 patients assessed, 2 patients received chemotherapy, 7 patients received immunotherapy, and 12 patients received targeted agents as their first line treatment. Median overall survival (OS) in the overall cohort was 18.0 months (95% CI 6.9-22.0). By MSKCC criteria, patients with poor-risk disease had a median OS of 4.7 months, compared with 20.1 months for patients with intermediate-risk disease [hazard ratio (HR) 0.02, 95%CI 0.003-0.15; P = 0.0001]. A similar difference in median OS was seen poor- and intermediate-risk groups when stratifying by Heng criteria (HR 0.17, 95%CI 0.001-0.12). There was no significant difference in survival in patients with sarcomatoid predominant disease vs. nonpredominant disease (HR 0.62, 95%CI 0.23-1.65; P = 0.34), nor was there a difference amongst patients who received targeted therapies vs. nontargeted therapies (HR 1.0, 95%CI 0.61-1.40; P = 0.36).
Conclusions: Compared with previous series and prospective trials assessing patients with sarcomatoid mRCC, the observed survival was prolonged. Although both Heng and MSKCC risk scores may be useful in determining prognosis, further studies are needed to identify relevant biomarkers and define the optimal therapeutic strategy for this disease.
By Sumanta K Pal, Jeremy O Jones, Courtney Carmichael, Junmi Saikia, Joanne Hsu, Xueli Liu, Robert A Figlin, Przemyslaw Twardowski & Clayton Lau