If you require a lumpectomy for breast cancer, your surgeon will remove the tumor and a border of normal tissue around it. This border is called the surgical margin. A pathologist will then examine this margin to determine if all the cancer cells in that area are gone.
If cancer cells are found anywhere between the tumor itself and the outer edge of the margin, additional surgery may be recommended. The goal of negative margins at surgery is to reduce the risk of breast cancer returning in that area, called a local recurrence.
This article will review the use of surgical margins in breast cancer treatment, and how surgical margins impact breast cancer surgery.
Margin Sizes
To establish the width of a margin, the pathologist will measure the distance between the outer edge of cancer cells and the edge of the tissue that was removed. The tumor is usually “inked” on the edges. This allows the pathologist to clearly see the end of the tumor.
A guideline put out by three national cancer organizations recommends removing a margin of 2 millimeters. However, some practitioners may consider removing a 1 millimeter or less rim of healthy tissue. You may want to ask your surgical oncologist what their definition of “clear margin” is.
Surgical Margin Findings
A pathologist uses a special type of ink to draw a line along the outer edge of the entire tissue sample before slicing it into thin sections and examining it under a microscope.
The pathologist will use one of three terms to describe what they see:
Positive margins, on the other hand, may indicate that all of the cancer was not removed, and another surgery in the same area may be needed to remove more tissue.
Close margins found after a lumpectomy might require another surgical procedure, called a re-excision. In this case, your surgeon would return to the original site and remove additional tissue to try to get negative margins.
A mammogram may be done to confirm that the entire tumor was removed and to determine if more tissue will need to be taken out.
For women who’ve had a mastectomy, cancer cells in the margins within the breast usually have no effect on treatment decisions, since the whole breast was removed. In rare cases, however, cancer cells may be found close to the chest wall, possibly requiring more surgery, radiation, and/or chemotherapy, depending on the stage and other features of cancer.
Summary
Determining surgical margins with breast cancer surgery is very important for the oncologist to know. The goal of removing the tumor is to reduce the risk of cancer returning in the future. Having negative, or clear margins can reduce the risk.
Positive or close margins may require additional surgery for the surgeon to feel confident that all of the cancerous tissue was removed.
A Word From Verywell
Once you’ve had a lumpectomy, you’ll find out if your surgical margins were negative, positive, or close. This, along with cancer type, stage, and lymph node status, will help you and your healthcare provider choose the most effective follow-up treatment for you.
Read more about a phyllodes breast cancer tumor.
There was an error. Please try again.
