Aims: In colonic cancer the prognostic significance of extracapsular lymph node involvement (LNI) is not established and is therefore the objective of this study.
Methods: Between January 1994 and May 2005, all patients who underwent resection for primary colonic cancer with lymph node metastasis were reviewed. All resected lymph nodes were re-examined to assess extracapsular LNI. In uni- and multivariate analysis disease-free survival (DFS) was correlated with various clinicopathologic factors.
Results: One hundred and eleven patients were included. In 58 patients extracapsular LNI was identified. Univariate analysis revealed that pN-stage (5-year DFS pN1 vs. pN2: 65% vs. 14%, p<0.001), extracapsular LNI (5-year DFS intracapsular LNI vs. extracapsular LNI: 69% vs. 41%, p=0.003), and lymph node ratio (5-year DFS <0.176 vs. > or =0.176: 67% vs. 42%, p=0.023) were significant prognostic indicators. Among these variables pN-stage (hazard ratio 3.5, 95% confidence interval [CI]: 1.72-7.42) and extracapsular LNI (hazard ratio 1.98, 95% CI: 1.00-3.91) were independent prognostic factors. Among patients without extracapsular LNI, those receiving adjuvant chemotherapy had a significantly better survival (p=0.010). In contrast, chemotherapy did not improve DFS in patients with extracapsular LNI.
Conclusion: Together with pN2 stage, extracapsular LNI reflects a particularly aggressive behaviour and has significant prognostic potential.