A cancerous tumor in the breast is composed of a mass of cancer cells that are growing in an abnormal, uncontrolled way. The tumor may invade surrounding tissue, or it may shed cells into the bloodstream or lymph system. If the tumor cells migrate beyond the original site and spread to other parts of the body, it is considered metastatic breast cancer.
A breast tumor requires treatment by surgery, and may require chemotherapy, radiation, targeted biological therapy, and hormonal therapy. When a breast tumor is found at an early stage of breast cancer, it is more likely to be successfully treated, to prevent its spread or recurrence.
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Source:
Dr. Dwight Kaufman. Diagnosis: Mammogram: Cancer (obvious) National Cancer Institute. February 1994.



