Lymph node correlations and thresholds in colorectal cancer specimens.

Lymph node yield is a key factor in enabling the accurate determination of prognosis in colorectal cancer patients. The Royal College of Pathologists guidelines state a "minimum" recommended mean number of 12 lymph nodes. In this study of 391 patients, the authors aim to determine the optimal node counts in patients with colorectal cancer, examine for correlations between maximum tumor diameter and lymph node yield, and examine for correlations between lymph node yield and involved node numbers. Furthermore, the authors aim to examine the impact of specimen type on the harvested node numbers and assess whether the personal differences between surgeons and pathologists have significant influence on node yield. A moderate positive correlation between maximum tumor diameter and final lymph node yield was noted (Spearman's correlation coefficient = .328, P = .0001). There was significant variation shown by pathologists (Kruskal-Wallis test P = .001) and by differing specimen type (Kruskal-Wallis test P = .029) on the lymph node yield.