KRAS and Lung Cancer

What is the KRAS mutation?

An error in the KRAS gene is one type of lung cancer biomarker. It is called KRAS because it was first identified as causing cancer in Kirsten rat sarcoma virus. There are other types of RAS mutations, but right now, targeted treatment is only available for KRAS in patient withs lung cancer and specifically for one type of KRAS mutation called a G12C mutation. The KRAS gene normally serves as an information hub for signals that lead to cell growth. When there is a mutation in KRAS, it signals too much and cells grow, which causes cancer.

Who is most likely to have a KRAS mutation?

KRAS gene mutations tend to occur in people who currently or have formally smoked, but KRAS mutations have been found in people with diverse backgrounds. About 25% of all patients with lung cancer have some kind of KRAS mutation.

How do you know if you have a KRAS mutation?

There are several ways to detect KRAS mutations. One way is through next-generation sequencing (NGS). For this type of testing, tissue from a patient’s tumor (gathered from a biopsy) is analyzed to look for many possible biomarkers (including mutations) in many cancer-related genes simultaneously. There may be some situations where a patient can’t undergo the biopsy needed to perform NGS, so a liquid biopsy is recommended instead. A liquid biopsy can look for certain biomarkers in a patient’s blood. Talk to your doctor to make sure one of these tests was performed.

Learn more about the different types of biomarker tests.

Are there different types of KRAS mutations?

There are multiple types of KRAS mutations. About half of patients with lung cancer with a KRAS mutation have a KRAS G12C mutation. The other types of KRAS mutations show up in the other half of patients.

What is the course of treatment like for someone with a KRAS mutation?

Currently, the standard first-line therapy for a patient with KRAS-positive lung cancer may be surgery, radiation, chemotherapy, immunotherapy or a combination based on the stage of their cancer.

There are two targeted therapy pills (also called KRAS inhibitors) approved for patients with KRAS G12C. If a patient’s cancer stops responding to chemotherapy or immunotherapy, or a combination both, then they may be able to go on the targeted drugs sotorasib (Lumakras) or adagrasib (Krazati).

There are many other medicines being studied to address KRAS-positive lung cancer. All patients with lung cancer should discuss clinical trials with their doctor.

Work with your doctor to discuss your goals and options each time you have to make a treatment decision. The three big questions to ask are:

1. What is the goal of this treatment?
2. What are the potential side effects?
3. What other options do I have?

Research is happening at a rapid pace and your doctor should be up to date on the recommendations for your specific type of lung cancer. If you don’t feel comfortable with the answers you are receiving, do not hesitate to seek out a second opinion.