['Preoperative chemoradiotherapy (CRT) followed by esophagectomy is becoming one of the standard treatment strategies for esophageal cancer. Pathologic complete response (pCR) after CRT is the best predictor of survival in squamous cell carcinoma (SCC) of the esophagus. Although no adjuvant treatment is recommended for individuals who achieve pCR, approximately 30% of these patients develop recurrence. Herein we sought to retrospectively investigate the independent predictors of tumor recurrence in this patient group.', 'Between 1995 and 2004, we investigated seventy patients (69 males and 1 female; mean age: 56.1 years) with esophageal SCC who achieved pCR following preoperative chemoradiotherapy. Study end points included tumor recurrence, disease-specific survival (DSS), and disease-free survival (DFS). Univariate and multivariate analyses were used to identify risk factors for the study end points.', 'Mean follow-up time for patients who survived was 65.8 months. At the time of analysis, 18 patients (25.7%) died of the disease and 22 patients (31.4%) developed recurrence. Multivariate analysis showed that pretherapy T3-4 disease was the most important adverse factor for tumor recurrence (P = 0.007), DFS (P = 0.005), and DSS (P = 0.026). The 5-year DFS was 45% for patients with clinical T3-4 disease and 85% for those with clinical T1-2 disease (P = 0.02).'] Is pretreatment T3-4 stage an adverse prognostic factor in patients with esophageal squamous cell carcinoma who achieve pathological complete response following preoperative chemoradiotherapy?