Optimal lymph node yield in oesophagectomy for oesophageal cancer: a nationwide population-based study

OBJECTIVES The desirable lymph node count was determined to maximize the survival time expectancy according to the lymph node count among patients who have undergone oesophagectomy for oesophageal cancer.METHODS The data of national Finnish population-based cohort including all patients who have undergone oesophagectomy due to oesophageal cancer during 2002-2016 were used. Restricted mean survival time (RMST) estimates were determined by lymph node count, and the desirable count was determined using locally estimated scatterplot smoothing regression.RESULTS A total of 883 patients with the median follow-up time of 3.73 (interquartile range 1.43-7.50) years were included. The lymph node count of 27 (95% confidence interval 25-28) was associated with the highest RMST estimates. Sensitivity analyses indicated that in pN0 patients, the highest RMST estimates was observed at 26 (95% confidence interval 24-28) lymph nodes and in pN+ patients, the RMST estimates peaked at 28 (95% confidence interval 25-33) lymph nodes.CONCLUSIONS According to the findings of this study, at least 24 examined lymph nodes is the recommended target for the lymph node count after oesophagectomy for oesophageal cancer. The beneficial effect of this count on survival may be achieved regardless of nodal metastases. Oesophageal cancer holds a poor prognosis with the 5-year survival of 22% after diagnosis [1].