Do brca1 and brca2 mutations affect men the same way they affect women?

No. The penetrance of a mutation defines the risk of developing the disease in those that carry a particular mutation. Women with brca mutations have lifetime risks estimated between 40-80%; men's risks are much less-studied but are probably in the range of 10% or less.
Male breast cancer. Men with a brca mutation have a dramatically elevated relative risk of developing breast cancer, but because the overall incidence of breast cancer in men is so low, the absolute risk is equal to or lower than the risk for women without a brca mutation. Approximately 1% to 2% of men with a brca1 mutation will develop breast cancer by age 70 and 6% of men with a brca2 mutation will develop cancer.

Related Questions

If a man is found to have brca1 or brca2 mutations, what should his next step be?

Genetic counseling. The penetrance of a mutation defines the risk of developing the disease that one is at risk for. The penetrance of the brca mutations varies between 40-80% for women and less than 10% for men, depending on the specific mutation and patient factors. The best method to prevent breast cancer at this time is to have a prophylactic bilateral mastectomy. Read more...
Surgical consult. I would recommend any patient who tests positive for brca 1 or 2 meet with a genetic counselor and breast surgeon to discuss their risk of developing breast cancer as well as treatment options available. This should be followed by a consultation with a plastic surgeon to discuss reconstruction of the breast. Read more...
Medical Oncologist. One experienced with brca assoc risks. Men that are carriers have an approx. 8% risk of developing breast cancer (compared to less than 1% for the general population) this usually does not justify prophylactic surgery in men, but there are surveillance recommendations that can be followed. Also the risk of prostate and pancreatic cancer are higher. Genetic counselor will not help with surveillance. Read more...

Are genetic tests available to detect brca1 and brca2 mutations, and how are they performed?

Yes. But they are expensive and really should be done in conjunction with a genetic counselor since results can be misleading. Read more...
Yes. Brca1 and 2 mutation analysis is performed at myriad lab in usa. One can either use an oral swab or blood for testing. It is strongly recommended that the testing is done in the context of genetic counseling as the interpretation of the test and risk assessment for breast/ovarian cancer are complex and requires professional explanations. Read more...

I was told that if someone was treated for breast cancer 20yrs ago with tamoxifen, that they did not carry the BRCA1 & BRCA2 mutations? Is this true?

BRCA test was not av. BRCA test is not often done, unless there is strong family history of breast Cancer in multiple members. This test was not available 20 years back, so it would not have been done. But it is not to be done except in selected cases where we suspect it may be abnormal. Read more...