The impact of positive circumferential margin on survival following oesophagectomy using the new 7th TNM classification.

Previous studies looking at the influence of positive circumferential margin (CRM) on survival after oesophagectomy are conflicting. This may be due to the fact that older versions of the TNM classification were used, which do not predict survival as accurately as the new 7th edition. We examine whether CRM involvement has an impact on survival when the 7th TNM classification is used. Over a 10-year period, 199 patients who had undergone potentially curative resection for oesophageal cancer with postoperative histopathological T3 were identified. A total of 151 (75.9%) were found to have CRM involvement (< 1 mm), and these were compared with patients in whom the CRM was free of tumour. Cancers were staged according to the International Union against Cancer TNM 7th edition. First, univariate and then multivariate Cox regression analysis were performed to assess the factors influencing survival. Potentially significant predictors (P < 0.1) from the univariate analysis were inserted in the forward-stepwise Cox regression model and was allowed to remain in the final model if a P-value of < 0.05 was achieved. A sub-group analysis was also performed for different N-stages (N0-N3). After all analyses were performed, CRM involvement was found to have no effect on survival following oesophagectomy [hazard ratio 1.28 (95% CI: 0.82-2.01) (P = 0.28)]. This was seen for all N-stages. Stage of disease, age at operation, % predicted forced expiratory volume in 1 second and shortness of breath [(according to New York Heart Association classification)] were all significant predictors of survival. With this study, it became clear that CRM involvement does not affect long-term survival of patients after oesophagectomy. Patients with CRM involvement should not necessarily be considered to have had an incomplete resection.