Some of the most surprising data presented at the GI Symposium in January 2011 in San Francisco was the negative result of the European trial called AVANT.

Dr. HJ Lenz

In that clinical trial patients who underwent a curative resection for colon cancer received either FOLFOX or FOLFOX with Avastin® (bevacizumab) treatment after their surgery. Chemotherapy was given over 6 months, but patients who were randomly selected for Avastin received 6 months with chemotherapy and additional  6 months alone after chemotherapy ended for a total of 12 months of Avastin. Read the rest of this entry »

Dr. Lenz

We are making significant progress in understanding what genetic alterations in tumors really mean.

Over the last two years, we have learned or the first time that there is an alteration in a gene called KRAS in colon cancer, and tumors which have this mutation do not respond to treatment with Erbitux® (cetuximab) or Vectibix® (panitumumab).

This is the first time we have a marker to test for sensitivity of an antibody we have to treat colon cancer.

It is very important to know that patients with tumors who carry a KRAS mutation (alteration) are not doing worse overall. They just don’t have any benefit from an antibody which targets the Epithelial Growth Factor Receptor (EGFR). Read the rest of this entry »

We are getting more sophisticated in evaluating biomarkers. It is a serious challenge to develop a biomarker which is validated and can be used with confidence in the clinic. We have only ONE biomarker which is kras mutation a marker to predict resistance to EGFR inhibitors

I just reported in my previous blog that not all of the mutations are equal.  Some of them act like wild- type (normal), and patients with these mutations should be considered for Erbitux therapy. Patients with wild-type KRAS  have a higher chance of response from Erbitux, but that does not predict response.

There have been a lot of efforts to increase the predictive value of wild-type KRAS for response. Many potential candidates have been studied. These include PTEN, EGFR ligands, BRAF and PI3K mutations. Most of the studies revealed controversial findings. Some found an associations and other did not.

Why is that? Read the rest of this entry »

Dr. Lenz

Recent data suggest that some KRAS mutations act like normal or wild-type KRAS. Maybe for those mutations, Erbitux could be used for treatment.

A recent publication in the Journal of the American Medical Association by Dr. Sabine Tejpar using an international collaboration showed that some mutations act like wild-type KRAS and that these patients actually may benefit from Erbitux therapy.

Maybe we were wrong thinking that all KRAS mutations are the same. Haven’t we learned from our mistakes before? Read the rest of this entry »

Dr. Lenz

I wanted to share with you an amazing story which began a few weeks ago.  A 28 year old woman with metastatic colon cancer with intra-abdominal spread came for a second opinion. She is well-educated and knows what she wants. She already had two opinions from the National Institutes of Health and the University of California at San Diego, and was open to hear what we would suggest.

I love patients who are informed (although it does not necessarily mean they have all the statistics and data correct). The discussion can move more quickly to create a plan, and there is no need to spend much time on the basics. But sometimes the problem with having a lot of information, especially from the internet and all the good friends you have, is prioritizing it. You have to decide what is the most important, what is validated, and what is a scam. Read the rest of this entry »