Indeterminate Surgical Margins after Partial Nephrectomy: Results from the Cancer Registry of Norway

Abstract

Objectives : To determine the predictors and incidence for indeterminate surgical margins (ISMs) following partial nephrectomy (PN) and to assess associated clinical outcomes. Patients and Methods: A retrospective analysis of 524 patients from the Cancer Registry of Norway who underwent PN between January 2014 and December 2015, with follow-up in 2021. Univariate and multivariate analysis were utilized to identify risk factors, while survival plots were employed to assess local recurrence, metastasis and overall survival. Results : ISMs occurred in 24 patients (5%). Hospitals performing < 10 PNs/year and non-university hospitals had higher risk of ISMs (7.6%) compared to university hospitals (2.4%) and those performing > 30 PNs/year (3.3%). Fuhrmann grade and number of histological sections emerged as significant risk factors, with ISMs in 8.3% of patients with Fuhrmann grade 1 and 10.8% in > 10 histological sections compared to 3.6% in <10 sections. The hazard ratios for Local recurrence with ISMs were 3.65 (p = 0.238) and 18.14 (p = 0.021) with univariate and multivariate analysis. Conclusion : ISMs is an uncommon finding following PNs. Low surgical volume, the use of more than 10 histological sections, Fuhrmann grade 1 and treatment at non-university hospitals are risk factors for ISMs. Patients with ISMs have a higher risk for local recurrence and should be followed more closely than those with negative margins.