Clinical characteristics and outcome of tumor-associated acute pancreatitis: a single-center cohort study

Background: What features should alert clinicians to suspect underlying tumors in patients with acute pancreatitis (AP) was largely unknown. This study aimed to assess the clinical characteristics and outcome in patients with tumor-associated AP. Methods: Patients who presented with AP and were diagnosed with tumor after admission were included according to the inclusion and exclusion criteria and followed up by hospital notes, telephone, WeChat and/or e-mail. The clinical characteristics and outcome were analyzed with multivariable logistic regression and were compared with AP patients without tumor. Results: Out of a cohort of 1,792 AP patients we identified 103 who had a neoplastic etiology. The 103 patients had a median age of 57 (range, 13-81) and 65 were males. AP was mild in 92 patients, moderately severe in 7 and severe in 4. The three most common tumors included pancreatic cancer (PC) (40), periampullary carcinoma (PAC) (25), and neoplastic pancreatic cysts (NPC) (22). The following ranked features were predictive of a tumor etiology: dilation of main pancreatic duct (MPD) (OR 417.83, 95% CI: 80.40-2,171.42), vascular invasion (OR 82.04, 95% CI: 6.05-1,113.14), mild AP (8.29, 95% CI: 1.98-34.73), and anemia (OR 5.73, 95% CI: 2.02-16.26). The median survival period of AP patients with PC, PAC, and NPC was 10.0 (7.0-23.5), 21.0 (5.0-37.0), and 35.0 (30.0-96.0) months, respectively. Conclusions: Mild AP patients with dilation of MPD, vascular invasion, and anemia were more frequently suggested a tumor etiology. Thus, clinical vigilance is needed for timely detection of tumor-associated pancreatitis with these characteristics.