Treatment outcome for metastatic papillary renal cell carcinoma patients

BACKGROUND. Most clinical trial reports in metastatic renal cell carcinoma (RCC) do not distinguish between histologic subtypes, making it difficult to assess specific treatment efficacy. The current retrospective study sought to define clinical features and outcome data for metastatic papillary RCC. METHODS. Clinical features, treatment outcome, and survival were evaluated in 38 patients with metastatic papillary RCC who underwent clinical evaluation at Memorial Sloan-Kettering Cancer Center (MSKCC) between 1985 and 2005. Twenty-three of 513 individuals were identified from a clinical trial database, 14 of 1895 from a surgery database, and 1 of 357 from a pathology database. A literature review of systemic therapy in metastatic papillary RCC was performed. RESULTS. Among the 38 patients, 30 had been treated at MSKCC with various systemic therapies, including cytokines. Twelve therapies resulted in stable disease, 30 in initial progression of disease, and 1 in an unknown response. One patient had a partial response to sunitinib, a novel multitargeted tyrosine kinase inhibitor. The median overall survival time for the entire study group was 8 months (95% confidence interval, 5-12). A literature review on treatment of metastatic papillary RCC produced 4 reports, confirming a lack of efficacy for systemic therapy. CONCLUSIONS. A resistance to systemic therapy characterizes patients with metastatic papillary RCC. Further understanding of the genetics and molecular biology and subtypes involved may provide the basis for more effective agents. Treatment with targeted therapies or other experimental agents is warranted.