Diagnostic impact of postoperative CA19-9 dynamics on pancreatic cancer recurrence: a single-institution retrospective study.

Postoperative CA19-9 elevation after pancreatic cancer resection suggests recurrence but can also occur in benign conditions. This study aimed to investigate the interpretation of postoperative CA19-9 elevation after pancreatic cancer surgery in terms of cancer recurrence. A cohort of patients undergoing pancreatectomy for pancreatic cancer at our hospital was included. Among them, 52 patients exhibited postoperative CA19-9 elevation without radiological evidence of recurrence. These patients were evaluated with follow-up CA19-9 measurements. The CA19-9 increase rates were calculated based on the first elevation and the follow-up measurement. The association between the CA19-9 increase rate and tumor recurrence was assessed. Patients with a CA19-9 increase rate of ≥ 30% had a significantly higher frequency of recurrence within 3 months compared to those without such an increase (p = 0.0002). Multivariate analysis demonstrated that a CA19-9 increase rate of ≥ 30% was an independent risk factor for recurrence (odds ratio 8.17, p = 0.0309). The CA19-9 value at the first elevation (p = 0.1794) and at the follow-up measurement (p = 0.1121) were not associated with recurrence. After the first postoperative CA19-9 elevation, the CA19-9 increase rate based on follow-up measurements can serve as a predictive factor for tumor recurrence.