Risk factors associated with poor lymph node harvest after colon cancer surgery in a national cohort

Evaluation of ≥ 12 lymph nodes (LNs) is recommended after surgery for colon cancer. A harvest of ≤ 8 is considered poor, but few reports have evaluated risk factors associated with a poor harvest. This aims of this study were to analyse the clinical, surgical and pathological factors associated with poor LN harvest (LNH), the total number of examined nodes and the effect of LN number on stage.

All patients reported to the Norwegian Colorectal Cancer Registry during 2007 and 2008 who underwent curative resection for Stage I-III colon cancer were studied. Risk factors for poor LNH and the proportion of Stage III disease were analysed by univariate and multivariate analyses.

A total of 2879 patients were included in the study. The median LNH was 14. Overall, 69.9% had ≥ 12 lymph nodes and 14.4% had ≤ 8 LN (poor harvest). Multivariate analysis showed that male sex, age > 75 years, sigmoid tumours, pT category 1-2, failure to use the pathology report template and distance of ≤ 5 cm from the bowel resection margin were all independent factors for poor LNH. Age < 65 years, pT category 3-4, and poor tumour differentiation were independent predictors of Stage III disease. An increased LNH did not increase the proportion of patients identified as being LN positive at the ≤ 8, 9-11 and ≥ 12 LN levels.

Adequate LNH was achieved in the majority of curative colon cancer resections in this national cohort. Elderly, male patients with sigmoid cancers, and a short distal margin were at increased risk of a poor LNH.