Exploring metastasis and recurrence patterns in low-risk grade 3 endometrial cancer: A multicenter retrospective cohort study

Objective: Females with low-risk endometrial cancer typically have low lymph node metastasis risk and promising prognosis without lymphadenectomy. However, the impact of grade 3 endometrial cancer on nodal involvement, recurrence, and prognosis within this specific subgroup remains unclear. Therefore, in this study, we aimed to investigate the prognosis, patterns of metastasis, and recurrence in a subgroup of females with grade 3 early-stage low-risk endometrioid endometrial cancer. Methods: We identified patients from the endometrial cancer cohorts of seven institutional hospitals. The study included patients who underwent hysterectomy between January 2013 and December 2021 with preoperative endometrioid histological type, less than half myometrial invasion, no tumor spread outside the corpus on imaging, normal CA-125 level, and histological grade 3. The clinicopathological characteristics and survival outcomes of the patients were collected. Recurrence-free survival was estimated using the Kaplan–Meier method and compared using the log rank test. Results: Overall, 36 patients were included in this analysis. Of the 33 patients who underwent lymphadenectomy, 1 (1/33, 3.0 %) had lymph node metastasis and 27 (75.0 %) received adjuvant therapy. At a median follow-up of 58 months, three females (8 %) had recurrence and all cases involved lymph nodes. The 5-year recurrence-free survival was 88.7 %. No significant difference was observed in the recurrence-free survival between females who did and did not undergo lymphadenectomy (p = 0.554). Conclusion: Females diagnosed with low-risk grade 3 endometrial cancer typically have favorable prognosis. However, lymph node metastasis and recurrence risks still exist, with all recorded instances of recurrence involving lymph nodes.