Bone metastasis is associated with poor prognosis in metastatic papillary renal cell carcinoma patients treated with first agent angiogenesis inhibitors.

OBJECTIVE: Papillary renal cell carcinoma (papRCC) is a rare (10%-15%) subtype of renal cancer. Few prognostic biomarkers have been described in metastatic papRCC (m-papRCC) patients treated with vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKIs). We aimed to study the prognostic impact of bone metastases (BM) on response rate, progression-free and overall survival (PFS and OS) in patients with m-papRCC treated with first agent VEGFR-TKIs. PATIENTS AND METHODS: A multicentric, retrospective analysis of patient records was conducted. BM were detected by computed tomography and/or bone scintigraphy. The International Metastatic RCC Database Consortium (IMDC) score was calculated at start of first agent VEGFR-TKI treatment. RESULTS: Forty-nine patients were included. Best objective response was partial response in 20%, stable disease in 60% and early progressive disease in 20% of patients. Median PFS (mPFS) was 6.0 months and median OS (mOS) 14.0 months after start of first agent VEGFR-TKI. The IMDC score correlated with mOS: 77.5 months in good, 17.0 months in intermediate and 8.0 months in poor risk patients (P = 0.002). Patients with BM had a poorer outcome compared to patients without BM: mPFS was 4.0 vs. 7.0 months (P = 0.006) and mOS 7.5 vs. 19.0 months (P = 0.002). On bivariate analysis, the presence of BM was independently associated with PFS (P = 0.02) and OS (P = 0.049), independent of the IMDC risk groups. CONCLUSION: In m-papRCC patients treated with first agent VEGFR-TKIs, the presence of BM is an unfavorable prognostic factor, associated with shorter PFS and OS.

Clear-cell Renal Cell Carcinoma: Molecular Characterization of IMDC Risk Groups and Sarcomatoid Tumors.

INTRODUCTION: Recent trials have suggested predictive biomarkers in advanced clear-cell renal cell carcinoma (accRCC): International Metastatic RCC Database Consortium (IMDC) good risk or angiogenic gene signature for sunitinib and IMDC intermediate/poor risk for ipilimumab-nivolumab and T-effector cell signature or sarcomatoid dedifferentiation for atezolizumab-bevacizumab. We hypothesized that earlier described molecular subtypes, ccrcc1 to ccrcc4, could provide similar information as a single generic biomarker and molecularly characterize the heterogeneous intermediate-risk group. PATIENTS AND METHODS: Patients with accRCC treated with systemic therapies were included. We assessed associations between the 5 biomarkers and their impact on progression-free survival (PFS) and response rate (RR) on first-line sunitinib or pazopanib. The cutoff percentage of sarcomatoid dedifferentiation with optimal discriminative value was determined. RESULTS: In total, 430 patients were included (163 with molecular data). The molecular ccrcc2 subtype identified tumors with higher angiogenic gene expression across IMDC risk groups: prevalence was high in IMDC good risk and low in IMDC poor risk (P < .001). Molecular subtype, IMDC, and angiogenic gene expression had comparable C-indices to predict PFS and RR (range, 60%-66%). The ccrcc2 subtype and angiogenic gene expression were positive predictors of PFS in IMDC intermediate-risk patients (P = .006; P = .04). Immune signature did not differ between IMDC groups, but was strongly correlated with molecular subtype (P = .8 and P = .0007). A cutoff value of 25% sarcomatoid differentiation discriminated tumors with distinct molecular characteristics and therapeutic sensitivity. CONCLUSION: In accRCC, molecular subtypes can explain differences in IMDC risk group, expression of angiogenesis and immune response genes, and sarcomatoid dedifferentiation. They can identify molecularly different patient populations within the heterogeneous IMDC intermediate group and select patients for systemic therapies.