Dec. 13, 2010 (San Antonio) -- Men who are diagnosed with breast cancer are more likely than female patients to die in the next 15 years, researchers report.
"This may be due to a difference in tumor characteristics and treatment," says study leader Hui Miao, a PhD candidate at the National University of Singapore.
Male breast cancer is rare, accounting for less than 1% of all breast cancers in the U.S. Given its scarcity, few studies have assessed its prognosis "and we know of no recent studies looking at trends in survival," Miao tells WebMD.
So Miao and colleagues studied 459,846 women and 2,664 men diagnosed with breast cancer in Denmark, Finland, Switzerland, Norway, Singapore, and Sweden between 1970 and 2007.
Among the findings, presented at the San Antonio Breast Cancer Symposium:
Men were diagnosed at an older age: 69 vs. 61 for women.
Twice as many men had later stage III or IV disease: 18% vs. 9% of women.
Only 25% of men were alive 15 years after diagnosis, compared with 44% of women.
However, when the analysis took into account men's older age, later stage at diagnosis, and the treatment they received, men actually had a better prognosis than women, Miao reports.
More Men With Breast Cancer Eligible for Lifesaving Hormone Therapy
Steven J. Isakoff, MD, PhD, a breast cancer specialist at Massachusetts General Hospital Cancer Center in Boston, says the fact that more men are eligible for hormone therapy with tamoxifen and/or aromatase inhibitors may be one reason they appear to do better once treatment is taken into account.
About 90% of men have tumors that are fueled by hormones and will be helped by hormone therapy, he tells WebMD. In contrast, only about 60% to 70% of women have hormone-driven breast cancers, Isakoff says.
"In general, people with hormone receptor-positive breast cancer live longer than those with hormone receptor-negative disease," he says.
The fact that men don't think they’re susceptible to breast cancer and therefore don't perform breast self-examinations or get regular mammograms may account for their later stage at diagnosis, he hypothesizes.
Their older age at diagnosis "probably has to do with fact many men develop obesity as they get older, which can contribute to increased estrogen levels," Isakoff says. Estrogen is one of the hormones that fuels breast cancer.
This study was presented at a medical conference. The findings should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.