Top Line: We recently saw a Japanese single-arm study of definitive chemoradiation with salvage surgery for stage II/III esophageal squamous cell carcinoma where 59% had a complete response to 50.4Gy with concurrent cis/5FU achieving a 3-year overall survival rate of 74%.
The Study: Here is a Chinese randomized phase 2 trial where 213 patients with stage II-IVa esophageal squamous cell carcinoma received neoadjuvant chemoradiation consisting of 40 Gy in 20 fractions with 4 cycles of cisplatin and docetaxel. All patients underwent restaging with imaging and endoscopy to assess response. Seventy-nine patients (37%) had a clinical complete response and were randomized to definitive chemoradiation or surgery. Important to note is that the median turnaround time for response assessment was 5 days. On the one hand, this means minimal delay in proceeding with definitive chemoradiation. On the other hand it means there wasn’t much time to observe more complete responses. Patients in the definitive chemoradiation arm received an additional 10-20 Gy (median total dose 56 Gy) with 1-2 more cycles of chemo. Among those who had surgery after a clinical complete response, 90.5% had a true pathologic complete response. At 3 years, there was no difference in disease-free survival (56% after surgery v 55% after chemoradiation alone) or overall survival (70% v 62%). There were also no differences in the rates of any disease progression (40% v 33%) or locoregional disease progression (14% v 11%). As expected, esophagitis and hematologic toxicity were worse with definitive chemoradiation.
TBL: Interim response assessment after neoadjuvant chemoradiation identifies a third of patients with esophageal squamous cell carcinoma who might safely complete definitive chemoradiation without further surgery. | Qian, Radiother Oncol 2022