Burg L, et al. J Gynecol Oncol. 2019 Jun;31:e58. https://doi.org/10.3802/jgo.2020.31.e58

Objective Sentinel 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. Methods A 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. Results Fifteen 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). Conclusion Pathological 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.

Burg LC, et al. J Gynecol Oncol. 2022 Jun;33:e66. https://doi.org/10.3802/jgo.2022.33.e66

To assess the cost-effectiveness of sentinel lymph node mapping compared to risk factor assessment and routine full lymph node dissection for the assessment of lymph nodes in patients with low- and intermediate-risk endometrioid endometrial cancer. A decision-analytic model was designed to compare three lymph node assessment strategies in terms of costs and effects: 1) sentinel lymph node mapping; 2) post-operative risk factor assessment (adjuvant therapy based on clinical and histological risk factors); 3) full lymph node dissection. Input data were derived from systematic literature searches and expert opinion. QALYs were used as measure of effectiveness. The model was built from a healthcare perspective and the impact of uncertainty was assessed with sensitivity analyses. Base-case analysis showed that sentinel lymph node mapping was the most effective strategy for lymph node assessment in patients with low- and intermediate-risk endometrial cancer. Compared to risk factor assessment it was more costly, but the incremental cost effectiveness ratio stayed below a willingness-to-pay threshold of €20,000 with a maximum of €9637/QALY. Sentinel lymph node mapping was dominant compared to lymph node dissection since it was more effective and less costly. Sensitivity analyses showed that the outcome of the model was robust to changes in input values. With a willingness-to-pay threshold of €20,000 sentinel lymph node mapping remained cost-effective in at least 74.3% of the iterations. Sentinel lymph node mapping is the most cost-effective strategy to guide the need for adjuvant therapy in patients with low and intermediate risk endometrioid endometrial cancer.

The aim was to investigate the incidence of sentinel lymph node (SLN) metastases and the contribution of SLN mapping in presumed low- and intermediate-risk endometrial cancer (EC). A multicenter, prospective cohort study in presumed low- and intermediate-risk EC patients was performed. Patients underwent SLN mapping using cervical injections of indocyanine green and a minimally invasive hysterectomy with bilateral salpingo-oophorectomy. The primary outcome was the incidence of SLN metastases, leading to adjusted adjuvant treatment. Secondary outcomes were the SLN detection rate and the occurrence of complications. Descriptive statistics and univariate general linear model analyses were used. A total of 152 patients were enrolled, with overall and bilateral SLN detection rates of 91% and 61%, respectively. At final histology, 78.9% of patients (n = 120) had truly low- and intermediate-risk EC. Macro- and micro-metastases were present in 11.2% (n = 17/152), and three patients had isolated tumor cells (2.0%). Nine patients (5.9%) had addition of adjuvant radiotherapy based on SLN metastases only. In 2.0% of patients with high-risk disease, adjuvant therapy was more limited due to negative SLNs. This study emphasizes the importance of SLN mapping in presumed early-stage, grade 1 and 2 EC, leading to individualized adjuvant management, resulting in less undertreatment and overtreatment.

Objectives. The aim was to evaluate the cost-effectiveness of sentinel lymph node (SLN) mapping in comparison to routine pelvic lymphadenectomy for lymph node assessment in patients with high-risk endometrial cancer (EC). Methods. A decision–analytic model was developed to compare SLN mapping with pelvic lymphadenectomy for guiding adjuvant therapy in patients with high-risk endometrioid and non-endometrioid EC, focusing on costs and health outcomes. The input data were obtained from systematic literature searches and expert consensus. Quality-adjusted life years (QALYs) was utilized as the measure of effectiveness. The model was constructed from a healthcare perspective, and the impact of uncertainty was evaluated through sensitivity analyses. Results. The base case analysis indicated that sentinel lymph node mapping is the dominant strategy for lymph node assessment in patients with high-risk endometrial cancer, as it was found to be both more effective and less costly than lymphadenectomy. The improved outcomes and reduced costs associated with SLN mapping primarily result from a decrease in the side effects related to lymph node assessment. Sensitivity analyses demonstrated that the outcome of the model was robust to variations in input values. Conclusion. SLN mapping is the most cost-effective strategy to determine the need for adjuvant therapy in patients with high-risk endometrioid and non-endometrioid endometrial cancer.