Study: Are more men with breast cancer opting for prophylactic mastectomy?

IN DEPTH 

Study background: 

Researchers have noted increased rates of double mastectomy in women diagnosed with invasive cancer in one breast. This trend is especially true for younger women. Factors that researchers believe contribute to the increased rates of double mastectomy include:

• increased BRCA testing
• use of MRI (some research suggests MRI findings cause patients to worry about cancer developing in the opposite breast)
• the desire to achieve symmetry through reconstructive surgery

Although more women are opting to undergo double mastectomy – which comes with a risk of complications and costs – studies have not shown a survival benefit from the surgery.  Unlike women, the double mastectomy rates among men with cancer in one breast and the various factors that contribute to their decisions are unknown.

Researchers of this study wanted to know:

Whether the double mastectomy rate in men has increased.

Population(s) looked at in the study:

6332 men who:

• Were at least 20 years old
• Had been diagnosed with stage I-III invasive breast cancer in one breast
• Underwent surgery between 2004 and 2011

Study finding(s):  

1. Comparing the double mastectomy rates during 2004-2005 to 2010-2011 indicates that the rate of this surgery increased from 3% to approximately 6%.
   • 35 of 1166 men with invasive cancer in one breast chose to undergo double mastectomy in 2004-2005 while 106 of 1884 men with invasive cancer in one breast chose to undergo double mastectomy in 2010-2011
2. The factors that were associated with a higher likelihood of double mastectomy were:
   • younger age
   • white race
   • having private insurance rather than Medicaid. 

Limitations:

The researchers note that studies have found that increased BRCA testing has increased prophylactic mastectomy rates in women with breast cancer. This research was not able to look at the BRCA status of those in the study population. However, because male breast cancer is linked to BRCA1, BRCA2 and other inherited mutations, it is possible that a sizable number of study participants may have been found to be mutation carriers.

Discussion:

According to study author Dr. Ahmedin Jemal, quoted in a Newsweek, article, “it’s important for male patients to ask a physician about their individual risk for contralateral breast cancer before making any decisions about the surgery…It’s only the patients at high risk who are likely to benefit from the procedure.”

Although not as much research has been done on men with breast cancer, we do know that those with a BRCA2 mutation have a 7% risk of developing breast cancer by age 70. No studies, however, look at the risk of a second breast cancer diagnosis in men with BRCA2 mutations. By looking only at male survival rates and failing to also look at recurrence rates, researchers are unable to consider the possibility that double mastectomy may be decreasing the occurrence of a second cancer, helping these patients avoid further treatment.

In women without a BRCA mutation, the chance of a second breast cancer diagnosis 10 years after the initial diagnosis is approximately 10%. The risk is 10%-30% for breast cancer survivors with a BRCA mutation.

Additionally, it is important to note that the researchers were able to see a significant difference in the rate of double mastectomy only between the years 2004-2005 and 2010-2011. They were unable to see any significant differences when comparing rates in 2004-2005 to those in 2006-2007 or in 2008-2009. Although the lack of a rate increase between 2006 and 2009 may strengthen the researchers’ argument that the increased rate of double mastectomy is, in fact, new, more data needs to be collected to ensure the trend is stable rather than something unique to 2010 and 2011. 

Conclusions:

For both men and women, the decision to undergo a prophylactic mastectomy should be an individual, personal one, made by patients in consultation with their healthcare providers. Although the data from this study indicate the rates of this surgery in men with breast cancer have increased, more research is needed, both to understand why the rates have increased and to determine if there is a subset of men who will benefit from the procedure.