For the treatment of resected pancreatic cancer, adjuvant chemotherapy with S-1–an oral drug related to 5-fluorouracil–significantly improves survival in Japanese patients, a study published in the journal The Lancet has shown.1

For the multicenter, open-label, phase 3 trial, investigators enrolled 377 patients with histologically proven invasive ductal carcinoma of the pancreas, pathologically documented stage I-III, with no local residual or microscopic residual tumor. Participants were randomly assigned 1:1 to receive gemcitabine 1000 mg/m2 IV on days 1, 8, and 15 of each 28-day cycle for up to 6 cycles, or S-1 at a dose of 40 mg, 50 mg, or 60 mg orally twice daily for 28 days on, 14 days off, of each 6-week cycle, for up to 4 cycles.

Results showed that S-1 reduced the risk of death by 43% (hazard ratio, 0.57; 95% CI, 0.44-0.72; Pnon-inferiority < .0001; P < .0001 for superiority) compared with gemcitabine. Five-year overall survival was 24.4% (95% CI, 18.6-30.8) with gemcitabine versus 44.1% (95% CI, 36.9-51.51) with S-1.

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Researchers found that grade 3 to 4 leukoepenia, neutropenia, as well as increased aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were more frequently observed in the gemcitabine group, while stomatitis and diarrhea were common in the S-1 arm.

RELATED: FOLFIRINOX May Have Longer Median OS Than Gemcitabine for Pancreatic Cancer

The findings suggest that adjuvant chemotherapy with S-1 may be an improved standard of care for Japanese patients with resected pancreatic cancer. Future studies should be conducted to compare the efficacy and safety of these therapies in non-Asian patients.


1. Uesaka K, Boku N, Fukutomi A, Okamura Y, Konishi M, Matsumoto I, et al. Adjuvant chemotherapy of S-1 versus gemcitabine for resected pancreatic cancer: a phase 3, open-label, randomised, non-inferiority trial (JASPAC 01) [published online ahead of print June 2, 2016]. Lancet. doi: 10.1016/S0140-6736(16)30583-9.