The first treatment for breast cancer is usually surgery. This includes surgery on the breast and, for most women, some of the glands in the armpit (the axillary lymph nodes) are removed. Examination of the cancer and the lymph glands by the pathologist will indicate whether further treatment should be considered after the surgery.

The aim of surgery is to remove all of the cancer. The type of surgery depends on a number of factors including the size of the cancer, the size of the breast, the position of the cancer in the breast, and the patient’s choice. Surgery will remove the cancer and a margin of healthy breast tissue around it (wide local excision) or the whole breast (mastectomy). At the same time, some of the lymph glands in the armpit are also removed.

Studies have shown that women who have a wide local excision followed by radiation treatment (breast-conserving surgery) have the same survival rates as women who have a mastectomy. For more information, see the section “Breast-conserving treatment (wide local excision)”.


Mastectomy is the removal of the whole breast including some of the skin and the nipple. The chest muscles are not removed. Some lymph glands in the armpit are also removed during the operation.

Usually, the lymph nodes are removed through the same incision during this operation. This is called axillary node clearance (or dissection).

Mastectomy is less disfiguring than the radical mastectomy of the past. The new type of mastectomy performed today allows for easier breast reconstruction. After mastectomy, most women will have a horizontal scar across their chest. Breast reconstruction can be performed for women having mastectomy. This can be done at the same time as mastectomy (immediate reconstruction) or after all the treatments for the cancer are completed as a separate operation (delayed reconstruction).

Diagram of a mastectomy

Breast-conserving treatment (wide local excision)

For many women it is now possible to have smaller operations, such as partial mastectomy (wide local excision).

A breast-conserving operation involves removing the breast lump with some surrounding normal breast tissue to ensure a good clearance. Surgery is then followed by radiation treatment to the remaining part of the breast. This is usually six to eight weeks after surgery. Often, if chemotherapy is also needed, radiation treatment will be delayed until after chemotherapy treatment is finished. This significantly reduces the risk of cancer recurring in the remaining breast tissue.

Diagram of breast-conserving treatment

Lymph glands are also removed for examination in these smaller operations and this is often through a separate incision (cut) in the armpit.

Breast-conserving operations have been routinely performed now for many years. Breast-conserving surgery followed by radiation treatment is as effective as mastectomy for most women with early breast cancer. However, with breast-conserving surgery followed by radiation treatment there is a higher chance that the cancer could come back in the breast area. This is called local recurrence and does not increase the chance of cancer spreading to other parts of the body. Checking for local recurrence is one of the reasons why follow-up tests are important after treatment for breast cancer

Checking the lymph nodes under the arm

Women with early breast cancer will have their lymph nodes in their armpit checked for spread of breast cancer cells. This is usually done by sentinel node biopsy or lymph node dissection.

Sentinel node biopsy

A sentinel node biopsy locates the first lymph node(s) that drains from the area where the breast cancer developed. This node(s) is detected after injecting a blue dye and a radioactive tracer into the breast tissue where the cancer was found. The node(s) is then removed surgically so that the tissue can be examined. It is thought that removing this node(s) alone may avoid larger operations in the armpit (called axillary clearance). This will reduce the likelihood of surgical side effects (for example lymphoedema). It is also an accurate way of checking if cancer has spread to the lymph nodes.

If the sentinel node shows cancer cells, the surgeon will need to remove further lymph nodes from the armpit, usually 10 to 20 nodes (axillary clearance). This may be done at the same time or in a separate operation.

Sentinel node biopsy is not always possible if there is a larger cancer (greater than 3cm) or more than one cancer (known as multifocal) in the breast.

Lymph node dissection (axillary clearance) is the removal of lymph nodes in the armpit that could drain breast tissue. There are usually more than 10 glands removed and care is taken to avoid damage to nerves and blood vessels. There is usually a plastic tube, called a drain, left in the armpit after axillary clearance. The drain is removed when fluid reduces to a very small amount after surgery. Side effects of axillary clearance include shoulder stiffness, nerve pain or numbness in the upper arm, and lymphoedema.

Diagram showing lymph node areas adjacent to breast area

Drainage after breast surgery

After your operation you may have one or two tubes (drains) coming from the area of your operation into small bags. These drain fluid, which if not removed can cause discomfort, delay wound healing, and may cause an infection. They are usually left in place for a few days. Many women are discharged with their drains in place. If this happens, your nurse will show you how to care for them at home. Your doctor will arrange for them to be removed at a later date or this may be managed by a district nurse. Removing the drains is quick and causes only mild discomfort. It can be done at the doctor’s rooms or at the outpatients clinic.

Advantages and disadvantages of surgical methods

While many women may want a breast-conserving operation, the choice between a mastectomy and a breast-conserving operation depends upon the size of the breast cancer and the size of the breast.

It is helpful to weigh up the advantages and disadvantages of each method for yourself.

The main advantage of the smaller operation is that the breast is saved. However, a disadvantage is that further treatment with radiation treatment is almost always needed. This can take up to six weeks. In the future, a small number of patients with small tumours may be candidates for partial breast irradiation.

Small-breasted women may also find that the smaller operation still leaves them with a big change in their breast shape.

An advantage of mastectomy is that radiation treatment may not be needed. However, in some cases if the tumour is large, close to the underlying muscle, or if there are many lymph nodes involved, radiation treatment is still recommended to reduce the risk of cancer recurring.

The main disadvantage of mastectomy is the loss of the breast.

Reconstruction is possible and can be carried out at the time of the mastectomy or in the future. In some small-breasted women, mastectomy and reconstruction will give a better cosmetic result than breast-conserving surgery.

Side effects of surgery      

Side effects of surgery may include:

  • wound infection – the wound may feel tender, swollen, and warm to touch. There may be redness in the area and/or discharge from the wound. You may feel unwell with a fever and need antibiotics.

  • bruising and haematoma (a collection of blood within the tissues surrounding the wound causing swelling, discomfort, and hardness). The body will reabsorb the blood within a few weeks.

  • pain – if you have lymph glands removed you are more likely to have pain in the armpit or down the arm. You will be advised about exercises to reduce pain and improve arm movement after surgery (see the information on arm care in the section ’After treatment’).

  • cording – a pain like a tight cord running from your armpit, down your upper arm and through to the back of your hand. Cording is thought to be due to hardening of the lymph vessels. Cording may restrict movement and may continue for many months (physiotherapy and exercise may help).

  • reduced sensitivity of the inner side or down the back of your upper arm, due to nerve damage, may sometimes occur. This is usually temporary and improves or disappears about three months after surgery.

  • some women have a swelling caused by fluid build-up (seroma) that may need to be drained several times over a period of days or weeks.

  • swelling of the arm (lymphoedema) may occur in some women after lymph glands have been removed from the armpit. Occasionally, this swelling can extend into the chest wall or abdomen (see the information on arm care section in the section ‘After treatment’).

  • reduced range of movement in the shoulder. You will be given an exercise programme to improve this after surgery. Sometimes a physiotherapist will help you with this.

A health professional examines a planning CT scan

By Louise Goossens.

Image above: Information from the planning CT scan and/or simulator is used to create an individual map of where the radiation will be delivered.

Discuss possible side effects with your doctor before your operation. Report any problems that occur after surgery to your breast care nurse or doctor.

After your cancer has been removed, your surgeon will discuss your tumour with other specialists to determine what further treatment, if any, will be recommended.

For additional practical tips regarding breast surgery, phone the cancer information nurses on the Cancer Information Helpline 0800 CANCER (226 237).

“My whole breast was sore, it was so uncomfortable but the nurses put on me this beautiful dressing. And I loved that dressing.” Silei