Final analysis of single-arm confirmatory study of definitive chemoradiotherapy including salvage treatment in patients with clinical stage II/III esophageal carcinoma: JCOG0909.

Abstract

4545 Background: Definitive chemoradiotherapy (dCRT) consisting of 5-fluorouracil (5-FU) and cisplatin (CDDP) with 60 Gy radiotherapy (RT) for clinical (c) Stage II/III esophageal carcinoma (EC) is a standard treatment for patients (pts) refusing surgery (S) in Japan based on the previous trial (JCOG9906). However, poor survival, high incidence of late toxicities, and severe complications of salvage S are problems. We conducted a single-arm confirmatory study of CRT modifications including salvage treatment (ST) to reduce CRT toxicities and facilitate ST to improve survival. We reported the 3-year survival at 2018 ASCO Annual Meeting. We report the final data after 5-year follow-up. Methods: EC pts with cStage II/III (UICC 6th, non-T4), PS 0-1, and age 20-75 years were eligible. Chemotherapy (CT) was CDDP (75 mg/m2 on days 1, 29) and 5-FU (1000 mg/m2/d on days 1-4, 29-32). RT was administered to a total dose of 50.4 Gy with elective nodal irradiation of 41.4 Gy. Good responders after dCRT received additional 1-2 cycles of CT. For residual or recurrent disease, salvage endoscopic resection (ER) or S was performed based on the prespecified criteria. Planned sample size was 95, with one-sided alpha of 5% and power of 80%, expected and threshold 3-year overall survival (OS) as 55% and 42%. Key secondary endpoint was ST related toxicity. Final analysis was planned after 5-year follow-up for all pts. Results: From 4/2010 to 8/2014, 96 pts were enrolled, two were ineligible and 94 were included in efficacy analysis (cStage IIA/IIB/III, 22/38/34). Complete response was achieved in 55 pts (59%). Salvage ER and S were performed in 5 (5%) and 27 pts (29%). R0 resection of salvage S was achieved in 23 (85%). With a median follow-up of 5.95 years, 3- and 5-year OS was 74.2% (90% CI 65.9-80.8%) and 64.5% (95% CI 53.9-73.3%). 5-year progression-free survival and esophagectomy-free survival were 48.3% (95% CI 37.9-58.0%) and 54.9% (95% CI 44.3-64.4%). 5-year OS after salvage S was 31.0% and hazard ratio of R1-2 to R0 was 5.635 (95% CI: 1.818-17.467). No complications occurred after salvage ER. Five pts (19%) showed ≥ grade 3 operative complications and 1 treatment related death due to bronchus-pulmonary artery fistula occurred after salvage S. Only 9 pts (9.6%) showed grade 3 late toxicities. And no late operative complications more than grade 3 were observed. Conclusions: This combined modality treatment of dCRT with ST showed acceptable toxicities, favorable 5-year survival, and promising esophageal preservation. Clinical trial information: jRCTs031180110 .