Stages, types and treatment of breast cancer

Breast cancer is not just one disease but a complex collection of many different subtypes of cancers and may be referred to in an often baffling variety of ways. Health professionals may refer to a tumour by its size, grade or spread, and describe it as hormone receptive, invasive or metastatic – all terms that will help determine the right treatment plan for each patient.

Treatments may include surgery to remove part of the breast (lumpectomy) or the entire breast (mastectomy), as well as systemic treatment before or after surgery and radiotherapy to reduce the chance of the tumour returning or spreading beyond the breast.

Staging is a way for healthcare professionals to describe the size of your breast cancer, whether it is limited to one area in the breast, or it has spread to healthy tissues inside the breast, whether the cancer has spread to the lymph nodes or to other parts of the body beyond the breast. The stage is based on a pathologist’s study of the tumour tissue and any lymph nodes removed during biopsy or surgery and is used to decide what treatment options are recommended. Stages of breast cancer are numbered from 0 to 4:

Stage 0 – Pre-breast cancer

Learn why non-invasive or 'pre-invasive' breast cancer is still important to be aware of and what needs to be done to prevent it from developing further.

Stage 1 or 2 – Early breast cancer

Stage 1 breast cancers are smaller than two centimetres and have not spread to the lymph nodes in the armpit (axillary nodes) Stage 2A breast cancers are either larger than two centimetres but less than 5 cm or have spread to the axillary nodes.

Stage 2 or 3 – Locally advanced breast cancer

Locally advanced breast cancer (stage 3 & some stage 2) has spread beyond the breast to the chest wall or the skin of the breast, or to lymph nodes in the underarm area or near the breastbone (internal mammary lymph nodes), but not to other organs.

Stage 4 – Metastatic Breast Cancer

Metastatic or advanced breast cancer (stage 4) has spread beyond the breast to other organs in the body (most often the bones, lungs, liver or brain).

Molecular types of breast cancer

Breast cancer treatments are based on the tumour’s specific biological or molecular signature. Find out about the different types of breast cancer, current research and personalised treatments.

Types of treatment

The goal of treatment for stages 1-3 of breast cancer is to eradicate the cancer and prevent it from returning. The goal of treatment for stage 4 breast cancer is to reduce symptoms and pain, maintain quality of life and to prolong life.

Increasingly research is allowing a combination of these treatments based on a person’s individual situation, overall health, age, lifestyle risk factors and the molecular make-up of their tumour – this is called personalised therapy and is a major evolution in treating breast cancer.

  • Surgery: The goal of breast cancer surgery is to remove the entire tumour from the breast. A lumpectomy aims to preserve the breast and remove only cancerous tissue, and a mastectomy removes the entire breast. Some of the lymph nodes from the underarm area (axillary nodes) may also be removed to see if cancer cells are present.
  • Radiation therapy: Delivers a dose of radiation therapy to the breast, chest, collarbone and underarm area to kill any cancer cells that might be left after surgery.
  • Chemotherapy: A chemical compound that kills rapidly dividing cells, such as cancer cells. It is usually given to those with early breast cancer after surgery (adjuvant chemotherapy). For large tumours it can be used before surgery (neoadjuvant chemotherapy) to shrink the tumour.
  • Hormone therapy: Some breast cancer cells need estrogen and/or progesterone (female hormones) to grow. Hormone therapy slows or stops the growth of these tumours by preventing the cancer cells from getting the hormones they need to grow. Hormone therapy is usually given after surgery as a long term preventative treatment. High-risk women who have never had breast cancer may take it as a preventive therapy.
  • Targeted therapies: A targeted therapy is a drug that has been designed to attack a certain molecular agent or pathway that have been identified as involved in the development of a particular cancer. For example, HER2 positive breast cancer has too many copies of a particular gene known as HER2 which stimulate cell growth. The drug trastuzumab (Herceptin) works by attaching itself to the HER2 receptors on the surface of breast cancer cells and blocking them from receiving growth signals. Unlike chemotherapy drugs, targeted therapies kill cancer cells with little harm to healthy cells.
  • Emerging areas of treatment: Researchers are working towards preventing deaths from breast cancer by kick-starting the body’s own immune system to recognise and kills cancer cells, developing vaccines for breast cancer, designing nano-particles that can deliver drugs to a more targeted area and kill tumour cells from the inside out, and many more areas designed to improve quality of life for those affected by breast cancer.