Breast cancer, BRCA and familial cancer syndromes

Question 1

Counsel a woman what BRCA 1 or 2 is and her risk of cancers

Answer 1

• BRCA is an autosomal dominant condition where carriers of this tumour suppressor gene mutation are at increased risk of breast and ovarian cancer.
• Children of BRCA carriers have a 50% risk of becoming carriers.

BRCA1:

• Lifetime risk of breast cancer 70%
• Lifetime risk of ovarian cancer 50%

BRCA2:

• Lifetime risk of breast cancer 70%
• Lifetime risk of ovarian cancer 20%.

Question 2

Counsel a BRCA carrier woman on strategies to reduce her risk of ovarian cancer

Answer 2

Conservative:

• Para 3 + breastfeeding 50% RR

Medical:

• COCP >5 years 50% RR, no increased risk of breast cancer.
• Para 2 + COCP >5 years 70% RR

Surgical:

• rrBSO 95% RR if performed by 40 years old. Also reduces risk of breast CA.
  
  • If BRCA2 can delay till 45 years old due to later onset of increased risk.
  • S/E: surgical menopause, increased CVD, osteoporosis. If never had breast CA can have HRT until 51 years old.
  • Does not eliminate 1% risk of primary peritoneal cancers.

Question 3

Outline investigations and work up for breast cancer in pregnancy

Answer 3

• Breast USS + biopsy
• Mammogram: assess extent/contralateral breast.
• Staging imaging: CXR, liver USS
• Bloods: FBC, LFTs, U&Es

Question 4

Outline management plan for treatment of breast cancer in pregnancy including obstetric care.

Answer 4

Antenatal:

• MDT: MFM, breast surgeon/physician, medical oncologist.
• Termination of pregnancy is an option.
• Surgery: mastectomy + sentinel node radioisotope scintigraphy +/- axillary node clearance.
• Chemotherapy: anthracycline (doxirubicin) from 2nd trimester.
  
  • S/E: neutropenia for mum and fetus
• Serial growth scans

Intrapartum:

• Aim delivery at term. CS reserved for usual indications.
• Ideally birth should be a few weeks after chemotherapy to minimise risk of neutropenia.

Postpartum:

A - avoid pregnancy for 2 years due to risk of recurrence.

B - limited BFing to facilitate bonding. Herceptin and tamoxifen not safe.

C - Non-hormonal methods i.e. copper IUD, condoms.

D - VTE prophylaxis

E - psychosocial support, screening for PND.

Question 5

Outline your preconceptual counselling for a woman who has had breast cancer

Answer 5

• MDT: obstetrician, oncologist, breast surgeon.
• Contraception:
  
  • Delay pregnancy for 2 years after due to high risk of recurrence.
  • ER positive: complete 5 years of tamoxifen before conception.
  • Pregnancy contraindicated if metastatic disease.
• Genetic counsellor / testing for BRCA/Lynch syndrome:
  
  • 50% risk of inheritance.
  • PIGD
• Prep for pregnancy:
  
  • Stop tamoxifen 3/12 before.
  • Complete routine imaging
  • Risks: delivery complications and CS.
• During pregnancy:
  
  • ECHO every trimester: cardiomyopathy risk from anthracyclines.
  • Lactation support.

Question 6

Counsel a woman regarding fertility following breast cancer treatment:

Answer 6

• Referral to fertility specialist.
• Genetic counselling / PIGD: 50% inheritance of BRCA.
• Cryopreservation: unknown risks of ovarian stimulation on breast cancer especially ER +ve.
• Chemotherapy side-effects on fertility: loss of germ cells, anovulation and subfertility.
• ART options: egg donor with short-term HRT; transfer cryopreserved embryos with HRT; surrogacy; adoption; childless.
  
  • HRT may have deleterious effect on breast cancer.