Correlation between lymphatic endothelial markers and lymph node status or N-staging of colorectal cancer

Background: The purpose of this study is to examine the expression levels of lymphatic endothelial markers in colorectal cancer and to explore the correlation between the expression levels of markers and lymph node status. Methods: Forty-seven paired fresh tumor tissues and para-cancerous tissues were collected from colorectal cancer patients who received surgical treatment between August 2015 and March 2016 in Cancer Hospital, Chinese Academy of Medical Sciences. Real-time quantitative PCR (RTQ-PCR) was used to check the expression levels of LYVE-1, VEGFR-3, Podoplanin, and Prox-1 in tumor and para-cancerous tissues. Results: The positive expression rates of LYVE-1, VEGFR-3, Podoplanin, and Prox-1 in tumor tissues were 100, 93.6, 100, and 91.4%, but 100, 100, 100, and 87.2% in para-cancerous tissues. Comparing with para-cancerous tissues, tumor tissues had significantly lower expression levels of LYVE-1 (P < 0.001) and VEGFR-3 (P = 0.013) and higher levels of Podoplanin (P = 0.016) and Prox-1 (P = 0.078). There was no correlation between lymph node status and the expression level of LYVE-1 in tumor tissues (P = 0.354) or par-cancerous tissues (P = 0.617); similar results were found for VEGFR-3 (P = 0.631, 0.738), Podoplanin (P = 0.490, 0.625), and Prox-1 (P = 0.503, 0.174). Meanwhile, there was no correlation between N-staging and the expression level of LYVE-1 in tumor tissues (P = 0.914) or para-cancerous tissues (P = 0.784); similar results were found for VEGFR-3 (P = 0.493, 0.955), Podoplanin (P = 0.199, 0.370), and Prox-1 (P = 0.780, 0.234). Conclusions: There was no correlation between expression levels of lymphatic endothelial markers and lymph node status; LYVE-1, VEGFR-3, Podoplanin, and Prox-1 could not be used for predicting the lymph node status or N-staging of colorectal cancer.