LAUSR

To the Editor: We read with interest the article by Huang et al on the investigation of the associations of examined lymph node (ELN) number with accurate staging and long-term survival in pancreatic adenocarcinoma and to robustly determine the minimal and optimal ELN thresholds. This study suggested that 19 ELNs as the optimal cutpoints, for the ability to well discriminate different probabilities of survival. We congratulate Huang et al for this innovative and excellent statistical method used to identify the optimal number of nodes required, but one point of the study need to further discussion. This study showed that the breakpoint for survival was smaller in patients<60 years (13 ELNs) than those aged 60 years (18 ELNs). It is reasonable to assume that the optimal number of nodes is dependent on the patient’s age. However, the optimal cutpoints were not validated in the study by Huang et al. Based on the inclusion and