A mastectomy is mainly used as a treatment for breast cancer or to reduce the risk of breast cancer developing.

Although breast cancer in men is much rarer than female breast cancer, it can also be treated with a mastectomy.

Treating breast cancer

The aim of a mastectomy operation is to remove all cancerous tissue from the breast. This is very important because if any cancerous cells are left behind, there's a risk that the cancer will grow back and spread to other parts of the body.

A mastectomy isn't always the most suitable treatment for breast cancer, although in many cases it's very effective. The specialist responsible for your care will be able to advise you on this.

A mastectomy may be recommended when:

• the tumour is large in proportion to the breast
• the cancer is present in more than one area of the breast
• pre-cancerous cells, called ductal carcinoma in situ (DCIS), have affected most of the breast

Once a diagnosis of breast cancer has been confirmed, it should be treated as soon as possible. Early detection and treatment of breast cancer improves the chances of a successful outcome and a full recovery. 

Preventing breast cancer

Risk-reducing (prophylactic) mastectomies are sometimes carried out on non-cancerous, healthy breasts to reduce the risk of breast cancer developing.

The procedure may be considered if a woman has a very high risk of developing breast cancer. This might be because she has a family history of breast cancer and carries a mutated (altered) version of the BRCA1, BRCA2 or TP53 gene. Having one of these altered genes greatly increases a woman's risk of developing breast cancer. 

Prophylactic mastectomies can reduce the risk of breast cancer by up to 90% in people at a high risk of developing the condition. In some cases, a lumpectomy (removing a lump from the breast) may be all that's required, rather than removing the whole breast. 

If you're concerned about your risk of developing breast cancer in a healthy breast, you should discuss the risks and benefits of surgery with your doctor or surgeon before making a decision. Prophylactic mastectomies aren't usually recommended if there's no evidence of an increased risk of breast cancer.

Non-surgical alternatives

If you're at an increased risk of breast cancer, it may be possible to reduce your chances of developing the condition using medication rather than surgery.

The National Institute for Health and Care Excellence (NICE) recommends two medications called tamoxifen and raloxifene for this purpose. These medications aren't suitable for everyone, but they should be considered before making a decision about having a mastectomy.

For more information, read "Drugs to be offered to women at high risk of breast cancer".