Predictive risk factors for early recurrence in patients with localized pancreatic ductal adenocarcinoma who underwent curative-intent resection after preoperative chemoradiotherapy

BACKGROUND: The optimal surgical indication after preoperative chemoradiotherapy (CRT) remains a subject of debate for patients with pancreatic ductal adenocarcinoma (PDAC) because early recurrence often occurs even after curative-intent resection. The present study aimed to identify perioperative risk factors of early recurrence for patients with PDAC who underwent curative-intent resection after preoperative CRT. METHODS: Two hundred three patients with PDAC who underwent curative-intent resection after preoperative CRT from February 2005 to December 2018 were retrospectively analyzed. The optimal threshold for differentiating between early and late recurrence was determined by the minimum p-value approach. Multivariate regression analysis was performed to identify predictive factors for early recurrence. RESULTS: In 130 patients who developed recurrence after resection, 52 who had an initial recurrence within 12 months were defined as the early recurrence group, and the remaining 78 were defined as the late recurrence group. The incidence of hepatic recurrence was significantly higher in the early recurrence group than in the late recurrence group (39.7 vs. 15.4%). The early recurrence group had significantly lower 3-year rates of post-recurrence and overall survival than the late recurrence group (4.0 and 10.7% vs. 9.8 and 59.0%, respectively). Serum level of CA19-9 before surgery ≥56.8 U/ml was identified as an independent risk factor for early recurrence (OR:3.07, 95%CI:1.65–5.73, p<0.001) and associated with a significantly higher cumulative incidence rate of hepatic recurrence and lower rates of recurrence-free and overall survival. CONCLUSION: Serum level of CA19-9 before surgery after preoperative CRT was a strong predictive factor for early recurrence.