What is breast cancer

Breast cancer is a malignant area in the breast.

When it spreads into the surrounding breast tissue, it is called invasive breast cancer.

  • There are a number of different types of breast cancer
  • Most start in the milk ducts of the breasts (ductal cancers), others start in the lobules of the breast (lobular cancers)
  • Cancers can develop slowly over years or more quickly over months
  • Some breast cancers have a better chance of successful treatment than others
  • When the cancer spreads into the surrounding breast tissue, it is called invasive breast cancer
  • Breast cancer can spread to the lymph nodes, which is the drainage system of the human body.¬† Cancer cells can spread to other parts of the body too, such as the lungs, bones and liver
  • Breast cancer can also spread through the bloodstream.

The risk of being diagnosed with breast cancer increases with age. Breast cancer is uncommon in women under 50. About 70 percent of women who are diagnosed with breast cancer and about 80 percent of women who die from it are 50 years or older.

Some women are at greater risk of breast cancer because there is a history of close family members having the disease. However, most women who develop breast cancer have no relatives with the disease. Even among women who do have relatives with breast cancer, most will never develop it.

Visit the Breast Cancer Aotearoa Coalition website for information and support for women with breast cancer.

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Page last updated: 24 November 2014
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