Main Pancreatic Duct to Parenchymal Thickness Ratio at Preoperative Imaging is Associated with Overall Survival in Upfront Resected Pancreatic Cancer

Abstract

Background Pancreatic cancer induces parenchymal atrophy and duct dilation. The aim of this study was to evaluate whether these radiologic modifications are associated with outcomes. Methods Upfront pancreaticoduodenectomy patients with available preoperative contrast enhanced CT scan imaging were retrospectively analyzed. Thickness of the pancreas, size of the main pancreatic duct (MPD), and distance of the tumor from the ampulla were assessed. A training cohort was selected, including short- (3–12\xa0months following surgery) and long-term (≥\u200936\xa0months) survivors. Identified survival determinants were validated in the overall cohort. Results Two-hundred-sixteen patients were analyzed. In the training cohort ( N \u2009=\u2009118), 68 patients (57.6%) were in the short-term and 50 (42.4%) in the long-term survival group. The short-term survival group had significantly higher CA 19–9 levels ( p \u2009=\u20090.027), larger tumors (32.6\u2009±\u200912.1\xa0mm vs. 26.5\u2009±\u200911.6\xa0mm, p \u2009=\u20090.007), poorer differentiation ( p \u2009=\u20090.003), higher rate of R \u2009<\u20091\xa0mm resections (54% vs. 32%, p \u2009=\u20090.008), and reduced receipt of adjuvant chemotherapy ( p \u2009=\u20090.020). The MPD-to-pancreatic thickness ratio was significantly lower in the short-term survivors (3.6\u2009±\u20096.2 vs. 8.2\u2009±\u200912.0, p \u2009=\u20090.016). In the entire cohort, an MPD-to-pancreatic thickness ratio ≥\u20093.5 was associated with improved OS [median 33.0\xa0months IQR (19.7–48.1) versus 17\xa0months IQR (14.8–19.2), p \u2009=\u20090.004], and confirmed by a Cox-proportional hazards model independently associated with OS (HR\u2009=\u20090.58; p \u2009=\u20090.009), together with tumor size (HR\u2009=\u20091.02; p\u2009 =0.012), R 1/ R 2 status (HR\u2009=\u20091.53; p \u2009=\u20090.029), and receipt of adjuvant treatment (HR\u2009=\u20090.61; p \u2009=\u20090.021). Conclusions High MPD-to-pancreatic thickness ratio was associated with improved long-term survival in pancreaticoduodenectomy for cancer. Whether these features are related to tumor chronicity, indolent biology, or local growth over metastasis remains to be determined.