Prognostic significance of preoperative and postoperative CA 19-9 normalization in pancreatic adenocarcinoma treated with neoadjuvant therapy or surgery first

Background: Normal(ization) of serum carbohydrate 19-9 (CA19-9) before/after surgery has not been compared in patients with pancreatic adenocarcinoma (PDAC) treated with neoadjuvant therapy (NT) versus surgery-first (SF). Methods: Characteristics for patients with PDAC who underwent resection from July 2011 to October 2018 were collected. Patients with pre-/postoperative CA19-9, bilirubin <2 mg/dL, and initial CA19-9 > 1 U/ml were included. Overall survival (OS) and recurrence-free survival (RFS) were compared by pre-/postoperative CA19-9. Results: In patients receiving NT, normal pre/postoperative CA19-9 (“NT^nl/nl”) was associated with median RFS and OS (26 and 77mo), followed by those who normalized after surgery (“NT^abnl/nl” 16 and 44mo). For SF patients, normal pre-/postoperative CA19-9 (“SF^nl/nl”) was associated with median RFS and OS (115 and not estimable mo), followed by those who normalized after resection (“SF^abnl/nl” 18 and 49mo). Groups “NT^abnl/abnl” and “SF^abnl/abnl” with elevated CA19-9 both before and after resection had the worst median RFS and OS durations. Conclusions: While a normal(ized) postoperative CA19-9 may result in similar survival as preoperative normal(ization), postoperative normalization failed to occur in nearly 30% of SF patients. NT should be considered in patients presenting with elevated CA19-9. If considering SF, ideal patients may include those with normal CA19-9 at presentation.