The minimum apparent diffusion coefficient value on preoperative magnetic resonance imaging in resectable pancreatic cancer: a new prognostic factor for biologically borderline resectable pancreatic cancer

Purpose To identify the prognostic factors that can define biologically borderline resectable pancreatic cancer (BRPC) in resectable pancreatic cancer (RPC) patients. Methods This retrospective study included 121 R/BRPC patients who underwent upfront surgery. Univariate and multivariate analyses were conducted to investigate the relationship between preoperative factors and overall survival (OS) for RPC. The OS of RPC patients was stratified based on a score, with each independent prognostic factor receiving 1 point. The OS of the R/BRPC patients was compared based on their scores. Results Overall, 113 and eight patients had RPC and BRPC. Serum CA19-9 > 500 U/mL (p = 0.048), maximum tumor diameter > 30 mm (p = 0.01), superior mesenteric/portal vein contact < 180 degrees (p = 0.04), and minimum apparent diffusion coefficient (ADCmin) <= 1020 x 10-6 mm2/s (p = 0.01) were identified as independent prognostic factors in RPC patients. RPC patients with a score of 0 had a significantly better prognosis than those with scores of 1 and 2-4 and BRPC patients (median OS: 99.3, 35.1, 19.0, and 8.4 months; p = 0.007, p < 0.001, and p = 0.003, respectively). No significant difference in the prognosis was observed between BRPC and RPC patients with scores of 1 and 2-4. Conclusions Preoperative ADCmin in RPC may be a new prognostic factor for biological BRPC.