Men are diagnosed with breast cancer at less than one per cent the rate of women, but when they are the disease is often more advanced on average, and they are more likely to die from it, according to an international study.
Researchers led by Mikael Hartman at the National University of Singapore combined cancer registries from Denmark, Finland, Norway, Sweden, Singapore and Geneva, Switzerland, with cases dating back to 1970.
The data included about 460,000 women diagnosed with breast cancer, and about 2,700 men.
Men were more likely to have the disease that had spread beyond the breast by the time they were diagnosed. In treatment, they had less surgery and radiation than women but similar rates of chemotherapy and hormone treatment.
Over the entire time period, men had a 72 per cent chance of surviving breast cancer in the five years after a diagnosis, compared to 78 per cent in women.
"Men who develop a breast lump delay seeing their doctor longer than a comparable woman with similar symptoms," Hartman said in an email to Reuters Health.
"Male breast cancer is rare but men can develop the disease and should be aware that they should seek care if a breast lump develops."
His team said in the Journal of Clinical Oncology that previous studies have shown that it typically takes a few months from when men start getting symptoms until they are diagnosed with breast cancer.
Men are most commonly in their 60s or 70s when diagnosed, according to the US National Cancer Institute. Radiation exposure and diseases that increase estrogen levels, such as liver cirrhosis or the genetic disorder Klinefelter syndrome, are among the factors that raise a man's risk.
"It's not surprising that men with breast cancer present with later stages," said Susan Dent, from the Ottawa Hospital Cancer Centre in Canada, who was not involved in the study.
"That's just because the awareness of the fact that breast cancer can occur in men is just not as acute. Men aren't as likely to think of it, and health care providers aren't as likely to think of men having breast cancer."
Men should be particularly aware of breast cancer, and possibly consider getting screened for it, if they have a family history of the disease, including a predisposition to cancer caused by mutations in the BRCA1 and BRCA2 genes, which are well known to raise women's risk of breast and ovarian cancers, she added.
Because of recommendations for regular mammograms in women starting in their 40s or at age 50, depending on the country, many cancers are caught in women before they have any symptoms.
But the United States Preventive Services Task Force, a federally-supported panel that sets guidelines for cancer screening, does not recommend regular breast cancer screening in men without symptoms.
"In total, male breast cancer is still a rare event. Never would I recommend that all men routinely go out and get screened," said Dent.