Improving lymph node detection in colon cancer in community hospitals and their pathology department in southern Netherlands

Aim: The aim was to investigate whether a set of measures directed at increasing lymph node (LN) detection among colon cancer patients led to clinically relevant changes in LN detection rate.

Methods: Data of all patients with curative colon cancer (pT(any) N(any) M0) diagnosed in 1999-2007 whose resection specimens were evaluated by the Institute for Pathology and Medical Microbiology in Eindhoven (n=1501) were included. Feedback to specialists, increased fixation time, and ex-vivo injection of the specimen with Patent blue V dye were used to increase LN detection rate. Trends in the proportion of patients with insufficient LNs examined were investigated; moreover, the Patent blue-stained patients (n=86) were compared with a group of unstained patients (n=84). Based on the decrease in the proportion of high-risk node-negative patients, a calculation of chemotherapy-related costs saved was made.

Results: The proportion of patients with <12 LNs examined decreased from 87% in 1999 to 48% in 2007 (p(trend)<0.0001). In the stained group this was 37%, versus 56% for the unstained group (p=0.010). In 1999, 79% of stage II patients were high-risk compared to 55% in 2007, which translates to a saving of almost 1,000,000 euro based on 92 stage II patients diagnosed in 2007.

Conclusion: A diverse set of measures increased the number of examined lymph nodes among patients with colon cancer. Large savings can be made due to the reduced proportion of high-risk node-negative patients who would otherwise have received adjuvant chemotherapy.