Expression of vascular endothelial growth factor by photodynamic therapy with mono-L-aspartyl chlorin e6 (NPe6) in oral squamous cell carcinoma.

Photodynamic therapy (PDT) is a method for treating pre-cancerous and cancerous lesions of the skin, bladder and oral cavity. However, tumour recurrence after PDT remains problematic despite good initial response. Some studies have shown that PDT induces vascular endothelial growth factor (VEGF) expression in human oral squamous cell carcinoma and other organs.