Biomarkers in Oncology
Data shows that anti-cancer treatments may only benefit a small portion of patients. Integrating biomarkers into routine clinical practice will help physicians select the right treatment, for the right patient. Doing this could have many positive outcomes including sparing patients unnecessary toxicity from an ineffective treatment or being able to select a treatment that may be more effective in battling their disease.
KRAS - Biomarker for EGFr Therapies
KRAS, also known as Kras, K-RAS or KRAS2, is a gene present in all cancer tumours and plays an important role in cell growth and the development of tumours. In order to understand the relevance of the KRAS gene in the treatment of colorectal cancer, it is first important to understand the Epidermal Growth Factor receptor (EGFr).
The EGFr is a protein which promotes cell growth in normal epithelial tissues, such as skin and hair follicles, and is often over-expressed on a variety of tumour cells, including colon cancer cells. When growth factors (other body proteins) attach to the EGFr, the cancer cell is then stimulated to grow and divide.
In order to help prevent the growth and division of cancer cells, new anti-EGFr therapies have been developed to block the activation of the EGFr. Although considered a breakthrough in the treatment of colorectal cancer, not all cancers will respond to anti-EGFr therapies because of a KRAS gene mutation present in approximately 40 per cent of colorectal cancer tumours.
In patients whose tumours have a mutation in the KRAS gene, cancer cells continuously receive messages to grow and divide despite anti-EGFr treatment. Because these patients do not respond to anti-EGFr therapy, detecting the mutated gene is important in determining and prescribing an alternate treatment.
Patients with the non-mutant KRAS gene, also known as wild-type, should have a dialogue with their physician to see if anti-EGFr therapies are a valid option for them.
Personal information about genetic constitution, such as a patient’s KRAS gene, provides healthcare professionals with specific information about how the patient may respond to certain treatments.This process is also referred to as personalized medicine – healthcare tailored to each individual’s genetic makeup.