Metastatic Clear-cell Renal Cell Carcinoma With a Long-term Response to Sunitinib: A Distinct Phenotype Independently Associated With Low PD-L1 Expression.

BACKGROUND: Long-term responders (LTRs) are defined by at least 18 months of response to sunitinib in metastatic clear-cell renal cell carcinoma (ccRCC). Well-described by clinical studies, the phenotype of these tumors has never been explored. PATIENTS AND METHODS: In a retrospective and multicenter study, 90 ccRCCs of patients with metastatic disease were analyzed. Immunohistochemistry (carbonic anhydrase IX, vascular endothelial growth factor, c-MET, programmed death-ligand 1 [PD-L1], and PD-1) and VHL status were performed. Progression-free survival and overall survival were calculated from sunitinib introduction and from progression. LTRs and their corresponding tumors were compared with others using univariate and multivariate analysis. RESULTS: Twenty-eight patients were LTRs. They had a median progression-free survival of 28 months versus 4 months for other patients (P < .001). Similarly, LTRs had a median overall survival of 49 months versus 14 months (P < .001), even from progression (median, 21 vs. 7 months; P = .029). They were associated with a favorable or intermediate risk (International Metastatic Renal Cell Carcinoma Database Consortium model) (P = .007) and less liver metastasis (P = .036). They experienced more frequent complete or partial responses at the first radiologic evaluation (P = .035). The corresponding ccRCCs were associated with less nucleolar International Society for Urological Pathology grade 4 (P = .037) and hilar fat infiltration (P = .006). They were also associated with low PD-L1 expression (P = .02). Only the International Metastatic Renal Cell Carcinoma Database Consortium model and PD-L1 expression remained significant after multivariate analysis (P = .014 and P = .029, respectively). CONCLUSION: Primary tumor characteristics of LTRs were studied for the first time and demonstrated a different phenotype. Interestingly, they were characterized by low expression of PD-L1, suggesting a potentially lower impact of targeted immunotherapy in these patients.

Clinical, histological and molecular predictors of metastatic melanoma responses to anti-PD-1 immunotherapy.

BACKGROUND: Prescribing anti-programmed death-1 (PD-1) immunotherapy for advanced melanoma is currently not restricted by any biomarker assessment. Determination of programmed death-ligand-1 (PD-L1)-expression status is technically challenging and is not mandatory, because negative tumours also achieve therapeutic responses. However, reproducible biomarkers predictive of a response to anti-PD-1 therapy could contribute to improving therapeutic decision-making. METHODS: This retrospective study on 70 metastatic melanoma patients was undertaken to evaluate the relationships between clinical, histological, immunohistochemical and/or molecular criteria, and the 6-month objective response rate. RESULTS: Better objective response rates were associated with metachronous metastases (P = 0.04), PD-L1 tumour- and/or immune-cell status (P = 0.01), CD163+ histiocytes at advancing edges (P = 0.009) of primary melanomas and NRAS mutation (P = 0.019). Moreover, CD163+ histiocytes at advancing edges (P = 0.04) were associated with longer progression-free survival (PFS), and metachronous metastases with longer overall survival (P = 0.02) and PFS (P = 0.049). CONCLUSIONS: Combining these reproducible biomarkers could help improve therapeutic decision-making for patients with progressive disease.

Hilar fat infiltration: A new prognostic factor in metastatic clear cell renal cell carcinoma with first-line sunitinib treatment.

INTRODUCTION: The selection of patients with metastatic clear cell renal cell carcinoma (ccRCC) who may benefit from targeted tyrosine kinase inhibitors has been a challenge, even more so now with the advent of new therapies. Hilar fat infiltration (HFI) is a validated prognostic factor in nonmetastatic ccRCC (TNM 2009 staging system) but has never been studied in metastatic patients. We aimed to assess its phenotype and prognostic effect in patients with metastatic ccRCC treated with first-line sunitinib. MATERIALS AND METHODS: In a multicentric study, we retrospectively included 90 patients and studied the corresponding ccRCC at the pathological, immunohistochemical, and molecular levels. Patient and tumor characteristics were compared using univariate and multivariate analysis. All the features were then studied by Cox models for prognostic effect. RESULTS: HFI was found in 42 patients (46.7%), who had worse prognosis (Heng criteria) (P = 0.003), liver metastases (P = 0.036), and progressive diseases at first radiological evaluation (P = 0.024). The corresponding ccRCC was associated with poor pathological prognostic factors that are well known in nonmetastatic ccRCC. For these patients, median progression-free survival was 4 months vs. 13 months (P = 0.02), and median overall survival was 14 months vs. 29 months (P = 0.006). In a multivariate Cox model integrating all the variables, only poor prognosis, according to the Heng criteria and HFI, remained independently associated with both progression-free survival and overall survival. CONCLUSION: HFI was demonstrated for the first time to be an independent poor prognostic factor. Its potential role in predicting resistance to antiangiogenic therapy warrants further investigation.

Correlation of c-MET Expression with PD-L1 Expression in Metastatic Clear Cell Renal Cell Carcinoma Treated by Sunitinib First-Line Therapy.

BACKGROUND: Clear cell renal cell carcinoma (ccRCC) is highly metastatic. Cabozantinib, an anti-angiogenic tyrosine kinase inhibitor that targets c-MET, provided interesting results in metastatic ccRCC treatment. OBJECTIVE: To understand better the role of c-MET in ccRCC, we assessed its status in a population of patients with metastatic ccRCC. PATIENTS AND METHODS: For this purpose, tumor samples were analyzed for c-MET expression by immunohistochemistry (IHC), for c-MET copy number alterations by fluorescence in situ hybridization (FISH), and for c-MET mutations by next generation sequencing (NGS) in a retrospective cohort of 90 primary ccRCC of patients with metastases treated by first-line sunitinib. The expression of c-MET was correlated with pathological, immunohistochemical (VEGFA, CAIX, PD-L1), clinical, and molecular criteria (VHL status) by univariate and multivariate analyses and to clinical outcome using Kaplan-Meier curves compared by log-rank test. RESULTS: Of ccRCC, 31.1% had low c-MET expression (absent to weak intensity by IHC) versus 68.9% with high expression (moderate to strong intensity). High expression of c-MET was associated with a gain in FISH analysis (p=0.0284) without amplification. No mutations were detected in NGS. Moreover, high c-MET expression was associated with lymph node metastases (p=0.004), sarcomatoid component (p=0.029), VEGFA (p=0.037), and PD-L1 (p=0.001) overexpression, the only factor that remained independently associated (p<0.001) after logistic regression. No difference was observed in clinical outcomes. CONCLUSION: This study is the first to analyse c-MET status in metastatic ccRCC. The high expression of c-MET in the majority of ccRCC and its independent association with PD-L1 expression, may suggest a potential benefit from combining c-MET inhibitors and targeted immunotherapy.