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Evaluation of the prognostic relevance of the recommended minimum number of lymph nodes in colorectal cancer-a propensity score analysis

Michaela Ramser, Leonard A Lobbes, Rene Warschkow, Carsten T Viehl, Johannes C Lauscher, Raoul A Droeser, Christoph Kettelhack, Markus Zuber & Benjamin Weixler


Nodal status in colorectal cancer (CRC) is an important prognostic factor, and adequate lymph node (LN) staging is crucial. Whether the number of resected and analysed LN has a direct impact on overall survival (OS), cancer-specific survival (CSS) and disease-free survival (DFS) is much discussed. Guidelines request a minimum number of 12 LN to be analysed. Whether that threshold marks a prognostic relevant cut-off remains unknown.

Patients operated for stage I-III CRC were identified from a prospectively maintained database. The impact of the number of analysed LN on OS, CSS and DFS was assessed using Cox regression and propensity score analysis.

Of the 687 patients, 81.8% had ≥ 12 LN resected and analysed. Median LN yield was 17.0 (IQR 13.0-23.0). Resection and analysis of ≥ 12 LN was associated with improved OS (HR = 0.73, 95% CI: 0.56-0.95, p = 0.033), CSS (HR 0.52, 95% CI: 0.31-0.85, p = 0.030) and DFS (HR = 0.73, 95% CI: 0.57-0.95, p = 0.030) in multivariate Cox analysis. After adjusting for biasing factors with propensity score matching, resection of ≥ 12 LN was significantly associated with improved OS (HR = 0.59; 95% CI: 0.43-0.81; p = 0.002), CSS (HR = 0.34; 95% CI: 0.20-0.60; p < 0.001) and DFS (HR = 0.55; 95% CI: 0.41-0.74; p < 0.001) compared to patients with < 12 LN.

Eliminating biasing factors by a propensity score matching analysis underlines the prognostic importance of the number of analysed LN. The set threshold marks the minimum number of required LN but nevertheless represents a cut-off regarding outcome in stage I-III CRC. This analysis therefore highlights the significance and importance of adherence to surgical oncological standards.
keywords *Colorectal Neoplasms/pathology/surgery
*Lymph Nodes/pathology/surgery
Neoplasm Staging
Propensity Score
Retrospective Studies
Colorectal cancer
Disease-free survival
Lymph nodes
Overall survival
Propensity score analysis
citation Ramser M, Lobbes L A, Warschkow R, Viehl C T, Lauscher J C, Droeser R A, Kettelhack C, Zuber M, Weixler B. Evaluation of the prognostic relevance of the recommended minimum number of lymph nodes in colorectal cancer-a propensity score analysis. Int J Colorectal Dis 2021; 36:779-789.
type journal paper/review (English)
date of publishing 16-1-2021
journal title Int J Colorectal Dis (36/4)
ISSN electronic 1432-1262
pages 779-789
PubMed 33454816
DOI 10.1007/s00384-021-03835-8
contact Ulrich Beutner