Sentinel Lymph Node Mapping in Endometrial Cancer: A Comprehensive Review

Abstract

Endometrial cancer (EC) is known as a common gynecological malignancy. The incidence rate is on the increase annually. Lymph node status plays a crucial role in evaluating the prognosis and selecting adjuvant therapy. Currently, the patients with high-risk (not comply with any of the following: (1) well-differentiated or moderately differentiated, pathological grade G1 or G2; (2) myometrial invasion< 1/2; (3) tumor diameter < 2 cm are commonly recommended for a systematic lymphadenectomy (LAD). However, conventional LAD shows high complication incidence and uncertain survival benefits. Sentinel lymph node (SLN) refers to the first lymph node that is passed by the lymphatic metastasis of the primary malignant tumor through the regional lymphatic drainage pathway and can indicate the involvement of lymph nodes across the drainage area. Mounting evidence has demonstrated a high detection rate (DR), sensitivity, and negative predictive value (NPV) in patients with early-stage lower risk EC using sentinel lymph node mapping (SLNM) with pathologic ultra-staging. Meanwhile, SLNM did not compromise the patient’s progression-free survival (PFS) and overall survival (OS) with low operative complications. However, the application of SLNM in early-stage high-risk EC patients remains controversial. As revealed by the recent studies, SLNM may also be feasible, effective, and safe in high-risk patients. This review aims at making a systematic description of the progress made in the application of SLNM in the treatment of EC and the relevant controversies, including the application of SLNM in high-risk patients.

Sentinel Lymph Node Biopsy in Endometrial Cancer: Dual Injection, Dual Tracer—A Multidisciplinary Exhaustive Approach to Nodal Staging

“…In our study, seven patients (14.6%) were upstaged to stage III for lymph node involvement. This has clinical implications, and these results are similar to the literature [ 7 ]. The patients who most benefited from the SLN technique (with systematic para-aortic lymphadenectomy when SLN mapping failed) were intermediate–high-risk.…”

“…On the other hand, when pelvic lymph nodes were positive, 51% had para-aortic metastases [ 7 ]. We found very similar results (50%).…”

“…Superficial and deep cervical injection with indocyanine green (ICG) tracer is the more accepted detection technique. However, cervical injection alone is associated with a significantly lower rate of aortic detection compared with uterine injection [ 7 ]. The possibility of missing occult para-aortic lymph nodes metastasis is from 1% to 3% [ 8 , 9 ].…”

The Application of Different Surgical Methods in Endometrial Cancer

“…Currently, the most commonly used criteria are the "Mayo criteria" proposed by Mariani et al This means that lymph node dissection can be omitted in patients in the low-risk group (meeting all of the following criteria): (1) endometroid type, grade G1 or G2; (2) myometrial invasion < 1/2; (3) tumor diameter < 2 cm). According to the Lirong Zhai [27], this criterion possesses 90% sensitivity but only 36% specificity, with nearly 80% of patients without metastases undergoing lymph node dissection. Furthermore, the criterion is dependent on intraoperative frozen sections (FS) and pathologists, with approximately 18% of EC patients staged up in the final pathology report.…”

Sera Protein Signatures of Endometrial Cancer Lymph Node Metastases

“…Metastasis to the locoregional (pelvic and para-aortic) lymph node basins are classified as stage IIIC1 and IIIC2, respectively. Currently, the method and extent of evaluation for lymph node metastases at the time of surgery is highly controversial [ 6 ]. Removal and evaluation of lymph nodes (lymphadenectomy) has the benefit of reducing the potential of hematogenous and lymphatic spread of the cancer to distant sites, but at the cost of increased patient morbidity due to surgical complications such as lymphedema, lymphocyst formation, cellulitis, endothelial and neurovascular injury [ 6 , 7 ].…”