Colorectal Cancer Coalition

KRAS Status Doesn’t Impact Treatment with 5-FU Alone

While researchers have found that colorectal cancer tumors that have mutated KRAS genes don’t respond to treatment with EFGR inhibitors Erbitux®(cetuximab) and Vectibix™(panitumumab), is the same thing true for other drugs?

5-FU (fluorouracil) is the backbone of most colorectal cancer treatment, given alone or in combination with other drugs.  What does KRAS status mean when 5-FU is the only treatment?

To see whether or not, KRAS mutation status affected outcome of 5-FU treatment, researchers analyzed tumor tissue from patients who had 5-FU treatment only.  Patients in the study had cancer that had spread to their liver (liver metastases), and the liver mets could not be surgically removed.

They found:

• 38.7 percent of the patients had a KRAS mutation in their tumors.
• KRAS mutations in liver tumors matched exactly with those in primary tumors in the colon.
• There was no significant difference in the percentage of liver tumors that got smaller with 5-FU treatment (objective response rate).
• There was no difference in survival between the group of patients with mutated KRAS and those with normal or wild-type KRAS.

Marie-Christine Etienne-Grimaldi and her French colleagues concluded,

The present data indicate a perfect concordance of K-Ras mutations between primary and liver metastasis and suggest that any predictive and/or prognostic value of K-Ras mutations in treatments combining anti-EGFR monoclonal antibodies with 5-FU should be exclusively linked to the anti-EGFR agent.

Other research has found that Avastin®(bevacizumab) treatment outcomes are not affected by KRAS status.

SOURCE:Etienne-Grimaldi et al.,Clinical Cancer Research, Volume 14, Number 15, August 1, 2008.

This news article was originally posted on August 2nd, 2008 and was accurate at the time of publication. Since then, information may have changed or links may now be outdated. Please call our Answer Line 1-877-427-2111 for the latest information, or talk to your doctor before making any medical decisions.

Posted by Kate Murphy on August 2nd, 2008
Tags: 5-FU, KRAS, survival benefit

Leave a Comment Comments RSS

Your comments are welcome. However, specific medical advice will not be provided, and we urge you to consult with a qualified physician for diagnosis and for answers to your personal questions. C3 is not responsible for the medical accuracy of any comments left by persons other than C3 staff members. C3 staff members monitor comments and may respond publicly where appropriate.

Please note that we automatically publish the name that you enter next to your post. Also note that our pages are automatically indexed by Google and other search engines, and your name may therefore appear in search results on those sites. So if you wish to remain anonymous please use a different name or enter 'Anon' as the name.

We regret that we are unable to privately answer questions left as comments. So please do not include your phone number, email or mailing address in the body of your comment. For the best personal and direct response to your colorectal cancer treatment questions, please call our Answer Line at 1-877-4CRC-111 (1-877-427-2111).

Name Email (hidden) URL Comments (Basic HTML is allowed - a href, strong, em, blockquote)