3.1 Specialist diagnostic work-up
The treatment team, after taking a thorough medical history and making a thorough medical examination of the patient, may need to undertake additional investigations under the guidance of a specialist.
Although the diagnosis of MDS is confirmed by a bone marrow biopsy, it may be reasonable to monitor the patient rather than proceed to bone marrow biopsy. This will depend on the severity of cytopenias, patient request, age, comorbidities and the need for therapeutic intervention.
Further investigations and blood tests to exclude other causes of cytopenias and dysplasia should be completed.
Diagnosis and prognosis of MDS is based on peripheral blood and bone marrow aspirate and trephine. Investigations of the bone marrow aspirate may include (Sekeres & Cutler 2014):
- immunophenotyping
- cytogenetics and, in some circumstances, FISH studies
- molecular testing or a myeloid gene panel test for some patients.
Urgency of investigation timeframes depends on the severity of cytopenias and clinical presentation. Results of bone marrow biopsies and ancillary investigations should be returned within two weeks. Specialised testing such as cytogenetics and molecular tests may take longer.
An inherited predisposition panel as part of the work-up may be appropriate in selected patients with MDS. This should be undertaken after appropriate counselling and discussion with a haematologist with experience in this area and/or a genetic counsellor.
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.
For detailed information and referral guidelines for MDS risk assessment and consideration of genetic testing, consult these resources:
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).
