Sentinel lymph node (SLN) biopsy can be regularly used in surgical staging among high-risk patients with early-stage endometrial carcinoma, as well as in low-risk groups, rather than systematic pelvic and para-aortic lymphadenectomy, according to findings published in the International Journal of Environmental Research and Public Health.

Examining the Role of SLN Biopsy in High-Risk Patients

Antonio Raffone, MD, of the University of Naples Federico II, and colleagues examined the role of SLN biopsy through cervical injection of indocyanine green (ICG) among high-risk patients with early-stage endometrial carcinoma. They searched seven electronic databases from inception to February 2021 for studies assessing detection rate and accuracy of SLN biopsy through the cervical injection of ICG and calculated pooled sensitivity, false negative (FN) rate, detection rate of SLN per hemipelvis (DRh), detection rate of SLN per patient (DRp), and bilateral detection rate of SLN (DRb) with 95% CI.

Following a full-text assessment, the researchers used five observational cohort studies in the qualitative and quantitative analysis, including three prospective studies and two retrospective studies, for a total of 684 patients with endometrial carcinoma, most of whom (N=578; 84.5%) had high-risk disease. Mean patient age and BMI ranged from 53-71 years and 24.8-27.5 kg/m2, respectively.

SLN Biopsy Demonstrates Sensitivity for High-Risk Disease

Endometrial carcinoma histotype included endometrioid (57.6%), serous (24.6%), carcinosarcoma (6.6%), clear cell (6.1%), and undifferentiated (1.6%). Surgical staging was laparoscopic in two studies, robotic in one study, laparoscopic or robotic in one study, and unspecified in one study. Pathological ultra-staging was conducted in four studies.

Sensitivity of SLN biopsy for identifying endometrial carcinoma metastasis was 0.90 (95% CI, 0.03-0.95), and the FN rate was 2.8% (95% CI, 0.6-11.6%). DRh was 88.4% (95% CI, 86%-90.5%), DRp was 96.6% (95% CI, 94.7-97.8%), and DRb was 80% (95% CI, 75.4-83.9). The researchers noted that detection rates were determined without evaluating ICG injection, as only one study included in the analysis used the ICG injection.

SLN biopsy began as a way to decrease perioperative morbidity and long-term lymphatic complications of systematic lymphadenectomy, according to the study team, and to overcome technical difficulties associated with the procedure. It has been identified as a suitable replacement for systematic lymphadenectomy for lymph node staging in high-intermediate/high-risk patients with endometrial carcinoma. The current study determined that SLN biopsy showed high sensitivity in high-risk patients with endometrial carcinoma, similar to that seen among patients with endometrial carcinoma at both low (96%) and undetermined risk (93%), and shows that SLN biopsy is appropriate for high-risk patients. The investigators also suggested that further study on this topic, particularly in randomized controlled trials, is needed.