USE OF CONTRALATERAL MASTECTOMY IN MALES WITH BREAST CANCER

The use of contralateral prophylactic mastectomy (CPM) for men with a diagnosis of unilateral breast cancer has increased substantially over time in the United States, according to new research.

As in women, the procedure is more common in younger, white, and privately insured men, lead author Ahmedin Jemal, DVM, PhD, from the American Cancer Society in Atlanta, and colleagues write in a letter published online September 2 in JAMA Surgery.

"Contralateral breast cancers are more common in men than in women," Dr Jemal told Medscape Medical News. In fact, "among breast cancer survivors, the risk of developing contralateral breast cancer is over five times higher in men than in women. But whether this is a factor in men choosing CPM is not known," he said.

Reasons for the Increase in CPM

In recent years, there have been marked increases in the rates of CPM in women in the United States diagnosed with unilateral invasive breast cancer, especially younger women. Rates in women rose from approximately 2.2% in 1998 to 11.0% in 2011, and the increase occurred without evidence of a survival benefit for CPM, Dr Jemal and colleagues report.

In women, CPM has been shown to be associated with the use of genetic testing for BRCA1 and BRCA2 mutations, MRI, and reconstruction surgery for symmetry. However, in men, it is not known whether CPM is associated with genetic testing, family history, MRI, or fear of contralateral breast cancer, they explain.

Dr Jemal's team wanted to shed light on the temporal trends in CPM and possible factors leading men diagnosed with breast cancer to go this route. To that end, they identified 6332 men 20 years and older with stage I to III unilateral breast cancer who underwent surgery from 2004 to 2011 who were entered in the North American Association of Central Cancer Registries, a nationwide population-based cancer database.

Of these, 1254 (19.8%) underwent breast-conserving surgery, 4800 (75.8%) underwent a mastectomy, and 278 (4.4%) underwent a bilateral mastectomy.

Rates of CPM increased by 86.7% during the study period, from 3.0% in 2004/05 to 5.6% in 2010/011 (P < .001).

And rates were higher in younger men than in older men.

Table. Rates of CPM by Age Range

Age Range	Rate of CPM, %
20–39 years	16.5
50–59 years	6.8
≥70 years	1.4

In addition, white males were 25% more likely to undergo CPM than black men, and privately insured men were 26% more likely to undergo CPM than Medicaid-insured men.

"The reasons for these changing patterns are unknown. The reasons that drive the decision to undergo CPM have not been studied in men," Dr Jemal said. "We do not know why they choose CPM without indications, such as being positive for BRCA1 or BRCA2 mutations, but this information is needed for planning interventions to reduce the rate of CPM."

"It is ironic that this increase in the rate of CPM in both men and women is unfolding in the face of a greater emphasis on value in cancer care. Doctors should discuss with their patients the current scientific evidence of the benefit, risk, and cost of CPM so that patients can make informed decisions about their treatments," he said.

The study was funded by the American Cancer Society. Dr Jemal has disclosed no relevant financial relationships.