Objective: To study the molecular risk factors of lymph node metastasis in stage T1 and T2 colorectal cancers by tissue microarray and immunohistochemistry techniques.
Methods: Two hundred and three patients with stage T1 and T2 colorectal carcinoma who underwent radical surgery from 1999 to 2010 in our department were included in this study. Their clinicopathological data were retrospectively analyzed. Expression of the following 14 molecular markers were selected and assayed by tissue microarray and immunohistochemistry: VEGFR-3, HER2, CD44v6, CXCR4, TIMP-1, EGFR, IGF-1R, IGF-2, IGFBP-1, ECAD, MMP-9, RKIP, CD133, MSI. Chi-squared test and logistic regression were used to evaluate the variables as potential risk factors for lymph node metastasis.
Results: The positive expression rates of biomarkers were as following: VEGFR-3 (44.3%), EGFR (30.5%), HER-2 (28.1%), IGF-1R (63.5%), IGF-2 (44.8%), IGFBP-1 (70.9%), ECAD (45.8%), CD44v6 (51.2%), MMP-9 (44.3%), TIMP-1 (41.4%), RKIP (45.3%), CXCR4 (40.9%), and CD133 (49.8%). The positive rate of MSI expression was 22.2%. Both univariate and multivariate analyses showed that VEGFR-3, HER-2, and TIMP-1 were significant predictors of lymph node metastasis. Univariate analysis showed that CD44v6 and CXCR4 were significant significant predictors of lymph node metastasis.
Conclusions: VEGFR-3, HER2 and TIMP-1 are independent factors for lymph node metastasis in stage T1 and T2 colorectal cancers.