Mastectomy involves removal of the whole breast (usually including the nipple) and usually removal of one or more lymph nodes from the armpit.

Mastectomy is usually recommended if the breast cancer is large compared to the size of the breast or there’s more than one cancer in the breast (multifocal disease).

Mastectomy may also be recommended after breast conserving surgery if:

• there are cancer cells in the surgical margin around the breast cancer that was removed
• breast cancer comes back in the same breast
• the woman has previously had radiotherapy to the breast area.

Some women choose to have a mastectomy as their first surgery to avoid having radiotherapy or further surgery to the breast.

Radiotherapy to the chest wall may be recommended after mastectomy if there’s an increased risk of breast cancer coming back in the chest area. Some women also have radiotherapy to lymph nodes at the base of the neck and occasionally to the armpit.

Breast reconstruction may be possible after a mastectomy.

How long does a mastectomy take?

Mastectomy usually takes 1–2 hours. There will also be preparation time and time to recover from the general anaesthetic. A woman could be hospital anywhere between 1 day and 1 week, depending on her individual situation.

If a woman has a breast reconstruction at the same time as the mastectomy, surgery is likely to take longer. This means the hospital stay may be longer than after a mastectomy only.

What happens after a mastectomy?

A soft temporary external breast prosthesis can be worn while the wounds are healing. Once the wounds have healed, a woman can be fitted for a permanent prosthesis. Women are usually given a soft temporary prosthesis while they’re in hospital.

Side effects of mastectomy

Everyone responds differently to mastectomy. Some side effects happen to most people, others happen only occasionally. Some side effects happen straight after surgery, others take longer to develop.

Most side effects can be reduced or managed with appropriate care.

Common side effects of mastectomy:

• pain, discomfort or numbness in the breast and/or armpit while the wounds are healing – this usually settles after a few weeks
• fluid may collect in or around the scar in the breast or armpit – this is called a seroma and may need to be drained using a fine needle and a syringe; this can be done by a breast care nurse or another health professional in the clinic or by a GP
• stiffness in the arm or shoulder – it may be helpful to do some approved exercises after surgery
• numbness or tingling in the arm or shoulder if lymph nodes have been removed – this may improve with time, but feeling in these areas may change permanently
• mild pain in the armpit or upper arm – this can last a year or more after surgery if lymph nodes have been removed

Side effects that sometimes develop after mastectomy:

• swelling or bruising around the wound in the chest or armpit – this usually settles in a few weeks
• if lymph nodes have been removed, there may be swelling in the arm, breast, hand or chest that lasts after the initial side effects of surgery are over; this is called lymphoedema and can develop a few months or years after surgery.

Rare side effects of breast conserving surgery:

• infection or bleeding in the scar on the chest; some women might need further surgery.

Find out more about:​

• Breast prostheses
• Breast reconstruction
• Lymphoedema