NOMINATOR: Feasibility of genomic testing of rare cancers to match cancer to treatment.

Abstract

103 Background: Rare cancers (RCs) often lack proven treatments and consequently have poorer outcomes. Identification of molecular biomarkers can facilitate treatment selection and trials access for RC patients (pts) where histology-based trials are not feasible. We assessed the potential for next-generation sequencing (NGS) to impact RC care. Methods: Pts with a rare histology, poor-prognosis solid-tumor and no standard of care therapy underwent NGS genomic profiling of paired FFPE tumor and blood (PMCC comprehensive cancer panel; 391 genes). A virtual molecular tumour board (MTB) reviewed curated results regarding diagnosis, actionability (OncoKB) and treatment recommendations. Results: Between July 2017 and Nov 2019, 121 pt were prospectively enrolled across 4 Australian sites. 109 (91%) pts had a tumour with an incidence of < 1/100,000 person/years with 83 diverse RC histologies represented. 100 (83%) cases were successfully sequenced. The most commonly aberrant genes ( > 10%) were: TP53 (45%), CDKN2A/B, RB1, PTEN and NF1. 51 (51%) had at least one potentially actionable finding, with 27 matched to a clinically validated drug (OncoKB level 3 or better) [Table]. In 6 cases NGS resulted in a revised diagnosis (includes 4 with FDA approved therapy). Actionable germline mutations were detected in 3 individuals of which 2 were previously known. The majority of pts remain in follow-up, however, 8 died prior to or within 28 days of NGS result availability. Drug access remains a limitation with only 12 receiving therapy based on NGS/MTB guidance. Clinical trial information: ACTRN12616001000493 . Conclusions: NGS in RCs is feasible with potential impact in half of cases. Earlier testing and improved off-label/trial drug access is necessary to increase the likelihood that RC patients may benefit from molecularly guided therapy. [Table: see text]