Abstract 1927: High-sensitivity screening of a large number of samples for KRAS and PIK#CA mutations using digital PCR

Abstract Colorectal cancer (CRC) is one of the top commonly occurring cancers with 1.9 million new cases and 935,000 deaths worldwide in 2020 according to CDC. KRAS plays an important role in colorectal metastasis and progression, affects the tumor microenvironment and has been implicated in angiogenesis. KRAS mutations are the most common, presenting in approximately 25% of all tumors and is one of the most common gene mutations linked to cancers. It drives 40% of colorectal cancers, 32% of lung cancers, and 85% of pancreatic cancer cases. Phosphatidylinositol 3-kinases (PI3Ks) participate in signaling pathways essential for cell proliferation, adhesion, survival and motility; and are the initiators of carcinogenic process. PI3K mutations produce an altered p110a subunit, which allows PI3K to signal without regulation and initiates broad spectrum carcinogenic process. (Cell Cycle. 2009 May 1; 8(9): 1352-1358). Studies have shown a strong association of simultaneous mutations in PIK3CA exon 9 and KRAS exon 2 were the most common (67.2% of CRC cases) (Oncol.Rep.25(6) (2011) 1691-1697). When that happens, tumors with the bi-mutations were found to be significantly associated with aggressive pathological features compared with WT tumors, for example, increased proportions of proximal colon cancer that were prone to metastasize to distal organs at initial surgery. (Q. Luo et. al. Elsevier Translational Oncology 13 (2020) 100874). There is an increasing need for simple and robust tools to frequently screen and monitor such activating mutations with a sensitivity of 0.05-0.5%, which is suitable for testing of FFPE DNA samples. (I. Oscorbin et. al. Cellpress Heliyon 8 (2022) e11804). Here we introduce a novel digital PCR instrumentation and nanoplate technology that allows the screening of a large number of samples within 2 hours. We selected KRAS/G12S and PIK3CA/H1047R LNA mutational assays from the QIAGEN Geneglobe assay database and tested them against mutants from 2 germline cell models (Horizon Discovery) under various amount of WT gDNA backgrounds. Data shows good detection sensitivity at the 0.05-0.1% level. Citation Format: James Qin. High-sensitivity screening of a large number of samples for KRAS and PIK#CA mutations using digital PCR [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 1927.