Presenter(s)
J. N. N. Ntambi1,2, H. Koo1, A. Mancharia3, H. Chang4, J. Dottino5,6, K. M. Esselen5,6, and J. W. Jang1,6; 1Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Boston, MA, 2Tufts Medical Center, Boston, MA, 3Department of OB/GYN Beth Israel Deaconess Medical Center, Boston, MA, 4Beth Israel Deaconess Medical Center, Boston, MA, 5Department of OB/GYN, Beth Israel Deaconess Medical Center, Boston, MA, 6Harvard Medical School, Boston, MA
Purpose/Objective(s):
The clinical and prognostic implications of isolated tumor cells (ITCs) in sentinel lymph nodes in endometrioid endometrial adenocarcinoma are currently not well known, particularly in relation to patients who are node-negative (N0), have micrometastasis (micromets), or macrometastasis (macromets). This study aims to analyze survival and recurrence of those with endometrioid endometrial cancer with ITCs, compared to patients with other sentinel lymph node pathologies, which could help to refine patients' options for adjuvant interventions.Materials/Methods: We retrospectively reviewed all patients with endometrioid endometrial cancer who had a sentinel lymph node dissection (SLND) between 2018 and 2023 at our institution. Patients were classified as being N0, having ITCs, micromets, or macromets. Macromets were defined as > 2 mm, micromets were defined as > 0.2 mm but =2 mm, or > 200 cells, and ITCs were defined as = 0.2 mm or < 200 cells. Demographics, cancer and treatment characteristics, and recurrence data were extracted from the electronic medical record by retrospective review. Univariate analyses were performed using the Chi-square, Fisher’s exact, or Kruskal-Wallis tests. Overall survival (OS) and recurrence-free survival (RFS) were estimated using Kaplan-Meier curves and log-rank tests.
Results: There were 453 patients included, with a median follow-up of 52 (37-66) months. 404 patients (89%) were N0. Of the remaining 49 patients, 19 (38%) had ITC, 13 (27%) had micromets, and 17 (35%) had macromets. Compared to the N0, ITC, and micromet cohorts, patients with macromets were more likely to have a non-sentinel lymphadenectomy (p = 0.08), deeper myometrial invasion (median 68%, p < 0.001), any lymphovascular space invasion (p < 0.001), and a larger primary tumor diameter (median 4.5 cm, p < 0.001). Patients with micromets or macromets were more likely to receive both chemotherapy and RT vs. RT alone (p < 0.001), and if they received radiation, were more likely to have external beam radiation vs. vaginal brachytherapy (p < 0.001), compared to patients that were N0 or had ITCs. Recurrence was seen in 47/453 (10.4%) patients overall, including 41/404 (10%) in N0, 3/19 (16%) in ITC, 0/13 (0%) in micromet, and 3/17 (18%) in the macromet group. The 3 ITC patients that recurred had recurrences in the vagina, lung, peritoneum, and brain. 5-year RFS was 89%, 83%, 100%, and 82% in the N0, ITC, micromets, and macromets groups, respectively. 5-year OS was 93%, 86%, 100%, and 93% among the N0, ITC, micromets, and macromets groups, respectively.
Conclusion: Our ITC cohort had a 16% recurrence rate, similar to those with macromets. However, direct comparisons of recurrence and survival are confounded by differences in adjuvant treatment. Future directions include examining prognostic factors associated with recurrence in ITCs to better triage adjuvant therapy and surveillance practices.