Higher cut-offs for the number of lymph nodes harvested do not predict better prognosis in patients with colon cancer

Abstract

AbstractBackground Current threshold for minimum lymph node harvest may not be adequate for appropriate staging in colon cancer and newer surgical techniques may allow more lymph nodes to be harvested. The aim of this study was to examine the prognostic role of harvesting and examining lymph nodes higher in number than the recommended threshold (≥12), in patients with colon cancer.Methods This retrospective study included 179 patients that underwent open colon resection for adenocarcinoma of the colon. A D3 resection with high vascular ligation was made so that large number of lymph nodes was removed in most patients. Differences in overall survival between below and above three cutoff points (≥18, ≥24, ≥40) were estimated.Results During median 33 months of follow-up, 45 patients died and mean overall survival was 108.7 ± 5.6 months (95% CI, 97.7–119.7). The mean number of lymph nodes harvested and examined was 44.0 ± 25.7 (median 38; range, 7–150). No significant effect was found for three different cut-off values (≥18, ≥24, or ≥40 nodes) on mean overall survival (p > 0.05 for all comparisons). The same was true for the whole study population as well as for N0 (N negative) and N1-2 (N positive) patient subgroups, when they are analyzed separately.Conclusions Our findings do not support the survival benefit of substantially higher number of lymph nodes harvested in colon cancer.