Inherited Prostate Cancer

Cancer genetics

Cancer is a genetic disease, it is caused by alterations in genes that control the way cells grow and multiply.  Most prostate cancers are caused by gene alterations that occur as a man goes through life and are not inherited.

There are around 55,100 new prostate cancer cases in the UK every year, that’s around 150 every day (2017-2019). Incidence rates for prostate cancer in the UK are highest in males aged 75 to 79.

Factors that can affect the risk of developing prostate cancer include age, ethnicity, diet etc. Some gene alterations can be inherited. Inheriting a gene alteration means that a person has an increased risk of developing particular types of cancer. It is estimated that about 9-12% of prostate cancer diagnosed, may be due to an inherited predisposition Scheinberg et al (2021). Genetic testing can help to identify some of these families.

Clues that there may be an inherited risk to prostate cancer in a family include

• Several close relatives affected with prostate cancer
• Young diagnosis of prostate cancer- younger than 55 years
• Prostate cancer in a family with other cancers such as breast cancer, ovarian cancer and pancreatic cancer.

Treatment for Prostate cancer

Your treatment will depend on how abnormal your prostate cancer cells and the stage and severity of your cancer.

You may be offered surgery, radiotherapy, hormone treatments, targeted drug treatments and chemotherapy.

Why am I being offered genetic testing?

You are being offered a genetic test to see if your prostate cancer might be due to an inherited prostate cancer gene alteration (variant).  Inherited a gene alteration may increase the risk of developing more aggressive form of prostate cancer.

What genes can I be tested for

BRCA1 and BRCA2

There are several genes known to influence the risk of a prostate cancer developing, two of these genes are called BRCA1 and BRCA2. They are known as BRCA, BReast CAncer genes as they also can give a higher risk of breast cancer.

(Figures taken from the UK Cancer Genetic Group leaflet, 2023)

 What will it mean if I have an inherited BRCA gene alteration?

Your test result can help you and your doctor understand why you developed prostate cancer, it may help guide the risk that your prostate cancer might come back after treatment and or your risk of developing other cancers.

Targeted treatment

We are learning about certain drugs that may benefit some patients. An example of this is are medications known as PARP inhibitors. Prostate cancer cells with either a BRCA1 or BRCA2 gene variant need a protein called PARP, as this protein helps repair damaged DNA. PARP inhibitors works by blocking the effect of PARP, this means the damaged DNA can’t be repaired and the prostate cancer cells are more likely to die.   These drugs may be offered in certain situations such as if you have an advanced prostate cancer.

Your doctor will advise the best treatment for you, based on your specific cancer type, cancer stage and your genetic test result and let you know if there is a targeted therapy that might be suitable for you.

Risk of other cancers for Men who inherit a BRCA1 or BRCA2 variant:

They are known as BRCA genes, BReast CAncer genes as inheriting a faulty BRCA gene also can give a higher risk of breast cancer.  Men who inherit a BRCA gene variant have a small risk of developing breast cancer, it is estimated to be <1%   risk for BRCA1, and between 2%-8% for BRCA2 (Figures taken from the UK Cancer Genetic Group leaflet, 2023).

We can advise you on how to be aware of any changes in your chest area. Mammograms are not usually arranged unless you have excess tissue in the chest area.

In some families with BRCA2, we notice other cancers such as melanoma and pancreatic cancer.

 Family implications if you are a BRCA carrier

If you have found to have a BRCA gene alteration, your children have a 50% (1 in 2 risk) of also carrying the same BRCA gene alteration. Testing is available to your adult relatives. The risk of breast and/or ovarian cancer is high for women who inherit a BRCA gene alteration whereas male carriers have an increased risk of prostate and breast cancer.

What genes can I be tested for

We offer testing for gene variants in BRCA1, BRCA2, PALB2, ATM, Chek2, HOXB13, MLH1, MSH2, MSH6, PMS2 and EPCAM genes.

You can decide what testing feels right for you and your family at this time. However, knowing you have a cancer gene variant will give you and your family access to personalised treatments, advice and tailored surveillance programs if applicable.

It is important that you are aware that your genetic test result might give information about your risk of developing other cancers apart from prostate cancer.   If you are found to have a gene alteration, your genetic counsellor and doctor will discuss your result with you in detail.

How are prostate cancer genes inherited?

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

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

No. Not everyone who carries a cancer variant will go on to develop cancer.  It just means that your risk to develop certain cancer(s) is higher, than someone who is not a gene carrier.

 Family implications:

If a gene variant is detected in you, your family members can opt for genetic testing to see if they have inherited the same gene variant.   It is important to remember that there can be significant risk of specific cancers in female family members who inherit a gene variant. Testing can be offered to male and female adult relatives (related by blood).

As the risk of developing cancer is higher than for a person who does not carry a cancer gene carrier, certain screening procedures, risk reducing options may be advised.

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.