Sentinel lymph node mapping in patients with endometrial hyperplasia: A practice to preserve or abandon?

ABSTRACT

OBJECTIVES: To compare outcomes of patients with premalignant endometrial pathology undergoing hysterectomy with or without sentinel lymph node (SLN) removal. Outcomes of interest included surgical adverse events (AEs), cancer status on final pathology, postoperative treatment, and The Cancer Genome Atlas (TCGA) molecular risk profiles. METHODS: We retrospectively identified patients with premalignant pathology on preoperative endometrial biopsy who underwent hysterectomy with or without SLN mapping/excision at our institution from 01/01/2017-12/31/2021. Clinical, pathologic, surgical, and TCGA profiling data were abstracted. Appropriate statistical tests were used. RESULTS: Of 221 patients identified, 161 (73%) underwent hysterectomy with SLN excision and 60 (27%) underwent hysterectomy without SLN excision. Median age and body mass index were similar between groups. Median operative time was 130 min for those who underwent SLN mapping/excision versus 136 min for those who did not (p = 0.6). Thirty-day postoperative AE rates were 9% (n = 15/161) and 13% (n = 8/60), respectively (p = 0.9). Ninety-eight (44%) of 221 patients had grade 1-2 endometrioid endometrial cancer on final pathology (4 [4%] were stage IB or higher). Ten (10%) of 98 patients, all within the SLN group, received adjuvant treatment. Among all patients, of 33 (15%) with TCGA molecular classification data, 27 (82%) had copy number-low, 3 (9%) microsatellite instability-high, 2 (6%) POLE-ultramutated, and 1 (3%) copy number-high disease. CONCLUSIONS: SLN assessment appears safe, detects a small number of occult nodal metastases for those upstaged, and provides additional staging information that can guide adjuvant treatment. SLN mapping should be discussed in preoperative counseling and offered using a shared decision-making approach.