What is BRCA?

What is BRCA?

BRCA refers to two genes, BRCA1 and BRCA2, that every person (male and female) has. They are just two of the 30,000 genes found in almost every cell of our body.  

The BRCA genes fall into a category of genes known as ‘tumour suppressor genes’ and they play a vital role in the prevention of cancer.  

What if someone has a faulty BRCA gene?

Some people may have a fault, often called a mutation, in one of their BRCA genes. Mutations compromise the gene’s ability to function, and therefore if an  individual inherits a mutation in either BRCA1 or BRCA2 they have an increased risk for developing certain cancer types.  

Both men and women can have BRCA mutations and can pass these on to their children, whether that is daughters or sons. For a couple in which one partner has a BRCA mutation there is a 50% chance with every pregnancy that the faulty gene will be passed on. This is referred to as dominant inheritance and is illustrated in the image below. 

The rest of the information about BRCA on this website refers to someone who has one BRCA mutation i.e. one copy of either their BRCA1 or BRCA2 gene is mutated. In very rare cases someone may have a mutation in both of their BRCA2 genes, one mutation inherited from each parent. This causes a genetic disorder called Fanconi Anaemia Type A. You can read more about this here

I have a BRCA gene mutation – which cancers am I at risk of developing?

Someone with BRCA gene mutation has a higher risk of developing certain cancer types, often referred to as the ‘BRCA related cancers’ These are as follows:

I have a BRCA gene mutation – what is my risk for developing BRCA–associated cancers?

Someone with a BRCA gene mutation has a greater risk for developing the BRCA-associated cancers compared to someone who has fully functioning BRCA genes (I.e. the rest of the general population).  The risks are different for each cancer type and depend on which BRCA gene is mutated. 

The tables below show the detailed cancer risks for females and males.  Ranges are given, as the risk to each individual depends on multiple factors.  

Female Cancer Risk Over Lifetime (to age 80)
Cancer General Population With BRCA1 gene fault With BRCA2 gene fault
Breast 11.5% 72% (65-79%) 69% (61-77%)
Ovarian 1.5% 44% (36-53%) 17% (11-25%)
Pancreatic 1.0% Not elevated 2% (1-4%)
Male Cancer Risk Over Lifetime (to age 80)
Cancer General Population With BRCA1 gene fault With BRCA2 gene fault
Breast Less than 0.1% 0.4% (0.1-1.5%) 4% (2-8%)
Prostate 12.5% Not elevated 27% (21-35%)
Pancreatic 1.0% 3.0% 4.0-5.0%

Sources: Cancerresearchuk.org; UKCGG BRCA1 Germline Pathogenic Variant Carriers Management Guidelines for Healthcare Professionals; UKCGG BRCA2 Germline Pathogenic Variant Carriers Management Guidelines for Healthcare Professionals

I have a BRCA gene mutation – is there anything I can do to manage or reduce my cancer risks? 

YES. Someone who is identified as having a BRCA gene mutation is eligible, on the NHS, to access several options that help to manage or reduce their cancer risk.  These options, often referred to as ‘risk management options’, are designed to either: 

  •  catch the cancers earlier when the prognosis is likely better 
  •  reduce the chance of BRCA-associated cancers developing altogether 

There are also options for couples in which one partner has a BRCA gene mutation to avoid passing on the gene to their children. 

Much more information about these risk management options can be found here

 

What is the role of BRCA gene testing?

BRCA gene testing, carried out primarily via saliva sample, allows an individual to find out if they have a BRCA gene mutation.

Without testing it is impossible to know if you have a mutation or not. Without testing, is it impossible for those with the mutation to be aware of their increased cancer risk and it is impossible for them to take steps to manage this (via the options discussed above). 

The role of BRCA testing is huge. It is the ‘key’ to the risk management that have life-saving potential those who have a mutation. It provides knowledge that has the power to change their life and future in a big way.