Male breast cancer

The incidence of male breast cancer varies throughout the world. In the United Kingdom it counts for about 0.7% of all breast cancers. There seems to be an increasing incidence in America, especially amongst black males, with about a thousand cases being diagnosed per year. The mean diagnosis age in America is about sixty. If you look at Africa, particularly sub-Saharan, the incidence of male breast cancer varies between 3% to 10%.

Risk factors for male breast cancer are interesting, it is definitely not associated with benign breast lumps or gynaecomastia (large breasts). There does appear, however, to be an inherited component, the mechanism of which is unknown. The lifetime risk of breast cancer for a man whose mother and sister had breast cancer is about 2.5%.

Male breast cancer is increased in families who have the BrCa2 gene mutation. It increases in males who have Kleinerfelters Syndrome which is XXY; a chromosome abnormality. It seems to be increasing in men who work on electrical lines, and ionising radiation and electromagnetic fields have also been implicated.

Male breast cancers are almost always ductal carcinomas. Lobular carcinomas are very rarely seen and usually in association with Kleinerfelters Syndrome. All variations of ductal carcinomas are found, including Paget’s Disease, and 80-90% are oestrogen receptor positive. Only about 7% are progesterone receptor positive and 50% of them also contain androgen receptors.

The disease parallels female breast cancer but tends to present in an older age group, and at a more advanced stage, and this is due to the decreased amount of breast tissue so it is more frequent to see skin and chest fixation.

90% of all male breast cancers present as a, usually, painless breast lump, 14% present with nipple discharge, about 20% with nipple changes, 4% with breast pain and in 3% it is metastic, i.e. spread throughout the body.

Detection

Breast cancers usually present as an asymmetrical eccentric firmness either with fixation or ulceration of the breast. Any unilateral breast mass which is firm, fixed or ulcerated should be investigated via a mammogram and a sonar. Sensitivity in mammograms is the same as it is in females. An ultrasound is also of benefit and a needle biopsy should give the diagnosis.

Treatment

Treatment for male and female breast cancer is multi-disciplinary, in other words it involves both surgery and oncology (chemotherapy and radiation therapy). The usual treatment is a modified radical mastectomy with a lymph node dissection followed by radiation treatment to the chest wall, followed by adjuvant chemotherapy or endocrine therapy to improve survival.

As there is a great propensity for local reccurrence it is important that the correct treatment is done initially. As stated, these tumours are mainly oestrogen receptor positive and endocrine therapy such as Tamoxifen, Progesterone or an orchodectomy (removal of the testes) works incredibly well.

Adjuvant therapy, i.e. chemotherapy, where there are positive lymph nodes or tumours which show signs of aggressiveness, has similar benefits as seen in women. If more than ten lymph nodes are positive there is only a 10% chance of having a ten-year, disease-free, survival. If four to nine lymph nodes are positive, 25% of the patients will be disease free in ten years. With one to three lymph nodes positive, 50% will be disease free in ten years. If no nodes are involved, 70% of the patients will be disease free in ten years. In lymph node negative male breast cancer, where the tumours are greater than 2cm, the risk of relapse is twice that for lesions less than 1cm.

Prognosis

The prognosis is identical to female breast cancer, stage for stage. Because most men are diagnosed at a later stage it gives the impression of a worse prognosis. It is important then for men with firm, unilateral breast masses to seek medical attention, see their physician or contact a breast centre as quickly as possible.

Written by Dr Carol-Ann Benn

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