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

A lumpectomy is a type of breast-conserving surgery, also known as a wide local excision.

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.

Lumpectomy or wide local excision


A far less common operation is a quadrantectomy, where around a quarter of the breast is removed. This is sometimes called a segmental excision.

After a quadrantectomy the treated breast will usually be smaller due to the amount of tissue removed and it may also be misshapen. However, oncoplastic surgical techniques, which combine breast cancer surgery with plastic surgery, are increasingly used. This means it’s less likely you’ll notice a dent or a great difference between the breasts.


It’s important that the cancer is removed with an area (margin) of healthy breast tissue around it to make sure no cancer cells have been 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.

Illustration of positive and negative 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.        

Last reviewed: August 2016
Next planned review begins 2018