Number of lymph node metastases may indicate the regimen for adjuvant chemotherapy in patients with stage III colorectal cancer

Background: Adjuvant chemotherapy (ACT) may prevent recurrence in patients with stage III colorectal cancer (CRC). However, only 10% of patients benefit from ACT and no effective indicators exist to predict which patients are likely to benefit. The present study validated metastatic lymph node (MLN) number as a new indicator for ACT. Patients and Methods: We retrospectively reviewed 173 patients with stage III CRC, who were classified by Union for International Cancer Control (UICC) stage or N category, and analyzed their overall survival (OS) and disease-free survival (DFS) according to stage, number of MLNs and ACT use. Results: Among 173 patients, we found 65 with only one MLN (N1a). For N1a patients treated with ACT, the 5-year OS rate was 100%; the 3-year DFS rate was 92.7% for those treated with oral ACT. Conclusion: The number of MLNs is a simple indicator for ACT in patients with stage III CRC. For patients with only one MLN, oral chemotherapy is a good option.