Photofrin-PDT for gastric cancer in the era of endoscopic submucosal dissection

Abstract

Background: Endoscopic mucosal resection (EMR) was originated to treat early gastric cancer (EGC). EMR was suitable for small, mucosal and well-differentiated adenocarcinoma without ulceration. It was difficult to resect larger tumors en bloc by this method. In recent years, a more useful method, endoscopic submuscosal dissection (ESD) has been developed, which enables en bloc resection of large mucosal lesions. On the contrary, photodynamic therapy (PDT) is applicable to submucosal, poorly differentiated, or carcinoma with ulceration. In the era of ESD, we evaluated the value of Photofrin-PDT. Patients & Methods: We applied PDT to 36 patients including three advanced cancers, who had been excluded from EMR (ESD) and were at high risks for surgery or refused surgery. Four EGC patients who had not been cured by EMR (ESD) were included. Our PDT procedure consisted of polyhematoporphyrin ether/ester administration (Photofrin, 2 mg/Kg) and pulsed excimer dye laser irradiation at 630 nm 48 hours (and 96 hours) after sensitization. Results: Complete response (CR) at three months was obtained in 84% (21/25) of mucosal cancer and in 50% (4/8) of submucosal cancer. Although three patients with an advanced cancer improved but were not cured, quality of their life was maintained. There were no serious side effects except skin photosensitivity. Conclusion: Photofrin-PDT should be applied not only EGC patients who are excluded from ESD and have not been cured by ESD with poor risk for surgery, and have high possibilitiy to be cured by PDT, but also advanced cancer patients for local improvement of lesions.