Outcomes of neoadjuvant gemcitabine plus S-1 and radiation therapy for borderline resectable pancreatic cancer

Background: The efficacy of multidisciplinary treatment, including neoadjuvant treatment, in borderline resectable pancreatic cancer (BRPC) remains unclear. We assessed the efficacy of neoadjuvant chemoradiotherapy with gemcitabine and tegafu/gimearcil/oteracil (S-1) for BRPC.

Methods: In a single center, nonrandomized prospective study, neoadjuvant chemoradiotherapy (NACRT) with gemcitabine plus S-1 was administered for BRPC (no. B090312028) in 122 patients enrolled between 2009 and 2015. Gemcitabine plus S-1 comprised gemcitabine on days 8 and 15, and daily S-1 on days 1-14. After two courses of gemcitabine plus S-1, 30 Gy radiotherapy was administered in 10 fractions with S-1.

Results: Eighty-four and 38 patients had BR-PV and BR-A, respectively. No deaths occurred during NACRT. Ninety-four patients (77%) underwent resection with curative intent. R0 resection was performed in 91% of resected cases. Patients who underwent post-NACRT resection had better overall survival than did patients without resection (mean survival time [MST]: 24.7 vs 9.6 months, 5-year-survival rate (5 years): 30.3% vs 0%, P < .001). Adjuvant chemotherapy was administered in 73% of patients. MST and 5-year survival rate of the patients treated with NACRT followed by resection and adjuvant chemotherapy were 29.6 months and 34.3%, respectively.

Conclusions: Neoadjuvant chemoradiotherapy with gemcitabine and S-1 can be safely administered in BRPC and may require adjuvant chemotherapy.

Clinical trial registration number: This study was registered with the University Hospital Medical Information Network-Clinical Trials Registry (UMIN-CTR) UMIN000006782.