Medicine that is tailored to each patient’s genetic makeup is the future of cancer care. In some cases, it is already making a big difference in the ways patients are treated. Learn about these cutting edge treatments and about emerging findings that will be important for future diagnoses and treatments of colorectal cancer. Discussion led by Carolyn Grande, CRNP, AOCNP.

If there is a KRAS mutation in the primary colon or rectal tumor, there is almost always a matching mutation when that tumor spreads to the liver.

Researchers in the Netherlands tested both tumors for KRAS mutations in over 300 patients whose cancer had spread to their livers.

They found about a third of patients had KRAS mutations and KRAS status matched in 96 percent of the cases, making it possible to test either tumor to make decisions about treatment with Erbitux® (cetuximab) or Vectibix® (panitumumab) 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 »