NEW YORK (Reuters Health) - An increased number of gene copies for epidermal growth factor receptor (EGFR) predicts treatment response to anti-EGFR antibody therapy in patients with metastatic colorectal cancer, researchers in Italy report.
“Currently, there are no diagnostic tools to identify those likely to benefit from treatment with panitumumab or cetuximab, so patients are exposed to the risk of ineffective therapy with undesired side effects,” study co-author Dr. Salvatore Siena, from Ospedale Niguarda Ca’Granda in Milan, said in a statement. Thus, there is a need for tests that can guide therapy.
As reported in the April 14th online issue of The Lancet Oncology, Dr. Siena’s team determined EGFR copy number in 10 patients with an objective response to panitumumab or cetuximab and 21 patients with stable or progressive disease.
An increased EGFR copy number was seen in eight of nine patients with an objective response who were assessed using fluorescence in situ hybridization. In contrast, just 1 of 21 non-responders had an increased EGFR copy number (p < 0.0001).
In vitro analysis showed that the cetuximab concentration that completely blocked the proliferation of cancer cells with increased EGFR copy number had no affect on cancer cells with unamplified EGFR.
Although the findings are encouraging, the authors note that further studies are needed to determine if therapy based on the EGFR copy number actually improves patient outcomes.
Source: Lancet Oncol 2005. [ Google search on this article ]
MeSH Headings:Membrane Proteins: Receptors, Cell Surface: Receptor, Epidermal Growth Factor: Receptors, Gastrointestinal Hormone: Receptors, Growth Factor: Receptors, PeptideCopyright © 2002 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.
