Patient and tumor characteristics of histological subtypes of renal cell carcinoma and its risk of upstaging to ≥pT3

Abstract

ObjectiveTo explore how histological subtypes impact upstaging to nonorgan confined renal cell carcinoma (≥pT3 RCC) in patients treated with partial/radical nephrectomy for cT1-2 RCC. Materials and methodsWe relied on an institutional tertiary-care database to identify RCC patients treated with partial/radical nephrectomy between January 2002 and December 2021. Patients were stratified according to histological subtype of RCC. Upstaging was defined as any cT1-2 tumor classified as ≥pT3 at final pathology. Uni- and multivariable logistic regression models were fitted to predict upstaging. ResultsOf overall 1,020 surgically treated RCC patients, 743 harbored clear-cell (72.8%) vs. 193 (18.9%) papillary vs. 49 (4.8%) chromophobe vs. each 4 (0.4%) collecting duct and sarcomatoid vs. 27 (2.6%) other/mixed pathology of RCC. Median tumor size ranged from 3.0 cm (mixed RCC) to 7.7 cm (sarcomatoid RCC). In total, upstaging rate to ≥pT3 was 22% and ranged from 6.1% (chromophobe RCC) to 75% (collecting duct RCC). In univariable logistic regression models, chromophobe and papillary histological subtypes were significantly associated with lower upstaging of all cT1-2 RCC tumors. After controlling for patient and tumor characteristics in multivariable logistic regression models, papillary RCC independently lowers the risk of upstaging, even in sensitivity analyses for cT1 RCC only. ConclusionImportant differences between histological subtypes of RCC exist regarding characteristics such as stage and tumor size at presentation, as well as upstaging to ≥pT3 at final pathology. Specifically, papillary RCC is significantly associated with lower chance of upstaging even after controlling for confounding parameters. The study is limited by missing central pathological/radiographic review and lack of survival analyses.