Prospective genomic testing of unselected cancer patients yields insights about cancer susceptibility and noncancer disease with therapeutic implications.

Abstract

10603 Background: Clinicians have used strict criteria to determine eligibility for cancer susceptibility (CS) testing and have limited genetic assessment to cancer-related genes. However, half of all CS mutation carriers are missed by criteria-based testing and there may be an unrecognized opportunity to modify care for patients who have rare but actionable genetic disorders as defined by the American College of Medical Genetics (ACMG). With the aim of improving patient outcomes through precision genomics, we initiated an enterprise-wide program to offer somatic and germline sequencing to all patients. Methods: We offer consented patients clinical grade paired somatic & germline WES/ RNA seq and panel germline testing for cancer (156 genes) and ACMG disorders (59 genes). Results are reviewed by a Precision Oncology Tumor Board. Somatic results are returned by the treating team. Germline results are returned by phone (genetic counselor, GC) followed by a clinic visit (GC+MD) for those with pathogenic/likely pathogenic (P/LP) mutations and selected variants of uncertain significant. We evaluated the proportions of patients with somatic findings suggestive of germline conditions and those carrying P/LP mutations in CS and ACMG genes. Results: 1,804 patients enrolled and received somatic sequencing: 52% female; 51% non-Hispanic White/ 20% Hispanic White/ 18% Asian/ 4% Black/ 7% other; median age 64. Review of somatic data suggest that 14% have findings suggestive of germline conditions based on factors such as TMB, MSI, and young age. Of the patients offered germline testing, >95% opted to receive CS/ACMG results. To date, we have sequenced 684 patients for CS and 647 for ACMG. 18% of patients had P/LP mutations in CS genes and 4% had P/LP mutations in ACMG non-cancer genes (Table). Conclusions: Prospective somatic/germline sequencing of unselected cancer patients reveals tumor findings suggestive of germline disorders and identifies patients with CS and non-cancer genetic conditions. These findings highlight the promise of a comprehensive sequencing approach to help guide cancer treatment, management of unrecognized cancer risk and the need for concomitant management of rare disorders such as arrhythmogenic cardiomyopathy and susceptibility to adverse reactions with anesthesia.[Table: see text]