Inadequate lymph node sampling as a risk factor in stage II colon cancer

The aim of this study is to clarify the magnitude of the risk-to-benefit ratio with adjuvant therapy in high risk stage II colon cancer.

162 patients with pathologically documented stage II colon cancer were randomly distributed into two groups. The first group (80 patients) received Capecitabine for 6 cycles and the second group (82 patients) received FOLFOX4 for 6 cycles . All patients in both groups were assessed for disease-free survival (DFS) and overall survival (OS) as regards to chemotherapy regimen and high risk factors. Tolerability and safety were assessed for all study population in both groups.

Three-year DFS rates were 73% and 87% (Hazard ratio (HR)=2.051, 95%Cl(1.13-3.721) , P-value= 0.018), 3-year OS rates were 87% and 93% (P-value=0.26); corresponding 5-year OS rates for patients with stage II disease were 34% and 93% (HR=2.555, 95%Cl(1.276-5.119), P-value=0.008) in the Capecitabine and Folfox4 groups, respectively. Statistical significant differences in 5-year DFS and OS with lymph node sampling > 12 lymph nodes in favor Folfox4 group (HR=0.172, 95%Cl(0.0080- 0.370), P-value=<0.001) and (HR=0.087, 95%Cl(0.028-0.268), P-value=0.001) respectively. Multivariate analysis for all study population stated that the only significant risk factor was the inadequate lymph node sampling as regards to relapse (HR= 0.244, 95%CI (0.094-0.631), P-value=0.004) in stage II colon cancer. Diarrhea and peripheral sensory neuropathy (PSN) were the most pronounced side effects in FOLFOX4 treatment arm.

This study has demonstrated that patients with microscopic disease do behave more like stage III colon cancer patients; our data suggest that we must analyze tumors at this level if at all possible and those patients with more than 12 lymph nodes resection should received adjuvant chemotherapy in favor of FOLFOX4 regimen with significant improvement in DFS which can be translated into an OS benefit.