Expression of PD-1 and CTLA-4 Are Negative Prognostic Markers in Renal Cell Carcinoma.

Andreas Kahlmeyer,Peter Goebell,Helge Taubert,Christine Stöhr,Franziska Erlmeier,Sven Wach,Bernd Wullich,Arndt Hartmann

doi:10.3390/jcm8050743

Abstract

Immuno-oncological therapy with checkpoint inhibition (CI) has become a new standard treatment in metastatic renal cell carcinoma (RCC), but the prognostic value of the expression of CI therapy target molecules is still controversial. 342 unselected consecutive RCC tumor samples were analyzed regarding their PD-1, PD-L1, and CTLA-4 expression by immunohistochemistry (IHC). The prognostic values for cancer-specific survival (CSS) and overall survival (OS) were analyzed for those not exposed to CI therapy. The expression of PD-1 in tumor-infiltrating mononuclear cells (TIMC) and PD-L1 in tumor cells was detected in 9.4% and 12.3%, respectively (Immune reactive score (IRS) > 0). Furthermore, PD-L1 expression in TIMC (IRS > 0) and CTLA-4 expression in TIMC (>1% positive cells) was detected in 4.8% and 6.3%. PD-1 expression and CTLA-4 expression were significantly associated with a worse OS and CSS in log rank survival analysis and univariate Cox regression analysis. CTLA-4 expression is a prognostic marker that is independently associated with a worse outcome in multivariate Cox regression analysis in the whole cohort (OS: p = 0.013; CSS: p = 0.048) as well as in a non-metastatic subgroup analysis (OS: p = 0.028; CSS: p = 0.022). Patients with combined CTLA-4 expression and PD-1-expression are at highest risk in OS and CSS. In RCC patients, PD-1 expression in TIMC and CTLA-4 expression in TIMC are associated with a worse OS and CSS. The combination of PD-1 expression in TIMC and CTLA-4 expression in TIMC might identify high risk patients. This is, to our knowledge, the first description of CTLA-4 expression to be a prognostic marker in RCC.

Highlights

With a worldwide incidence of about 338,000 in 2012, kidney cancer accounts for 2–3% of all malignant tumors [1,2]
The expression of PD-1 in tumor-infiltrating mononuclear cells (TIMC), PD-L1 in tumor cells, PD-L1 in TIMC, and CTLA-4 in TIMC was detected in 9.4% (31), 12.3% (41), 4.8% (16), and 6.3% (20), respectively (Figure 1, Table 1)
PD-1 expression in TIMC is associated with a high grade tumor (G3, p < 0.001, correlation coefficient 0.215) or primary metastatic diseases (p = 0.007, not significant with Bonferroni correction, correlation coefficient 0.149)

Summary

Introduction

With a worldwide incidence of about 338,000 in 2012, kidney cancer accounts for 2–3% of all malignant tumors [1,2]. 85–95% are renal cell carcinomas (RCC), with an increasing incidence worldwide [3]. 75–80% are clear cell renal cell carcinomas (ccRCC), followed by papillary, chromophobe, and other histological subtypes [4,5]. Renal cell carcinoma is considered to be an immunogenic tumor [9]. The characterization of immune subtypes has revealed that renal cell carcinoma belongs mainly to the inflammatory subtype with an increased leukocyte fraction [10], and enhanced MHC-I expression is a good prognostic factor in ccRCC [11]. Current checkpoint inhibition (CI) therapies show promising effects in RCC patients by inhibiting two of the immune escape mechanisms addressing the differentiation and activity of effector T cells [12]

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