Advantages of salvage photodynamic therapy using talaporfin sodium for local failure after chemoradiotherapy or radiotherapy for esophageal cancer

Background Photodynamic therapy (PDT) is a salvage treatment for local failure following chemoradiotherapy (CRT) for esophageal cancer. This study aimed to evaluate the efficacy and safety of salvage PDT using the second-generation photosensitizer, talaporfin sodium (L-PDT), and compare L-PDT to PDT using porfimer sodium (P-PDT). Methods We retrospectively analyzed clinical outcomes of patients treated with L-PDT and P-PDT. Patients with histologically proven local failure limited to the shallow muscularis propria layer (T2) after CRT or radiotherapy (RT) for esophageal cancer were enrolled. Results A total of 121 patients were enrolled in this study. L-PDT and P-PDT groups consisted of 44 and 77 patients, respectively. The overall local complete response (L-CR) rate was 62.1% (95% confidence interval [CI], 52.6-70.9), and the L-PDT group showed a better L-CR rate than did the P-PDT group (69.0% [95% CI 52.9-82.4] vs. 58.1% [95% CI 46.1-69.5]). The common complications of skin phototoxicity, esophageal stricture, and esophageal fistula were all less frequent in the L-PDT group than in the P-PDT group. The only treatment-related death in this study was in the P-PDT group. With a median follow-up period of 15.8 months (interquartile range 7.1-37.4) in all 121 patients, overall survival rate at 1 year was significantly higher among patients who achieved L-CR (91.2% [95% CI 80.2-96.3]) than among those who could not achieve L-CR with PDT (50.8% [95% CI 33.6-65.6]). Conclusions L-PDT represented better short-term outcomes than P-PDT as a salvage treatment for local failure following CRT or RT for esophageal cancer.