Definitive chemoradiotherapy for locoregional recurrence of esophageal squamous cell carcinoma patients after radical surgery: Retrospective study

314 Background: The prognosis of esophageal squamous cell carcinoma (ESCC) patients with recurrence after radical surgery remains poor, with a median overall survival (OS) of 5-10 months. Locoregional recurrence (LR) have a potential to cure by definitive chemoradiotherapy (dCRT) or surgery. However, there are a few data on clinical outcomes of the patients with LR. We evaluated the efficacy and safety of dCRT for LR after radical surgery retrospectively. Methods: The subjects who had LR after surgery were corrected from medical record between January 2015 and April 2020 in our hospital. LR was defined as recurrence within the regional and supraclavicular lymph nodes after curative surgery. CRT consist of fluoropyrimidine and platinum with radiation at a dose of 50.4-60Gy. Complete response (CR) rate, progression-free survival (PFS), OS, and safety was evaluated. Results: Twenty-five patients who had LR after surgery were analyzed with the median follow-up time of 21.5 (range: 0.47-60.2) months. Patients’ characteristics at the initiation of dCRT were as follows; median age (range): 70 (40-70) years old, male/female: 20 (80%)/5 (20%) patients, PS 0/1/2: 11 (44%)/12 (48%)/ 2 (8%) patients. Chemotherapy regimens were cisplatin and 5-fluorouracil in 23 (92%) patients, nedaplatin and 5-fluorouracil in 1 (4%) patient, and S-1 in 1 (4%) patient. Radiation doses were 60 Gy in 24 (96%) patients and 50.4 Gy in 1 (4%) patient. CR was achieved in 13 (53%) patients. The median PFS was 9.7 (95%CI: 5.6-NA) months, and the median OS was 28.8 (95%CI: 21.2-NA) months. The one-year survival rate was 78.7 (95%CI: 56.1-90.6) % and the three-years survival rate was 25.9 (95%CI: 5.1-54.1) %. Grade 3 or higher adverse events were observed in 3 (12%) patients of neutropenia, in 3 (12%) patients of leukopenia, and in 2 (8%) patients of febrile neutropenia. Treatment-related death due to febrile neutropenia was observed in 1 (4%) patient. No patient presented with severe late toxicity after dCRT. Conclusions: In this study, dCRT for LR after surgery was tolerable and promising efficacy with curative intent.