Staging and grading breast cancer

What are the stages of breast cancer?

Staging means finding out how big the cancer is and if it has spread to other parts of your body. Staging will help your doctor to plan the best treatment for you.

The staging system normally used in breast cancer is called TNM. 

This stands for:

• Tumour (T): How big is the tumour?
• Node (N): Is there cancer in your lymph nodes? N0 means no lymph nodes are affected. If the cancer has spread to the lymph nodes (positive lymph nodes) the N will have a number to describe how many lymph nodes are affected.
• Metastasis (M): Has the cancer has spread to other parts of your body? M1 means the cancer has spread (metastasised) to other organs. M0 means it hasn't.

Your doctor often uses this information to give your cancer a number stage – from 0 to 4.

A higher number, such as stage 4, means the cancer has spread to other parts of the body.

• Stage 0: Non-invasive breast cancer, e.g. DCIS
• Stage 1: The cancer is found only in your breast
• Stage 2: The cancer is found your breast and nearby lymph nodes
• Stage 3: The cancer has spread to more lymph nodes
• Stage 4: The cancer has spread to other organs in your body. This is called metastatic breast cancer

What are the grades of breast cancer?

The cells can be graded as 1, 2 or 3, depending on how different they are to normal breast cells and how quickly they are growing. The grade gives your doctor information about how quickly the cancer may grow and spread. 

Grade 1: Low-grade breast cancer

The cancer cells look only slightly abnormal, much like normal breast cells. The cancer is usually slow-growing and less likely to spread than high grade breast cancer.

Grade 2/3: High-grade breast cancer

The cancer cells look fairly or very abnormal and are more likely to grow quickly.