Clinical validation of prospective liquid biopsy monitoring in patients with wild-type RAS metastatic colorectal cancer treated with FOLFIRI-cetuximab

• Published in: Oncotarget Vol. 8; no. 21; pp. 35289 - 35300
• Main Authors: Toledo, Rodrigo A, Cubillo, Antonio, Vega, Estela, Garralda, Elena, Alvarez, Rafael, de la Varga, Lisardo U, Pascual, Jesús R, Sánchez, Gema, Sarno, Francesca, Prieto, Susana H, Perea, Sofía, Lopéz-Casas, Pedro P, López-Ríos, Fernando, Hidalgo, Manuel
• Format: Journal Article
• Language: English
• Published: United States Impact Journals LLC 23.05.2017
• Subjects: Antineoplastic Agents, Immunological - therapeutic use; Antineoplastic Combined Chemotherapy Protocols - therapeutic use; Camptothecin - analogs & derivatives; Camptothecin - therapeutic use; Cetuximab - therapeutic use; Class I Phosphatidylinositol 3-Kinases - genetics; Clinical Research Paper; Colorectal Neoplasms - drug therapy; Colorectal Neoplasms - genetics; Colorectal Neoplasms - pathology; DNA Mutational Analysis - methods; Female; Fluorouracil - therapeutic use; GTP Phosphohydrolases - genetics; Humans; Leucovorin - therapeutic use; Liquid Biopsy; Male; Membrane Proteins - genetics; Neoplasm Metastasis; Prospective Studies; Proto-Oncogene Proteins B-raf - genetics; Proto-Oncogene Proteins p21(ras) - genetics; ras Proteins - genetics; Survival Analysis; Treatment Outcome; anti-EGFR; cetuximab; colorectal cancer; cfDNA; liquid biopsy
• ISSN: 1949-2553; 1949-2553
• DOI: 10.18632/oncotarget.13311

Cancer genomics and translational medicine rely on the molecular profiling of patient's tumor obtained during surgery or biopsy. Alternatively, blood is a less invasive source of tumor DNA shed, amongst other ways, as cell-free DNA (cfDNA). Highly-sensitive assays capable to detect cancer genetic events from patient's blood plasma became popularly known as liquid biopsy (LqB). Importantly, retrospective studies including small number of selected patients with metastatic colorectal cancer (mCRC) patients treated with anti-EGFR therapy have shown LqB capable to detect the acquired clonal mutations in RAS genes leading to therapy resistance. However, the usefulness of LqB in the real-life clinical monitoring of these patients still lack additional validation on controlled studies. In this context, we designed a prospective LqB clinical trial to monitor newly diagnosed KRAS wild-type (wt) mCRC patients who received a standard FOLFIRI-cetuximab regimen. We used BEAMing technique for evaluate cfDNA mutations in KRAS, NRAS, BRAF, and PIK3CA in twenty-five patients during a 2-y period. A total of 2,178 cfDNA mutation analyses were performed and we observed that: a) continued wt circulating status was correlated with a prolonged response; b) smoldering increases in mutant cfDNA were correlated with acquired resistance; while c) mutation upsurge/explosion anticipated a remarkable clinical deterioration. The current study provides evidences, obtained for the first time in an unbiased and prospective manner, that reinforces the utility of LqB for monitoring mCRC patients.