Tumor-localizing and photosensitizing properties of hematoporphyrin derivative in hamster buccal pouch carcinoma.

The tumor-localizing and photochemotherapeutic properties of hematoporphyrin derivative (HPD) were examined in 7, 12 dimethylbenzanthracene (DMBA)-induced oral cancers in the Syrian hamster. Oral tumors in hamsters injected with HPD (50 micrograms per gram of body weight) exhibited bright salmon pink fluorescence when exposed to long-wave ultraviolet light 24 hours after intraperitoneal HPD injection. Adjacent tumor-free mucosa did not fluoresce. Similarly, tumors not treated with HPD, normal mucosa treated with HPD, and normal mucosa not treated with HPD did not fluoresce. Tumors in animals that received HPD and photochemotherapy (PCT) were examined for gross and microscopic pathologic changes following the phototreatment. Tumors displayed edema, hemorrhage, and cellular necrosis that progressed with the time of sampling after photochemotherapy. Complete tumor necrosis was evident in the majority of oral tumors 24 hours after HPD PCT.