Optimal margins and lymphadenectomy in colonic cancer surgery

Background: A standard management policy has not yet been established with respect to the extent of lymphadenectomy for colonic cancer. Methods: A total of 914 consecutive patients who underwent potentially curative surgery for T2-T4 colonic cancer were reviewed retrospectively. The number of lymph nodes (LNs) examined and the potential contributions to the staging accuracy of the distinct area were analysed. The survival benefit of dissection was compared for pericolic (local), mesocolic (intermediate) and main arterial trunk (main) LN. Results: Removal of the pericolic LNs within 5 cm of the tumour and intermediate LNs resulted in a mean LN number of 15.9, a sensitivity for overall node positivity of 97.5 per cent, and a survival benefit calculated as a therapeutic value index of 31.4 points. The additional removal of LNs more than 5 cm from the tumour and main LNs did not improve the staging accuracy, while adding only 3.4 points to the survival benefit. Conclusion: Current guidelines may encourage needlessly extensive surgery. Clinical trials to establish the optimal extent of lymphadenectomy are warranted.