The Clinical Significance of the Extent of Positive Surgical Margins in Partial Nephrectomy performed for Renal Cell Carcinoma

Abstract

PurposeThis study aims to review the occurrences of extensive positive surgical margins and focal positive surgical margins after partial nephrectomy for kidney cancer, comparing their associations and clinical outcomes with those with negative surgical margins. Materials and MethodsBetween 2014 to 2019, a total of 137 partial nephrectomies for cancer was performed. Pathological surgical margins were classified according to negative surgical margins (n=156), extensive positive margins (n=7), or focal positive surgical margins (n=15). Peri-operative data, functional and oncological outcomes were compared among the three groups.ResultsBaseline clinical characteristics were comparable in all three groups except for gender, with a significantly greater proportion of male patients (P=0.02) with extensive positive surgical margins and focal positive surgical margins than negative surgical margins. Negative surgical margins was associated with shorter operative time compared with extensive and focal positive surgical margins. Pathologically, perinephric fat invasion was significantly associated (P<0.01) with positive surgical margins but there were no other differences in terms of cell type, grade and necrosis. There were a total of 4 local recurrences, all in the extensive positive surgical margins group with a median follow up period of 32.8 months.ConclusionsExtensive positive surgical margins and focal positive surgical margins share similar peri-operative associations when compared with negative surgical margins but have different pathological and oncological implications to each other. The higher association of pathological T3a stage with extensive positive margins may account for the finding that local recurrences exclusively occur in patients with extensive positive surgical margins.