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Surgery to remove your breast (mastectomy)

Find out how you have surgery to remove the whole breast for breast cancer.

A mastectomy means that the surgeon removes all of the breast, including the nipple.

Your surgeon is most likely to recommend this operation if you have:

  • a large lump (tumour), particularly in a small breast
  • a tumour in the middle of your breast
  • more than one area of cancer in your breast
  • areas of DCIS in your breast
  • had radiotherapy to the breast before

They will talk to you before the operation about the options for breast reconstruction. This means the surgeon creates a new breast shape using tissue from another part of your body or an implant, or both.

You may have breast reconstruction at the same time as the mastectomy (immediate reconstruction). Or you might have it some months or years afterwards (delayed reconstruction).

You might need radiotherapy after a mastectomy if your doctor thinks you have a risk of the cancer coming back in the area of the scar. In this case, your surgeon might recommend delaying breast reconstruction until after treatment.

If you are not having an immediate breast reconstruction, your nurse will talk to you about artificial breast shapes (prostheses). You put these inside your bra to create a breast shape.

What happens

During the mastectomy operation, the surgeon removes the breast tissue (including the nipple and some of the skin) and the tissues that cover the chest muscles. Rarely, the surgeon also removes the muscles of the chest wall. This is called a radical mastectomy.

The scar from a mastectomy extends across the skin of the chest and into the armpit.

Breast - mastectomy diagram

During the operation, the surgeon might also remove some or all of the lymph nodes in the armpit (axilla).

Checking lymph nodes

Sometimes breast cancer cells can spread into the lymph nodes near the breast.

Diagram showing the network of lymph nodes in around the breast

Checking the lymph nodes before surgery

You have an ultrasound scan of the lymph nodes under your arm when you are diagnosed with breast cancer. If they look abnormal, the doctor takes a sample and sends it to the laboratory to check for cancer cells.

If cancer cells are in the lymph nodes, the surgeon will remove most or all of your lymph nodes at the same time as your mastectomy. This is called axillary lymph node dissection (ALND) or axillary clearance.

Checking lymph nodes during surgery (sentinel lymph node biopsy)

If your lymph nodes look normal on ultrasound, your surgeon will check them during your operation to remove the breast cancer.

A few hours before the operation, your doctor injects a small amount of mildly radioactive liquid into your breast close to the tumour. The radioactive liquid is called a tracer.

During the operation, your surgeon also injects a small amount of blue dye into the breast. The dye and the tracer drain away from the breast tissue into nearby lymph nodes.

The surgeon can see when the dye reaches the first group of lymph nodes (the sentinel nodes). They also use a radioactive monitor to see when the tracer reaches the nodes.

Removing the nodes

The surgeon removes about 1 to 3 of these nodes. They might remove other lymph nodes if they look as though they might contain cancer cells. They send the nodes to the laboratory to check for cancer cells. The results can take about a week.

The dye can stain your breast slightly blue. It gradually fades over a few weeks or months. The dye also turns your urine green for a few days.

If none of the lymph nodes contain cancer cells, you won’t need to have any more nodes taken out.

If there are cancer cells in the sentinel nodes, you might have another operation to remove most or all of the lymph nodes under your arm. This is generally about 2 weeks after you get the results.

Some people have radiotherapy to the armpit to destroy any remaining cancer cells instead of surgery.

Getting results during the operation

In some hospitals, the surgeon gets the results of the sentinel lymph node biopsy during the operation. They can then remove the rest of the nodes if necessary and you avoid having a second operation.

Lymph node sampling

Instead of sentinel lymph node biopsy, your surgeon might take a sample of 4 or more lymph nodes from under your arm to check for cancer cells. This is called axillary sampling. They might use a blue dye to help to find the nodes.

Information and help

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