Important CT and histopathological findings for recurrence and overall survival in patients with pancreatic ductal adenocarcinoma who underwent surgery after neoadjuvant FOLFIRINOX.

OBJECTIVES

To investigate important factors for recurrence-free survival (RFS) and overall survival (OS) in patients with pancreatic ductal adenocarcinoma (PDA) who underwent surgery after neoadjuvant FOLFIRINOX using CT and histopathological findings.

MATERIALS AND METHODS

Sixty-nine patients with PDA who underwent surgery after neoadjuvant FOLFIRINOX were retrospectively included. All patients underwent baseline and first follow-up CT. Two reviewers assessed the CT findings and resectability based on the NCCN guideline. They graded extrapancreatic perineural invasion (EPNI) using a 3-point scale focused on 5 routes. Clinical and histopathological results, such as T- and N-stage, tumor regression grade (TRG) using the College of American Pathology (CAP) grading system, and resection status, were also investigated. Kaplan-Meier methods were used for RFS and OS. The Cox proportional hazard model and logistic regression model were used to identify significant predictive factors.

RESULTS

There were 57 patients (82.6%) without residual tumors (R0) and 12 patients (17.4%) with residual tumors (R1 or R2). The median RFS was 13 months (range 022 months). For RFS, EPNI on baseline CT (hazard ratio (HR) 2.53, 95% confidence interval (CI) 1.116-5.733, p = 0.026) and TRG (HR 1.76, 95% CI 1.000-3.076, p = 0.046) were important predictors of early recurrence. The mean OS was 48 months (range 1135 months). For OS, TRG (HR 1.05, 95% CI 1.251-6.559, p = 0.013) was a significant factor. However, there were no independent predictors for residual tumors according to the CT findings.

CONCLUSION

EPNI on baseline CT and TRG were important prognostic factors for tumor recurrence. In addition, TRG was also an important prognostic factor for OS.

KEY POINTS

• CT and histopathological findings are helpful for predicting early recurrence and poor survival. • EPNI on baseline CT (HR 2.53, p = 0.026) is an important predictor of early recurrence. • The TRG is an important prognostic factor for early recurrence (HR 1.76, p = 0.046) and poor survival (HR 1.05, p = 0.013).