Understanding Your Breast Cancer Diagnosis

Finding out about the types of breast cancer and breast cancer stages can help you become a proactive member of your health team.

Health Monitor Staff
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If you just learned you have breast cancer, the first thing you'll probably want after a good strong hug is answers. After all, knowing exactly what kind of breast cancer you have—where it is, how big it is, if it's invasive or not—will determine the next steps.

The good news? Today's tests, including biopsies and imaging tests, can paint a detailed picture of your cancer and help your healthcare team decide on the potent cancer-fighting strategy that will be most effective for you.

Types of breast cancer
It's likely your abnormal cells will fall into one of these common classifications or types of breast cancer:

  • Lobular carcinoma in situ (LCIS): an overgrowth of cells confined to the lobules—the part of the breast that produces milk. This is not a true breast cancer; however, it raises your risk of developing an invasive cancer in the future.
  • Ductal carCinoma in situ (DCIS): a noninvasive cancer in which abnormal cells are confined to the milk ducts.
  • Invasive ductal carcinoma (IDC): cancer that originates in the milk duct and spreads to surrounding breast tissue; the most common type of breast cancer.
  • Invasive lobular carcinoma (ILC): cancer that originates in a lobule and spreads to surrounding breast tissue.
  • Inflammatory breast cancer: a fast-growing cancer that begins with an area of redness, swelling and inflammation of the breast rather than a lump.

Breast cancer stages
Knowing the type of breast cancer you have is just one factor. Next, a pathologist will determine the breast cancer stage and other critical data by examining your cancer cells under a microscope—information that you'll find on your pathology report.

First your cancer will be assigned a grade from I to III. The higher the grade, the more aggressive the tumor. The pathologist assigns the grade by examining the cancer cells' appearance and determining how many cells are dividing.

Next, the pathologist will determine how extensive the disease is. The system often used is called TNM, for tumor (size), nodes (cancer present or not) and metastasis (cancer spread to distant organs). A number is assigned to each category. Once the TNM categories are determined, this info is combined with the grade to create an overall stage, from 0 for noninvasive to IV for the most invasive (see the chart).

Review your pathology report with your oncologist to make sure you understand your cancer. That will help you make the best treatment decisions and learn how to be a proactive member of your health team.



Cancer cells are contained within the breast ducts only



Early stage, tumor less than 2 centimeters (cm), with no or microscopic involvement of lymph nodes



Early stage, tumor greater than 2 cm or with spread to underarm lymph nodes



Tumor greater than 5 cm, tumor involves skin, or more extensive involvement of lymph node



Metastatic (has spread to other parts of the body)

November 2013