Classification of stages
Breast cancer is classified by where it originated and how far it has spread.
In situ carcinoma (noninvasive)—In situ means “in place.” Generally, this type of cancer is at an early stage
and has not spread beyond where it started.
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Carcinomas that start in the milk ducts of the breast are called ductal carcinoma in situ (DCIS). |
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Carcinomas that start in the milk glands are called lobular carcinoma in situ (LCIS). |
Invasive cancer—This type of cancer may be localized in the breast or metastatic
(spread to other parts of the body).
Classification of stages
Once breast cancer is detected, physicians can determine the stage by measuring tumor size, evaluating whether the cancer has spread to the lymph
nodes (pea-sized collections of tissue) under the arm (axillary lymph nodes), and determining if the tumor has metastasized.
