Breast-Conserving Surgery (Lumpectomy or Partial Mastectomy)

What is breast-conserving surgery?


Breast-conserving surgery involves removal of a previously biopsied breast cancer (invasive or noninvasive) with a margin (or rim) of normal tissue around the cancer. The goal of this surgery is to remove the cancerous tissue before it can spread to other areas of the body while preserving the breast. Breast-conserving surgery may be combined with surgery for the axillary lymph nodes (under the arm), including either a sentinel lymph node biopsy or an axillary lymph node dissection. In most cases, survival is the same for mastectomy (removal of all breast tissue) and breast-conserving surgery. There may be a slightly higher risk of the cancer coming back in the breast after breast-conserving surgery. To lower this risk, it is important to obtain "negative margins" (a rim of normal tissue around the cancer). Radiation to the breast also may be considered (see below).


Not all women are good candidates for breast-conserving surgery, and this is something your surgeon will discuss with you. You and your surgeon will discuss:

  • The cancer size compared to your breast size
  • Whether the cancer is located in a single spot in the breast or whether it is multicentric (multiple cancers present in different sections of the breast)
  • Your preference for saving the breast
  • Your ability (based on your other medical conditions or prior history of radiation to the chest) to have radiation therapy after the breast-conserving surgery. Radiation is recommended for many women after breast-conserving surgery to decrease the chance of the cancer coming back, and this is important to consider.
  • Whether you have an "inflammatory breast cancer"

For many women, the decision for breast-conserving surgery rather than mastectomy is a personal choice that must be made based on each patient's values and needs. Although there are many reasons why a woman may choose breast-conserving surgery, some common reasons include:

  • The patient has a strong desire to preserve her breast to maintain her personal body image and sexuality.
  • The patient values the shorter surgery and quicker recovery time that comes with breast-conserving surgery.

For women who decide against breast-conserving surgery, concerns about the cancer coming back in the breast and desire to avoid radiation often are strong reasons for their decision.


What if after my breast conserving surgery the pathologist reports that the "margins" contain cancer?


At the time of the surgery, your surgeon will remove a rim (or "margin") of what appears to be normal tissue around the cancer. Some cancers may extend into what looks like normal tissue, but these cancerous cells cannot always be seen on X-rays and cannot be seen or felt by the surgeon in the operating room. After the cancer is removed, a pathologist will look at the tissue. A pathologist is a doctor who specializes in using a microscope to examine human tissue and determine the amount and type cancer that is present. The pathologist will determine the size of the cancer and if it extends to the edges of what was removed. Most often, you will have the pathologist’s report within a week.


If cancer is seen at the edge of the margin, it will be noted as a "positive" margin. A positive margin may increase the risk of the cancer coming back in the breast. Therefore, if the margins are positive, the surgeon often suggests a second surgery to take more tissue from the area where the margin was positive. This is called a re-excision surgery, and it can occur in up to one out of five people who have a lumpectomy.


Why is radiation given, and what are the side effects?


For most women, radiation is given to reduce the risk of the cancer coming back in the breast. With radiation, the risk of cancer returning can be as low as 5 percent to 10 percent. If radiation is not completed, the risk of the cancer coming back in the "conserved" breast can be as high as 30 percent to 40 percent. Radiation is recommended most often for younger women. However, the risk of having the cancer come back may be lower for some older women. Therefore, radiation may not be recommended for some older women whose cancers appear to be at a lower risk of coming back.


Radiation can be given in different ways and over different periods of time. Side effects include local reactions similar to a sunburn, which later fades. Many people say it makes them feel tired. However, most people are able to work during radiation therapy and the treatments may be scheduled around your work times. If you would like more information about this treatment, you can meet with a radiation oncologist before making a decision about surgery. You also will meet with a radiation oncologist after your surgery.


What can I expect my breast to look like?


The goal is to maintain the shape of the breast and prevent "dents." There will be a scar, and sometimes the breast is smaller or the nipple is slightly moved to one side. Many factors affect this, including the size and location of the cancer and the size of your breast. You should speak with your surgeon about what you can expect your breast to look like after the surgery.