Cancer outcomes are independent of preoperative CA 19-9 in anatomically resectable pancreatic ductal adenocarcinoma: A retrospective cohort analysis

Background and Objectives: Current guidelines recommend neoadjuvant therapy for pancreatic ductal adenocarcinoma (PDAC) patients with anatomically resectable tumors but elevated CA 19-9. However, this recommendation is based on data from anatomically resectable and borderline resectable PDAC patients. Therefore, we analyzed the association of preoperative CA 19-9 with oncologic outcomes in a cohort of anatomically resectable PDAC patients. Methods: A single-institution PDAC database from 2007 to 2015 included patients who underwent guideline-based staging and were anatomically resectable. Patients with bilirubin above 1.5 after decompression, nonsecretors of CA 19-9, and borderline resectable patients were excluded. Statistical analysis included frequency testing and regression modeling for recurrence and survival. Results: One hundred forty-four PDAC patients were identified; 16 (11.1%) had elevated preoperative CA 19-9 ≥ 1000. A CA 19-9 level ≥1000 was not associated with demographic, clinical, or pathological factors. After adjustment for potential confounders, CA 19-9 levels (continuous, median, 500 U/mL, or 1000 U/mL cut-offs) were not associated with recurrence or overall survival (OS). Conclusions: Although guidelines recommend CA 19-9 to determine the management of anatomically resectable PDAC patients, CA 19-9 was not associated with recurrence or OS in this cohort. Our findings do not suggest that CA 19-9 alone should determine the PDAC treatment strategy.