Distribution of Metastatic Cancer Cells in Colorectal Mesentery

To investigate the distribution of metastatic cancer cells in the mesentery (referred to as metastasis V) and enrich the understanding of the metastasis of colorectal cancer.

A total of two hundred ninety-nine patients who received colorectal operations at the Department of Gastrointestinal Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology between April 2018 and December 2018 were included. Samples were acquired from the dissected mesentery after the operation, and hematoxylin-eosin staining or immunohistochemistry was used to detect metastatic cancer cells. Pathological factors, including tumor position, tumor size, invasion depth, tumor differentiation, lymph node involvement, local vessel invasion, and perineural invasion, were recorded.

Metastatic cancer cells in the colorectal mesentery (metastasis V) were detected in 62 of 299 patients. Metastasis V was closely correlated with tumor invasion depth, lymph node metastasis, tumor differentiation, and perineural and vessel invasion by cancer cells. Metastasis V occurred more frequently in patients with T3 stage (26.27%) and T4 stage (40.00%) than in patients with T1 and T2 stages (0% and 2%, respectively). Metastasis V was frequently detected in patients with N2a and N2b stage tumors (51.72% and 61.54%, respectively). Metastasis V was more frequently detected in patients with perineural metastasis and local vessel invasion. In addition, metastasis V incidences in colon and rectal cancer were similar.

The incidence rate of metastasis V is correlated with tumor staging factors and occurs more frequently in advanced-stage patients.