Abstract Background: Nanomechanical properties of tumors are emerging biomarkers reflecting extracellular matrix (ECM) remodeling, immune exclusion, and aggressiveness. The AFM-based ARTIDIS platform measures nanomechanical signatures (NS) from fresh biopsies within hours, providing rapid diagnostic and prognostic information while preserving tissue for conventional analyses. Prior work showed that ARTIDIS NS distinguishes malignant from uninvolved lung tissue and predicts early postoperative recurrence. However, the relationship between NS and oncogenic drivers such as KRAS remains unclear. As KRAS influences ECM composition, matrix remodeling, and stromal activation, we evaluated the preliminary nanomechanical and microenvironmental features of KRAS-mutant NSCLC in our prospective cohort. Methods: Fresh tumor and paired uninvolved lung tissue were collected from 70 early-stage NSCLC patients undergoing curative resection. NS were measured on the ARTIDIS platform. Samples were formalin-fixed for quantitative immunohistochemistry (IHC) of α-SMA, picrosirius red, Ki-67, CD31, CD4, CD8, FOXP3, CD68, and PD-1. Clinical characteristics, driver mutations, and outcomes were recorded with a 36-month follow-up. A focused analysis was performed in KRAS-mutant cases. Results: Preliminary analyses showed that ARTIDIS NS distinguished malignant from uninvolved tissue with 88% sensitivity, 86% specificity, and 87% accuracy (n = 52 paired samples). Eleven patients carried KRAS mutations (G12A/D/F/S, G13D, Q16H). Median age was 68.5 years; 63.4% were former smokers. Most tumors were early-stage (IA-IIB), and 45.5% were poorly differentiated. Across the full cohort, 17 patients recurred, including 3 patients (27.3%) with KRAS mutations. ARTIDIS NS predicted progression within 10 months after surgery with 100% sensitivity and 93% specificity, including predictions derived from uninvolved tissue. KRAS-mutant tumors showed higher stiffness than KRAS-wild-type or driver-negative tumors. Quantitative IHC demonstrated a higher percentage of proliferating cancer cells together with increased Treg infiltration and PD-1 expression in KRAS-mutant samples compared with uninvolved lung tissue, suggesting immune exhaustion. Conclusions: This study provides the first evidence that KRAS-mutant NSCLC displays a distinct, stiffer nanomechanical phenotype. These findings support tumor stiffness as a functional characteristic of KRAS-driven biology and highlight ARTIDIS NS as a rapid biomarker complementing histopathology and molecular profiling. A 200-patient prospective validation study is underway to confirm the clinical utility of NS for risk stratification and personalized treatment planning. Citation Format: Jordi Alcaraz, Elba Marin, Héctor Sanz-Fraile, Marina Querol, Paula Gausa, Keat Neal, Marselina Arshakyan, Marc Rico-Pastó, Marc Boada, David Sanchez, Carolina Ortiz Velez, Reinier Oropesa Nunez, Gitika Srivastava, Ahmed Jizawi, Sara Nizzero, Tobias Appenzeller, Philipp Oertle, Marko Loparic, Marija Plodinec, Noemi Reguart. Tumor stiffness as a functional biomarker of KRAS-mutant NSCLC: Insights from the ARTIDIS prospective clinical cohort abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 767.
Alcaraz et al. (Fri,) studied this question.