Inherited Breast Cancer in Men

Cancer genetics

Cancer is a genetic disease, it is caused by alterations in genes that control the way cells grow and multiply.

It is rare for a man to develop a breast cancer, about 400 new cases occur in the UK each year.

Factors that can affect the risk of a man developing breast cancer include older age ( 60 years+), being overweight, increased  amount of breast tissue, previous chest radiation, increased alcohol use and  having existing  liver damage.

Family history- you may have an increased risk of breast cancer if you have relatives with breast cancer, especially if they are close relatives to you and diagnosed at a young age. Sometimes we see a pattern of breast cancer, ovarian cancer and prostate cancer in families where there is an inherited breast cancer gene alteration.

Most cancers are caused by gene alterations that happen as we go through life and are not inherited. Some gene alterations can be inherited. Inheriting a gene alteration means that person has an increased risk of developing certain cancer(s) as they go through life.

Why am I being offered genetic testing?

 You are being offered a genetic test to see if your breast cancer might be due to an inherited Breast cancer gene alteration (variant).

What genes can I be tested for:

BRCA1 and BRCA2

Two sets of genes that are known to give an increased risk of breast cancer in men are called BRCA1 and BRCA2, this stands for BReast CAncer gene1 and BReast CAncer gene 2.

Figures taken from the UK Cancer Genetics Group guidelines 2023

 If you inherit a BRCA gene variant you also have a higher lifetime risk of prostate cancer.

Figures taken from the UK Cancer Genetics Group guidelines 2023

 Female BRCA carriers

Inheriting a BRCA variant gives female carriers a very high lifetime risk of developing Breast cancer and or ovarian cancer.

Figures taken from the Uk Cancer Genetics Group guidelines 2023

BRCA carriers- Prostate Risk

 We advise men to consider annual prostate surveillance, such as the PSA blood test with their GP from 40 years, especially if you are found to have a BRCA2 gene variant.

BRCA variant carrier –risk of other cancers

There may be an increase risk to other cancers such as melanoma and pancreatic cancer, especially for BRCA2 variant carriers. No pancreatic surveillance is currently recommended.

 Other genes

As science moves forward we are learning more about other genes that may influence the risk of developing breast cancer. You will be offered the choice to be tested for BRCA1 and BRCA2 only or you can decide to opt for testing for a number of breast cancer genes. You can decide what testing feels right for you and your family at this time.

For most of these genes, research suggests there is a known low- moderate risk of breast cancer risk associated for female gene variant carriers.  Testing has not been available for these genes for very long and as men do not get breast cancer as often as women, it is difficult to fully understand the risk of breast and other cancers associated with these genes for men.

Your genetic counsellor and your doctor will advise you using the data available to date. As time goes on we hope to be able to offer more accurate information.

Genes we can offer testing for include PALB2, PTEN, ATM, CHEK2, TP53, CDH1.

How are Breast cancer genes inherited?

Most breast cancer genes are inherited following a pattern known as autosomal dominant inheritance. If you have an alteration in a Breast cancer gene then each child, male or female, has a 50% chance of inheriting the Breast cancer gene with the alteration.

Breast cancer genes have an important job in the body

Most of the breast cancer genes work as tumour suppressor genes to protect you from getting breast cancer. If you inherit a tumour suppressor gene that is not working, this means you are more likely to develop certain cancers.

Does everyone who inherits a Breast cancer gene variant develop cancer?

No. Not everyone who carries a Breast cancer variant will go on to develop cancer. If you have a gene variant, your family members can opt for genetic testing to see if they also have inherited the same gene variant.

As the risk of developing breast and other cancers are higher than for a person who is not a Breast cancer gene carrier, certain surveillance procedures and follow up are recommended.

The risk of various cancer(s) and options available to manage risks, will vary depending if you are male or female.

Having a diagnosis of a cancer can be difficult. You may find yourself worrying more. It is important to know you are not alone and the team here in International Gene Clinic want to support you.