Stage 1 breast cancer

Stage 1 breast cancer means that the cancer is small and only in the breast tissue or it might be found in lymph nodes close to the breast. It is an early stage breast cancer.

The stage of a cancer tells you how big it is and how far it has spread. It helps your doctor decide the best treatment for you. There are different systems used in the UK to stage breast cancer. Stage 1 is part of the number staging system. Doctors may also use the TNM staging system.  

Staging for breast cancer is very complex. Many different factors are considered before doctors can confirm your final stage. Speak to your doctor or breast cancer nurse specialist if you have any questions about your staging.

Stage 1 can be divided into 1A and 1B. Below is a simplified description of stage 1A and 1B breast cancer. 

Stage 1A

Stage 1A means that the cancer is 2 centimetres (cm) or smaller and has not spread outside the breast.

Stage 1B

Stage 1B means that a few breast cancer cells are found in the lymph nodes close to the breast and that:

• no cancer is found in the breast or
• the breast cancer is 2 cm or smaller

TNM stages

TNM stands for Tumour (T), Node (N) and Metastasis (M). The staging is different depending on the type of cancer you have.

The information below is an overview of the TNM staging for all types of cancer.

• T describes the size of the tumour (cancer)
• N describes whether there are any cancer cells in the nearby lymph nodes
• M describes whether the cancer has spread to parts of the body further away from where the cancer started

The doctor gives each factor (T, N and M) a number. The number depends on how far the cancer has grown or spread.

So, a very small cancer which hasn't spread to the lymph nodes or elsewhere in the body may be T1 N0 M0.

A larger cancer that has spread into the nearby lymph nodes and to another part of the body may be T3 N1 M1.

In the TNM staging system, stage 1A breast cancer is the same as T1 N0 M0. 

Stage 1B is the same as:

• T0 N1mi M0

• T1 N1mi M0

Treatment

The number staging helps your doctor decide which treatment you need. Treatment also depends on:

• the type of cells the cancer started in
• whether your cancer cells have receptors for particular cancer drugs
• the grade of the cancer 
• whether you have had the menopause  
• other health conditions you may have

Your doctor will take many different factors into account when deciding which treatment is best for you.

Surgery is the usual treatment for stage 1 breast cancer. There are different types of surgery you might have:

• surgery to remove just the cancer a border of normal breast tissue around it. This is called breast conserving surgery or a wide local excision. 
• surgery to remove the whole breast (mastectomy). You can then choose to have a new breast made (a breast reconstruction).

Treatments you might have after surgery

You may have other treatments after surgery. They include:

• radiotherapy 
• chemotherapy 
• hormone therapy
• targeted cancer drugs
• drugs that strengthen the bones called bisphosphonates 

Checking the lymph nodes

Before your surgery, you have an ultrasound scan to check the lymph nodes in the armpit (axilla). This is to see if they contain cancer cells. If breast cancer spreads, it usually first spreads to the lymph nodes close to the breast.

Depending on the results of your scan you might have:

• a sentinel lymph node biopsy during your breast cancer operation
• surgery to remove the lymph nodes under your arm

Other stages of breast cancer