WHERE THERE IS SMOKE, THERE IS FIRE: UNDERSTANDING THE IMPLICATIONS OF POSITIVE SENTINEL LYMPH NODES IN ENDOMETRIAL CANCER

ObjectivesThe objective of this study is to identify clinicopathologic characteristics associated with non-sentinel lymph node (SLN) metastasis and non-vaginal recurrences in patients with SLN-positive endometrial cancer (EC).MethodsConsecutive patients with surgically staged EC and at least one positive SLN were included. SLNs were ultra-staged. Positive SLNs were reviewed and patients classified according to the size of the largest SLN metastasis.Results103 patients (36 isolated tumor cells (ITC), 27 micrometastasis, 40 macrometastasis) were included. Multiple positive SLNs were observed in 38.8% of patients. Size of SLN metastasis (adjusted OR (aOR) 3.0 for macrometastasis vs ITC, 95%CI 1.1–8.1), and age (aOR 1.8 per 10-year increase, 95%CI 1.1–3.0) were independent predictors of multiple positive SLNs. Extracapsular compared to intracapsular invasion of the SLN metastasis was significantly associated with multiple positive SLNs at univariate analysis (71.4% vs. 33.7%, p=0.008). Forty-seven percent (18/38) of patients who underwent completion pelvic lymphadenectomy, had additional positive lymph nodes. This was associated with increased size of SLN metastasis (0/8, 5/10, and 13/20 in ITC, micro- and macrometastasis, respectively, p=0.004). SLN macrometastasis (adjusted HR (aHR) 3.4, 95%CI 1.1–11.0), non-endometrioid histology (aHR 5.7, 95%CI 1.9–17.3), and cervical stromal invasion (aHR 9.4, 95%CI 2.9–30.4) were independent predictors of non-vaginal recurrence (table 1).ConclusionsSize and location of SLN metastasis can predict an increased risk of multiple positive SLNs, non-SLN positive nodes, and non-vaginal recurrence in SLN positive EC patients. These factors should be assessed when considering adjuvant treatment in these high-risk patients.