Assessing para-aortic nodal status in high-grade endometrial cancer patients with negative pelvic sentinel lymph node biopsy

ObjectiveTo determine the accuracy of pelvic sentinel lymph node biopsy (SLN) in detecting positive para-aortic (PA) lymph nodes in high-grade uterine cancer, and to determine the recurrence rate in patients with high-grade uterine cancers who did not receive adjuvant chemotherapy based on negative pelvic SLNs.MethodsThis was a retrospective cohort study of patients with newly diagnosed, high-grade endometrial cancer who underwent surgery, including pelvic SLNs with or without PA node dissection, at a tertiary care institution between 2015 and 2020. Baseline demographics, surgical management, pathology data, and outcomes were analyzed using descriptive statistics, and survival analysis.ResultsPostoperative histology of the 110 patients meeting inclusion criteria was 45.5% grade 3 endometrioid, 36.4% serous, 10.9% clear cell, and 7.3% carcinosarcoma. On final pathology, 63.7% were stage 1, and 23.6% were stage 3C with positive nodes. A total of 63 patients (57.3%) had a PA lymph node dissection (56 bilateral, 7 unilateral) in addition to the pelvic SLN. Among this group, 5.8% (95% confidence interval 1.2%-16.0%) had a positive PA node despite a negative pelvic SLN. Among those with a negative pelvic SLN and no adjuvant chemotherapy (n = 75), the rate of distant recurrence was 14.7%, and 3-year recurrence-free survival was 71.9%.ConclusionThe rate of isolated PA node metastasis in high-grade endometrial cancers despite a negative pelvic SLN may be significantly higher than the accepted rate of isolated PA node metastasis in low-grade endometrial cancer. This supports adjuvant treatment decisions continuing to incorporate primary tumor pathology and molecular classification. The rate of isolated positive para-aortic lymph nodes in high-grade uterine cancer was 5.8% after pelvic sentinel lymph node biopsy assessment, indicating adjuvant treatment decisions should be contextualized.