3.1 Specialist investigations (diagnostic work-up for people with breast cancer)
The treatment team, after taking a medical history and making a medical examination of the patient, should undertake the following investigations under the guidance of a specialist:
- appropriate breast imaging tests including bilateral mammography and ultrasound (if conventional imaging is insufficient to help guide treatment, consider MRI)
- ultrasound of the axilla (including fine-needle aspiration of nodes if the axillary ultrasound is abnormal)
- breast core biopsy, if not already undertaken (which allows determination of breast cancer receptor profiles [ER, PR, HER2]).
Patients should be assessed for the possibility of a breast cancer predisposition gene and considered for genetic counselling/testing if appropriate. For more information refer to eviQ’s Referral guidelines for breast cancer risk assessment and consideration of genetic testing.
Diagnostic investigations should be completed within two weeks of the initial specialist consultation.
People with breast cancer should be referred for genetic work-up early in their treatment journey if they fulfil germline testing criteria using CanRisk or the Manchester score, or have a triple-negative breast cancer under 50 years of age. Other factors pertaining to genetic work-up include a personal or family history suggestive of:
- Peutz-Jegher syndrome (oral pigmentation and/or gastrointestinal polyposis)
- PTEN hamartoma syndrome (macrocephaly, specific mucocutaneous lesions, endometrial or thyroid cancer)
- Li-Fraumeni syndrome (breast cancer < 50 years, adrenocorticocarcinoma, sarcoma, brain tumours).
Family history-based testing threshold can be assessed using the Manchester score APP.
In some cases certain pathological subtypes of cancer or tumour tests (immunohistochemistry or tumour genetic tests) may suggest an underlying inherited cancer predisposition, especially triple-negative breast cancers.
Genetic testing is sometimes able to identify the cause of cancer in a family and may be used to guide treatment for the affected people.
A familial cancer service assessment can determine if genetic testing is appropriate. Genetic testing is likely to be offered when there is at least a 10 per cent chance of finding a causative ‘gene error’ (pathogenic gene variant; previously called a mutation). Usually testing begins with a variant search in a person who has had cancer (a diagnostic genetic test). If a pathogenic gene variant is identified, variant-specific testing is available to relatives to see if they have or have not inherited the familial gene variant (predictive genetic testing).
Medicare funds some genetic tests via a Medicare Benefits Schedule item number. Depending on the personal and family history, the relevant state health system may fund public sector genetic testing.
Pre-test counselling and informed consent is required before any genetic testing. In some states the treating team can offer ‘mainstream’ diagnostic genetic testing, after which referral is made to a familial cancer service if a pathogenic gene variant is identified. The familial cancer service can provide risk management advice, facilitate family risk notification and arrange predictive genetic testing for the family.
Visit the Centre for Genetics Education website for basic information about cancer in a family.
For detailed information and referral guidelines for breast cancer risk assessment and consideration of genetic testing, read eviQ’s Referral guidelines for breast cancer risk assessment and consideration of genetic testing.
