Prognostic significance of circumferential resection margin involvement in patients receiving potentially curative treatment for oesophageal cancer

Introduction: The utility of Circumferential Resection Margin (CRM) status in predicting prognosis in oesophageal cancer is controversial, with different definitions used by the College of American Pathologists and the Royal College of Pathologists. We aimed to determine prognostic significance of CRM involvement and evaluate which system is the best predictor of prognosis. Methods: A cohort of 390 patients who had potentially curative oesophagectomy (- + neoadjuvant chemotherapy) were analysed. Associations between CRM involvement and patient outcome were assessed for the whole cohort, and for pre-specified subgroups of T3 tumours and those who received neo-adjuvant chemotherapy. Results: CRM-involvement was associated with higher T and N stage, tumour differentiation, increased tumour length and both lymphovascular and perineural invasion. Overall Survival (OS) and Recurrence Free Survival (RFS) significantly worsened with CRM-involvement (p = 0.001, p < 0.001). R1a (<1 mm but no macroscopic involvement) resulted in significantly improved OS (p = 0.037) and RFS (P = 0.026) compared to R1b (macroscopic involvement), but did not differ significantly from R0 (≥1 mm). The association between CRM-involvement and both OS and RFS remained significant regardless of whether neoadjuvant chemotherapy was given. However, CRM-involvement was not a significant prognostic marker in T3 patients (p = 0.148). Multivariable analysis found N stage, lymphovascular invasion, patient age and neoadjuvant chemotherapy to be significantly predictive of patient outcome. CRM-involvement was not a significant independent prognostic marker. Conclusions: CRM-involvement was not found to be independently predictive of prognosis, after accounting for other prognostic markers. As such, CRM should not be considered a major prognostic factor in patients with oesophageal cancer.