Fluorescent Anti-EGFR Imaging to Access OSCC Bone Invasion in Vivo

Objectives: Introduction: Oral Squamous cell carcinoma (OSCC) is one of the most common cancers of the oral cavity and in 9% of OSCC patients have invasion into bone. Current surgical standard of care for of OSCC with bone invasion is surgical resection. This often leaves patients with an extensive recovery period and an overall diminished quality of life. We hypothesize that epidermal growth factor receptor (EGFR), which is expressed in the 90% of OSCC patients, can be targeted with a fluorescent antibody that will allow for more accurate assessment of bone invasion. Objective: Our objective is to develop an animal model of bone invasion to demonstrate the specificity and sensitivity of fluorescently labeled anti-EGFR antibody, panitumumab-IRDye800, to OSCC cells in an intraosseous environment.
Methods: Athymic nude rats were injected with OSCC cells along the alveolar process and parallel to the mandible.
Results: We injected 8 athymic nude rats with SCC-1 luciferase+ cells. Once a week rats were imaged for the detection of bioluminescence using the IVIS Lumina system indicating cancer cell uptake. Two weeks later, rats received an intravenous injection of either panitumumab-IRDye800 (n=4) or IgG-IRDye800 (n=4). Rats were imaged on days 0, 4, 7, 10, and 14 using the LI-COR Pearl imaging system. On day 14, mandibles were excised and imaged. Two of the mandibles from rats that received panitumumab-IRDye800 a significantly strong fluorescent signals compared to background and the IgG-IRDye800 group. H&E staining and immunohistochemistry for EGFR were used to confirm the presence of an intraosseous tumor in the rats.
Conclusions: We are developing a novel mandibular model of oral tumors and cancers. This model may be used in conjunction with near infrared fluorescently labeled antibodies to allow non-invasive imaging. This would allow for surgical assessment of tumor margins within bone to improve surgical outcomes.