What are the stages of breast cancer?

Breast cancer starts as malignant cells within the breast. It may then progress and spread to the lymph nodes (bean-shaped collections of immune-system cells that help fight infections) under the arm and/or it may spread to the bones, liver, lungs, or other organs.

Following is a brief review of the various stages of breast cancer:

Lobular Carcinoma In Situ (LCIS)

LCIS is a condition in which abnormal cells have reproduced in a part of the breast called a terminal ductal lobular unit. In situ means that the abnormal cells are confined to where they first developed. Most LCIS is considered a risk marker for the development of breast cancer. Treatment options for LCIS vary from close follow up with clinical exams and imaging surveillance, to medications, to surgery. A variant of LCIS called “pleomorphic LCIS” may carry an increased risk for development of an invasive cancer and is usually treated similarly to Ductal Carcinoma in Situ.

Stage 0 - Ductal Carcinoma In Situ (DCIS)

DCIS is the earliest stage at which breast cancer can be diagnosed. This type of breast cancer arises in the milk-carrying ducts of the breast. In DCIS, the tumor cells are confined within the ducts of the breast and have not yet spread into the surrounding tissue. If left untreated, however, these tumor cells can grow through the duct walls, develop into an invasive cancer, and have the ability to spread.

Stage I

The tumor is invasive (cancer cells have spread through the ducts of the breast and into the surrounding breast tissue), measures 2 centimeters or less in diameter, and has not spread to the underarm lymph nodes or elsewhere.

Stage II

The tumor is invasive, measures more than 2 centimeters in diameter but less than 5 cm, and/or it has spread to the axillary (underarm) lymph nodes.

Stage III

The breast cancer is more advanced at this stage. The tumor may be larger than 5 cm, it may involve the skin or chest wall and/or have spread to the axillary lymph nodes..

Stage IV

Regardless of the size of the tumor, the cancer has spread to distant organs away from the breast – like bones, lung, brain, or liver.

Understanding Pathology for Breast Cancer

In the video below, Dr. Sean Thornton of Cellnetix Pathology & Laboratories explains pathology for breast cancer and the role of a pathologist in diagnosis and treatment.


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