PS02.034: EFFICACY AND SAFETY OF SALVAGE PHOTODYNAMIC THERAPY USING TALAPORFIN SODIUM FOR LOCAL FAILURE AFTER CHEMORADIOTHERAPY IN PATIENTS WITH ESOPHAGEAL CANCER

Abstract

Abstract Background We previously conducted an investigator-initiated trial of photodynamic therapy (PDT) using talaporfin sodium (talaporfin-PDT) and laser irradiation (PD-laser) against local failure after chemoradiotherapy (CRT) in patients with esophageal cancer (EC) and reported a high local complete response rate (L-CR) (88.5%) (Yano et al., Oncotarget 2017). Thereafter, talaporfin-PDT has been applied clinically as a salvage treatment for local failure after CRT in Japan since October 2015. The current study retrospectively reviewed the efficacy and safety of talaporfin-PDT in patients who underwent this treatment in our clinical practice. Methods This study was a single-center retrospective observational study. Patients who received salvage talaporfin-PDT for local failure of EC limited to T1–2 after definitive CRT or radiotherapy from May 2011 to July 2017 in our hospital were included. PDT was applied with an intravenous administration of talaporfin sodium (40 mg/kg) followed 4 h later by diode laser irradiation at 100 J/cm2. The primary and secondary endpoints were the rate of L-CR and the safety of PDT, respectively. The criteria for L-CR were as follows: 1) no residual tumor, 2) disappearance of post-PDT ulcer and scar formation, and 3) disappearance of cancer cells as assessed histologically. Results Thirty-one patients were analyzed in this study (26 men, 5 women, median age: 68 years). Histological types were squamous cell carcinoma and adenocarcinoma (30 and 1 patients, respectively). The failure patterns of lesions after CRT were recurrence after achieving a CR and residual lesion just after CRT (25 and 6 patients, respectively). The recurrent T stages were T1a, T1b, and T2 (1, 18, and 12 patients, respectively). The median total laser exposure dose was 500 J (range: 200–900). The L-CR rates were 84.2% (16/19), 41.7% (5/12), and 61.3% (19/31) in patients with T1, T2, and all stages, respectively. No severe adverse events greater than grade 3 related to PDT were observed. Although four patients had grade 2 esophageal stenosis after PDT, the stenosis was controlled by endoscopic balloon dilation. Conclusion Salvage talaporfin-PDT is a safe and curative treatment for local failure, especially stage T1, after CRT in patients with EC. Disclosure All authors have declared no conflicts of interest.