Ultrastaging methods of sentinel lymph nodes in endometrial cancer – a systematic review

Abstract

ObjectiveSentinel lymph node mapping has emerged as an alternative to lymphadenectomy in evaluating the lymph node status in endometrial cancer. Several pathological methods to examine the sentinel lymph node are applied internationally. The aim of this study was to determine the value of ultrastaging and to assess the ultrastaging method with the highest detection rate of metastases.MethodsA systematic review was conducted. Inclusion criteria were: pathologically-confirmed endometrial cancer with sentinel lymph node mapping, report of the histological outcomes, metastases found by hematoxylin and eosin staining and metastases found by ultrastaging were separately mentioned, and description of the ultrastaging method. The primary outcome was the detection of metastases found by ultrastaging that were not detected by routine hematoxylin and eosin staining. The secondary outcome was the difference in detection rate of metastases between several ultrastaging methods. Random effects meta-analyses were conducted.ResultsFifteen studies were selected, including 2259 patients. Sentinel lymph nodes were examined by routine hematoxylin and eosin staining. Subsequently, multiple ultrastaging methods were used, with differences in macroscopic slicing (bread-loaf/longitudinal), number of microscopic slides, and distance between slides, but all used immunohistochemistry. A positive sentinel lymph node was found in 14% of patients. In 37% of these, this was detected only by ultrastaging. Using more ultrastaging slides did not result in a higher detection rate. Bread-loaf slicing led to a higher detection rate compared with longitudinal slicing (mean detection rates 53% and 33%, respectively).ConclusionPathological ultrastaging after routine hematoxylin and eosin staining in endometrial cancer patients has led to an increased detection rate of sentinel lymph node metastases. Different ultrastaging methods are used, with a preference for bread-loaf slicing. However, due to the large heterogeneity of the studies, assessing which ultrastaging method has the highest detection rate of sentinel lymph node metastases was not possible.

One-Step Nucleic Acid Amplification (OSNA) of Sentinel Lymph Node in Early-Stage Endometrial Cancer: Spanish Multicenter Study (ENDO-OSNA)

“…Around 10% of early-stage EC patients have lymph node metastases at the time of diagnosis and their presence negatively influences survival [5]. The prognostic value of systematic lymphadenectomy for patients with early-stage EC is controversial, with several studies reporting conflicting results [6][7][8][9][10][11].…”

Sentinel Lymph Node Mapping in High-Grade Endometrial Cancer

“…It is performed in cases where SLNs are negative for metastases in routine H&E staining. This technique improves the identification of nodal metastases, especially for low-volume disease that would have been missed on traditional pathologic assessment [ 49 , 50 ]. The use of this algorithm and ultra-staging in clinical stage I EC results in the identification of node-positive disease and upstaging in approximately 36% of cases [ 26 , 49 ].…”

“…The advantages of SLN mapping lie in the higher rate of identifying node-positive disease and lower morbidity compared to complete lymphadenectomy [ 50 , 51 ]. SLN dissection is less invasive than a complete pelvic and para-aortic lymphadenectomy, resulting in lower rates of intra-operative complications and post-operative lymphedema [ 51 ].…”

Role of sentinel lymph node in endometrial cancer: rationale and surgical aspects, a review of the literature

“…The "breadloafing" method usually comprises: (i) slicing of the SLN perpendicular to the long axis; (ii) obtaining only one block; (iii) obtaining approximately 5 H&Es and 3 IHCs slides per block (each inclusion at an interval of 100 μm). However, many different and also less intensive ultra-staging protocols than what we use have been described [21,43,72,76].…”