Temporal Trends in and Factors Associated With Contralateral Prophylactic Mastectomy Among US Men With Breast Cancer

Previous studies have reported marked increases in the rates of contralateral prophylactic mastectomy (CPM) among US women who received a diagnosis of unilateral invasive breast cancer, and this increase is particularly evident among younger women.¹ Rates of CPM among women vary depending on the population studied, although national statistics show that the percentage of women with unilateral invasive breast cancer undergoing a CPM increased from approximately 2.2% in 1998 to 11% in 2011.¹ This increase has occurred despite the lack of evidence for a survival benefit from bilateral surgery, in addition to the complications and associated costs described in Lostumbo et al.² Factors that are thought to contribute to the increase in the rate of CPM include increased testing for BRCA1/2 mutations, magnetic resonance imaging, and reconstruction surgery for symmetry, among others.³ However, whether the CPM rate is also increasing among US men is unknown.² Herein, we used a nationwide population-based cancer database, the North American Association of Central Cancer Registries,⁴ to examine the temporal trends in and the factors associated with CPM among men who received a diagnosis of unilateral invasive breast cancer.

After excluding patients who did not undergo surgery (n = 231) or whose type of surgery (n = 85), race/ethnicity (n = 72), insurance (n = 640), tumor grade (n = 328), or tumor size (n = 10) was unknown, we identified 6332 men 20 years of age or older with American Joint Committee on Cancer stage I to III unilateral breast cancer who underwent surgery during the period from 2004 to 2011. Temporal trends in the use of surgery (CPM, mastectomy, or breast-conserving surgery) were evaluated using the Cochran-Armitage trend test. Multivariate logistic regression was used to examine demographic and clinical factors associated with CPM. Our study was deemed exempt research by the institutional review board of the North American Association of Central Cancer Registries located in Springfield, Illinois.

During the period from 2004 to 2011, of 6332 men undergoing surgery, 1254 (19.8%) underwent breast-conserving surgery, 4800 (75.8%) had a mastectomy, and 278 (4.4%) underwent a bilateral mastectomy (Table 1). Between 2004-2005 and 2010-2011, the rates of CPM among men who underwent surgery increased by 86.7%, from 3.0% to 5.6% (P < .001). The rate monotonically decreased with age, from 16.5% for men 20 to 39 years of age to 6.9% for men 50 to 59 years of age to 1.4% for men 70 years of age or older (P < .001). The factors associated with a higher likelihood of CPM included younger age (eg, 20-39 years vs ≥70 years, with an adjusted odds ratio of 15.3 [95% CI, 7.7-30.4]), white race (blacks vs whites, with an adjusted odds ratio of 0.6 [95% CI, 0.4-0.9]), and private insurance (Medicaid vs private insurance, with an adjusted odds ratio of 0.5 [95% CI, 0.2-1.0]) (Table 2).

We report, for the first time to our knowledge, that the use of CPM for men who received a diagnosis of unilateral breast cancer has substantially increased over time in the United States, with the procedure more common in younger, white, and privately insured patients. The reasons for these changing patterns are unknown, although similar factors are also associated with the use of CPM for women with breast cancer. In addition, the use of CPM for women has been shown to be associated with the use of genetic testing and magnetic resonance imaging during diagnosis,⁵ which have increased over the past decade. However, it is unknown whether the use of CPM for men is associated with genetic testing, family history, magnetic resonance imaging, or fear of contralateral breast cancer (contralateral breast cancers are more common in men than women), and we do not have these variables in our analytical database to examine their associations with use of CPM.

Ironically, the increase in the rate of CPM, a costly procedure without a survival benefit, is unfolding in the face of a greater emphasis on value in cancer care.⁶ Health care professionals should be aware that the trends in CPM are not limited to women alone, and clinicians should educate male patients about the existing evidence of the benefit, harm, and cost of CPM in order to help patients make informed decisions about their treatments.

Corresponding Author: Ahmedin Jemal, DVM, PhD, Surveillance and Health Services Research, American Cancer Society, 250 Williams St, NW, Atlanta, GA 30303 (ahmedin.jemal@cancer.org).

Published Online: September 2, 2015. doi:10.1001/jamasurg.2015.2657.

Author Contributions: Dr Lin had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Study concept and design: Jemal, Lin, Freedman.

Acquisition, analysis, or interpretation of data: All authors.

Drafting of the manuscript: Jemal, Lin, Freedman.

Critical revision of the manuscript for important intellectual content: DeSantis, Sineshaw, Freedman.

Statistical analysis: Jemal, Lin, Freedman.

Administrative, technical, or material support: Lin.

Study supervision: Jemal, Freedman.

Conflict of Interest Disclosures: None reported.

Funding/Support: The American Cancer Society Intramural Research funded the analysis and interpretation of the data.

Role of the Funder/Sponsor: The American Cancer Society had no role in the design and conduct of the study; collection or management of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.