244P Clinicopathologic Feature and Treatment Outcome of Metastatic Non Clear Cell Kidney Cancer: A Single Centre Experience from India

Non clear cell renal cell carcinoma (nccRCC) refers to a rare diverse heterogeneous group of tumors; usually treated with immunotherapy (IO) and or tyrosine kinase inhibitors (TKI). Prospective large-scale data from Asia specific countries is limited. We aimed to present the demographic profile and treatment outcome of nccRCC patients from single centre in India. This is a retrospective study on patients with metastatic nccRCC treated at Tata Medical Centre, Kolkata-West Bengal from 2012-2022. Demographic profiles, histologic subtypes, treatment details, response to therapy (by RECIST v1.1) and survival status were captured from electronic medical records of hospitals up till March 2023. Progression free survival (PFS) and Overall survival (OS) were estimated using Kaplan Meier method. A total of 89 patients were screened;24 excluded due to inadequate records. 65 patients were included in analysis, with a median age at diagnosis of 59 years (range 20-84). Histologic subtypes comprised 43% (n=28) papillary, 31%(n=20) clear cell with mixed histology, 3%(2) sarcomatoid & 23%(15) others including chromophobe, oncocytoma. The most common site of metastasis was lung 62% (n=40).15% presented with haematuria and 62%(n=40) underwent cytoreductive nephrectomy. Majority received pazopanib 46% (n=30) then chemotherapy 20% (n=13) including bevacizumab plus erlotinib, sunitinib 15%(10), cabozantinib 14%(9). Only 3(5%) received IO plus TKI combination. The best response was CR in 1.5%, PR 20%, SD 51% & PD 23% as per RECIST v1.1. Total 17 (26%) patients required dose reduction & interruption due to adverse effects & 33% received second-line therapy with nivolumab,axitinib & everolimus were commonly used. After a median follow up of 44 months; median PFS was 13 months (95%CI 7.2-18.9) & median OS was 17 months (95%CI 12.1-22.1). Regression analysis identified better outcome for PFS & OS with sarcomatoid subtype & those underwent prior nephrectomy. The overall response and survival was quite impressive in comparison with published data; despite limited number of cases treated with IO due to its cost.This study also highlighted better survival with sarcomatoid subtype and prior nephrectomy.