Immune infiltration and angiogenesis as markers of outcome in the post-nephrectomy setting: Transcriptomic data from patients receiving placebo on a randomized phase III trial (PROTECT).

Abstract

5082 Background: Defined stromal and immune features of the tumor microenvironment (TME) have proven relevant for outcomes with systemic therapy in advanced clear cell renal cell carcinoma (ccRCC). We hypothesized that these may matter beyond therapeutic applications and could be relevant much earlier in the disease course. We sought to study the TME in high risk ccRCC patients undergoing definitive surgery. Methods: Clinical, pathologic, immunohistochemical, and whole-genome microarray data were acquired on 236 out of 769 patients in the Placebo arm of PROTECT trial (NCT01235962 - pazopanib vs placebo). Transcriptomic scores assessing angiogenesis and myeloid infiltration with individual annotations above/below median were used to categorize patients into four groups (angiogenesis high vs. low; myeloid high vs. low). We tested categorical association with disease free (DFS) and overall survival (OS) using logrank testing and assessed interdependence with relevant clinicopathologic variables, including the UCLA Integrated Staging System (UISS) in a cox regression model. Results: Tumors from236 patients were available for analysis. Overall, 37% developed metastatic recurrence and 81% were alive at last follow up. On univariate analysis increasing tumor stage, higher UISS score, and angiogenesis/myeloid subgroups (high – H and low – L) were associated with worse DFS and OS (all p values <0.05). On multivariate analysis TME subgroups remained significant for worse DFS and OS (Table). Conclusions: Microenvironmental subgroups stratified into angiogenic and myeloid expression profiles carry independent prognostic significance and should be further explored to guide future biomarker-directed adjuvant trials. Clinical trial information: NCT01235962 . [Table: see text]