The impact of histological subtype on positive surgical margins in patients with renal cell carcinoma undergoing robot-assisted partial nephrectomy: a multicenter retrospective cohort study using propensity score matching (the MSUG 94 group)

Suguru Oka, Koji Iinuma, Tomoki Taniguchi, Kentaro Muraoka, Kohei Nishikawa, Yoshinori Ikehata, Kiyoshi Setoguchi, Akira Fujisaki, Shinji Urakami, Kazuhide Makiyama, Takahiro Inoue, Hiroshi Kitamura, Kazutaka Saito, Takuya Koie

This study aimed to examine the impact of histological differences on positive surgical margins (PSM) and postoperative renal function in patients with renal cell carcinoma (RCC) who underwent robot-assisted partial nephrectomy (RAPN). This multicenter retrospective cohort study included patients with RCC who underwent RAPN at eight Japanese facilities between March 2016 and November 2023. The enrolled patients who underwent RAPN were divided into those with clear cell RCC (ccRCC group) and those with other histological subtypes (non-ccRCC group). The primary endpoint was to determine the differences in PSM rates according to histological type among patients who underwent RAPN. Secondary endpoint was the chronological assessment of renal function in patients undergoing RAPN, which was categorized according to histological type. To ensure a balance between the two groups with respect to variables that may influence perioperative outcomes, 3:1 propensity score matching was performed using logistic regression. Following propensity score matching at a 3:1 ratio, the analysis included 735 ccRCC and 245 non-ccRCC patients. No significant association was identified between the histological subtypes and PSM in multivariate analysis. Despite a decline in renal function of approximately 10% in both groups postoperatively, no significant difference was observed between the groups in the chronological changes in renal function over time. There was no statistically significant differences in the incidence of PSM based on histological type among the study groups nor substantial variations in postoperative renal function.