Molecular Staging of Patients with Colon Cancer. The C-Closer-II Study: A Multicentre Study in Portugal

Abstract

Introduction: Approximately 20% - 30% of histological lymph node-negative patients with colorectal cancer relapse at five years after surgical treatment. This recurrence is likely due to occult nodal disease undetected by standard histopathological practice which has implications in terms of the clinical management of patients.Material and Methods: Lymph nodes were collected from colectomy specimens. A central section from each lymph node was histologically examined following haematoxylin-eosin staining and the remaining tissue was subjected to OSNA - one step nucleic acid amplification analysis.Results: A total of 1046 lymph nodes from 59 pN0 patients were assessed. Of these, 753 lymph nodes were examined by both methods. The median number of lymph nodes assessed with OSNA - one step nucleic acid amplification was 12 (IQR: 7;16). Among pN0 patients, 17 had OSNA - one step nucleic acid amplification-positive lymph nodes, resulting in a positive molecular staging rate of 28.8% (95% CI: 17.8 - 42.1). Among these patients, 12 (70.59%) were molecular-staged as pN1 and 5 (29.41%) were molecular staged as pN2. The tumour burden of lymph nodes assessed with OSNA - one step nucleic acid amplification ranged from 270 to 17 000 cytokeratin 19 mRNA copies/μL. Most of these patients (88.2%) were found to have lymph nodes with micrometastases only (250 - 4999 copies/μL).Discussion: We provide the results from the first study of the use of the OSNA - one step nucleic acid amplification assay in colorectal cancer patients in Portugal. Our results are in-line with other international studies, showing the improvement on patients’ staging by molecular examination of lymph nodes.Conclusion: In our study, 28.8% of patients with histologically negative lymph nodes were found to have metastatic lymph nodes using OSNA - one step nucleic acid molecular assessment. OSNA - one step nucleic acid assay allows a more accurate staging of patients with colorectal cancer and standardizes lymph node assessment.

Lymph Node Positivity in One-Step Nucleic Acid Amplification is a Prognostic Factor for Postoperative Cancer Recurrence in Patients with Stage II Colorectal Cancer: A Prospective, Multicenter Study

“…Other studies also showed that pN0 CRC patients were up-staged by OSNA test in 15.3-28.8%. 13,15,24,25 It is suggested that difference of detection rate depends on sampling of LN volume and number. 24 Notably Rakislova et al 24 reported that 20.8% pN0 cases were OSNA-positive by the pooling method which would be helpful as compared to time consuming and expensive individual analysis of LNs.…”

A Novel Prognostic Prediction Model for Colorectal Cancer Based on Nine Autophagy-Related Long Noncoding RNAs

“…Generally, the prognosis is better with earlier staging. In recent years, however, some studies have shown that the combination of biomarkers and TNM staging is more accurate in predicting the prognosis of CRC patients (3,4).…”

The advantage of one‐step nucleic acid amplification for the diagnosis of lymph node metastasis in colorectal cancer patients

“…Although the prognostic value of an OSNA analysis in stage II CRC is still unclear compared with that of ctDNA, more recent studies have hypothesized that positive results on an OSNA assay in stage II CRC patients correlate with a poor disease prognosis. Brito et al examined 753 LNs from pathologically node‐negative colon cancer patients (n = 59) by an OSNA assay and showed that 28.8% of the patients had OSNA‐positive LNs 22 . In addition, most of the OSNA‐positive patients (88.2%) were found to have LNs with micrometastases by a CK19 copy number analysis in the OSNA assay.…”

“…The injected dyes for the detection of SLNs were blue dye or indocyanine green. An intraoperative OSNA assay was performed in two studies, and a postoperative OSNA assay using SLNs stored at −80°C was performed in the remain-A comparison of the diagnostic accuracy of the OSNA assay in CRC patients with stage II CRC (T3-4N0M0) form a heterogeneous group with very different prognoses, and some patients with stage II CRC may have a worse prognosis than patients with low-= 59) by an OSNA assay and showed that 28.8% of the patients had OSNA-positive LNs 22. In addition, most of the OSNA-positive patients (88.2%) were found to have LNs with micrometastases by a CK19 copy number analysis in the OSNA assay.…”