Role of one-step nucleic acid amplification (OSNA) to detect sentinel lymph node low-volume metastasis in early-stage cervical cancer

Abstract

IntroductionGrowing evidence in the literature supports the accuracy of sentinel lymph node (SLN) biopsy in early-stage cervical cancer. One-step nucleic acid amplification (OSNA) is a rapid assay able to detect cytokeratin 19-mRNA in SLNs, and it can be used for intra-operative detection of low-volume metastases. The aim of this study was to evaluate the rate of low-volume metastasis in SLNs detected by OSNA in patients with early-stage cervical cancer. Secondary aims were to define the sensitivity and the negative predictive value of SLN biopsy assessed with OSNA.MethodsAfter IRB approval, consecutive patients who underwent surgery for International Federation of Gynecology and Obstetrics stage IA1 with lymph-vascular space involvement to IB1 between November 2017 and July 2019 and had SLN biopsy and pelvic lymphadenectomy were included. SLNs were detected with indocyanine-green cervical injection and sent intra-operatively for OSNA.ResultsEighteen patients underwent SLN assessment with OSNA and systematic pelvic lymphadenectomy in the study period. Four (22.2%) patients had unilateral and 14 (77.8%) had bilateral mapping. OSNA detected micro-metastasis in 6/18 (33.3%) patients. All micro-metastases were detected in patients with bilateral SLN mapping. The sensitivity and negative predictive value of SLN in detecting lymph node metastasis with OSNA calculated per pelvic sidewall were 85.7% and 96.1%, respectively. The false negative rate in mapped sidewalls was 14.3%.DiscussionThis is the first series entirely processing SLNs for OSNA in early-stage cervical cancer. OSNA is able to intra-operatively detect low-volume metastases in SLNs. Further studies are necessary to confirm the accuracy of this technique and to assess survival implications of low-volume metastases detected by OSNA.

Micrometastases in Sentinel Lymph Nodes Represent a Significant Negative Prognostic Factor in Early-Stage Cervical Cancer: A Single-Institutional Retrospective Cohort Study

“…In such cases, a protocol for SLN assessment would be much less time-consuming, less expensive, and would not include immunohistochemistry. An intraoperative one-step nucleic acid amplification method (OSNA) has been recently proposed as an alternative method to ultrastaging [21].…”

Sentinel lymph node processing in gynecological cancer histopathology and molecular biology

“…The intra-operative molecular detection of metastasis by OSNA ® shows a good correlation with classical SLN work-up of 96% (39,41). The study of Bizzarri et al (42), which describes for the first time OSNA ® processing of the entire lymph node tissues, detected MICs in 33.3% with a sensitivity of 85.7% and NPV of 96.1%. However, we should keep in mind, that the risk of false positive results is not negligible since 19-44% of PLNs may harbour benign CK19+ endosalpingiosis, endometriosis or mesothelial inclusions (23).…”

Sentinel Lymph Node Biopsy Is Feasible in Cervical Cancer Laparoscopic Surgery: A Single-Center Retrospective Cohort Study

“…Our results further supported the above findings. Besides, in previous studies, SLN ultrastaging and molecular detection methods also increased the diagnostic accuracy of SLN biopsy [ 23 , 24 ]. Nevertheless, the effects of micrometastasis and isolated tumor cells of lymph nodes on cervical cancer prognosis were still debatable.…”