Male Carriers of BRCA gene alterations
Alterations in BRCA genes are most well known for their association with breast or ovarian cancer in women.
However, men that inherit BRCA gene alterations may also be at risk of cancer.
The most common cancers that occur in men with BRCA gene alterations include cancer of the male breast, and prostate cancer. Men that inherit a BRCA gene alteration may, in turn, pass the alteration on to their children.
The risk of prostate cancer in a man with a BRCA1 gene alteration is slightly increased compared to the population risk of approximately 12-13%. The risk of prostate cancer in a man with a BRCA2 gene alteration is greater, with an estimated lifetime risk of 20-25%.
Most cases of Prostate Cancer in men with BRCA gene alterations are diagnosed after the age of 40.
Screening for Prostate Cancer
As you know, it’s important to diagnose cancer at as early a stage as possible. Treatment is more effective the sooner cancer is detected.
There are positive developments taking place with research underway to develop a screening test to detect prostate cancer in men with BRCA gene alterations at the earliest stage. Most current research is directed at using markers in the blood that show a cancer is present before symptoms develop.
A blood marker of interest for detecting Prostate Cancer is a protein called PSA or Prostate Specific Antigen, which is often produced by prostate cancer. Men with prostate cancer often have high levels of PSA in their blood.
However, PSA can be increased for a number of reasons. PSA levels can increase if the prostate is inflamed, called prostatitis, or enlarged, as in BPH. PSA can also be increased after normal activities, such as cycling or ejaculation. PSA levels may also be increased after doctors perform rectal examinations to check the prostate.
Furthermore, some men with prostate cancer may have normal PSA levels.
PSA levels also change as men age, and the blood PSA level of a man in his 70s may be greater than a man in his 40s.
A large global study, called the IMPACT study, coordinated by the Royal Marsden Hospital and Institute of Cancer Research, has been running for many years. The aim of this study is to investigate the role of PSA blood testing as a screening tool in men with BRCA gene alterations compared to men without such alterations.
As part of this study, PSA levels were checked every year. If the PSA level rose above a certain level, biopsy of the prostate gland was recommended.
Early findings of this study have shown that this approach may be particularly useful in men with BRCA2 gene alterations, but further analysis is required to determine if it is useful in men with BRCA1 gene alterations.
Male Breast Cancer
Prostate cancer is not the only cancer that can occur in men with BRCA gene alterations, including of male breast cancer.
A man with a BRCA1 gene alteration may also have a 0.1-2% risk of developing Breast Cancer, while a man with a BRCA2 gene alteration has a 5-10% risk of developing breast cancer. Male carriers of BRCA gene alterations are advised to check for any changes in the texture of the small amount of breast tissue on their chest, and to inform their doctor if they notice anything new or unusual. Mammograms are not recommended for men with such alterations, as they are technically difficult, and because the risk in men with BRCA gene alterations is still less than the average woman in the general population.
Risks of Other Cancers
Rarely, other cancers, such as pancreatic cancer, or melanoma, can occur in individuals with BRCA gene alterations. However, the absolute risk of these cancers is quite small.