Oral Cancer Diagnosis by Mechanical Phenotyping

¹Department of Oral, Maxillofacial and Facial Plastic Surgery, ²Institute of Experimental Physics I, and ³Institute of Pathology, University of Leipzig, Leipzig, Germany; ⁴Oral and Maxillofacial Surgery, School of Dentistry and Oral Health, Griffith University, Brisbane, Queensland, Australia; and ⁵Department of Physics, Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom

^* To whom correspondence should be addressed. E-mail: jg473{at}cam.ac.uk.

	Abstract

Oral squamous cell carcinomas are among the 10 most common cancers and have a 50% lethality rate after 5 years. Despite easy access to the oral cavity for cancer screening, the main limitations to successful treatment are uncertain prognostic criteria for (pre-)malignant lesions. Identifying a functional cellular marker may represent a significant improvement for diagnosis and treatment. Toward this goal, mechanical phenotyping of individual cells is a novel approach to detect cytoskeletal changes, which are diagnostic for malignant change. The compliance of cells from cell lines and primary samples of healthy donors and cancer patients was measured using a microfluidic optical stretcher. Cancer cells showed significantly different mechanical behavior, with a higher mean deformability and increased variance. Cancer cells (n 30 cells measured from each patient) were on average 3.5 times more compliant than those of healthy donors [D_normal = (4.43 ± 0.68) 10^-3 Pa^-1; D_cancer = (15.8 ± 1.5) 10^-3 Pa^-1; P < 0.01]. The diagnosis results of the patient samples were confirmed by standard histopathology. The generality of these findings was supported by measurements of two normal and four cancer oral epithelial cell lines. Our results indicate that mechanical phenotyping is a sensible, label-free approach for classifying cancer cells to enable broad screening of suspicious lesions in the oral cavity. It could in principle be applied to any cancer to aid conventional diagnostic procedures. [Cancer Res 2009;69(5):1728–32]

Key Words: oral squamous carcinoma, keratinocyte, cell mechanics, optical stretcher