PARTIAL: study protocol for a clinical and cost-effectiveness of complex PARTIAL vs radical nephrectomy for clinically localised renal cell carcinoma randomised trial

Abstract Background Localised renal cell carcinoma is treated with radical nephrectomy (RN) or partial nephrectomy (PN). Nephron-sparing PN increases preservation of renal function, reducing incidence of end stage renal failure and associated cardiovascular events. In patients with exophytic T1a (≤ 4 cm) tumours and normal contralateral kidney, PN is standard of care. In patients with T1b (> 4–7 cm) or endophytic T1a tumours and normal contralateral kidney, the benefits of PN over RN are less clear as there are increased surgical complications and more tissue may be excised reducing the preservation of renal function. There are no high-quality studies to address if PN is superior to RN in these more complex cases. Methods PARTIAL is a pragmatic randomised controlled parallel group unblinded superiority trial with embedded internal pilot and economic and process evaluation. A total of 420 participants will be recruited in UK NHS centres with expertise in minimally invasive nephrectomy techniques. Eligible consenting adults with a single T1 renal cell carcinoma, normal contralateral kidney and equipoise within the multidisciplinary team confirming suitability to receive both interventions by minimally invasive approaches are randomised 1:1 to PN or RN. Patients with metastatic disease, existing chronic kidney disease, solitary functioning kidney, congenital renal abnormality, inherited kidney cancer syndrome, who lack capacity to consent or are pregnant or breast feeding are excluded. Primary outcomes are gains in preservation of renal function at 2 years and surgical complications over the peri-operative period. Secondary outcomes are quality of life and recovery, cost and cost-effectiveness, rates of positive surgical margin, recurrence and cardiovascular events, overall survival, progression to chronic kidney disease and end stage renal failure, operative conversion and patient acceptability. Participants are followed up for 2 years with outcomes collected from medical records and participant questionnaires. Discussion PARTIAL will determine if gains from PN are superior to RN and offset the potential harms and costs in complex T1 renal tumours suitable for either approach. If PN is not found to provide clinically significant gains and excess complications are confirmed, then a practice-changing case for RN as standard of care could be made. Trial registration ISRCTN 11293415. Registered prospectively on 19 January 2023.