Prof Jürgen Wolf, MD, University Hospital of Cologne, Cologne, Germany, discusses methods of measuring whole mutation burden, i.e. the sum of all mutations present in a tumour. Whole mutation burden is currently investigated as a predictive biomarker for response to immunotherapy, with the hypothesis that the higher the mutation burden, the higher the probability of a response to immunotherapy.
Prof Wolf compares two methods: Whole exome sequencing and next generation sequencing (NGS) diagnostic panels. Whole exome sequencing, which looks at the sequence of transcribed genes, is expensive, requires fresh biopsy samples and is difficult to implement in a clinical setting.
In contrast, next generation sequencing (NGS) diagnostic panels focus on a certain set of genes, are faster, cheaper and can be applied to paraffin-embedded tissue to measure the mutation load in a tumour.
Several retrospective studies have shown that NGS diagnostic panels provide comparable results to whole exome sequencing. Prof Wolf and other investigators are now working to validate these data with prospective studies.
Recorded at the 2017 meeting of the British Thoracic Oncology Group (BTOG) in Dublin, Ireland.