Can a simplified CT response criteria for vascular involvement in pancreatic adenocarcinoma after neoadjuvant therapy predict survival in patients who achieved subsequent R0 resection?

Abstract

Purpose: To investigate if a simplified image based scoring system assessing treatment response after neoadjuvant therapy (NAT) can predict survival in patients with pancreatic ductal adenocarcinoma (PDAC) who achieved subsequent R0 resection.

Methods: Retrospective analysis of 57 PDAC patients (male = 29, 51%) with mean age of 64 at diagnosis (range 42-79) who received NAT and R0 resection. Post-NAT overall, arterial and venous imaging response was characterized as improved, similar, or worse by 2 readers independently followed by consensus review. Kaplan-Meier Analysis was performed to compare overall survival (OS) with post-NAT overall imaging response. A Multivariable Cox proportional hazards analysis was performed to evaluate the association of the following variables with OS: overall, arterial and venous radiology response, clinical staging, postoperative CA19-9, and patient age.

Results: At study conclusion, 30/57 patients were deceased (53%), 26/57 (46%) alive, and 1 patient unknown. Post-NAT, 39/57 (68.4%) had overall improved disease and 18/57 (31.6%) had similar disease. The median OS was 55.7 months (95% CI 33.4-not reached, NR) for those with improved disease vs. 53.9 months (95% CI 14.3-NR) with similar disease (p = 0.859) after NAT. Among all clinical parameters, only post-operative CA 19-9 level was associated with OS (p = 0.002) and PFS (p = 0.005), respectively.

Conclusion: Pancreatic cancer patients who underwent R0 resection showed no difference in survival when comparing those with similar vs improved disease on post-NAT imaging.

Keywords: Imaging response; Neoadjuvant therapy; Pancreatic cancer; R0 resection; Survival analysis.