Impact of circumferential resection margin distance on locoregional recurrence and survival after chemoradiotherapy in esophageal squamous cell carcinoma

Background: Close circumferential resection margin (CRM) is an established predictor for locoregional recurrence (LR) in rectal cancer but remains controversial in esophageal malignancy. As yet, little is known about the significance of CRM after chemoradiotherapy (CRT), especially in squamous cell carcinoma (SCC). This study investigated the relationship between CRM distance and recurrence after neoadjuvant CRT in esophageal SCC patients. Methods: Between 1997 and 2005, esophageal SCC patients who underwent surgery after neoadjuvant CRT and with pathology stage T3N0M0 and T3N1M0 (metastatic lymph nodes <2) were selected. CRM distance was reassessed and divided into three groups (group 1: CRM >1 mm, group 2: uninvolved CRM but <1 mm, group 3: CRM involved). Results: The cohort comprised 145 male and 6 female patients with mean age of 57 years. There were 74, 51, and 26 patients in group 1, 2, and 3, respectively. With median follow-up period of 50 months, LR developed in 30.5% of patients. Both group 2 and group 3 had significantly higher LR than group 1 (37 and 42% vs. 21%, P < 0.05). Meanwhile, mean time from operation to recurrence was also significantly shorter in group 2 and group 3 than in group 1 (267 and 269 days versus 402 days, P < 0.05). Five-year disease-specific survival (DSS) was highest in group 1 (40%). Despite the similarity in LR, 5-year DSS significantly differed between group 2 and group 3 (22 vs. 7%, P < 0.05). The higher rate of distant recurrence (DR) and concomitant LR + DR in group 3 accounted for the survival difference. Conclusion: In ypT3 esophageal SCC patients, CRM distance provides useful information for risk stratification in cancer recurrence and survival.