Lung Cancer Basics

What is Lung Cancer?

Lung cancer is the most common cancer globally and ~2.48 million people are diagnosed annually. It’s estimated that 234,580 people will be diagnosed in the US in 2024. Lung cancer is highly treatable, no matter the size, location and/or whether the cancer has spread. Although smoking is the leading cause of lung cancer, people who don’t smoke can also develop this cancer. Lung cancer begins when healthy cells in your lungs change and grow out of control, forming a mass known as a tumor, lesion, or nodule.

Your lungs are a pair of sponge-like organs in your chest that move gases in and out of your body so that you take in oxygen when you inhale and get rid of carbon dioxide when you exhale. This transfer of gases is called respiration, and the lungs are the main organs of the respiratory system. There are two tubes called a bronchus, one for each lung, and inside the lungs there are small tubes called bronchioles and small air sacs called alveoli. Lung cancer usually starts in the cells that line the bronchi and other parts of the lung such as the bronchioles or alveoli. Pulmonary is a term you may hear that describes issues pertaining to the lungs.

There are two main classifications of lung cancer, which are treated differently.