Comment on "Prognosis-Based Definition of Resectability in Pancreatic Cancer: A Road Map to New Guidelines".

To the Editor: T he nomogram proposed by Richard Schulick et al, which was based solely on objective preoperative variables of pancreatic cancer patients, provides a tool for predicting the prognosis of resectability beyond existing tumor anatomic features. We highly appreciate the unique perspective and would like to share our opinions. First, the nomogram aims to redefine or guide resectability based on the prognosis of pancreatic cancer. However, the prognosis is also significantly determined by the surgical margin, pathological characteristics and adjuvant therapeutics. To better identify objective preoperative prognostic factors that are able to predict the probability of survival, important indicators such as histopathological grading, TNM stage, and adjuvant chemotherapy duration should be considered in baseline matching. It is only after matching on the basis of the above baseline characteristics that it would be possible to identify real and valid preoperative variables that could be extrapolated to patients preoperatively. Furthermore, we noticed that the authors did not specify which edition of T-staging was adopted for determination of the baseline variables. The AJCC, 8th edition, published in 2017, made major revisions to the widely criticized 7th edition, especially regarding Tstage category definitions. In addition, in the 8th edition, the cutoff values for tumor size are classified according to 3 ranges ( 2 cm, 2–4 cm, >4 cm), which may further improve the prognostic value. Second, the inclusion of T4-stage patients, who only account for 4.4% of resectable patients in this study, might be a limitation. The overwhelming majority of T4-stage patients are locally advanced pancreatic cancer (LAPC) patients and do not undergo surgical resection, and surgical resection for LAPC following neoadjuvant treatment continues to be debated. The