Surveillance With Serial Imaging and CA 19-9 Tumor Marker Testing After Resection of Pancreatic Cancer: A Single-Center Retrospective Study.

Objectives: Most patients receiving curative-intent surgery for pancreatic cancer will experience cancer recurrence. However, evidence that postoperative surveillance testing improves survival or quality of life is lacking. We evaluated the use and characteristics of surveillance with serial imaging and CA 19-9 tumor marker testing at an NCI-designated comprehensive cancer center.

Methods: We conducted a retrospective cohort study of patients who entered surveillance after curative-intent resection of pancreatic adenocarcinoma. We abstracted information from the electronic medical record about oncology office visits, surveillance testing (cross-sectional imaging and CA 19-9 tumor marker testing), and pancreatic cancer recurrence, with follow-up through 2 years after pancreatectomy. We conducted analyses to describe the use of surveillance testing and to characterize the sensitivity and specificity of CA 19-9 tumor marker testing for the identification of cancer recurrence.

Results: We identified 90 patients entering surveillance after pancreatectomy. CA 19-9 was the most frequently used surveillance test, followed by CT imaging. Forty-seven patients (52.2%) experienced recurrence within two years of pancreatectomy. Recurrence risk was 58.8% versus 31.8% in patients with elevated versus normal CA 19-9 at diagnosis ( P =0.03). Elevated CA 19-9 at any point during surveillance was significantly associated with 2-year recurrence risk ( P <0.001). Elevated CA 19-9 had a sensitivity of 83% (95% CI 0.72-0.95) and specificity of 87% (0.76-0.98) for identification of recurrence within 2 years of pancreatectomy.

Conclusions: CA 19-9 demonstrates clinical validity for identifying recurrence of pancreatic cancer during surveillance. Surveillance approaches with reduced reliance on imaging should be prospectively evaluated.