Endometrial cancer surgical staging: Is sentinel lymph node biopsy a viable option for high-risk histologies?
Cusimano MC, Vicus D, Pulman K, et al. Assessment of sentinel lymph node biopsy vs lymphadenectomy for intermediate- and high-grade endometrial cancer staging. JAMA Surg. 2021;156:157-164.
The use of intraoperative sentinel lymph node mapping and biopsy to identify lymph node metastases among patients undergoing surgical staging for endometrial cancer has become increasingly common. Lymph node status is an important prognostic factor, and it guides adjuvant treatment decisions in endometrial cancer. However, traditional pelvic and para-aortic lymphadenectomy is associated with increased risk of lower-extremity lymphedema, postoperative complications, and intraoperative injury.
Sentinel lymph node biopsy seeks to identify lymph node metastases while minimizing surgical morbidity by identifying and excising only lymph nodes that directly receive lymphatic drainage from the uterus. The combination of a fluorescent dye (indocyanine green) and near infrared cameras have led to the broad adoption of sentinel lymph node biopsy in endometrial cancer staging surgery. This practice is supported by prospective studies that demonstrate the high diagnostic accuracy of this approach.11,12 However, because most patients included in prior studies had low-grade endometrial cancer, the utility of sentinel lymph node biopsy in cases of high-grade histology has been less clear.
Sentinel lymph node biopsy vs lymphadenectomy for staging
In the SENTOR trial, Cusimano and colleagues examined the diagnostic accuracy of sentinel lymph node mapping and biopsy, using indocyanine green, in patients with intermediate- or high-grade early-stage endometrial cancer.13
All eligible patients (N = 156) underwent traditional or robot-assisted laparoscopic hysterectomy with sentinel lymph node biopsy. Subsequently, patients with grade 2 endometrioid carcinoma underwent bilateral pelvic lymphadenectomy, and those with high-grade histology (grade 3 endometrioid, serous, carcinosarcoma, clear cell, undifferentiated or dedifferentiated, and mixed high grade) underwent bilateral pelvic and para-aortic lymphadenectomy. The investigators evaluated the diagnostic characteristics of sentinel lymph node biopsy, treating complete lymphadenectomy as the gold standard.
Of the 156 patients enrolled, the median age was 65.5 and median body mass index was 27.5; 126 patients (81%) had high-grade histology. The sentinel lymph node biopsy had a sensitivity of 96% (95% CI, 81%–100%), identifying 26 of the 27 patients with nodal metastases. The false-negative rate was 4% (95% CI, 0%–9%) and the negative predictive value was 99% (95% CI, 96%–100%). Intraoperative adverse events occurred in 5 patients (3%), but none occurred during the sentinel lymph node biopsy. ●
WHAT THIS EVIDENCE MEANS FOR PRACTICE
The high sensitivity and negative predictive value of sentinel lymph node biopsy in the intermediate- and high-grade cohort included in the SENTOR trial are concordant with prior studies that predominantly included patients with low-grade endometrial cancer. These findings suggest that sentinel lymph node mapping and biopsy is a reasonable option for surgical staging, not only for patients with low-grade endometrial cancer but also for those with intermediate- and high-grade disease.
The high sensitivity and negative predictive value of sentinel lymph node biopsy in the intermediate- and high-grade cohort included in the SENTOR trial are concordant with prior studies that predominantly included patients with low-grade endometrial cancer. These findings suggest that sentinel lymph node mapping and biopsy is a reasonable option for surgical staging, not only for patients with low-grade endometrial cancer but also for those with intermediate- and high-grade disease.