A Look at the Supported and Unsupported Factors that Influence Contralateral Prophylactic Mastectomy

Oct. 20, 2016

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Take-Home Message:

Contralateral Prophylactic Mastectomy (CPM) is being performed increasingly in the United States. There are many considerations that must be addressed before proceeding with surgery.

 

Contralateral Prophylactic Mastectomy Consensus Statement from the American Society of Breast Surgeons: Additional Considerations and a Framework for Shared Decision Making

Authors: Boughey, JC, Attai, DJ, Chen, SL, et al.
Source: Annals Surg Onc (2016). doi:10.1245/s10434-016-5407-8
link.springer.com/article/10.1245/s10434-016-5408-8

This article is the second part of a series that the authors recently published. The authors observed that the rate of CPM is on the rise in the United States, and that many of the reasons for this trend are not reliably supported by valid studies. In the first article in this series, the group sought to educate the public about the true risks and benefits of CPM and to share guidelines for the scenarios where CPM is appropriate. This second article provides guidance for providers and patients when contemplating the procedure.

Consideration of axillary sentinel lymph node (SLN) surgery is the standard of care in breast cancer surgery. When performing CPM, there is little evidence to support SLN. The chance of finding cancer in the breast tissue removed is less than 2%, and the rate of positive lymph nodes in those cases is also less than 2%. The risks of complications of SLN (such as lymphedema) are greater than any possible benefits. Therefore, the group advises against SLN surgery for CPM.

The cost of long term breast cancer surveillance has been suspected to be higher than the cost of CPM. Therefore, many providers see CPM as a cost-effective strategy for their patients. The authors note that a patient’s quality of life must be improved by CPM to consider it a cost-effective strategy. Available studies do not evaluate quality of life in consistent, valid ways. Therefore, it is unproven that CPM is cost-effective. The one exception is with women with BRCA mutations. There are multiple, reliable studies that support the notion that CPM in these individuals is cost-effective.

It is understood that a woman’s decision to undergo CPM is highly personal and often determined by perceptions about future cancer risk, anxiety over future screening and possible procedures and by unknown outcomes (physical and emotional) of surgery. The investigators reviewed studies that looked at women’s personal experiences after CPM. They summarized that while 80-90% of women stated that they were satisfied with their decision for CPM, up to 30% of them reported dissatisfaction with their physical appearance and their sexuality. Furthermore, the investigators found that CPM did not affect overall quality of life for any of these women. It is important, therefore, that women considering CPM be closely counseled on the possible long-term outcomes of the procedure on their own body image.

The trend of CPM in the United States was compared to the trends in the United Kingdom and mainland Europe. While the rates of CPM are lower compared to the United States, the procedure is on the rise in the United Kingdom (there appears to be no change in the low rates in mainland Europe). This trend is suspected to be due to the same factors present in the United States: the influence of the media, poor understanding of possible complications of breast reconstruction, fear of recurrence and poor understanding of the risk of recurrence and the lack of impact of CPM on that risk. Comparing rates of CPM in the United States and the United Kingdom, the investigators attribute the differences to two factors: 1) all breast surgeons in the United Kingdom receive training in oncoplastic surgery, which often eliminates the question of mastectomy and 2) private health insurers and the National Health Service in the United Kingdom do not fund CPM unless a woman carries a BRCA mutation. Therefore, in the United Kingdom, CPM is considered with much less frequency.

The group studied reasons why women in the United States are increasingly choosing CPM. They found that many women base their decisions upon fear of recurrence, input from friends and family and the publicized experiences of celebrities. These influences are, for the most part, based on misinformation or unsupported assumptions. Patient education for CPM is lacking. Additional resources and engagement are needed.

Literature review showed that most women with a breast cancer diagnosis consider CPM on their own. Younger patients note that their physicians’ opinions have little to do with their final decision about CPM. The group noted that 45-80% of women recall discussing CPM with their physicians; however, only about half of them discussed reasons to not have a CPM. The input of the physician plays a crucial role in decision-making for CPM. Providers can correct false assumptions and provide reliable, helpful data. The investigators strongly recommend a comprehensive discussion about the risks and benefits of CPM.

In the spirit of increased physician-patient engagement regarding the use of CPM, the investigators provide a template to encourage a detailed discussion about the procedure. It is hoped that this tool will enhance the shared decision-making that should be incorporated for CPM. The template is reproduced below:

CPM discussion guide—Information for patients regarding CPM. Providers should provide this information to every patient considering CPM for unilateral breast cancer (excluding high-risk patients like BRCA carriers)

For most women, the estimated risk of cancer in the opposite breast is 2-6% over the next 10 years. This means you have a 94-98% chance of not getting cancer in your opposite breast over the next 10 years or more.
CPM is not 100% protective against cancer forming in your other breast.
CPM will not improve your cure rate for your known cancer.
CPM will not reduce your risk of cancer returning from your known cancer.
CPM will not reduce your need for other cancer treatments for your known cancer (adjuvant therapy), if indicated.
The risk of surgical complications at the surgical site (such as bleeding, infection, healing complications, and chronic pain) is approximately twice as high when CPM is performed.
CPM results in permanent numbness of the chest wall (and nipple if preserved).
CPM with reconstruction will result in an increased number of operations.
Complications from CPM may delay treatment of your known cancer, including chemotherapy and radiation that may be recommended after surgery.
CPM may be associated with negative impact on physical, emotional, and sexual well-being. Approximately 10 % of women regret their decision to undergo CPM.
Breast feeding will not be possible after CPM.
Women who undergo CPM will not need mammograms or routine breast imaging for cancer screening after surgery.