Whether screening men at high risk for breast cancer is worthwhile remains unclear. A retrospective study in these men found that mammography identified tumors when they were smaller and at an earlier stage in men who received screening than in those who received diagnostic exams.

An analysis of 12 years of data suggests that mammography allows early tumor detection in men at high risk for breast cancer. However, researchers need further evidence before they can establish widely accepted screening guidelines.

The chance of a man developing breast cancer in his lifetime is quite small—about 1 in 833—so screening all men is not worthwhile. However, men who carry mutations in either BRCA1 or BRCA2, or who have close relatives with breast cancer, are much more likely to develop the disease. In addition, men who have had the disease are susceptible to recurrence.

No studies have provided definitive evidence that screening is beneficial for these men, and current screening recommendations vary. The National Comprehensive Cancer Network's 2019 guidelines recommend that men at high risk who are 35 or older should undergo annual medical exams for breast cancer, but they don't recommend mammography. In contrast, the American Society of Clinical Oncology suggests mammography as an option for this group.

To determine whether screening is useful in high-risk men, Yiming Gao, MD, of the New York University Langone Medical Center in New York, and colleagues analyzed data on 1,869 men examined at the center between 2005 and 2017. Every patient visit included a mammogram, and 48.9% also involved a sonogram. Nearly 87% of the visits were for diagnosis, whereas about 13% were for screening.

The researchers found that screening pinpointed five tumors in high-risk men. When the scientists compared data from men who received diagnostic exams with data for those who received screening, they found that mammography identified tumors when they were smaller and at an earlier stage. For example, the average tumor size in the men receiving diagnostic exams was 2.1 cm, versus 1.2 cm in the screening group. Although 58.3% of the tumors in the diagnostic group had metastasized to the axillary lymph nodes, none of the tumors in the screening group had.

The detection rate in the screened men was 18 per 1,000 exams. In women who are at average risk for breast cancer, mammography typically reveals three to five tumors per 1,000 exams. “The finding that there may be an even higher cancer detection rate in high-risk men than in average-risk women suggests that targeted mammography screening in high-risk men may be worthwhile,” says Gao. “We hope to be able to expand our analysis to include data from other cancer centers to better delineate risk in men and to evaluate how to best screen in this patient population.”

Suleiman Alfred Massarweh, MD, of Stanford University Medical Center in California, who wasn't connected to the research, says that the results suggest “there is potentially some value in screening some male patients who are at high risk.” But he cautions that because the study is small and reflects the experience of only one institution “it's not going to change clinical practice.”

Earlier this year, Maria Adele Marino, MD, of the University of Messina in Italy, and colleagues published results from a similar study that showed screening high-risk men with mammography could detect 4.9 cancers for every 1,000 exams. To strengthen the case for screening, she says, researchers should conduct prospective trials to confirm that mammography benefits men at high risk of breast cancer. Although these studies are necessary, she predicts that “mammography screening in high-risk men will be a reality in the near future.” –Mitch Leslie