- Harmful mutations of the BRCA genes interfere with the protective function of these tumour suppressor genes, thus rendering the individual at higher risk of developing breast and other cancers.
- BRCA1 and BRCA2 are inherited in an autosomal dominant manner.
- Estimated lifetime risks
|Tumour type||Population risk||BRCA1||BRCA2|
- In primary care:-
- Do not actively seek to find persons with a family history of breast cancer
- First and second degree family history for those that present with concerns
- If clinically relevant take family history for those over 35 on combined OCP or considering HRT
- Second degree family history should include paternal and maternal relatives
- For referral decisions be as accurate as possible with:-
- Age of diagnosis
- Tumour sites
- Multiple cancers in an individual (including bilateral breast)
- Jewish ancestry (5-10 x more likely to carry BRCA mutation)
- NICE suggests that information that should be given to all patients presenting with concerns
- For genetic counselling and, where appropriate, testing the Cancer Genetics Service for Wales has an all-Wales remit.
- To access the Cancer Genetics service the patient must meet minimum referral criteria
- Depending on their individual risk calculation patients may be offered:-
- A change in their breast screening program
- Prophylactic surgery
- Genetic testing
- Lifestyle advice
- GPs in Wales may be asked to initiate chemoprophylaxis with Tamoxifen (premenopausal women) or Raloxifine or Tamoxifen (postmenopausal women). This therapy is endorsed by NICE but off licence.
- Chemoprophylaxis carries risks as well as benefits and the prescriber should be aware of these factors