Breast cancer

Friday 1 August, 2014

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On this page: The breasts | What is breast cancer? | What are the different types? | How common is breast cancer? | What are the symptoms? | What are the risks? | Inherited breast cancer gene

The breasts

Women and men both have breast tissue.

In women, breasts are made up of milk glands. A milk gland consists of:

  • lobules - where milk is made
  • ducts - tubes that carry milk to the nipples

In men, the development of the lobules is suppressed at puberty by testosterone, the male sex hormone.

Both female and male breasts contain supportive fibrous and fatty tissue. Some breast tissue extends into the armpit (axilla). This is known as the axillary tail.

Lymphatic system

The lymphatic system is part of the immune system and protects the body against disease and infection. It is made up of a network of thin tubes called lymph vessels. These connect to groups of small, bean-shaped structures called lymph nodes or glands.

Lymph nodes are found throughout the body, including the armpits (axillary), the breastbone, the neck, abdomen and groin.

A diagram of the breasts

What is breast cancer?

Breast cancer occurs when the cells lining the breast lobules or ducts grow abnormally and out of control. A tumour can form in the lobules or ducts of the breast.

Women and men can both get breast cancer, although it is rare in men.

What are the different types?

There are several types of breast cancer.

Non-invasive breast cancer
Ductal carcinoma in situ (DCIS)
Abnormal cells are contained within the ducts of the breast.
Invasive breast cancer
Early breast cancer
This means the cancer has spread from the ducts or lobules into surrounding breast tissue. It may also have spread to lymph nodes in the armpit. Most breast cancers are found when they are invasive.

The most common types are invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC).

Locally advanced breast cancer
The cancer has spread to other areas near the breast, such as the chest (including the skin, muscles and bones of the chest).
Secondary breast cancer
Metastatic breast cancer
Cancer cells have spread from the breast to other areas of the body, such as the bones, liver or lungs. This is also called advanced breast cancer.
Some women have abnormal cells in the lobules of the breast. This is called lobular carcinoma in situ or LCIS. This is not cancer. While LCIS increases the risk of developing cancer, most women with this condition will not develop breast cancer. Your medical team will monitor you with regular mammograms or other types of breast imaging.

How common is breast cancer?

Breast cancer is the most common cancer in Australian women, representing 28% of all cancers in women. About 14,000 women are diagnosed each year. One in eight women will be diagnosed with breast cancer by the age of 85.

Although it can occur at any age, breast cancer is more common in older women. More than two in three (69%) are diagnosed in women aged 40–69. About one in four (25%) are diagnosed in women aged 70 and over. Nearly 80% of women diagnosed had IDC, while about 11% had ILC.

About 130 men are diagnosed in Australia each year. This represents less than 1% of all breast cancers.

What are the symptoms?

Some people have no symptoms but if you do, you may notice a change in your breast or your doctor may find an unusual breast change during a physical examination.

Signs to look for include:

  • a lump, lumpiness or thickening
  • changes to the nipple, such as a change in shape, crusting, a sore or an ulcer, redness, unusual discharge, or a nipple that turns in (inverted) when it used to stick out
  • changes to the skin of the breast, such as dimpling, unusual redness or other colour changes
  • an increase or decrease in the size of the breast
  • a change to the shape of the breast
  • swelling or discomfort in the armpit
  • persistent, unusual pain that is not related to your normal monthly menstrual cycle, remains after a period and occurs in one breast only.

Breast changes don’t necessarily mean you have cancer. However, if you have any symptoms, have them checked by your doctor without delay. Some women have no symptoms and the breast cancer is found on a screening mammogram.

Women aged 50–74 should have regular screening mammograms through BreastScreen. Call 13 20 50 to make a free appointment.

What are the risks?

In women, the exact cause of breast cancer is not known, but some factors increase the risk. These include:

  • getting older (most common in women over 50)
  • having several close relatives, such as a mother, father, sister or daughter, diagnosed with breast cancer on the same side of the family
  • if you have had breast cancer before
  • if you have had certain breast conditions, such as atypical ductal hyperplasia, ductal carcinoma in situ or lobular carcinoma in situ.

Some lifestyle factors, such as being overweight or drinking more than one standard alcoholic drink a day, may also slightly increase the risk.

Having some of these risk factors does not necessarily mean that you will develop breast cancer. Most women with breast cancer have no known risk factors, aside from getting older.

In men, breast cancer usually occurs over the age of 60. It is most common in men who have:

  • several close family members (male or female) who have had breast cancer
  • a relative diagnosed with breast cancer under the age of 40
  • several relatives with cancer of the ovary or colon
  • a rare genetic syndrome called Klinefelter syndrome. Men with this syndrome have three sex chromosomes (XXY) instead of the usual two (XY).

Inherited breast cancer gene

Most women diagnosed with breast cancer do not have a family history of the disease.

However, a small number of women with breast cancer (about one in 20) have inherited a gene fault that increases their risk. The two most common breast cancer genes are called BRCA1 and BRCA2.

Everyone inherits a set of genes from each parent, so they have two copies of each gene. Sometimes there is a fault in one copy of a gene, which stops that gene working properly. This fault is called a mutation.

Women in families with an inherited gene change are at an increased risk of breast and ovarian cancer. Men in these families may also be at an increased risk of breast and prostate cancer.

People with a strong family history of breast cancer can be tested to see if they have inherited a gene change. If you would like to know more about genetic testing, talk to your doctor or breast care nurse, or call Cancer Council 13 11 20

Information reviewed by: Dr Carolyn Cho, Breast and General Surgeon, Surgical Oncology, Deakin, ACT; Lynn Buglar, Breast Physician, BreastScreen, NSW; Mena Crew, Consumer; Elizabeth Jacobson, Consumer; Jane Marsh, Clinical Manager, Breast Centre, Brian Fricker Oncology Centre and Burnside War Memorial Hospital, SA; Marie Murdoch, Breast Care Nurse, Cancer Council Queensland, QLD; and Marion Strong, Clinical Nurse Consultant Breast Care Nurse and Cancer Care Coordinator, Toowoomba Hospital, QLD.

Updated: 01 Aug, 2014