RET (REarranged during Transfection proto-oncogene) is a gene found in cells that Is important for cell growth and survival.  

In some people, the RET gene begins to change or join with a different gene. This causes the cells to grow out of control, causing cancer. When this happens in the lungs, it’s called RET-positive or RET+ lung cancer. 

RET-positive lung cancer can be found through biomarker testing. Biomarker testing tells your healthcare team what mutations or changes cancer cells have, and your results can help guide your healthcare team to the best treatment for you. People with stages 1B through 4B (IB through IVB) non-small cell lung cancer (NSCLC) should ask for comprehensive biomarker testing because it looks for all known biomarkers instead of just a few.

Scientists have found many different types of changes in RET in lung cancer. The most common change in RET found in people with lung cancer is when RET fuses with another gene called KIF5B. Currently, all RET-positive lung cancers are treated with the same targeted therapy drug options, regardless of the specific type of change in RET. 

• It occurs in about 2 out of every 100 cases (2%) of lung cancer. 
• It most often occurs in a type of NSCLC called adenocarcinoma. 
• Tends to occur in people who are younger than the average person diagnosed with lung cancer, and those who have little to no history of smoking.

If your biomarker testing finds that you have a change in the RET gene, you will most likely be given a type of treatment known as a targeted therapy. Targeted therapies are a special type of drug that can "target" cancer cells based on what makes them different from healthy cells. Because of this, healthy cells in the body are often not affected by targeted therapies, resulting in fewer side effects. 

Most targeted therapy treatments come in the form of a pill, but a few are given through an IV or a port (a small tube inserted in a vein). The drug names that end in -ib are pills and can be taken at home. The drug names that end in -mab are given through an IV at a cancer center. 

Below is a list of targeted therapy drugs that are approved by the Food and Drug Administration (FDA) for use with NSCLC RET fusions. The FDA approves each drug for use in NSCLC at specific stages of the disease. 

Everyone is different, and the side effects you may have while receiving treatment can vary. Some people experience side effects, while others don’t. Ask a member of your healthcare team about the possible side effects of your treatment and when to seek medical attention.