ABSTRACT
BACKGROUND: This study evaluated the association of pathological tumour response (tumour regression grade, TRG) and a novel scoring system, combining both TRG and nodal status (TRG-ypN score; TRG1-ypN0, TRG>1-ypN0, TRG1-ypN+ and TRG>1-ypN+), with recurrence patterns and survival after multimodal treatment of oesophageal adenocarcinoma. METHODS: This Dutch nationwide cohort study included patients treated with neoadjuvant chemoradiotherapy followed by oesophagectomy for distal oesophageal or gastro-oesophageal junctional adenocarcinoma between 2007 and 2016. The primary endpoint was the association of Mandard score and TRG-ypN score with recurrence patterns (rate, location, and time to recurrence). The secondary endpoint was overall survival. RESULTS: Among 2746 inclusions, recurrence rates increased with higher Mandard scores (TRG1 30.6%, TRG2 44.9%, TRG3 52.9%, TRG4 61.4%, TRG5 58.2%; P < 0.001). Among patients with recurrent disease, the distribution (locoregional versus distant) was the same for the different TRG groups. Patients with TRG1 developed more brain recurrences (17.7 versus 9.8%; P = 0.001) and had a longer mean overall survival (44 versus 35 months; P < 0.001) than those with TRG>1. The TRG>1-ypN+ group had the highest recurrence rate (64.9%) and worst overall survival (mean 27 months). Compared with the TRG>1-ypN0 group, patients with TRG1-ypN+ had a higher risk of recurrence (51.9 versus 39.6%; P < 0.001) and worse mean overall survival (33 versus 41 months; P < 0.001). CONCLUSION: Improved tumour response to neoadjuvant therapy was associated with lower recurrence rates and higher overall survival rates. Among patients with recurrent disease, TRG1 was associated with a higher incidence of brain recurrence than TRG>1. Residual nodal disease influenced prognosis more negatively than residual disease at the primary tumour site.