Prognostic Significance of Preoperative and Postoperative CA 19-9 Normalization in Pancreatic Adenocarcinoma Treated with Neoadjuvant Therapy or Surgery First

Abstract

Background: Normal(ization) of serum carbohydrate 19-9 (CA 19-9) before/after surgery has not been compared between patients with pancreatic adenocarcinoma (PDAC) treated with neoadjuvant therapy (NT) vs. surgery-first (SF). We hypothesized that postoperative normalized CA 19-9 is associated with dissimilar outcomes compared to normal(ization) before surgery. Methods: Clinicopathologic characteristics for patients with PDAC who underwent resection from July 2011 to October 2018 were abstracted from a prospective database. Patients with pre-/post-operative CA 19-9, total bilirubin <2mg/dL, and initial CA 19-9 >1 U/mL were included. Overall survival (OS) and recurrence-free survival (RFS) were compared among groups when stratified by pre-/post-operative CA 19-9. Results: In patients receiving NT (N = 171), normal pre-/post-operative CA19-9 (group “NT-1”) had the best median RFS and OS (26 and 77mo), followed by those who finally normalized after surgery (“NT-2,” 16 and 39mo). For SF patients (N = 57), normal pre-/post-operative CA19-9 (“SF-1”) had the best median RFS and OFS (28 and 57mo), followed by those who immediately normalized after resection (“SF-2,” 18 and 49mo). Groups “NT-3” (n=36) and “SF-3” (n=11) with elevated CA 19-9 both before and after resection had the worst median RFS and OS durations (Figure 1). Conclusion: While a normal(ized) postoperative CA 19-9 may result in similar survival as preoperative normal(ization), postoperative normalization failed to occur in 28.9% of SF patients, despite careful selection. Thus, NT should be considered in patients presenting with elevated CA 19-9. If considering surgery-first, the ideal patients are those with normal pre-operative CA 19-9.