Other Genetic Abnormalities

Damage to the genes can cause normal cells to change and become cancer cells. While genetic changes can be inherited, in the case of lung cancer, the genetic changes that cause cancer to develop can be caused by other factors, such as environmental exposure to pollutants like tobacco smoke. Each lung cancer is unique with different genetic changes, but scientists have found that there are certain changes, or mutations, that commonly occur in many types of cancers.1 In addition to EGFR, KRAS and ALK, scientists have found several additional genetic abnormalities that can occur in non-small cell lung cancer (NSCLC), including:

AKT1

Found in approximately 1% of all NSCLC, mutations on the AKT1 gene affect both adenocarcinomas and squamous cell carcinomas.

BRAF

Mutations on the BRAF gene have been found in 1-4% of all NSCLC and most often occurs in adenocarcinomas.

DDR2

Approximately 2.5-3.8% of lung squamous cell carcinomas and 4% of lung adenocarcinomas have a mutation on the DDR2 gene.

HER2

Mutations on the HER2 gene are found in 2-4% of all NSCLC. These mutations are more commonly found in never smokers with adenocarcinomas.

FGFR1

FGFR1 mutations are mainly found in squamous cell lung cancers, with approximately 20% of squamous cell lung cancers having the mutation.

FGFR3

Several different FGFR3 mutations have been identified in lung cancer. Each of the mutations on this gene is rare, found in 0.5% to 2.0% of NSCLC.

MEK1 (also known as MAP2K1)

Approximately 1% of all NSCLC have mutations on the MEK1 gene. These mutations are more common in adenocarcinomas.

MET

Researchers have found multiple mechanisms of MET activation in NSCLC, and overexpression of MET protein is found in 25-75% of NSCLC.

NRAS

Mutations on the NRAS gene have been found in approximately 1% of all NSCLC and are more common in adenocarcinomas.

NTRK1

NTRK1 mutations are found in approximately 3.3% of lung adenocarcinomas.

PIK3CA

Approximately 1-3% of all NSCLC have mutations on the PIK3CA gene. These mutations are more commonly found in squamous cell lung cancers.

PTEN

Mutations on the PTEN gene have been found in 4-8% of all NSCLC, most often in squamous cell lung cancers.

RET

Approximately 1.3% of lung cancers have RET mutations. These mutations occur almost entirely in adenocarcinomas.

RICTOR

Approximately 10.9-14.3% of lung adenocarcinomas and 10.6-16.9% of squamous cell lung cancers show a mutation on the RICTOR gene.

ROS1

Mutations on the ROS1 gene are present in approximately 2% of NSCLC, most commonly in patients who are light smokers or never-smokers.2

Scientists search to identify genetic mutations such as these for several reasons. Genetic changes may be associated with particular patterns of growth or different responsiveness to certain types of treatment (how effective the treatment will be against the cancer). For some specific genetic mutations, doctors have found targeted therapies to treat tumors that display the mutation. Targeted therapies are currently the focus of much research in lung cancer treatment.1,3

Written by: Emily Downward | Last reviewed: January 2017.
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