ROS1 Positive Non-Small Cell Lung Cancer

Lung cancer is a type of cancer that begins in the cells of lung. Lung cancer is the leading cause of cancer death worldwide.

There are two types of lung cancer: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). About 80% to 85% of lung cancers are NSCLC.

Most lung cancers do not cause any symptoms until they have spread, but some people with early lung cancer do have symptoms.

The most common symptoms of lung cancer are:

  • A cough that does sustain 
  • Coughing up blood or rust-colored sputum
  • Chest pain that is often worse with deep breathing, coughing, or laughing
  • Hoarseness
  • Loss of appetite
  • Unexplained weight loss
  • Shortness of breath
  • Feeling tired  
  • Infections such as bronchitis and pneumonia  
  • New onset of wheezing

If lung cancer spreads to other parts of the body, it may cause:

  • Bone pain  
  • Nervous system changes, from cancer spread to the brain
  • Yellowing of the skin and eyes (jaundice), from cancer spread to the liver
  • Swelling of lymph nodes (collection of immune system cells)

The treatment options for non-small cell lung cancer (NSCLC) are based mainly on the stage (extent) of the cancer and other factors, such as a person’s overall health and lung function, as well as certain traits of the cancer itself.

About 1-2% of NSCLCs have a change in the ROS1 gene. This change is most often seen in people who don't smoke (or who smoke lightly) and who have the adenocarcinoma subtype of NSCLC. Doctors may test cancers for changes in the ROS1 gene to see if drugs that target this change may help them.

In ROS1-positive patients, the ROS1 gene fuses (joins) with part of another gene. This activates the ROS1 gene in a way that causes uncontrolled cell growth and cancer. This gene change is called ROS1 fusion or ROS1 rearrangement. The ROS1 gene can fuse with many different partners. The most common gene partner in lung cancer is the CD74 gene. When ROS1 fuses or joins with another gene and causes cancer, a patient is said to have ROS1-positive cancer.

Patients with ROS1-positive NSCLC will likely be prescribed a pill called a ROS1 tyrosine kinase inhibitor (TKI) or ROS1 inhibitor. There are three FDA-approved drugs for ROS1-positive NSCLC: crizotinib, entrectinib, and repotrectinib.