US authorities are urging drug companies to include an unexpected demographic in future breast cancer clinical trials - men.
At present, there's surprisingly limited knowledge on male treatment methods.
"Male breast cancer (has) never had an important lobby," Dr Marleen Meyers, an assistant professor specialising in breast cancer at NYU Langone Medical Centre in Manhattan, told The Daily Beast.
"(It's) a less known and less spoken about breast cancer," said Meyers.
According to officials at the National Cancer Institute in the US, the disparity is directly correlated to numbers: Breast cancer is about 100 times less common among men than among women.
The Food and Drug Administration (FDA) is hoping to remedy the dearth of knowledge with a plea aimed at influential drug-makers.
"Men have historically been excluded from breast cancer trials," said Dr Tatiana Prowell, a breast cancer scientific lead at the FDA's Office of Haematology & Oncology Products.
"We are actively encouraging drug companies to include men in all breast cancer trials unless there is a valid scientific reason not to," said Prowell.
The lack of males is a departure from the many clinical trials where men are well represented, Prowell said. And it's a departure with pernicious side effects.
While males and females generally respond to the same chemotherapy or radiation regimens, Prowell said it's possible that successful treatments could differ between genders.
