Please read: Important 2013 cancer research update from Dr. Michael Camilleri

Free

E-newsletter

Subscribe to Housecall

Our weekly general interest
e-newsletter keeps you up to date on a wide variety of health topics.

Sign up now

Breast cancer types: What your type means

The type of breast cancer you have helps determine the best approach to treating the disease. Get the facts on types of breast cancer and how they differ.

By Mayo Clinic staff

Living With Cancer

Subscribe to our Living With Cancer e-newsletter to stay up to date on cancer topics.

Sign up now

Once you've been diagnosed with breast cancer, your doctor works to find out the specifics of your tumor. Using a tissue sample from your breast biopsy or using your tumor if you've already undergone surgery, your medical team determines your breast cancer type. This information helps your doctor decide which treatment options are most appropriate for you.

Here's what's used to determine your breast cancer type.

Is your cancer invasive or noninvasive?

Whether your cancer is invasive or noninvasive helps your doctor determine whether your cancer may have spread beyond your breast, which treatments are more appropriate for you, and your risk of developing cancer in the same breast or your other breast.

  • Noninvasive (in situ) breast cancer. In situ breast cancer refers to cancer in which the cells have remained within their place of origin — they haven't spread to breast tissue around the duct or lobule. One type of noninvasive cancer called ductal carcinoma in situ (DCIS) is considered a precancerous lesion. This means that if it were left in the body, DCIS could eventually develop into an invasive cancer. Another type of noninvasive cancer called lobular carcinoma in situ (LCIS) isn't considered precancerous because it won't eventually evolve into invasive cancer. LCIS does, however, increase the risk of cancer in both breasts.
  • Invasive breast cancer. Invasive (infiltrating) breast cancers spread outside the membrane that lines a duct or lobule, invading the surrounding tissues. The cancer cells can then travel to other parts of your body, such as the lymph nodes. If your breast cancer is stage I, II, III or IV, you have invasive breast cancer.

In what part of the breast did your cancer begin?

CLICK TO ENLARGE

Illustration showing parts of the breast Breast anatomy

The type of tissue where your breast cancer arises determines how the cancer behaves and what treatments are most effective. Parts of the breast where cancer begins include:

  • Milk ducts. Ductal carcinoma is the most common type of breast cancer. This type of cancer forms in the lining of a milk duct within your breast. The ducts carry breast milk from the lobules, where it's made, to the nipple.
  • Milk-producing lobules. Lobular carcinoma starts in the lobules of the breast, where breast milk is produced. The lobules are connected to the ducts, which carry breast milk to the nipple.
  • Connective tissues. Rarely breast cancer can begin in the connective tissue that's made up of muscles, fat and blood vessels. Cancer that begins in the connective tissue is called sarcoma. Examples of sarcomas that can occur in the breast include phyllodes tumor and angiosarcoma.
Next page
(1 of 2)
References
  1. Bleiweiss IJ. Pathology of breast cancer: The invasive carcinomas. http://www.uptodate.com. Accessed Jan. 5, 2012.
  2. Abeloff MD, et al. Cancer of the breast. In: Abeloff MD, et al. Abeloff's Clinical Oncology. 4th ed. Philadelphia, Pa.: Churchill Livingstone; 2008:1875.
  3. Harris L, et al. American Society of Clinical Oncology 2007 update of recommendations for the use of tumor markers in breast cancer. Journal of Clinical Oncology. 2007;25:5287.
  4. O'Toole SA, et al. Molecular assays in breast cancer pathology. Pathology. 2011;43:116.
  5. The Cancer Genome Atlas Network. Comprehensive molecular portraits of human breast tumours. Nature. In press. Accessed Sept. 26, 2012.
HQ00348 Oct. 2, 2012

© 1998-2013 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.com," "EmbodyHealth," "Enhance your life," and the triple-shield Mayo Clinic logo are trademarks of Mayo Foundation for Medical Education and Research.

  • Reprints
  • Print

  • Share on:

  • Email

Advertisement


Text Size: smaller largerlarger