Breast cancer is killing 70 men a year in Britain, often because men are too shy or too ignorant about the symptoms to get medical help.
Prof Ian Fentiman, a leading cancer specialist from Guy's Hospital, London, said yesterday that 250 men are diagnosed with breast cancer every year.
In a report in The Lancet he said: "There is evident need for national protocols for both information and support for men diagnosed with breast cancer."
Prof Fentiman added: "Half the men who get breast cancer in the United Kingdom are not diagnosed until their cancer is very advanced, and men are dying unnecessarily because they are unaware of the symptoms or because they are too embarrassed to seek help."
The most common signs of male breast cancer are a painless lump in the chest or a nipple which has turned inwards, but these are similar to the effects of gynaecomastia, a harmless swelling under the nipple.