ASCOT (JCOG1202)
After curative resection of biliary tract cancer, does adjuvant S-1 improve survival compared with observation?
Trial design and population
Key results
At 3 years, overall survival was 77.1% with S-1 vs 67.6% with observation (HR 0.694; 95% CI 0.514–0.935; one-sided p=0.008).
Source-reported outcome visualization
3-year overall survival · 3 years
Bars display source-reported values for the named endpoint; where the endpoint is a median, bars compare medians and do not represent probabilities. No unreported rates are inferred.
Absolute Effect
9.5 percentage-point difference in 3-year OS; source-reported.
NNT: 11 (approximate reciprocal of 9.5% absolute difference; endpoint/time-specific). No NNT is derived from median survival/PFS differences.
NNH / harm: Grade 3–4 biliary tract infection 7.2%, diarrhoea 2.9%, appetite loss 2.9%, fatigue 2.9% in S-1 arm; toxicity comparisons require full trial table.
NNT/NNH are only displayed where the endpoint and time horizon support a defensible absolute-risk calculation. Otherwise, the source-reported outcome is visualized.
Safety and treatment burden
Grade 3–4 biliary tract infection 7.2%, diarrhoea 2.9%, appetite loss 2.9%, fatigue 2.9% in S-1 arm; toxicity comparisons require full trial table.
Follow-up, maturity and limitations
Japanese population and S-1 regimen; regional availability and practice differ. The 3-year absolute difference is a Kaplan–Meier estimate, so NNT is approximate and time-specific.
Clinical interpretation
Current-practice context · reviewed 20 October 2026
This page separates original trial findings from contemporary treatment context. Confirm current disease-specific guidelines, local regulatory status, biomarker requirements, prior treatment exposure and patient-specific contraindications before applying the evidence. Historical comparators may no longer represent current standard practice; subgroup findings and immature endpoints should not be generalized.