Proper adjuvant therapy in patients with borderline resectable and locally advanced pancreatic cancer who had received neoadjuvant FOLFIRINOX

Background: The complete resection rate of pancreatic cancer has increased because of the advent of efficacious first-line treatments for unresectable pancreatic cancer. Still, strategies regarding adjuvant therapy after neoadjuvant FOLFIRINOX treatment remain to be established. Methods: Data on 144 patients with borderline resectable and locally advanced pancreatic cancer who underwent resection after neoadjuvant FOLFIRINOX between January 2013 and April 2021 were retrospectively reviewed. Results: Among the study patients, 113 patients (78.5%) were diagnosed with borderline resectable pancreatic cancer and 31 patients (21.5%) were diagnosed with locally advanced pancreatic cancer. Seventy-five patients (52.1%) received radiotherapy before surgery. After radical resection, 84 patients (58.3%) received 5-fluorouracil-based adjuvant therapy and 60 patients (41.7%) received non-5-fluorouracil-based adjuvant therapy. Adjuvant therapy with 5-fluorouracil-based regimen [hazard ratio (HR), 0.43 (95% CI, 0.21–0.87); p = 0.019], preoperative assessment as locally advanced pancreatic cancer [HR, 2.87 (95% CI, 1.08–7.64); p = 0.035], positive resection margin [HR, 3.91 (95% CI, 1.71–8.94); p = 0.001], and presence of pathologic lymph node involvement [HR, 2.31 (95% CI, 1.00–5.33), p = 0.050] were associated with decreased recurrence-free survival. Adjuvant therapy with 5-fluorouracil-based regimen [HR, 0.35 (95% CI, 0.15–0.84); p = 0.018], positive resection margin [HR, 4.14 (95% CI, 1.75–9.78); p = 0.001], presence of pathologic lymph node involvement [HR, 3.36 (95% CI, 1.23–9.15); p = 0.018], poor differentiation [HR, 5.69 (95% CI, 1.76–18.36); p = 0.004], and dose reduction during adjuvant therapy [HR, 1.78 (95% CI, 1.24–24.37); p = 0.025] were associated with decreased overall survival. Conclusions: The 5-fluorouracil-based adjuvant therapy seems to be the proper adjuvant therapy for patients who received neoadjuvant FOLFIRINOX for borderline resectable and locally advanced pancreatic cancer.