Differences of vascular endothelial growth factor (VEGF) expression between liver and abdominal metastases from colon cancer. Implications for the treatment with VEGF inhibitors

The vascular endothelial growth factor (VEGF) plays a central role in promo ting angiogenesis, and it is the target of innovative anti-cancer therapies . In colorectal carcinomas, differences in the VEGF expression have been fo und between the primary tumor and its metastases. We postulated that differ ences in the VEGF expression may also exist between liver and abdominal met astases from colon cancer. Consecutive colon cancer patients with liver or abdominal metastases were considered eligible for the study. Biopsies had t o be performed before chemotherapy and the VEGF analysis were conducted thr ough immunohistochemistry. The staining results were correlated to the meta static pattern. The study population consisted of 41 patients with a metast atic site in the liver in 19 patients and the abdomen in 22 patients. A pos itive VEGF staining was found in 19 of the 41 metastatic samples (46%). Cas es with positive VEGF expression were found more frequently in abdominal (1 5 out of 22 patients; 68%) than in liver metastases (4 out of 19 patients; 21%). Also, the degree of VEGF immunoreactivity was significantly higher in abdominal than in liver metastases. Evidence is supported that the VEGF ex pression may be different between colon cancer metastatic sites. The effica cy of anti-VEGF treatments may depend on the VEGF expression status, and th is finding deserves further investigation.