When breast cancer is surgically removed (during a surgical biopsy, lumpectomy or mastectomy), a rim of normal tissue surrounding the tumor is also removed. This rim is called a margin.
Margins help show whether or not all of the tumor was removed.
Learn about mastectomy and tumor margins.
A pathologist studies the tissue removed during surgery under a microscope and determines whether or not the margins contain cancer cells.
Read Komen advocate Peggy Johnson’s blog on her involvement in an expert panel’s recommendations on assessing margins.
You should get your results about a week after surgery.
With a mastectomy, the whole breast is removed during surgery. Whether the margins contain cancer cells doesn't usually affect your treatment.
However, in rare cases after a mastectomy, the deep margin (the margin closest to the chest wall) or skin margin contains cancer cells.
In these cases, more surgery and/or radiation therapy may be recommended.
Breast Cancer Surgery