20P Next generation sequencing and associated treatment changes: Results from Ireland East Hospital Group

Next-generation sequencing (NGS) is a DNA sequencing technology that uses parallel sequencing of multiple small fragments of DNA. This technology has allowed an increase in the speed and a decrease in the cost at which an individual's genome can be sequenced. The aim of NGS testing is to identify actionable mutations which may unlock further treatment options and help predict treatment response. NGS is not reimbursed in Ireland and is performed on an opportunistic basis via patient, charitable or research funds. This study examined when the test was performed, if it altered treatment choices and the resultant patient outcome. Using electronic and chart review we extracted the cancer specific and demographic data on patients (pts) who had NGS between Dec 2017 to May 2020 in two University Hospitals and a satellite centre. We extracted data on the types of mutations identified, subsequent cancer therapies and pt outcomes. 36 pts had NGS performed with Foundation One®. Median age was 47 and interquartile range was 20.3. The top 3 cancer types were gastrointestinal 20 (55.5%), breast 8 (22.2%) and gynae 4 (11.1%). 44% of pts had 1 previous line of treatment, followed by 42% with 2-3 previous lines and 14% having 4 or more lines of treatment. NGS was self-funded by 86% pts and charity by 14%. 35 pts (97.2%) had mutations detected and 22 (62.9%) were actionable. 45% had received appropriate therapy for mutations previously detected on routine panel testing. The most common untreated novel mutations were FGFR (33%), TMB (25%), ERBB (8%) and BRAF fusion (8%). 14% of pts with novel mutations detected were unfit for further treatment. The 41% who received NGS directed therapy had tumour responses ranging from 3-4 months. Treatment changed in over a quarter of our cohort as a result of NGS. Our cohort was heavily pretreated with a range of cancer types. Davis et al found 11.1% of 305 patients that had NGS testing resulted in a management change. Overall, the patients who received off label additional therapy had poor responses. Limitations of our study include small sample size and selection bias. In theory tumour genomic profiling may improve oncological outcomes, however our study is consistent with others and showed low clinical utility at this time.