Sentinel lymph node mapping with staging lymphadenectomy for patients with endometrial cancer increases the detection of metastasis

- Compared to traditional pelvic lymphadenectomy, the addition of SLN mapping identified more than twice as many lymph node metastasis.
- SLN mapping and enhanced pathology identified five-fold more low-volume metastases compared to pelvic lymphadenectomy.
- The addition of SLN mapping was associated with a near doubling of adjuvant chemotherapy plus radiation.

ObjectivesTo compare the performance of sentinel lymph node (SLN) mapping with staging lymphadenectomy versus staging lymphadenectomy alone for the detection of metastasis and the use of adjuvant therapies in patients with endometrial cancer.MethodsAll patients with apparent early-stage endometrial cancer (n = 780) who underwent robotic-assisted hysterectomy with pelvic ± aortic lymphadenectomy from July-2006 to June-2013 were compared [pelvic ± aortic lymphadenectomy (n = 661) versus SLN-mapped cases with pelvic ± aortic lymphadenectomy (n = 119)]. Isosulfan-blue and indocyanine-green with near-infrared imaging were used for SLN mapping. Clinico-pathological data, FIGO stage, GOG risk category, and adjuvant therapies were compared.ResultsNon-mapped and mapped cases were comparable with respect to BMI, histology, depth-of-invasion, and lympho-vascular space invasion. The mapped group had more pelvic lymph node (LN) harvested compared to non-mapped group (26.4 ± 10.5 vs. 18.8 ± 8.5, p < 0.001). Aortic LN yields were identical for both groups (9.0 ± 5.6 vs. 9.0 ± 6.0). The mapped group had more LN metastasis detected (30.3% vs. 14.7%, p < 0.001), more stage IIIC (30.2% vs. 14.5%, p < 0.001), more GOG high-risk cases (32.8% vs. 21.8%, p = 0.013), and received more chemotherapy + radiation (28.6% vs. 16.3%, p < 0.003). The SLN was the only metastasis in 18 (50%) mapped cases with positive nodes. The SLN false negative rate was 1/36 (2.8%). Micrometastases or isolated tumor cells were identified in 22/35 (62.9%) SLN metastases. Multivariate analysis demonstrated that SLN mapping imparted a significant effect on the detection of metastatic disease [adjusted OR = 3.29, p < 0.001].ConclusionsThe performance of SLN mapping with staging lymphadenectomy increased the detection of lymph node metastasis and was associated with more use of adjuvant therapies.