Breast cancer

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Cancerous tumours of the breast

A cancerous tumour of the breast can grow into and destroy nearby tissue. It can also spread (metastasize) to other parts of the body. Cancerous tumours are also called malignant tumours.

Ductal carcinoma and lobular carcinoma

Nearly all breast cancers are adenocarcinomas. These tumours start in gland cells. The most common adenocarcinomas of the breast are:

  • ductal carcinoma (including ductal carcinoma in situ, or DCIS), which starts in the milk ducts
  • lobular carcinoma, which starts in the groups of glands that make milk (called lobules)

Doctors will classify these tumours as non-invasive or invasive. Non-invasive means that the cancer cells have not spread beyond the duct or gland where they started. Invasive means that the cancer cells have started to spread into the surrounding tissue.

Other types of breast cancer

The following types of cancer can also develop in the breast:

  • inflammatory breast cancer
  • Paget disease of the nipple
  • triple negative breast cancer

Rare breast tumours

The following cancerous tumours of the breast make up less than 1% of all breast cancers:

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