Abstract PS1-03-05: Characterizing Nanomechanical Properties of Skin Tissue in Postmastectomy Implant Reconstruction

Abstract Introduction: Mastectomy remains a cornerstone of breast cancer treatment but often results in substantial disruption to body image and quality of life. Postmastectomy breast reconstruction (PMBR) offers physical and psychosocial restoration, yet failure rates, particularly following postmastectomy radiation therapy (PMRT), can exceed 20%. Known risk factors such as obesity, diabetes, smoking, and prior radiation increase complication rates, but no objective, individualized tool currently exists to guide patient selection or surgical planning. While patient-reported tools like the BREAST-Q provide retrospective insight into satisfaction and well-being, they do not predict outcomes or aid in preoperative decision-making. No validated nomogram or risk model broadly addresses implant failure in the setting of PMBR. Treatment-induced fibrosis alters tissue mechanics, suggesting that direct measurement of nanomechanical properties, such as stiffness, viscoelastic dissipation, and adhesion, could provide objective, biologically relevant markers of tissue quality and reconstructive risk. This study introduces dissipation; a quantifiable biomarker derived from high-resolution mechanical profiling and demonstrates its correlation with both subjective well-being and clinical outcomes. These findings offer an actionable, data-driven tool to stratify risk and optimize reconstructive planning, with immediate implications for clinical practice. Methods: This research is part of the EMPOWER study (NCT06584396), a single-center prospective trial at MD Anderson Cancer Center. Female patients undergoing preventive or curative mastectomy with tissue expander-based reconstruction were eligible. Since 2023, 130 patients have been enrolled, and 100 patients (131 samples) analyzed. At expander-to-implant exchange, surgeons collected skin and capsule specimens, which were trimmed and analyzed using the ARTIDIS ART-1 Nanomechanical Phenotype System, generating >10,000 data points per sample, including energy dissipation (aJ), stiffness (kPa), and adhesion (nN). Analyses assess associations between BREAST-Q Physical Well-Being scores (collected at 1 year post surgery) and the nanomechanical properties of resected tissues, combined with histopathological annotations. Results: Dissipation which refers to the ability of biological tissue to absorb and dissipate mechanical energy during deformation demonstrated strong correlations with subjective assessments from the BREAST-Q Physical Well-Being, particularly in parameters related to tissue softness, tightness, and discomfort. Dissipation values ranged from 150-800 aJ, with higher dissipation correlating with improved patient-reported softness and satisfaction of the breast hanging (p < 0.01) and lower values associated with fibrosis and dissatisfaction. Patients reporting chronic chest pain "all the time" exhibited dissipation peaks at 700 aJ, while those with no or occasional pain had peaks at 200-300 aJ. Conclusions: This is the first study to demonstrate that nanomechanical dissipation, a quantifiable measure of tissue viscoelasticity, correlates strongly with several measures of patient-reported physical chest wall properties. These early data support its potential as a biomarker to inform reconstructive planning and patient counseling in future workflows. Prospective correlation with clinical outcomes is ongoing, and further study is warranted to validate dissipation as a predictive tool in postmastectomy breast reconstruction. Citation Format: P. Ndiaye, S. Nizzero, M. Schaverien, V. Hassid, P. Shay, J. Shuck, C. Mark Warren, J. Yu, A. Ha, G. Reece, M. Roubaud, A. Mericli, M. Villa, A. Francis, D. Adelman, D. Baumann, J. Christensen, R. Dickey, P. Hanwright, S. Kapur, J. Olenczak, A. Sahin, E. Paredes, J. Tilley, A. Jizawi, G. Srivastava, S. Lasli, T. Appenzeller, M. Loparic, M. Plodinec, B. Smith. Characterizing Nanomechanical Properties of Skin Tissue in Postmastectomy Implant Reconstruction [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS1-03-05.