Benson Kaluba, Naohisa Kuriyama, Motonori Nagata, Takahiro Ito, Aoi Hayasaki, Takehiro Fujii, Yasuhiro Murata, Akihiro Tanemura, Masashi Kishiwada, Shugo Mizuno
Aim: To assess the ability of a new severity-based tumor-superior mesenteric/portal vein interface criteria to predict survival outcomes in pancreatic ductal adenocarcinoma patients undergoing pancreaticoduodenectomy after neoadjuvant chemoradiotherapy (CRT).
Methods: Two hundred and twenty-six post-CRT patients were enrolled and 22 had no tumor-SMV/PV contact, while the remaining 204 had. Based on correlation with overall survival (OS), circumferential (210 degrees) and contact length (25 mm) interface cut-off values were identified, then used to formulate no tumor-SMV/PV contact, non-severe, and severe interface criteria. Significant predictors of disease-free (DFS) and OS were identified.
Results: The severe group had significantly more UR-LA, cStage 3 cases, longer operation times, more intra-operative blood loss, R1 resection, and pPV invasion cases than the no tumor-contact and non-severe interface groups (p < 0.001). Median DFS were 37.7 (no tumor-contact), 17.0 (non-severe), and 5.2 (severe) months and OS was 56.7, 29.9, and 12.0. Among tumor-contact patients, the interface criteria (84.7%) had a better specificity in predicting pPV invasion than tumor-contact length (76.9%) and tumor-circumferential interface (73.8%). Those with pPV invasion had shorter DFS (16.7 vs. 5.7) and OS (28.3 vs. 13.6) than those without pPV invasion. Significant independent predictors of both DFS and OS were the interface criteria, resection margins, and pPV invasion. Clinical and pathological lymph node involvement also influenced DFS, while circumferential interface and pathological tumor stage also impacted OS.
Conclusion: Patients can be stratified as no tumor-contact, non-severe, or severe interface cases and the criteria might be useful in preoperatively predicting not only survival but also intra-operative outcomes and pPV invasion.