Lymphadenectomy in Endometrial Cancers-A Review

Most endometrial cancers are diagnosed in an early stage, and nearly three-fourths do not require any lymph node clearance. Surgical staging is considered the gold standard, but the role of lymphadenectomy is unclear. Most patients with endometrial cancers have other medical co-morbidities like hypertension, diabetes, obesity and remain high risk for prolonged procedures. The reported risk of lymphedema according to published literature could be as high as 30% vis-a-vis a 10% risk of upstaging with lymph node clearance. The confounding factors in endometrial cancers are the depth of myometrial invasion, tumor size, histology, tumor grade and variable lymphatic pathways. Visual inspection/palpation of the nodes or berry-picking enlarged nodes remain poor predictors of nodal involvement. The extent of clearance by convention ranges from bilateral pelvic only or addition of a formal retroperitoneal clearance upto the left renal vein. Adjuvant treatment for patients diagnosed with advanced-stage cancer after a comprehensive lymphadenectomy is not uniform. The path forward appears to revolve around sentinel mapping. Lymphadenectomy can be omitted in the low-risk group, while a cervical injection-based pelvic sentinel mapping can be performed in the intermediate-risk group. However, in the high-risk/ultrahigh-risk subgroups, para-aortic sentinel node mapping is needed. If there are no SLNs identified with a cervical injection, an additional corporeal ICG injection may be needed. This approach needs to be based on an institutional algorithm with the incorporation of ultrastaging. An additional benefit of the sentinel approach is a focused histopathological analysis of the most relevant nodes. Various dyes have been evaluated for sentinel mapping, methylene blue being the cheapest though studies show indocyanine green to be the safer alternative with better results.