Abstract:

Objective

To examine the expression of VEGF of middle and lower rectal carcinoma and to evaluate its correlation with lymph node micrometastases.

Methods

661 lymph nodes from 56 patients with middle and lower rectal carcinoma who received total mesorectal excision with lymphadenetomy were detected by cytokeratin-20 IHC in addition to hematoxylin and eosin （HE）staining.The expressions of VEGF of resected primary tumors were examined by IHC.

Results

The VEGF expression was positive in 32 （57.1%） specimens.74.1% T3 tumors were examined positive VEGF expression，while only 33.3% T1 tumors and 43.5% T2 tumors were examined positive VEGF expression，P=0.043.72.4% （21/29） rectal carcinomas with positive lymph nodes were examined positive VEGF expression，while only 40.7% rectal carcinomas with negative lymph nodes were examined positive VEGF expression，P=0.017.Micrometastases were identified in 67 （10.1%） lymph nodes from 20 （35.7%） patients.The expression of VEGF was positive in 15 （75%） of the 20 patients with lymph node micrometastases，and in 17 （47.2%） of the 36 patients without lymph node micrometastases.The difference between these two groups was statistically significant （P=0.044）.

Conclusion

The expression of VEGF in middle and lower rectal cancer specimens is significantly associated with depth of tumor invasion and lymph node metastasis.VEGF may play an important role in the development of lymph node micrometastases in patients with middle and lower rectal carcinoma.

Key words: Middle and lower rectal carcinoma, Lymph node micrometastases, VEGF