Photodynamic therapy leads to complete remission of tongue tumors and inhibits metastases to regional lymph nodes.

In patients diagnosed with oral cancer, the most important prognostic indicator for patient survival after primary treatment is metastasis to the cervical lymph nodes or distal sites. Therefore, we evaluated the utility of photodynamic therapy (PDT) mediated by aluminum-chloride-phthalocyanine entrapped in liposomes for the prevention of metastasis to regional cervical lymph nodes in the Erhlich tongue cancer model. The PDT protocol led to complete remission of tongue tumours and prevented the occurrence of regional metastasis. The prevention of regional metastasis was confirmed by histopathological and immunohistochemical analyses. In addition, PDT treatment increased the overall survival and reduced weight loss relative to control tumour-bearing mice. Thus, PDT should be clinically evaluated for use in the prevention of cervical lymph node metastasis in patients with oral cancer.