• pancreatectomy with arterial resection
• prognostic factors
• locally advanced pancreatic cancer

Introduction. Pancreatectomy with arterial resection is a treatment option in selected patients with locally advanced pancreatic cancer. This study aimed to identify factors predicting cancer-specific survival in this patient population.
Methods. A single-Institution prospective database was used. Pre-operative prognostic factors were identified by using univariate and multivariate proportional hazard models. A nomogram was developed and a prognostic score was calculated for each patient in order to classify them into different categories of risk. Matching with pathologic parameters was used for internal validation.
Results. In a patient population with a median Ca 19.9 level of 19.8 U/mL(IQR: 7.1–77), cancer-specific survival was predicted by: metabolic deterioration of diabetes (OR = 0.22, p = 0.0012), platelet count (OR = 1.00; p = 0.0013), serum level of Ca 15.3 (OR = 1.01, p = 0.0018) and Ca 125 (OR = 1.02, p = 0.00000137), neutrophils-to-lymphocytes ratio (OR = 1.16; p = 0.00015), lymphocytes-to-monocytes ratio (OR = 0.88; p = 0.00233), platelets-to-lymphocytes ratio (OR = 0.99; p = 0.00118), and FOLFIRINOX neoadjuvant chemotherapy (OR = 0.57; p = 0.00144). A prognostic score was developed and three risk groups were identified. Harrell’s C-Index was 0.74. Median cancer-specific survival was 16.0 months (IQR: 12.3–28.2) for the high-risk group, 24.7 months (IQR: 17.6–33.4) for the intermediate-risk group, and 39.0 months (IQR: 22.7–NA) for the low-risk group (p = 0.0003). Matching the three risk groups against pathology parameters, N2 rate was 61.9, 42.1, and 23.8% (p = 0.04), median value of lymph-node ratio was 0.07 (IQR: 0.05–0.14), 0.04 (IQR:0.02–0.07), and 0.03 (IQR: 0.01–0.04) (p = 0.008), and mean value of logarithm odds of positive nodes was − 1.07 ± 0.5, − 1.3 ± 0.4, and − 1.4 ± 0.4 (p = 0.03), in the high-risk, intermediate- risk, and low-risk groups, respectively. An online calculator is available at www.survivalcalculator-lapdac-arterialresection.org.
Conclusions. The prognostic factors identified in this study predict cancer-specific survival in patients with locally advanced pancreatic cancer and low Ca 19.9 levels undergoing pancreatectomy with arterial resection. Three different categories of risk with statistically different survival were highlighted based on these prognostic factors.