Low Expression of SNAI1 in Lymph Node Metastasis Indicates Delayed Recurrence of Colonic Cancer

Even though epithelial-mesenchymal transition markers in primary tumors are identified as a helpful indicator of cancer metastasis and prognosis, their expression in lymph node metastases (LNMs) remains poorly described. We aimed to investigate the difference between snail family transcriptional repressor 1 (SNAI1) and E-cadherin expression in primary tumors and LNMs, and how it affects prognosis.

From 2010 to 2014, 127 patients who underwent radical surgery for stage III colonic adenocarcinoma without preoperative treatment were retrospectively reviewed for SNAI1 and E-cadherin expression in primary tumors and LNMs.

High SNAI1 expression was found in 76% and 70% of primary tumors and LNMs, respectively, and low E-cadherin expression was found in 73% and 84%, respectively. High expression of SNAI1 in LNMs significantly correlated with poor overall and relapse-free survival rates. Even though the rate of liver metastasis at 5 years was similar for the groups with high and low SNAI1 expression in LNMs, the incidence in the group with low SNAI1 expression in the second year was higher than that in the first year (33% vs. 17%), whilst in the group with high SNAI1 expression, the incidence in the first year was higher than in the second year (71% vs. 29%). The rate of recurrence of lung metastasis was significantly lower when SNAI1 expression in LNMs was low (p=0.031).

Low expression of SNAI1 in LNMs of colonic adenocarcinoma may indicate delayed recurrence in the liver and lung.