THE CALCULATION OF LYMPH NODES RATIO ADDS PROGNOSTIC VALUE TO THE N-CATEGORY IN COLORECTAL CANCE robert.rosenberg@ksbl.ch

 

THE CALCULATION OF LYMPH NODES RATIO ADDS PROGNOSTIC VALUE TO THE N-CATEGORY IN COLORECTAL CANCE

5

Switzerland

Oral or Poster

The number of lymph node metastases (LNM) and the lymph node ratio (LNR) are relevant prognostic factors in colorectal cancer. Previous studies suggest superior prognostic predication of LNR compared to conventional N-stage. We aimed to evaluate the predictive value of pre-defined LNR groups, published by Rosenberg et al., on 5-year overall in patients with colorectal cancer.

We present a retrospective single-centre cohort study. The study population included all patients undergoing surgical resection for colorectal cancer between 2014 and 2022 in a specialized colorectal centre in Switzerland. Predefined LNR cut-off values (0.17, 0.41, 0.69) were evaluated to calculate survival rates, uni- and multivariate analyses.

In total, 493 patients were analyzed. The median number of resected lymph nodes was 28. Five-year overall survival was 94% in N0-stage (n=301/493). Patients with LNMs (n=192/493) had worse 5-year overall survival with 72% in pN1 and 52% in pN2 (p<0.001). Increasing LNR showed decreasing 5-year overall survival (50% in LNR2, 36% in LNR3 and 30% in LNR4, p < 0.001). Four patients had a tumor with N1-category and LNR groups 2 or 3, which was associated with worse overall survival. Lymph node ratio, pT and cM category were independent prognostic factors.

We were able to confirm the prognostic impact of pre-defined LNR groups in colorectal cancer in a patient cohort with a high number of resected lymph nodes. The additional evaluation of LNR improved the prognostic value of the pN-category.