LAUSR

In an era of increased utilisation of multimodality treatment for oesophageal adenocarcinoma the role of radical lymphadenectomy remains controversial. The objectives of this population-based cohort study were to evaluate the influence of lymph node harvest upon short- and long-term mortality following oesophagectomy for oesophageal adenocarcinoma, with subset analysis of patients receiving neoadjuvant therapy. The UK National Oesophago-Gastric Cancer Audit (NOGCA) was used to identify suitable patients operated on between 1st April 2012 and 31st March 2016. Logistic regression of confounders was used to generate predicted mortality probabilities for utilisation in Risk-Adjusted Cumulative Sum (RA-CUSUM) analysis to identify the lymph node harvest change-points associated with changes in one-, two- and three-year mortality. Within the three-year study period, 3883 patients were included of these 2192 patients (56%) received neoadjuvant chemotherapy. For all patients there were non-significant change-points in 1-, 2-, and 3-year mortality at 19, 27 and 19 lymph nodes respectively. For patients receiving neoadjuvant therapy change-point analysis did show statistically significant reductions in 2-year mortality (44.9% before to 39.2% after 19 lymph nodes; P = 0.017) and 3-year mortality (55.0% before to 47.4% after 20 lymph nodes; P = 0.035). 30-day and 90-day mortality and anastomotic leak were not significantly by lymph node harvest of greater than 19 lymph nodes. The results of this national population-based cohort study suggest that at least 20 lymph nodes should be harvested during oesophagectomy given the prognostic importance in oesophageal adenocarcinoma, and the benefits to improve pathological staging of the patient and appropriately allocate adjuvant therapy. All authors have declared no conflicts of interest.