Temporal Assessment of Prognostic Factors in Patients With Pancreatic Ductal Adenocarcinoma Undergoing Neoadjuvant Treatment and Resection.
BACKGROUND
The clinicopathologic factors associated with the survival of patients with pancreatic ductal adenocarcinoma (PDAC) during the different phases of neoadjuvant treatment (NT)-at diagnosis, restaging, or postoperatively-remain unclear.


METHODS
Data of patients with PDAC who underwent pancreatic resection after NT between 2008 and 2018 were retrospectively collected. Clinicopathologic characteristics and outcomes were compared stratified by resection margin status. Three multivariable regression models (at diagnosis, restaging, and postoperatively) were constructed to assess the temporal impact of different prognostic factors on all-cause survival (ACS) and disease-free survival (DFS).


RESULTS
All patients were diagnosed with a nonmetastatic PDAC and were appropriate candidates for NT according to the current National Comprehensive Cancer Network guidelines. From a total of 83 patients, 57 (68.7%) had a negative resection margin >1 mm (R0), whereas 26 patients (31.3%) had a positive resection margin (R1). At diagnosis, planned procedure (P = 0.017) and CA19-9 >100 U/mL (P = 0.047) were independent prognostic factors of decreased ACS. At restaging, planned procedure (P = 0.017), FOLFIRINOX (P = 0.026), and tumor size >30 mm (P = 0.030) were independent prognostic factors for increased and decreased ACS, respectively. Postoperatively, R0 was an independent prognostic factor for improved ACS (P = 0.005) and DFS (P = 0.002), whereas adjuvant therapy (P = 0.006) was associated with increased ACS. Lymph node involvement (P = 0.019) was associated with decreased DFS.


CONCLUSIONS
At diagnosis, restaging, and postoperatively, different, relevant clinicopathologic factors significantly impact the survival of patients with nonmetastatic PDAC undergoing NT. An R0 resection remains the most important prognostic factor and therefore should be the primary goal of surgical treatment in the neoadjuvant setting.