Prospective clinical study using expressed sequencing variants on stool-derived eukaryotic RNA transcripts (seRNA) for colorectal cancer screening.

Abstract

516 Background: Colorectal cancer (CRC) is the second leading cause of cancer related deaths in the United States. The high mortality rate is largely attributable to the high frequency of late-stage diagnoses, caused by low patient compliance with screening guidelines. A reliable and noninvasive screening alternative is needed for the 40 million noncompliant patients. The development of a novel nucleic acid extraction method to isolate stool-derived eukaryotic RNA (seRNA) permits reliable and noninvasive evaluation of biomarkers derived from the gastrointestinal (GI) epithelium. This method enables sequencing-based tools for the detection of patients with CRC and adenomas. Methods: Stool samples were obtained from 96 individuals prior to undergoing a screening colonoscopy. Fecal immunochemical tests (FITs) were obtained for each sample. RNA isolates underwent custom library preparation, next-generation sequencing, and somatic variant identification. An seRNA assay assessed the probability of CRC risk using results from the FIT, mutational burden of transcripts implicated in precancerous change (APC), and mutational burden of transcripts associated with malignant transformation (KRAS / TP53). Results: When compared to results from a colonoscopy and subsequent biopsy, the seRNA risk assessment attained a 100% sensitivity for CRC, a 71.4% sensitivity for advanced adenomas, and an 88.5% specificity for no neoplastic findings. Conclusions: A single-center, IRB-approved, prospective and blinded clinical study is being conducted in 450 patients to further develop this seRNA assay. Supplemental data will include expression from 408 seRNA transcripts. Preliminary analysis described herein indicates this assay could be the most sensitive noninvasive screening test for the detection of CRC and adenomas. [Table: see text]