The hamster cheek pouch model for field cancerization studies

Area of Science:

• Oral oncology
• Carcinogenesis research
• Biomarker discovery

Background:

• External carcinogens like tobacco and alcohol induce molecular changes in oral mucosa, increasing oral cancer risk through field cancerization.
• Field cancerization can be detected via histochemical techniques before histological changes appear, necessitating validated models for study.
• The hamster cheek pouch model effectively recapitulates human oral field cancerization stages, making it suitable for biomarker validation and therapeutic studies.

Purpose of the Study:

• To validate histochemical techniques as early biomarkers for field cancerization in an appropriate animal model.
• To assess the efficacy of boron neutron capture therapy (BNCT) in treating field cancerized oral tissue.
• To adapt the hamster cheek pouch model for long-term studies of field cancerization and BNCT.

Main Methods:

• Utilized the hamster cheek pouch model, applying carcinogens to induce oral field cancerization.
• Employed silver staining of nucleolar organizer regions, Feulgen reaction with ploidy analysis, and immunohistochemistry for FGF-2, proliferation markers, and angiogenesis markers (VEGF).
• Adapted the model for long-term BNCT studies on field cancerized tissue, monitoring tumor development and side effects like mucositis.

Main Results:

• Identified several histochemical techniques (silver staining, Feulgen reaction, FGF-2, proliferation markers, angiogenesis markers) as effective early biomarkers for field cancerization.
• Demonstrated that BNCT effectively controls tumor development in the hamster cheek pouch oral cancer model.
• Showed BNCT's inhibitory effect on tumor development in field cancerized tissue with manageable mucositis.

Conclusions:

• Histochemical techniques are reliable biomarkers for early detection of oral field cancerization.
• The hamster cheek pouch model is a valuable tool for studying field cancerization and evaluating cancer therapies like BNCT.
• BNCT shows promise as a therapeutic strategy for oral cancer, including in the context of field cancerization, with acceptable toxicity.