Renal outcomes and compensatory hypertrophy in survivors of unilateral non-syndromic Wilms tumour: a single-centre cross-sectional study from a tertiary-care institution in India.

BACKGROUND: This study evaluated renal outcomes and contralateral compensatory hypertrophy in Unilateral Wilms tumour survivors because of a solitary functioning kidney which is vulnerable to hyperfiltration injury. METHODS: This cross-sectional study (January 2005-May 2023) included children with non-syndromic unilateral Wilms tumour. Renal function was assessed using the modified Schwartz formula (eGFR), 99mTc-DTPA plasma clearance and urinary albumin/creatinine ratio(ACR). Blood pressure was evaluated by office measurement and 24-hour ambulatory blood pressure monitoring (ABPM). Compensatory hypertrophy was assessed by CT volumetric segmentation. RESULTS: A total of 117 children were included (median age 84 months, IQR 60-120; median follow-up 40.7 months, IQR 16.6-74.3). Reduced eGFR (< 90 ml/min/1.73 m²) was identified in 14 of 116 (12.1%), and reduced 99mTc-DTPA plasma clearance in 38 of 55 (69.1%). Microalbuminuria was identified in 7 of 56 (12.5%), ABPM-detected hypertension in 4 of 48 (8.3%), and compensatory hypertrophy in 36 of 48 (75.0%). Applying the composite definition (any of: low eGFR, low DTPA GFR, microalbuminuria or ABPM-detected hypertension), renal dysfunction was present in 53 of 117 patients (45.3%). In a analysis restricted to the 31 patients who completed all four investigations, renal dysfunction was present in 25 of 31 (80.6%). CONCLUSION: Isotopic GFR revealed silent nephron injury despite compensatory hypertrophy, with nearly half showing renal dysfunction undetected by creatinine-based eGFR. Creatinine-based eGFR alone risks under-detecting renal dysfunction.