Comparison of Sentinel Lymph Node Biopsy vs Lymphadenectomy in Endometrial Cancer Staging
In the FIRES prospective cohort study reported in The Lancet Oncology, Rossi et al found that sentinel lymph node mapping was highly accurate in detecting metastases compared with complete lymphadenectomy in women with endometrial cancer.
Study Details
The study included women with clinical stage 1 endometrial cancer of all histologies and grades who were undergoing robotic staging between August 2012 and October 2015. A total of 18 surgeons from 10 U.S. centers participated in the study.
Patients received a standardized cervical injection of indocyanine green, followed by sentinel lymph node mapping and pelvic lymphadenectomy with or without para-aortic lymphadenectomy. Sentinel lymph nodes that were negative on hematoxylin-and-eosin staining of sections were ultrastaged by immunohistochemistry for cytokeratin.
The primary study endpoint was sensitivity of sentinel lymph node–based detection of metastatic disease, defined as the proportion of patients with node-positive disease and successful sentinel lymph node mapping with correct identification of metastatic disease in the sentinel lymph node. The primary analysis was performed in the per-protocol population of patients with mapping of at least one sentinel lymph node.
Sensitivity and Negative Predictive Value
Sentinel lymph node mapping with complete pelvic lymphadenectomy was performed in 340 patients, including para-aortic lymphadenectomy in 196 patients (58%). Among these patients, 293 (86%) had successful mapping of at least 1 sentinel lymph node. Overall, 41 patients (12%) had positive nodes, including 36 with ≥ 1 mapped sentinel lymph node.
Metastases were found in sentinel lymph nodes of 35 of the 36 patients (97%), representing sensitivity for detecting node-positive disease of 97.2%. Among the 258 patients with negative sentinel lymph node findings, 257 had negative non–sentinel lymph nodes, representing a negative predictive value of 99.6%.
Adverse Events
The most common grade 3 or 4 adverse events or serious adverse events were postoperative neurologic changes in four patients (including peripheral nerve injuries and central nervous system symptoms such as syncope or vertigo), postoperative respiratory distress or failure in four patients, postoperative nausea and vomiting in three patients, and bowel injury in three patients. Overall, serious adverse events occurred in 22 patients; 1 event considered related to study intervention was ureteral injury during sentinel lymph node dissection.
The investigators concluded: “Sentinel lymph nodes identified with indocyanine green have a high degree of diagnostic accuracy in detecting endometrial cancer metastases and can safely replace lymphadenectomy in the staging of endometrial cancer. Sentinel lymph node biopsy will not identify metastases in 3% of patients with node-positive disease, but has the potential to expose fewer patients to the morbidity of a complete lymphadenectomy.”
The study was funded by Indiana University Health, the Indiana University Health Simon Cancer Center, and the Indiana University Department of Obstetrics and Gynecology.
Emma C. Rossi, MD, of the University of North Carolina, Chapel Hill, is the corresponding author of The Lancet Oncology article.
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