BACKGROUND This study evaluated the clinical significance of pathological factors associated with T3a upstaging according to the American Joint Committee on Cancer/Union for International Cancer Control 8th edition TNM-staging system in patients with clinical T1 renal cell carcinoma undergoing definitive surgery. METHODS We retrospectively investigated 418 patients with renal cell carcinoma who underwent partial or radical nephrectomy at our institution between 2006 and 2016. Surgical specimens were grossly and microscopically re-reviewed with respect to extrarenal extension patterns by two urological pathologists. Kaplan-Meier analysis and Cox regression were used to determine the impact of the factors associated with pathological stage T3a on recurrence-free survival. Harrell's c-index was used to compare the prognostic accuracy of the current and previous staging systems. RESULTS Overall, the 5-year recurrence-free survival was 94.5% (median follow-up duration, 60.8 months). Of 418 patients, 46 (11.0%) were upstaged to pathological stage T3a, including 12/267 (4.5%) and 34/151 (22.5%) in the partial and radical nephrectomy groups, respectively. Among these upstaged patients, partial nephrectomy was significantly associated with a higher recurrence rate than radical nephrectomy (5-year recurrence-free survival: 48.9 vs. 83.9%, P = 0.0172). Although perinephric fat invasion had the highest c-index in all patients (0.580-0.679), microscopic segmental renal vein invasion was a significant predictor of recurrence in patients undergoing partial nephrectomy (c-index, 0.60). CONCLUSION Assessing microscopic segmental renal vein invasion, which has been included in the current staging system recently, is essential to accurately predict the oncological outcome in the era of partial nephrectomy for clinical T1 renal cell carcinoma.

中文翻译：

---

部分肾切除术对临床T1肾细胞癌患者节段性肾静脉浸润对复发的临床影响。

背景技术根据美国癌症联合委员会/国际癌症控制联合会第8版TNM分期系统，本研究评估了T3a上调相关的病理因素在接受定型手术的临床T1肾细胞癌患者中的临床意义。方法我们回顾性调查了2006年至2016年间在本机构接受部分或根治性肾切除术的418例肾细胞癌患者。由两名泌尿科病理学家对手术标本进行了大体和显微镜检查，以探讨肾外扩展方式。使用Kaplan-Meier分析和Cox回归来确定与病理分期T3a相关的因素对无复发生存的影响。哈雷尔 s c指数用于比较当前和先前分期系统的预后准确性。结果总体而言，5年无复发生存率为94.5％（中位随访时间为60.8个月）。在418例患者中，有46例（11.0％）已升级为病理T3a期，部分和彻底肾切除术组分别为12/267（4.5％）和34/151（22.5％）。在这些病情恶化的患者中，部分肾切除术的复发率明显高于根治性肾切除术（5年无复发生存率：48.9 vs. 83.9％，P = 0.0172）。尽管在所有患者中，肾周脂肪浸润的c指数最高（0.580-0.679），但在部分肾切除术中，显微分段性肾静脉浸润是复发的重要预测指标（c-index，0.60）。