1709 – Somatic gene testing for the diagnosis of glioma, including glioblastoma

New MBS item.

Small to medium sized gene panel (up to 25 genes) testing in patients who have been pathologically diagnosed with a glioma or glioneuronal tumour, and who are immune-negative for IDH1 R132H. In accordance with the 2021 update to the World Health Organization (WHO) classification of tumours of the central nervous system (CNS), the panel must be able to detect at least, but not limited to: IDH1/2 variant status, BRAF variant status, H3F3A variant status including H3 K27 and H3 G34 ,TERT promoter variant status, EGFR amplification, CDKN2A/B deletion and 1p/19q co-deletion status.

The latest update to the WHO classification of tumours of the CNS highlights the critical importance of molecular diagnostics in the accurate diagnosis and classification of CNS tumours. For some disease entities, molecular information is required to provide an “integrated” diagnosis and only a descriptive histological diagnosis is acceptable if no molecular diagnostic testing is available. Identification of co-deletion of chromosome 1p/19q regions is important for accurate diagnosis of oligodendroglial tumours, and IDH1/2 mutations and MGMT promoter methylation add important prognostic and predictive information to the histopathological diagnosis of gliomas.

Type: Investigative technology

Brain cancer in Australia is relatively rare with a 2021 incidence of approximately 6.5 per 100,000 individuals. The most prevalent brain tumours are secondary metastases from non-CNS tumours, meningiomas (which are mostly benign), and the most common primary tumours of the central nervous system, gliomas. 

Gliomas include astrocytomas, oligodendrogliomas, ependymomas, and other rare histologies. Glioblastomas are the most common and most aggressive type of astrocytoma, representing 45% of malignant primary brain tumours.

Patients with a primary CNS tumour usually present with headaches, seizures, or focal neurological symptoms and due to their aggressive nature, symptoms tend to develop rapidly. Ongoing symptoms include medical and neurologic complications including seizures and cerebral oedema, neurocognitive decline, depression, fatigue, endocrinopathies, and venous thromboembolism.

In Australia, the average 5-year survival rate for persons diagnosed with brain cancer is only 22.3 per cent.

According to the 2021 update to the WHO classification of tumours of the central nervous system, accurate classification and grading of gliomas requires a combination of histological and molecular features identified on samples obtained through biopsy or surgical resection to arrive at an “integrated diagnosis”.

• PASC consultation: Not applicable
• MSAC consultation: Closed Friday 11 February 2022

• PASC meeting: Bypassing PASC
• ESC meeting: Bypassing ESC
• MSAC meeting: 31 March – 1 April 2022