Understanding breast cancer

Breast cancer happens when cells in breast tissue:

  1. Grow abnormally
  2. Multiply and
  3. Enter nearby breast tissue.

The breast is made up of:

  • Fatty tissue
  • Glandular tissue
  • Lobules (also known as milk glands)
  • Milk ducts
  • Nipple.

In women, the lobules are where breast milk is made. When breast feeding, this milk is carried to the nipple through very fine tubes called the milk ducts.

When cells in the breast duct grow abnormally, multiply and enter nearby breast tissue, they can form into a lump (also called a tumour). Breast cancer is mostly common in women however, a small number of men are affected by this disease.

Not all breast lumps are cancerous. If you are worried about your breasts, it is important you visit your GP (General Practitioner or local family doctor) for a breast exam.

Focusing on you

Placing you at the centre of our work, your specialist will determine where you cancer started (what type of cell) and what type of cancer it is.

Breast cancers can happen in any area of the breast but the most common start in either the milk ducts or the lobes.

There are different types of breast cancers and related diseases and each one is treated differently. These cancers and related diseases can be either:

  • Pre-invasive (meaning the abnormal cells remain within the lobule or milk duct)
  • Invasive (meaning they have grown past the lobules or milk ducts into nearby breast tissue. It may spread into the lymph nodes (drain/filtering system) in the armpit that is closest to the breast with cancer.

Invasive breast cancers can be further grouped into two different types. They can be either:

  • Early breast cancer – meaning it is found within the breast and closest lymph nodes.
  • Advanced breast cancer – meaning it has spread to other parts of the body, such as the bones and liver. This is also known as metastatic or secondary cancer.

Enhancing your care

We provide the most up-to-date diagnostics (tests) and treatment for breast cancers. Our breast cancer specialists will come together and work with you to assess your condition and plan and deliver the most effective treatment.

Your care plan will be custom-made to treat your specific breast cancer and the needs most important to you.

Find out about our Breast Cancer Survivorship Program and Shared Care.

Living with cancer

We know how hard cancer and treatment can be. Your lifestyle and that of your loved one's will be disrupted and changed. During this time, it is common to struggle with ongoing concerns about cancer and therapy. There are many expert groups available to provide more information and support you through this time, including:


At Peter Mac, we focus on all aspects of your health and wellbeing. Our breast experts will help support and guide you to the best information and managed care.

Our specialist nurses can refer you to our:


For more information about breast cancer, treatment and patient and carer support, download these fact sheets: 

Follow-up of survivors of breast cancer - Australian Cancer Survivorship Centre


Your needs come first, so we offer expert care across a number of different Breast diseases including:

Benign breast disease
Pre-invasive breast cancer
Early breast cancer
Locally advanced breast cancer
Metastatic breast cancer
Male breast cancer
Breast cancer risk assessment and management