Epithelial expression of VEGF receptors in colorectal carcinomas and their relationship to metastatic status.

BACKGROUND

Vascular endothelial growth factor (VEGF), originally identified as an endothelium-specific factor, can also bind to malignant cells, a mechanism by which a tumor could regulate its own progression. The biological effects of VEGF are mediated by three receptors (VEGFRs), VEGFR-1, VEGFR-2 and VEGFR-3. This study aimed at defining the expression of VEGFs in colorectal cancer (CRC) epithelia and their relationship to the metastatic status.

MATERIALS AND METHODS

Using immunohistochemistry, the levels of tumoral immunoreactivity for VEGFs in 105 nonmetastatic, lymphogenously-metastatic and haematogenously-metastatic CRC specimens were assessed. Statistical analysis was performed using Fisher's exact probability test.

RESULTS

VEGFR-1 immunoreactivity was positive in only 50% of the cases. However lack of expression of VEGFR-1 was significantly associated with lymphogenous and haematogenous metastases. VEGFR-2 and VEGFR-3 were expressed in all investigated specimens to varying degrees. Low levels of VEGFR-2 were significantly associated with distant metastases. No significant changes were detected in VEGFR-3 expression.

CONCLUSION

Epithelial expression of VEGFR-1 and VEGFR-2 appear to have a protective effect against tumor aggressiveness in CRC.