What is the Optimal Number of Lymph Nodes to be Dissected in Colorectal Cancer Surgery?

Abstract

Background Regional lymph node (LN) involvement in colorectal cancer (CRC) identifies the stage and the subset of patients who would benefit from adjuvant chemotherapy. We performed a retrospective analysis to determine if the number of recovered LNs was associated with long-term outcome in patients operated on for stage II and III CRC. Patients and methods Hospital records of 179 patients with CRC followed in our unit from 1997 to April 2003 were reviewed. Results On average 11.68 ± 7.3 LNs were sampled per surgical specimen. Sampling of at least nine LNs appeared to be the minimum number required for accurately predicting LN involvement ( P = 0.002). Three-year rates of disease-free survival (DFS), local recurrence-free survival (LRFS) and overall survival (OS) were lower in patients with fewer than nine LNs sampled ( P = 0.032, P = 0.006 and P = 0.04, respectively). However, this had no impact on the three-year distant metastasis-free survival rate (DMFS) ( P = 0.472). In stage II disease, patients with nine or more LNs dissected had significantly higher three year DFS and LRFS rates than the subgroup with fewer than nine LNs dissected ( P = 0.024 and P = 0.015, respectively), but this did not have any effect on DMFS or OS ( P = 0.406 and P = 0.353, respectively). Conclusion Current protocols provide adjuvant treatment in stage III patients; the problem is to correctly determine stage by recovering as many LNs as possible.