Characterization of a new rat model of head and neck squamous cell carcinoma.

To develop and characterize by imaging and pathological examination a new immunocompetent rat model of head and neck squamous cell carcinoma (HNSCC).Prospective animal research.Frozen specimens of HNSCC induced chemically by 4-nitroquinoline 1 oxide (4-NQO) in Sprague Dawley rats were used for the first graft. Serial allografts were then performed with fresh specimens of tumor in twenty-five Sprague Dawley rats. A specimen of tumor (100 mm3) was picked up by head and neck dissection during an autopsy. The graft was performed in a subcutaneous manner, in the ventral part of the neck, using an incision of 4 mm, through the masseter muscle. Tumors were clinically measured once a week and volumes were calculated. 2-[18F]Fluoro-2-deoxy-D-glucose positron emission tomography coupled with computed tomography (FDG-PET/CT) was performed on days 14 and 30 after the graft. Rats were euthanized and pathological features were assessed using hematoxylin-eosin (HE) staining and immunohistochemistry markers to characterize the tumor.An 80% take rate was achieved using fresh tumor specimens. Tumors grew rapidly; the mean tumoral volume was 1.013 cm3 on day 14 and 7.994 cm3 on day 30. FDG-PET/CT imaging targeted regions of metabolically active tumor. It showed a uniform uptake of 18F-FDG on day 14 and a large area of central necrosis on day 30. Pathological examinations showed a typical squamous cell carcinoma, with similar immunohistochemical analyses to the human squamous cell carcinoma.We propose a new allograft HNSCC rat model which is easily reproducible and rapidly obtained in comparison to that induced chemically with 4-NQO. This model was developed in immunocompetent rats, with similar conditions to human carcinogenesis and could be used for testing new therapeutics.