Martin Pešta

One‐Step Nucleic Acid Amplification Analysis of Sentinel Lymphatic Nodes in Endometrial Cancer Patients ( EU ‐ OSNA ): A European Multicenter Diagnostic Accuracy Study

ABSTRACT Objective This European multicenter study aimed to assess the diagnostic accuracy of one‐step nucleic acid amplification (OSNA) as the primary endpoint by comparing this method with ultrastaging for the detection of sentinel node metastases in endometrial cancer patients. Methods European multicenter prospective performance study including data from 10 centers across 5 European countries. Each node, upon removal of surrounding adipose tissue, was sliced in 2 mm thick sections and equally distributed between ultrastaging and OSNA. OSNA is based on cytokeratin‐19 detection, serving as a metastatic marker. Sensitivity, specificity, and concordance of OSNA versus ultrastaging were calculated at nodal and patient levels. Results Seven hundred forty‐three sentinel nodes from 366 patients were evaluated. Compared to ultrastaging, OSNA showed concordance, specificity, and sensitivity of 95%, 97.6%, and 41.2% at the nodal level and 93.2%, 96.2%, and 47.8% at the patient level, respectively. In reverse analysis, when compared to OSNA, the ultrastaging showed a sensitivity of 45.2% and 45.8% at the nodal and patient levels, respectively. Irrespective of the size of metastasis, both methods agreed in 14 positive and 692 negative nodes (95%). This resulted in 24 (6.56%) patients with a positive OSNA and 23 (6.28%) patients with a positive ultrastaging finding. The number of discordant nodes was 47 (6.33%), 40 (85.1%) of them were micrometastases. Benign epithelial inclusions occurred in 4 nodes (0.54%) and 4 patients (1.09%). Conclusion Compared with ultrastaging, OSNA showed high concordance and specificity, but sensitivity was low—similar to ultrastaging compared with OSNA as an index test in reverse analysis. The main limitation in comparing the two approaches by splitting the sentinel nodes was the tissue allocation bias. As reflected in the number of discordant cases, especially at the micrometastases level. The distribution of patients with node metastases was comparable between the two methods at both the nodal and patient levels. Trial Registration German Clinical Trial Register: Nr. DRKS00021520

One‐Step Nucleic Acid Amplification Analysis of Sentinel Nodes in Endometrial Cancer Versus Ultrastaging: First Long‐Term Follow‐Up Data of Discordant Cases

ABSTRACTAimsEndometrial cancer (EC) is the most common gynecological cancer worldwide and its incidence is rising. The cornerstone of its management is surgical treatment with nodal staging. A monocentric study investigating the potential of the molecular biology method of one‐step nucleic acid amplification (OSNA) in sentinel lymph node (SLN) analysis was conducted at our institution between April 2016 and January 2018. Histopathological ultrastaging was used as the reference standard for SLN examination and OSNA as the index test. The aim of this study was to assess the long‐term outcome of patients with discordant SLN and OSNA results. To our knowledge, this is the first study exploring this issue.Methods and ResultsPatients were followed in line with the current ESMO/ESGO/ESTRO recommendations. The institutional electronic database was retrospectively searched for patients' follow‐up data from April 2016 till March 2023. Only patients who provided a written valid consent and had a positive OSNA and negative ultrastaging of their SLN analysis were included in the study. The primary endpoint was the retrospective analysis of their clinical outcome. Data from 58 patients enrolled into our previous study were reviewed and 12 discordant patients who met the inclusion criteria for this study were identified. The median follow‐up was 83 months. Disease recurrence was detected in 3 (25%) patients, two of these were nodal and both patients died. One patient had a solitary lung metastasis which was surgically treated, and the patient was disease‐free during the whole study period.ConclusionThe recurrence rate of patients included in the study was in the intermediate‐high and high‐risk group range, and hence, higher than expected based on ultrastaging results. Furthermore, benign epithelial inclusions do not seem to adversely affect OSNA SLN analysis in EC patients.