Surgical Resection Length and Harvested Lymph Nodes in Colon Cancer

To determine the relationship between resected specimen length and tumor location, the number of LN harvested (LNh), and the positive LN ratio (LNR) in colon cancer.

A descriptive study. Place & Duration of Study: Department of General Surgery, University of Health Sciences, Dışkapı Yıldırım Beyazıt Training and Research Hospital, Ankara, Turkey, between January 2009 and December 2019.

Colon specimens resected for colon cancer were evaluated retrospectively, in terms of tumor location, type of surgery, resected colon length, LNh and the number of metastatic LN, based on hospital records. Chi-square test, Kruskal-Wallis along with Dunn-Bonferroni post hoc tests were applied. The lymph node ratio (LNR) (= ratio of LN+  to LNh), the number of lymph nodes per unit distance (LNh/cm), the ratio of LNR to length of specimen (LNR/cm) were evaluated.

The rate of ≥12 LNh in 644 colon cancer patients was 81.4%. The length of colon specimen and the number of harvested lymph nodes (LNh) were higher in patients, who underwent subtotal colectomy (StC), compared to patients who underwent right and left hemicolectomy (RhC and LhC, p<0.001). Inadequate LNh was more common in LhC patients (p<0.001). The ratio of the number of LNh to the length of the resected specimen (LNh/cm) was higher in RhC and LhC patients than StC patients (p<0.001). LNR and LNR/cm were higher in LhC patients, though mean specimen length was shorter in LhC patients (p<0.05). The number of LNh had a direct proportion with the resected specimen length; however, the LNh/cm and LNR/cm ratios decreased in >50 cm length specimen patients (p<0.001).

Central LN dissection and vascular high ligation, according to tumor site are more efficient than the length of the resected specimen for an adequate LN dissection in colon cancers. Key Words: Colon cancer, Harvested lymph node,  Specimen length, Adequate dissection.