Abstract
LESSONS LEARNED: Two courses of neoadjuvant therapy using S-1 plus cisplatin for clinical stage III esophageal squamous cell carcinoma did not achieve expected response rate according to endoscopic evaluation of primary tumors. Subsequent esophagectomy was safely performed. BACKGROUND: In Japan, esophagectomy after two courses of 5-fluorouracil plus cisplatin is regarded a standard strategy for treating stage II or III esophageal squamous cell carcinoma (ESCC). However, 5-fluorouracil plus cisplatin does not benefit cohorts with clinical stage III ESCC, suggesting the need for a more effective regimen. METHODS: A single-arm, open-label phase II trial was conducted to evaluate the safety and efficacy of two courses of neoadjuvant chemotherapy using S-1 plus cisplatin (NAC-SP) for clinical stage III ESCC. The primary endpoint was overall response rate as defined by endoscopic evaluation of primary tumors. RESULTS: We enrolled 26 patients. The completion rate for the two courses of NAC-SP was 61.5%. Grade 3 or higher adverse events were experienced by 38.4% of patients. The treatment response rate according to endoscopic findings, acquired before the second course, was 34.6% and below the expected level (55.0%). The morbidity rate of patients who underwent radical subtotal esophagectomy (96.2%) was 32.0%. Repeat surgery was unnecessary, and surgery-associated deaths did not occur. The 5-year progression-free survival (PFS) and overall survival (OS) rates were 84.6% and 92.2%, respectively. CONCLUSION: We demonstrate safety of NAC-SP, but not its efficacy, for patients with clinical stage III ESCC. Subsequent esophagectomy was safely performed.