Sentinel Lymph Node Vs. Full Lymphadenectomy in High-Risk Endometrial Cancer

Sep 22, 2023

The following is a summary of “Outcomes for patients with high-risk endometrial cancer undergoing sentinel lymph node assessment versus full lymphadenectomy,” published in the July 2023 issue of Gynecologic Oncology by Holtzman et al.

This study aimed to compare progression-free survival (PFS) and overall survival (OS) between patients with high-risk endometrial cancer (EC) who underwent sentinel lymph node (SLN) mapping and dissection and those who underwent pelvic +/- para-aortic lymphadenectomy (LND). Patients newly diagnosed with EC at significant risk were identified. The inclusion criteria included patients who underwent primary surgical treatment at researchers’ institutions between January 1, 2014, and September 1, 2020. Patients were classified into the SLN or LND group based on their intended lymph node assessment method. According to their institution’s protocol, patients in the SLN group received a dye injection, followed by a successful mapping, retrieval, and processing of bilateral lymph nodes. The patient’s medical records were mined for clinicopathological and follow-up data. The t-test or Mann-Whitney test was utilized for comparing continuous variables, whereas Chi-squared or Fisher’s exact test was used for categorical variables.

From the date of initial surgery until the date of progression, mortality, or last follow-up, progression-free survival (PFS) was calculated. From the date of surgical staging until the date of death or the last follow-up, overall survival (OS) was calculated. The Kaplan-Meier method was used to estimate PFS and OS at three years, and the log-rank test was used to compare cohorts. Adjusting for age, adjuvant therapy, and surgical approach, multivariable Cox regression models were used to examine the relationship between the nodal assessment cohort and OS/PFS while controlling for the nodal assessment cohort. At a significance level of p<0.05, a result was deemed statistically significant, and all statistical analysis was performed using SAS version 9.4 (SAS Institute, Cary, NC). Based on their criteria, 189 of the 674 patients diagnosed with EC during the study period were at high risk. About 46 (23.7%) patients underwent SLN assessment, and 143 (73.7%) experienced LND.

Age, histology, stage, body mass index, tumor myometrial invasion, lymphovascular space invasion, and peritoneal lavage positivity did not differ between the two groups. Patients in the SLN group were more likely to undergo robotic-assisted procedures than those in the LND group (P< 0.0001). The PFS rate at three years was 71.1% in the SLN group and 71.3% in the LND group (P = 0.91). The unadjusted hazard ratio (HR) for recurrence in the SLN versus LND group was 1.11 (95% CI: 0.56–2.18; P = 0.77), while the adjusted HR for recurrence was 1.04 (95% CI: 0.47–2.18; P = 0.91). The three-year OS rate was 81.1% (95% CI: 51.1–93.7%) in the SLN group and 95.1% (95% CI: 89.4–97.7%) in the LND group (P = 0.009). Although the unadjusted HR for death was 3.74 in the SLN group versus the LND group (95% CI: 1.39–10.09; P = 0.009), after adjusting for age, adjuvant therapy, and surgical approach, the HR was no longer significant at 2.90 (95% CI: 0.94–8.95; P = 0.06). In investigators’ cohort, there was no difference in PFS at three years between patients with high-risk EC who underwent SLN evaluation and those who underwent full LND. Unadjusted OS was shortened in the SLN group; however, after adjusting for age, adjuvant therapy, and surgical approach, there was no difference in OS between SLN and LND patients.