E-cadherin expression in primary colorectal cancer and metastatic lymph nodes

Colorectal cancer (CRC) is one of the most prevalent malignancies and fourth cause of cancer death worldwide but the current TNM staging system together with clinicopathological characteristics are not sufficient to identify cases that have a poor prognosis. The aim of the current study was to compare E-cadherin expression in primary CRC and lymph node metastases with the one exhibited by normal colic mucosa and normal lymph nodes, and to evaluate its association with disease severity. The authors retrospectively analyzed 65 patients that underwent colectomy for CRC at the First Surgical Clinic, "Sf. Spiridon" Emergency Hospital from Iassy, Romania, over a 10 years period, from January 2004 to December 2013. In all cases, immunohistochemical staining against E-cadherin was performed on primary CRC and associated lymph nodes slices. Primary CRC presented a higher rate (64.62%) of abnormal E-cadherin expression (no staining, cytoplasmic or mixed staining) compared to normal colic mucosa (16.67%) (p<0.001). Both primary CRC and corresponding metastatic lymph nodes displayed a predominantly membranous expression (pure or mixed) of E-cadherin (67.69% and 89.23%, respectively). Well and moderately differentiated tumors displayed an increased E-cadherin expression (44 of 56 cases) compared to poorly differentiated tumors that lacked E-cadherin expression in six out of nine cases. In conclusion, E-cadherin expression abnormalities in CRC are rather qualitative than quantitative and E-cadherin is an important marker of tumor aggressiveness and spreading potential.