Lung cancer is a type of cancer that starts in the lungs. It is one of the most common types of cancer and is a leading cause of cancer-related deaths worldwide.

There are two main types of lung cancer: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Non-small cell lung cancer is the most common type, accounting for about 85% of all cases, while small cell lung cancer is less common but tends to be more aggressive and grow more quickly.

The primary cause of lung cancer is smoking, with about 90% of cases attributed to tobacco smoke. However, non-smokers can also develop lung cancer, usually due to