7064 Photodynamic therapy (pdt) combined with tumor reduction for advanced gastric cancer.

Purpose: PDT is an effective treatment for early gastric cancer, where patients cannot undergo surgery or show no indication for other endoscopic treatment, or both; nevertheless, its efficacy is limited in case of advanced gastric cancer. In this study, we assessed the efficacy of our new approach of reducing tumor volume before PDT in the treatment of advanced gastric cancer. Methods: The procedure comprises several steps as follows: 1. Saline containing epinephrine (0.05 mg/ml) is injected endoscopically under the tumor to prevent bleeding. 2. Part of the tumor is resected by electric-cautery to reduce volume; in the case of bleeding, Nd:YAG laser is applied. 3. The patient is then subjected to PDT.A photosensitizer, hematoporphyrin derivative, is injected intravenously at a dosage of 2.5-3.0 mg/kg. After 48 and 72 hours, the cancerous lesion is irradiated as extensively as possible with a pulsed laser (a gold vapor laser; 200-380 mW or an excimer-dye laser; 320 mW). 4. If the cancerous lesion appears reduced, a hot biopsy is carried out. 5. If one course of the therapy is not effective or if recurrence occurs, additional therapy is an alternative according to the appearance of the remnant tumor: when polypoid lesions appear, the treatment from step 1 is repeated; when ulcerated lesions appear, the treatment from step 3 is repeated. Follow-up endoscopic examination is conducted 3, 6, and 12 months after treatment, and complications are also checked. This therapy was applied to 10 cancerous lesions in 10 patients (10 men; average, 77 years old) who could not undergo surgery and/or chemotherapy because of complications or other factors. Results: Two of the ten (20%) cancerous lesions disappeared completely by a single course of treatment, and no recurrence was found over two years of follow-up examinations. Six of the ten (60%) lesions showed over 50% reduction in tumor volume; 5 of these 6 patients lived for 2 to 6 years after several courses of the treatment. The main complication of sunburn in 9 of the 10 patients was entirely eliminated; no other significant complications appeared. Conclusion: The new treatment, PDT combined with tumor reduction, is effective in the treatment of advanced gastric cancer and could be an alternative treatment for patients who may be at risk from surgery or chemotherapy, or both.