Partial Mastectomy

A partial mastectomy (also known as a lumpectomy or breast conserving surgery) removes only the tumor and some healthy tissue around it.  It is considered a breast conservation therapy because only the affected area is removed from the breast. A partial mastectomy is typically followed with chemotherapy and/or radiation therapy.

In comparison to a full mastectomy, which removes the entire breast, partial mastectomy aims to preserve the breast as much as possible without altering its appearance. The amount of breast removed in a partial mastectomy depends on the size and location of the tumor, among other factors.

Our surgeons will typically recommend partial mastectomy when a biopsy shows the cancer is small and in its early stages. Partial mastectomy may also be a good option if the patient only has one area of cancer or multiple areas close enough to be removed without dramatically changing the look of the breast. The patient also has to be willing to have radiation therapy following surgery and cannot have certain genetic predispositions or complicating disorders.

Partial mastectomy is a less invasive surgery than removing the breast completely and it has been proven as effective as mastectomy in removing cancer and preventing recurrence in early-stage breast cancer. Partial mastectomy is often the first treatment option for women with the early form of cancer.

The procedure involves locating the area of the breast with the abnormality, removing it along with a band of surrounding tissue, and sending the removed area to the pathologist for analysis.

If the tumor is too small to be seen or felt on a patient’s exam, then the surgeon can employ a technique to localize the tumor, by using a wire placed pre-operatively so the surgeon can use the wire to guide their partial mastectomy.

After surgery is complete, a doctor, called a pathologist, will use a microscope to look at the tissue that was removed. If the pathologist finds no cancer cells at any of the edges of the removed tissue, it is said to have negative or clear margins . Sometimes breast cancer cells spread past what the preoperative imaging studies are able to show. So if cancer cells are found at the edges of the tissue that has been removed, it is said to have positive margins.

The presence of positive margins means that some cancer cells may still be in the breast after surgery, so the surgeon may need to return to the operating room and remove more tissue. This operation is called a re-excision. If cancer cells are still found at the edges of the removed tissue after the second surgery , a full mastectomy may be needed.


Side effects of partial mastectomy can include:

  • Pain or tenderness or a “tugging” sensation in the breast
  • Temporary swelling
  • Hard scar tissue that forms in the surgical site
  • Change in the shape of the breast
  • Nerve (neuropathic) pain (sometimes described as burning or shooting pain) in the chest wall, armpit, and/or arm that doesn’t go away over time. This can also happen in mastectomy patients and is called post-mastectomy pain syndrome or PMPS.

As with all operations, bleeding and infection at the surgery site are also possible.


After partial mastectomy:

Most women will need radiation therapy to the breast after breast-conserving surgery.

Many women receive hormone therapy after surgery to help lower the risk of the cancer coming back. Some women might also need chemotherapy after surgery. If so, radiation therapy is usually delayed until the chemotherapy is completed.



American Cancer Society

Susan G Komen