3.1 Specialist diagnostic work-up
To help patients decide whether to have a prostate biopsy, discuss with them their PSA level, DRE findings (including an estimate of prostate size) and comorbidities, together with their risk factors (including family history, increasing age and family origin) and any history of previously negative prostate biopsies. Do not automatically offer a prostate biopsy on the basis of serum PSA level alone (NICE 2019).
Several risk calculators are available (e.g. the European Randomized Study of Screening for Prostate Cancer risk calculator), which may be useful for patient counselling and decision making.
The following tests may be performed to confirm a diagnosis:
- DRE (prior to biopsy)
- multiparametric MRI – this should be interpreted by a radiologist with adequate training and experience (FRANZCR or equivalent) and with MRI-specific accreditation
- systematic and/or targeted prostate biopsy – in patients with a suspicious lesion on MRI, this should be specifically targeted.
An MRI before biopsy aids in diagnosis and biopsy planning and should be considered in all patients if available.
All biopsies should be completed by an adequately trained urologist or radiologist under transrectal ultrasound or MRI guidance, with biopsy needles placed either transrectally or transperineally.
Implications of both a positive and negative biopsy should be discussed with the patient before biopsy.
The specimen should be reviewed by an experienced uropathologist if there are uncertainties about diagnosis.
There should be standardised protocols for:
- the minimum number of cores in the biopsy sample
- interpreting the specimens
- follow-up/re-biopsy of equivocal findings.
The lead clinician should review the risk factors of all men who have had a negative first prostate biopsy, and discuss with the man:
- if there is still a risk that prostate cancer is present
- if the risk is slightly higher if any of the following risk factors are present:
- the biopsy showed atypical small acinar proliferation (ASAP)
- abnormal DRE (NICE 2019)
- a suspicious lesion on pre- or post-biopsy MRI.
If patients have a specific MRI lesion that hasn’t been targeted, there is increased risk of undiagnosed cancer. Discrepancies between imaging and biopsy findings need to be reviewed to avoid misdiagnosis.
Investigations should be completed within four weeks of the initial specialist appointment.
Five to 10 per cent of all cancers are due to a genetic predisposition. The features that suggest a genetic predisposition may include:
- early age at onset
- multiple primary cancers
- family history of similar or related cancers.
In some cases certain pathological subtypes of cancer or tumour tests (immunohistochemistry or tumour genetic tests) may suggest an underlying inherited cancer predisposition.
Anyone diagnosed with cancer should have a detailed personal and family cancer history taken. Consult relevant guidelines to determine if referral to a familial cancer service is appropriate.
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 (MBS) item number but most are not. 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.
Refer to section section 1.3.1 ‘Genetic family history screening’ for more information.
Visit the Centre for Genetics Education website for basic information about cancer in a family.
For detailed information and referral guidelines for prostate cancer risk assessment and consideration of genetic testing, refer to Royal Australian College of General Practitioners 2019 ‘Genomics in general practice’.
Pharmacogenetics describes how individual genetic differences can lead to differences in the way certain medicines interact with the body. These interactions can affect the effectiveness of medications and any side effects. Applying pharmacogenetics to treatment planning may help patients to be prescribed the most appropriate treatment at the optimal dose from the beginning of treatment (NHMRC 2013).
