Parenchymal biopsy in the management of patients with renal cancer.

ABSTRACT

PURPOSE: The role of non-tumour renal biopsy in predicting renal function after surgery for renal cell carcinoma (RCC) is poorly investigated. The aim of the study was to assess the impact of renal parenchymal histology on renal function after radical nephrectomy in a cohort of patients with RCC. METHODS: This cohort study included 171 patients with RCC submitted to radical nephrectomy between 2006 and 2018. Two biopsy samples from normal parenchyma were collected at nephrectomy and renal parenchyma damage (RPD) was scored on histologic samples according to validated methodology. The outcomes were eGFR after surgery and its reduction > 25% relative to baseline at maximum 12 months' follow-up. Linear and logistic multivariable regression were used, adjusting for age at surgery, presence of hypertension, diabetes, clinical tumour size, time from surgery and basal eGFR. RESULTS: 171 patients were enrolled and RPD was demonstrated in 64 (37%). Patients with RPD had more comorbidities (CCI > 2 in 25 vs. 9%, p < 0.001), in particular hypertension (70 vs. 53%; p = 0.03), diabetes with (5% vs. 0%, p = 0.007) or without (31 vs. 18%; p = 0.007) organ damage, cerebrovascular disease (19 vs. 5%; p = 0.006) and nephropathy (20 vs. 3%; p = 0.0004). At multivariable analyses, RPD was associated with lower eGFR (Est. - 5.48; 95% CI - 9.27 - 1.7; p = 0.005) and with clinically significant reduction of eGFR after surgery (OR 3.06; 95% CI 1.17 8.49; p = 0.026). CONCLUSIONS: Presence of RPD in non-tumour renal tissue is an independent predictor of functional impairment in patients with RCC. Such preliminary finding supports the use of parenchyma biopsy during clinical decision making.