TriangleFOR PATIENTS · SOURCE READING
Single vs. double mastectomy
Source: Mastectomy, National Cancer Institute.
Source updated: Not stated in this source · Captured 2026-09-09.
Selected source text with whitespace normalised. This Triangle page is not an NCI PDQ summary. Independent clinical review is pending.
NCI patient treatment article for this disease Exact source article; not a clinically reviewed indication or current-standard recommendation.
Context: Mastectomy
Single vs. double mastectomy
In a single (unilateral) mastectomy, only the breast with cancer is removed. A double (bilateral) mastectomy involves the removal of both breasts.
Your doctor may suggest a double mastectomy if:
cancer is in both breasts
you have cancer in one breast but are at high risk of developing cancer in the other breast because of a genetic mutation or strong family history of breast cancer
If you do not have a genetic mutation or strong family history of breast cancer, you do not have an increased risk of developing a new cancer in the other breast. For you, research shows that having a double mastectomy instead of a single mastectomy does not help you live longer.
You may choose to have a double mastectomy, even if your doctor suggests a single mastectomy, if:
you want to reduce the risk of developing a new breast cancer in the healthy breast
you prefer not to have routine screening to check for cancer in the healthy breast
you want both breasts to be the same size
you are concerned about how your chest will look after a single mastectomy
Discuss insurance coverage and the risks and benefits of a double mastectomy with your doctor before making a decision.
Preserved source evidence · Independent clinical review pending · Not medical advice