The staging of cancer is a system used to measure how severe the disease is. Tumors get larger and spread to other parts of the body as cancer gets worse.

There are three components to staging:

• Tumor size (T)
• Involvement of lymph nodes (N)
• Whether the tumor has spread (metastasized) from the original site to other parts of the body (M)

This staging system is commonly referred to as the TNM cancer staging system.