Prognostic significance and immune correlates of CD73 expression in renal cell carcinoma.

BACKGROUND: CD73-adenosine signaling in the tumor microenvironment is immunosuppressive and may be associated with aggressive renal cell carcinoma (RCC). We investigated the prognostic significance of CD73 protein expression in RCC leveraging nephrectomy samples. We also performed a complementary analysis using The Cancer Genome Atlas (TCGA) dataset to evaluate the correlation of CD73 (ecto-5'-nucleotidase (NT5E), CD39 (ectonucleoside triphosphate diphosphohydrolase 1 (ENTPD1)) and A2 adenosine receptor (A2AR; ADORA2A) transcript levels with markers of angiogenesis and antitumor immune response. METHODS: Patients with RCC with available archived nephrectomy samples were eligible for inclusion. Tumor CD73 protein expression was assessed by immunohistochemistry and quantified using a combined score (CS: % positive cells×intensity). Samples were categorized as CD73negative (CS=0), CD73low or CD73high (< and ≥median CS, respectively). Multivariable Cox regression analysis compared disease-free survival (DFS) and overall survival (OS) between CD73 expression groups. In the TCGA dataset, samples were categorized as low, intermediate and high NT5E, ENTPD1 and ADORA2A gene expression groups. Gene expression signatures for infiltrating immune cells, angiogenesis, myeloid inflammation, and effector T-cell response were compared between NT5E, ENTPD1 and ADORA2A expression groups. RESULTS: Among the 138 patients eligible for inclusion, 'any' CD73 expression was observed in 30% of primary tumor samples. High CD73 expression was more frequent in patients with M1 RCC (29% vs 12% M0), grade 4 tumors (27% vs 13% grade 3 vs 15% grades 1 and 2), advanced T-stage (≥T3: 22% vs T2: 19% vs T1: 12%) and tumors with sarcomatoid histology (50% vs 12%). In the M0 cohort (n=107), patients with CD73high tumor expression had significantly worse 5-year DFS (42%) and 10-year OS (22%) compared with those in the CD73negative group (DFS: 75%, adjusted HR: 2.7, 95% CI 1.3 to 5.9, p=0.01; OS: 64%, adjusted HR: 2.6, 95% CI 1.2 to 5.8, p=0.02) independent of tumor stage and grade. In the TCGA analysis, high NT5E expression was associated with significantly worse 5-year OS (p=0.008). NT5E and ENTPD1 expression correlated with higher regulatory T cell (Treg) signature, while ADORA2A expression was associated with increased Treg and angiogenesis signatures. CONCLUSIONS: High CD73 expression portends significantly worse survival outcomes independent of stage and grade. Our findings provide compelling support for targeting the immunosuppressive and proangiogenic CD73-adenosine pathway in RCC.

Comprehensive Genomic Profiling of Metastatic Tumors in a Phase 2 Biomarker Study of Everolimus in Advanced Renal Cell Carcinoma.

INTRODUCTION: Genomic events leading to activation of mechanistic target of rapamycin (mTOR) are common in renal cell carcinoma (RCC). Everolimus is an allosteric mTOR inhibitor with efficacy in metastatic RCC. We characterized the genomic profile of RCC tumors from metastatic sites and assessed whether particular alterations correlate with clinical response to everolimus. PATIENTS AND METHODS: An open-label, single-arm phase 2 biomarker study of everolimus 10 mg daily was conducted in metastatic RCC patients. Needle biopsy or metastasectomy was performed on metastatic tumors before everolimus initiation. Next-generation sequencing was performed using a targeted hybrid capture panel detecting alterations within exons and key introns of ≥ 300 cancer-associated genes. Disease assessments were obtained every 8 weeks using standard radiographic modalities and evaluated by Response Evaluation Criteria in Solid Tumors criteria. RESULTS: Objective response was seen in 1 (4.2%) of 24 patients. Two patients (8.3%) had stable disease lasting > 6 months. Median (90% confidence interval) overall and progression-free survival were 20.1 (8.6, NA) and 3.8 (2.4, 5.4) months, respectively. Next-generation sequencing was successful on 18 pretreatment specimens and 3 on-treatment specimens. Alterations in the phosphatidylinositol 3-kinase-protein kinase B-mammalian target of rapamycin (PI3K-AKT-mTOR) pathway were identified in 8 (44%) of 18 pretreatment samples. An mTOR E2419D mutation was identified in the patient who experienced partial response. Alterations in VHL, PBRM1, SETD2, KDM5C, and ATM were common in the RCC metastases before initiation of everolimus. CONCLUSION: Nearly half of heavily pretreated RCC metastases may harbor mutations in components of the PI3K-AKT-mTOR pathway. Commonly mutated genes in primary RCC were also altered at a high frequency in RCC metastases.