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Learn about increased risk groups, genetic testing, and tailored treatment options for managing inherited breast cancer. Understand the major and minor risk factors, high penetrant mutations like BRCA1/2, and the importance of genetic testing in management & surveillance.
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Shiva Sharma SHO to Professor Redmond The Surveillance and Management of Inherited Breast Cancer
Overview • Introduction • Increased risk groups • Consideration of genetic testing • Management of patients with mutation • Follow-up
Introduction • Lifetime average risk 1 in 8 • Approximately 184,450 breast cancer cases in USA • 5-10% due to high penetrance gene carrying patients • Breast Cancer gene first identified 1990 • BRCA 1/2 mutations found to be 1 in 250-500 • Increased prevalence in some ethnic groups • Specific screening consideration given to those classified as increased risk • Tailored treatment options for inherited risk groups
Increased Risk Patients • Risk factor: variable increasing the chances of developing breast cancer from the average population • Major risk factors – double the risk • Minor risk factors – risk between 1.0-2.0
High Penetrant Mutations • BRCA 1/2, PTEN, Tp53 • Tumour suppressor genes coding for DNA repair • Accounts for 5-10% breast cancers • Young age of diagnosis • Aim is to recognise individuals early to reduce morbidity/mortality
Characteristic history • Large number affected family • Young age of diagnosis • Multiple cancers in one person • Uncommon cancers • Common cancers at younger age
BRCA 1 and 2 • Tumour suppressor gene • 85% lifetime risk of Breast cancer • Found in 45% of families with multiple cases • 90% of families with both breast and ovarian cancer • Frequency 1/250-500 • More common in Ashkenazi Jewish population • 20-25% of cases where woman <30 found to be carriers
Major risk factors significantly increase risk • Once an major risk is identified minor factors add little
Risk Categories • Average Risk – the general population • Moderate Risk – increased risk for age group, but less than 5x • High Risk – 5-10x • LCIS, ADH, ALH • First degree relatives without mutation • Very High Risk - >10x • High penetrance gene mutation • Chest wall irradiation prior to 30
Average Risk • Accepted national screening programs • 40 in USA • 50 in UK and Ireland • Annual mammography and examination • Chemoprevention not indicated
Moderate Risk • Screening as in the average risk group • Patients should be acquainted with chemo preventative drugs
High Risk • Annual mammography • Semi-annual breast exam • Premenopausal – Tamoxifen • Postmenopausal – Tamoxifen or raloxifene
High Risk (2) • Woman with strong family history without BRCA mutation • MRI with annual mammography • Screening 10years before youngest diagnosed family member or 40 • Twice yearly breast exam • Consider chemoprevention
Very High Risk • History of irradiation • Annual mammography starting 5-10years after treatment • Annual MRI consideration • Semi-annual exam • Consideration for chemoprevention and risk reduction surgery
Very High Risk (2) • BRCA 1/2, PTEN, Tp53 mutations highly penetrant genes • Genetic testing in children only for suspected p53 mutation • BRCA mutation testing not before 25
Genetic Testing • Guidelines for consideration of testing • Early age of onset • Multiple affected family members • 2+ relatives diagnosed <50 • 2+ ovarian cancer • Multiple primary cancers including breast and ovarian in 1 patient • Male breast cancer
Genetic Testing (2) • Medullary and triple negative breast cancers more likely to be BRCA • Ashkenazi Jewish descent or other ethnic groups with known mutations • 1st and 2nd degree relatives with breast cancer • Family history prostate, thyroid sarcoma, endometrial, adrenocortical, brain, pancreatic cancer
Management • Testing for known mutations • If negative, then move on to full sequence testing • Issue with Variation of Unknown Significance • Recommend careful surveillance
Management of Mutations • Careful lifetime follow-up • +/- chemoprevention • +/- risk reduction surgery
Breast Retaining Cases • Semi-annual exam • Annual mammography and annual MRI offset by 6months
Surgical Management • Bilateral total mastectomy +/- reconstruction • 95% effective • Timing of surgery should be offered to patients in late 30’s, but before 50 • Axillary SNB • Pre-op MRI, if negative, biopsy not indicated
Surgical Management • Prophylactic oophorectomy • 50% reduction in Breast cancer in BRCA patients • HRT can still be used for symptomatic relief
Follow Up • Life time follow up for BRCA mutations • Gynaecology follow up with pelvic examination annually • Continued follow-up even if prophylactic mastectomy and oophorectomy performed
Conclusion • Genetic testing is a valuable investigation • Patient interest • Informing patients • Tailored treatment and follow-up