Unique prognostic features of grade 3 endometrioid endometrial carcinoma: Findings from 101 consecutive cases at a Japanese tertiary cancer center

Objective: The prognosis of and optimal treatment for grade 3 endometrioid endometrial carcinoma (G3EEC) currently remain unclear. This study aimed to clarify the baseline recurrence risk in patients with early-stage (stage I-II) G3EEC without adjuvant therapy and the prognosis of patients with advanced-stage (stage III-IV) G3EEC.Materials and methods: A total of 101 patients with pathologically confirmed G3EEC from 1997 to 2018 were identified. Their clinicopathological characteristics and survival outcomes were reviewed retro-spectively. Disease-free survival and overall survival values were estimated according to the Kaplan-Meier method and compared using a log-rank test.Results: Recurrence was observed in eight (13%) of 63 patients with early-stage G3EEC, none of whom had received adjuvant therapy. The 5-year disease-free survival and 5-year overall survival rates for these patients were 86.7% and 96.4%, respectively. Recurrence was also observed in 12 (41%) of 29 patients with stage III G3EEC. The 5-year overall survival rates for stage III patients who underwent adjuvant chemotherapy and adjuvant radiotherapy were 85.6% and 42.9%, respectively. The 3-year overall survival rate among stage IVB patients was only 12.7% despite multidisciplinary treatment provision. Conclusion: Our study newly demonstrates that patients with early-stage G3EEC have a favorable prognosis and a low recurrence rate in the absence of adjuvant therapy. In patients with stage III G3EEC, adjuvant chemotherapy was more beneficial than adjuvant radiotherapy. The poor prognosis of patients with stage IV G3EEC indicates the need for more effective treatments. Unique therapeutic approaches based on staging are recommended for treatment of G3EEC.(c) 2021 Taiwan Association of Obstetrics & Gynecology. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

目的：3级子宫内膜样子宫内膜癌（G3EEC）的预后及最佳治疗方法目前仍不明确。本研究旨在阐明未接受辅助治疗的早期（I - II期）G3EEC患者的基线复发风险以及晚期（III - IV期）G3EEC患者的预后。 材料与方法：确定了1997年至2018年间共101例经病理证实的G3EEC患者。回顾性分析了他们的临床病理特征和生存结果。根据卡普兰 - 梅尔方法估计无病生存期和总生存期，并使用对数秩检验进行比较。 结果：63例早期G3EEC患者中有8例（13%）出现复发，这些患者均未接受辅助治疗。这些患者的5年无病生存率和5年总生存率分别为86.7%和96.4%。29例III期G3EEC患者中有12例（41%）出现复发。接受辅助化疗和辅助放疗的III期患者的5年总生存率分别为85.6%和42.9%。尽管进行了多学科治疗，IVB期患者的3年总生存率仅为12.7%。 结论：我们的研究新发现，在未接受辅助治疗的情况下，早期G3EEC患者预后良好且复发率低。对于III期G3EEC患者，辅助化疗比辅助放疗更有益。IV期G3EEC患者预后不良表明需要更有效的治疗方法。建议根据分期采用独特的治疗方法来治疗G3EEC。 （c）2021台湾妇产科医学会。由爱思唯尔出版服务公司出版。这是一篇在CC BY - NC - ND许可（http://creativecommons.org/licenses/by - nc - nd/4.0/）下的开放获取文章。