The Use of ctDNA for BRAF Mutation Testing in Routine Clinical Practice in Patients with Advanced Melanoma

Use of ctDNA in identifying an actionable BRAF mutation in stage 4 metastatic melanoma

The identification of genetic variants in melanoma has enabled the development of targeted therapies. Under the National Institute for Health and Care Excellence (NICE) guidance, patients with BRAF V600E variant are eligible for BRAF and MEK inhibitor therapy. For those with advanced or highly symptomatic disease, a rapid response to treatment is often seen. Current practice relies on tissue biopsy to perform immunohistochemistry (IHC) or next generation sequencing (NGS) to identify these variants; however, this can take up to 2 weeks. In patients with widespread disease, rapid initiation of treatment can be lifesaving.We describe a case in which hotspot circulating tumour DNA (ctDNA) analysis confirmed BRAF variant 6 days prior to biopsy results. This was utilised to expedite treatment initiation and symptomatically, the patient had initial improvement within a few days.This article demonstrates the potential value of ctDNA analysis and the need for further research into this as an alternative to NGS for patients with rapidly progressive disease.

Circulating biomarkers of response to immunotherapy and immune-related adverse events

INTRODUCTION

Immune checkpoint blockade has revolutionized cancer treatment. However, response rates vary, and these treatments have a high rate of immune-related side effects, which can be limiting. Thus, tests to predict who will respond and who may experience side effects are of critical importance toward realizing the ultimate goal of precision oncology.

AREAS COVERED

We review several of the most recent advances in circulating biomarkers that have been reported to be useful in predicting response and immune-related adverse events (irAE) to checkpoint blockade immunotherapies (CBI). We focus on high-quality studies published within the last few years. We highlight significant findings, identify areas for improvement, and provide recommendations on how these biomarkers may be translated into clinical utility.

EXPERT OPINION

As newer immunotherapies are developed, there is a pressing need to identify circulating biomarkers that can help predict responses and side effects. Current studies are mostly small-scale and retrospective; there is a need for larger-scale and prospective studies to help validate several of the biomarkers detailed here. As oncology focuses more on precision-based approaches, it is likely that a combination of biomarkers, including circulating ones as detailed here, will have critical utility in guiding clinical decisions.