During the April 2016 meeting of the American Society of Breast Surgeons (ASBrS), a consensus conference was held to discuss contralateral prophylactic mastectomy (CPM). CPM is the removal of the healthy, opposite breast, and the rates of CPM have been increasing, for various reasons.
A patient’s decision to undergo a CPM is very difficult and is unique to each individual with breast cancer. Consensus statements and guidelines are not mandates. Rather, they are recommendations based on the best available evidence. In addition, the ASBrS statement specifically states that this document was developed to guide patient and physician discussion, and should not influence insurance coverage for the procedure.
The summary of the document states: “The consensus group agreed that CPM should be discouraged for an average risk woman with unilateral (one side) breast cancer. However, patient’s values, goals and preferences should be included to optimize shared decision making when discussing CPM. The final decision whether or not to proceed with CPM is a result of the balance between benefits and risks of CPM and patient preference”
The full statement is available online (open access) in two parts. Part 1 covers the data on CPM outcomes and risks. Part 2 discusses additional considerations and a framework for shared decision making.
Some key points noted in the manuscript include:
- Breast conservation is preferable in appropriate patients, and neoadjuvant therapy and/or oncoplastic approaches should be considered to facilitate breast conservation
- The risk of contralateral breast cancer (breast cancer developing in the opposite breast – CBC) in an average risk woman with breast cancer is 0.1-0.6% per year. CBC risk is higher for women diagnosed at a young age, those with a strong family history of breast cancer, and genetic mutation carriers
- CPM does not appear to be associated with a survival benefit, with the possible exception of BRCA mutation carriers
- CPM doubles the rate of surgical complications
- Bilateral reconstruction may provide for improved cosmetic outcome
- Sentinel lymph node surgery on the CPM side should not be routinely performed
- CPM is a cost effective strategy in women with BRCA mutations. There is insufficient evidence to support cost-effectiveness in average risk women, and this is highly dependent on quality of life assumptions
- 80-90% of women report satisfaction with their decision to undergo CPM but 20-30% of these women report post-surgical dissatisfaction with cosmesis, body image, and sexuality. Women should be counseled on the potential long term outcomes of CPM on body image and sexuality
- CPM rates should not be used as a national quality measure
- Additional education, resources on risks and benefits, stronger patient engagement, and enhanced decision making guidelines are needed. Shared decision making that includes a comprehensive discussion of risks and benefits is important
As I noted above, this is a difficult decision, and one that should not be made without significant education, thought, and discussion. The decision making process will likely be different for each woman. It is important that patients take their time to become educated about all of their options, and work with a treatment team who will provide you with the necessary time, educational resources, and support, to make the decision that is right for you.