Prognostic impact of imaging tumor regression adjacent to major arteries after preoperative chemotherapy in surgical patients with advanced pancreatic cancer.

BACKGROUND: In the multidisciplinary treatment for advanced pancreatic cancer (PC), the prognostic effect of imaging tumor regression adjacent to major arteries after preoperative chemotherapy remains unclear. METHODS: This study enrolled 196 surgical patients with PC, 13 patients with borderline resectable PC against major artery (BR-A) and 18 with unresectable locally advanced (URLA) PC who underwent surgical resection after preoperative chemotherapy. Improvements in tumor size, abutment angle, and tumor markers were compared with the prognosis of patients. RESULTS: The reduction rates of tumor size were 20.4% and 46.0% in patients with BR and URLA PC (p = 0.075), achieving abutment angle improvement in 7(54%) and 6(33%) patients, respectively (p = 0.25). Pancreatectomy with arterial resection in 11 (35%) and a negative margin against the hepatic artery was obtained in 30 patients (96.8%). However, the imaging improvement against the major artery was not associated with the recurrence-free or overall survival of patients postoperatively. Conversely, normal and normalization of CA19-9 values after chemotherapy were associated with better recurrence-free survival (p = 0.031 and p = 0.042, respectively). CONCLUSION: The radiographic improvement in arterial abutment was not significantly associated with postoperative outcomes among selected patients who ultimately underwent surgical resection for BR-A and URLA PC.