Breast Cancer in Men
It may be relatively rare (1% of what females get) but as for women, early diagnosis increase the chance of cure. Unfortunately, many men ignore the symptoms and present late. Healthy diet and lifestyle are the best preventions, along with getting your doctor to check everything unusual in the breast area.
With no known cause, risk factors for breast cancer in men are age (over 60), obesity, positive family history, liver disease and exposure to oestrogens or radiation. (Note that breast lumps can appear in teenage boys going through puberty but breast cancer is virtually non-existent at this age).
The classic symptoms are: lump, usually under the nipple; overlying skin changes or nipple redness; or discharge from the nipple (rare). Diagnosis is based on examination, imaging (mammogram or ultrasound), then a needle biopsy of the lump.
Treatment is a specialised area, as you can imagine - a combination of surgery, radiation or chemotherapy usually.