We teach you about bilateral or “double mastectomies.” You will learn about the advantages, disadvantages, and controversy of this approach to reducing your future risk for a new breast cancer.


Questions for your Breast Surgeon:

  • Will I improve my chances of survival with a “Bilateral Mastectomy?”
  • What are the disadvantages of a “Bilateral Mastectomy?”
  • What are the advantages of a “Bilateral Mastectomy?”
  • Isn’t it my choice to decide?
  • If I’m unsure, can I talk to a plastic surgeon?

What is a “Bilateral Mastectomy”?

Also called a “double mastectomy,” this is when both breasts are surgically removed. The term “Contralateral Prophylactic Mastectomy” is also used by the medical community for removal of the opposite, non-cancerous breast. Most of the time the decision to have a bilateral mastectomy is a personal one and is not required to treat a breast cancer that is on one side.


There are situations where a “bilateral mastectomy” may be offered for consideration by your breast surgeon. The medical aspects are more complicated than listed below, but we include some common scenarios.


  • Cancer in both breasts
  • BRCA (“breast cancer gene”) mutation or other high-risk genetic mutation
  • Strong family history of breast cancer
  • Younger than 35 with breast cancer
  • High risk for developing a new cancer
  • Radiation to your chest at a young age


Am I at risk of developing a “New Breast Cancer” in my other breast?

Simple statistics are important to understand this concept. Below is a common scenario where women consider undergoing bilateral mastectomies to treat their existing cancer and reduce the risk of developing a new cancer in the other breast.


Let’s say you are 45 years old, have an early, Stage I or II breast cancer and either need or have chosen to have a mastectomy to treat your cancer effectively. What is your risk of developing a new breast cancer in the other breast in the future?


If you were just diagnosed with breast cancer and have no other risk factors, you will have a slightly higher overall risk of developing a totally new breast cancer in your lifetime. This risk rises from the normal lifetime risk of 8% for both breasts to approximately 12%, assuming a lumpectomy is performed and you keep both breasts.


If you are in this situation and are trying to decide if you want a bilateral rather than a mastectomy on one side, your risk of developing a new cancer in your lifetime in the other breast if you choose to keep it is about 6% (half of the 12% above). We cure about 90% of all breast cancers with current treatments. Therefore, your lifetime chance of dying from a new cancer in that other breast will be about 0.6%.


“Bilateral Mastectomy” for cancer on one side?

Most of the time the choice to have a bilateral mastectomy is a personal one for a variety of reasons. Even when well informed, many women decide to proceed with removing both breasts for “peace of mind” and the desire to “never go through this again.” It is important to realize that everyone has different goals, unique personal situations, and their own reasons as to how they manage their own breast cancer. “Patient autonomy” is essential to a great “doctor-patient” relationship. Make sure no one on your treatment team is dismissive your personal needs and desires.


Controversy about “Contralateral Prophylactic Mastectomy”

There has been a trend over the last decade of more women choosing a “double mastectomy” when they have cancer in one breast. About 25 to 50% of all mastectomy surgeries done today are “bilateral” procedures. The more informed you become, the better decision you will make for your own situation.


There is an intense debate by breast specialists as to whether too many bilateral mastectomies are being performed. The controversy is that the risks, complications, and costs of these surgeries may be harming women without improving their cancer outcomes. There is an active push-back by many physicians and societies against “Contralateral Prophylactic Mastectomy.” Two statements about this topic from the American Society of Breast Surgeons covers this controversy in great detail (here) and (here). This debate will not be resolved anytime soon.


What are the “disadvantages” of a bilateral mastectomy?

  • Surgical complication risks are slightly increased
  • Loss of sensation in the skin of both breasts
  • Increased need for revision surgeries in the future
  • Does not improve your “overall survival” from breast cancer
  • Does not lessen the chance you will need chemotherapy
  • A chance you might regret the decision in the future


What are the “advantages” of a bilateral mastectomy?

  • Lessens the chance of a new cancer in the breast
  • Screening mammograms are no longer needed
  • Cosmetic outcomes have improved over the last decade
  • Reconstructing both sides gives matching cosmetic outcomes


Discuss with your Breast Surgeon

Work to develop a close relationship with your breast surgeon. Print out and take these course notes with you when covering this topic. Ask to see a plastic surgeon about reconstruction options if you are unsure. Ultimately, your breast cancer treatment decisions are yours to make.


Patient-Friendly References:

  • breast360.org
    This outline (here) about “Contralateral Prophylactic Mastectomy” lists the indications and the controversy about removing a breast without cancer. This non-profit organization provides excellent patient resources about breast cancer.


This excellent outline, “Breast Reconstruction after Mastectomy” (here) is a presentation of breast reconstruction options. The Option Grid Collaborative is one of the largest developers of clinical decision aids, based at the Dartmouth Institute for Health Policy and Clinical Practice.


This position statement (here) “Don’t routinely perform a double mastectomy in patients who have a single breast with cancer” argues against routine bilateral mastectomies. Choosing Wisely is an initiative by the American Board of Internal Medicine, Consumer Reports and the American Society of Breast Surgeons to discourage physicians and patients from using unneeded tests and treatments for breast cancer.



More Detailed References:

  • annsurgoncol.org
    These two consensus statements about “Contralateral Prophylactic Mastectomy” list detailed information about “Outcomes and Risks” (here) and “Additional Considerations & Shared Decision Making” (here). The statements were created by the American Society of Breast Surgeons and published in the Annals of Surgical Oncology.


This position statement (here) “Consensus Panel Recommends Against the Routine Use of Contralateral Prophylactic Mastectomy” outlines some of the hazards of removing both breasts for breast cancer on just one side. The American Society of Breast Surgeons is a leading organization of surgeons who treat diseases of the breast.


If you want to get deep into the details, this free 200-page pdf document (here) has guidelines to help clinicians to make treatment recommendations about nearly all aspects of breast cancer. You can easily register (here) as a non-professional to get access and more information about breast cancer. The National Comprehensive Cancer Network is the leading organization in developing clinical guidelines.



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