Patients with metastatic chromophobe renal cell carcinoma treated with sunitinib therapy: Analysis of an international database regarding outcome and comparison to clear cell histology (mccRCC).

429 Background: Sunitinib (Su) is a standard therapy (tx) for mccRCC. Data on its activity in the rare variant of metastatic chromophobe renal cell carcinoma (mchRCC) are limited by very small or heterogeneous (mixed histology with papillary type, or mixed targeted therapies) studies. We analyzed the activity of Su in a relatively large and homogenous international cohort of mchRCC pts, in terms of outcome and comparison to mccRCC. Methods: Records from mchRCC pts treated with first-line Su in 9 centers across 4 countries were retrospectively reviewed. Univariate and multivariate analyses of association between clinicopathologic factors and outcome were performed. Subsequently, mchRCC pts were individually matched to mccRCC pts. We compared the response rate (RR), progression free survival (PFS), and overall survival (OS) between the groups. Results: Between 2004-2014, 33 pts (median age 64, 45% male) with mchRCC were treated with Su as first-line tx. 76% had a prior nephrectomy. HENG risk was good 27%, i...