3.1 Specialist diagnostic work-up
The treatment team, after taking a thorough medical history, a thorough medical examination of the patient and reviewing prior tests (including imaging), should undertake some of the following investigations under the guidance of a specialist:
- additional imaging, which may include a PET-CT scan
- bronchoscopy, including endobronchial ultrasound-guided biopsy
- CT or ultrasound-guided biopsy or aspiration
- excisional biopsy or biopsy of a metastasis
- sputum cytology in rare cases.
Molecular and immunotherapy biomarker testing of the tumour can inform the most appropriate treatment therapy for non-small-cell lung cancer (NSCLC). Enough tissue needs to be removed to properly test the sample (NCCN 2020) and may demonstrate the need for a repeat or surgical biopsy.
All diagnostic investigations should be completed within two weeks of the first specialist appointment.
Familial causes are rare in lung cancer, and testing is not usually needed.
Five to 10 per cent of all cancers are due to a genetic predisposition, although hereditary factors are rare in lung cancer. 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.
Visit the Centre for Genetics Education website for basic information about cancer in a family.
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).
