Background: Lymph node ratio (LNR: the ratio of metastatic to total retrieved nodes) has shown prognostic significance in several tumors. Its role in patients with colorectal cancer submitted to laparoscopic resection is still not clearly defined. The aim of this study was to evaluate the impact of LNR on long-term outcome in patients undergoing curative laparoscopic resection.
Methods: Patients' data were retrieved from our prospective in-hospital collected data of patients that underwent laparoscopic surgery for curable colorectal cancer over a 6-year period. Long-term data were collected from our outpatient's clinic data and personal contact when necessary.
Results: Two hundred and five patients underwent laparoscopic resection for curable colorectal cancer in the study period. Sixty-five patients were node positive. Receiver operating characteristic (ROC) analysis selected 0.13 as the best LNR cutoff value in this group. Kaplan-Meier 5-year survival analysis revealed a significant decrease in overall and disease-free survival in patients with an LNR above 0.13. Long-term outcome of patients with an LNR below 0.13 was similar to node-negative stage II patients.
Conclusions: The lymph node ratio is a valuable prognostic factor in node-positive colon cancer patients undergoing laparoscopic resection. Patients with an LNR below 0.13 have the same long-term outcome as stage II node-negative patients. The laparoscopic approach presents the same trends in terms of overall survival and disease-free survival as conventional open access when LNR is considered.