The findings shed light on a rare disease in men, one that researchers had earlier assumed was deadlier for males.
“Men can develop it and should be aware that they should seek care if a breast lump develops,” said study co-author Dr. Mikael Hartman, an assistant professor at National University of Singapore.
The same mutation greatly boosts the risk of breast cancer in women.
It’s not clear why breast cancer is much less common in men. Women, of course, have much more breast tissue. But volume doesn’t appear to affect the risk of breast cancer in women, since those with large breasts don’t develop the disease more than those with small breasts, El-Tamer said.
Estrogen could be key, study co-author Hartman said, since it seems to fuel breast cancer and is almost entirely absent in men.