Mastectomy for breast cancer: when is it recommended?

A mastectomy, which is the surgical removal of the whole breast, remains an important treatment for breast cancer. But it is not always the only option, and the type of surgery recommended will depend on the individual person and their cancer.

Although radiotherapy, hormone therapy, chemotherapy, immunotherapy and other drug treatments are all used in early breast cancer treatment, surgical removal of the tumour in the breast is arguably the single most important part of the treatment pathway.

Until the late 1960s, mastectomy was the operation that was usually offered as standard for breast cancer, until clinical trials showed that removing only the tumour and the immediately surrounding tissue (a wide local excision) followed by radiotherapy to the breast gave results that were just as good.

Since then, a wide local excision has become the preferred option whenever possible, giving good cancer control and helping a patient preserve their breast.

Unfortunately, there are still some circumstances where a mastectomy may still be advised. These include: 

• If the cancer is multifocal, meaning that more than one area of the breast is affected by separate areas of cancer
• Where the tumour is too large to remove by wide local excision. The size of the tumour relative to the breast size is important. It may be possible to remove a large tumour with a wide local excision if the breast is very large. Conversely a relatively small tumour in a very small breast may be difficult to excise by wide local excision. Modern surgical techniques referred to as oncoplastics have allowed surgeons to remove much larger tumours by wide local excision than was previously possible and still leave a good cosmetic result.
• A rare subtype of breast cancer called inflammatory cancer where the disease affects the skin is usually treated with mastectomy alongside chemotherapy and radiotherapy.
• If the breast contains a large amount of pre-cancerous cells referred to as Ductal Cancer in Situ (DCIS)
• If the breast cancer has occurred because of an inherited gene defect which makes another future breast cancer more likely. In this case the mastectomy is recommended as a prevention against future problems.
• If there were important reasons that prevented someone receiving radiotherapy after a wide local excision, then a mastectomy may be considered.
• Patient choice.

The decision to offer mastectomy is a major one and therefore it is expected that this decision should be discussed and approved by a multidisciplinary team (MDT) made up of breast cancer surgeons, radiologists, oncologists, pathologists and nurses.

An MDT should take into account findings from imaging tests, biopsies, physical examination and the patient wishes before making a recommendation. This recommendation should then be considered as part of a shared decision-making process with the patient.

If a mastectomy is recommended because the tumour is large, it is sometimes possible to offer drug therapy prior to surgery to attempt to shrink the cancer down to a size where mastectomy can be avoided. This is referred to as neoadjuvant therapy.

If a mastectomy is offered, it may be possible to reconstruct the breast either at the same time as the cancer surgery (immediate) or at a later stage when cancer treatment is complete (delayed).

Reconstructions can sometimes be achieved with the patient's own body tissues (autologous) or using synthetic expanders or implants.

Data from a national audit shows that among women with breast cancer in England and Wales who had surgery within 12 months of diagnosis, around 3 in 4 had wide local excision, while around 1 in 4 had a mastectomy.i

If you have been diagnosed with breast cancer and are worried about treatment decisions such as a mastectomy, it is important to talk with your cancer doctor or specialist nurse. They can explain your treatment options and help you understand what is right for you.

We also have information about breast cancer treatment, including treatment options, coping with the effects of treatment, and support available before, during and after surgery.

• Call the Macmillan Support Line for free on 0808 808 00 00
• Chat to our specialists online.
• Speak to other people affected by breast cancer on our breast cancer forum .

i National Audit of Primary Breast Cancer (NAoPri). State of the Nation Report 2026. Accessed September 2026