Breast-conserving surgery

A lumpectomy or wide local excision is surgery to remove breast cancer along with a margin (border) of normal, healthy breast tissue.

The aim is to keep as much of your breast as possible while ensuring the cancer has been completely removed.

If you’re having breast-conserving surgery, you’ll usually have radiotherapy on the remaining breast tissue on that side.

Image: Depicting position of cancer in breast and example of scar position after wide local excision

Mammoplasty and oncoplastic operations

An increasingly common operation is a partial mastectomy, where around a quarter of the breast or more is removed. On its own the operation leaves the breast smaller due to the amount of tissue removed and it may also be misshapen.

It’s usually combined with oncoplastic surgery. This combines breast cancer surgery with plastic surgery techniques, and means it’s less likely you’ll notice a dent or a great difference between the breasts. This can sometimes be an operation in the form of a breast reduction if you have a large breast; sometimes it can use a flap of tissue from nearby to fill the defect. For more information, see below about breast reconstruction.


It’s important that the cancer is removed with an area (margin) of healthy breast tissue around it to reduce the risk of any cancer cells being left behind.

The breast tissue removed during surgery will be tested to check the margin around the cancer.

  • negative (clear) margins mean no cancer cells were seen at the outer edge of the tissue removed.
  • positive margins mean the cancer cells are very close to or reach the edge of the tissue.

Image: depicting negative (clear) margins and positive margins

If you have negative or clear margins, it’s unlikely you’ll need more surgery to the breast.

If there are cancer cells at the edges of the margin, you may need further surgery to remove more tissue. Some people may need a mastectomy to ensure all the cancer has been removed.