Lymph Node Ratio as a Risk Factor for Recurrence After Adjuvant Chemotherapy in Stage III Colorectal Cancer.

BACKGROUND: Although several markers, including the lymph node ratio (LNR), have been proposed as a clinically prognostic tool for colorectal cancer (CRC), it remains unclear which markers have the most relevance in determining recurrence following adjuvant chemotherapy for stage III CRC.

METHODS: Independent risk factors for recurrence-free survival (RFS) were retrospectively determined using the Cox proportional hazard model in 360 stage III CRC patients and validated using an independent cohort comprising 172 stage III CRC patients.

RESULTS: The LNR was independently associated with RFS (HR, 1.96; 95% CI, 1.11 to 3.28; P = 0.020). A higher LNR value was significantly associated with recurrence, microsatellite stable, and shorter time to recurrence. A combination of the LNR with pre-chemotherapy CEA and CA19-9, other independent risk factors, provided accurate risk stratification of RFS and conferred additional information on recurrence within each stage III CRC subgroup, which was then validated in an independent cohort. A beneficial effect in patients at risk of recurrence, and a reduced effect in patients at low risk, was exhibited by the addition of oxaliplatin to 5-fluorouracil-based adjuvant chemotherapy.

CONCLUSION: A higher LNR is one of the most aggressive phenotypes with recurrence risk following adjuvant chemotherapy for stage III CRC.