Crizotinib is a medicine studied to treat a type of lung cancer called non-small cell lung cancer (NSCLC) that has been removed by surgery. This cancer may have a special change, or mutation, in a protein called ALK (anaplastic lymphoma kinase). Crizotinib helps by blocking the ALK protein, which can stop the cancer cells from growing. This study is for people with specific stages (IB-IIIA) of cancer and who have had surgery to remove it.

• Participants may get crizotinib or be observed without it. The treatment with crizotinib lasts up to 2 years.
• Participants will have follow-up checks every 6 to 12 months for up to 10 years.
• Participants must have had no major health issues and not have used crizotinib before.

To join, patients should have had surgery and meet certain health requirements, like specific blood test results and no ongoing heart or lung issues. Women must not be pregnant, and everyone must use birth control if needed. This study helps researchers understand if crizotinib improves survival after surgery for this type of cancer.