Risk Management for Female from a High-Risk Breast Cancer only Family

This guideline discusses management for women where there is a strong family history of breast cancer but an inherited mutation in a breast cancer susceptibility gene (such as BRCA1 or BRCA2) is unlikely. It is unknown whether the increased risk is due to shared environmental exposures, other genes or a combination.

This risk management guideline has been developed for individuals who have NOT been diagnosed with a relevant cancer/tumour.

The target group is women who have an estimated >30% lifetime risk (or >8% risk between 40 -50 years) of breast cancer using a validated risk-assessment model (eg BOADICEA)

It also excludes

• Families with a history of breast and ovarian cancer (see separate guideline)
• Those individuals with a mutation in a known breast cancer predisposition gene
• An untested blood relative of an individual with a known mutation in a breast cancer predisposition gene

Lifetime Risks of Cancer

Cancer Management Guidelines

Breast

Surveillance
Individualised screening may be required if there has been a breast cancer diagnosed 35 years and younger.

Recommended Screening

• starting at 40 years
• Annual mammograms (with or without ultra sounds)
• Offer annual MRI’s from 40-49 years in addition to mammograms

Contraindications: Pregnancy but ultra sound scans can be considered

Risk Reducing Medications
Provide information on risk-reducing medication. Tamoxifen and raloxifene have been found to reduce breast cancer risk in unaffected high-risk women but there are risks and benefits to this and it is not suited for everyone.

Risk Reducing Surgery
Discuss bilateral risk reducing mastectomy followed by self-surveillance of the breast area Individualized discussion regarding the possible reduction of breast cancer risk achieved with a premenopausal risk-reducing salpingo-oophorectomy.

Management of Early Menopause

HRT and cancer risk
If RRBSO is undertaken prior to menopause, HRT should be considered to minimise potential cardiovascular complications and bone loss associated with premature menopause, until the time of natural menopause (approx. age 50 yrs). This use of HRT is safe and does not abrogate the protective effect of RRBSO on breast cancer risk in BRCA1/2 mutations, so is expected to have similar effects in other women undergoing RRBSO.

The use of combination HRT beyond age 50 yrs should only be considered after specialist advice.

Contraception and Fertility
Combination oral contraceptive pill (OCP) is not contraindicated. Studies suggest minimal to no significant increase in overall breast cancer risk although effects may vary with different formulations and duration of use.
OCP cannot be used concurrently with breast cancer risk-reducing medications due to interactions.