Pathology practice patterns affect lymph node evaluation and outcome of colon cancer: a population-based study.

BACKGROUND

A large variation in the number of nodes examined between patients, hospitals, and regions has been reported for patients with colon cancer. We studied determinants of this variation and its relation to survival in the south of The Netherlands.

PATIENTS AND METHODS

All patients who underwent resection for stage I-III colon carcinoma diagnosed from 1999 to 2002 in the Eindhoven Cancer Registry area were included (n = 2168). Determinants of lymph node evaluation and their relationship to survival were assessed, including variation between the six departments of pathology.

RESULTS

A median number of six lymph nodes per specimen had been examined. The median number for each department of pathology ranged from three to eight (P < 0.0001). After correction for relevant factors, this variation remained, resulting in differences in the proportion of N+ tumours between departments from 29% to 41% (P < 0.0001). The number of nodes examined was positively associated with survival. Survival for node-negative patients differed between the departments of pathology (up to hazard ratio 1.5; P = 0.02).

CONCLUSION

There was a large variation in lymph node evaluation between the departments of pathology, leading to differences in stage distribution and survival. Intervention strategies should be directed at nodal assessment.