# ASCOT (JCOG1202)

Source: https://onco.cc/trials/ascot-jcog1202/  
OnCo record `ascot-jcog1202` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

In Japan, six months of the oral chemotherapy S-1 after surgery for bile duct, gallbladder or ampullary cancer improved three-year survival from 68 to 77 percent. S-1 is not licensed for this use in the UK or Europe, so the result cannot be applied directly to NHS patients.

## Summary

ASCOT (JCOG1202, UMIN000011688) randomised 440 patients between 2013 and 2018 (218 to S-1, 222 to observation) after resection of biliary tract cancer, including gallbladder carcinoma, with no or only microscopic residual tumour. S-1 (tegafur, gimeracil and oteracil) was given at 40 to 60 mg twice daily for four weeks of every six for four cycles. At a median follow-up of 45.4 months, three-year overall survival was 77.1 percent with S-1 versus 67.6 percent with observation (adjusted hazard ratio 0.69, 95 percent confidence interval 0.51 to 0.94, one-sided p 0.0080), meeting the primary endpoint; three-year relapse-free survival was 62.4 versus 50.9 percent (hazard ratio 0.80, 0.61 to 1.04). Grade 3 to 4 neutropenia occurred in 14 percent and biliary tract infection in 7 percent of the S-1 group. The trial makes S-1 the Japanese adjuvant standard alongside capecitabine from BILCAP; the two have not been compared. In Europe S-1 (Teysuno) is licensed only for gastric cancer, and it is not commissioned for biliary cancer in the UK, so capecitabine remains the NHS adjuvant drug. Gallbladder carcinoma was an eligible site and a stratification factor (primary tumour site), but a gallbladder-specific effect is not reported in the abstract.

## Fields

- Kind: Trial
- Status: positive
- Last checked: 2026-09-24
- Also known as: ASCOT; JCOG1202
- Tags: registry:umin
- Phase: 3
- Setting: Adjuvant S-1 for four cycles versus observation after resection of extrahepatic cholangiocarcinoma, gallbladder carcinoma, ampullary carcinoma or intrahepatic cholangiocarcinoma (R0 or R1), 38 Japanese hospitals
- Sponsor: Japan Clinical Oncology Group
- Enrolled: 440
- Result: 3-year overall survival 77.1% vs 67.6%, adjusted HR 0.69 (0.51 to 0.94), one-sided p=0.0080.
- Outcomes: 3-year overall survival: S-1 77.1% vs Observation 67.6%, HR 0.69; 3-year relapse-free survival: S-1 62.4% vs Observation 50.9%, HR 0.8

## Notes

- Registered with the UMIN Clinical Trials Registry as UMIN000011688; no ClinicalTrials.gov entry.

## Sources

- Nakachi et al., Lancet 2023: adjuvant S-1 compared with observation in resected biliary tract cancer (JCOG1202, ASCOT): https://doi.org/10.1016/S0140-6736(22)02038-4
- UMIN000011688: https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000013683

## Connected records

- cancers: [Ampullary cancer (ampulla of Vater)](https://onco.cc/cancers/ampullary/), [Biliary tract cancer (all types)](https://onco.cc/cancers/biliary-tract-cancer/), [Biliary tract cancer (cholangiocarcinoma)](https://onco.cc/cancers/cholangiocarcinoma/), [Extrahepatic cholangiocarcinoma (perihilar and distal)](https://onco.cc/cancers/extrahepatic-cholangiocarcinoma/), [Gallbladder cancer](https://onco.cc/cancers/gallbladder/), [Intrahepatic cholangiocarcinoma](https://onco.cc/cancers/intrahepatic-cholangiocarcinoma/)
- technologies: [Cytotoxic chemotherapy](https://onco.cc/technologies/cytotoxic-chemotherapy/)
- drugs: [Tegafur, gimeracil and oteracil (S-1)](https://onco.cc/drugs/tegafur-gimeracil-oteracil/)
- terms: [Gallbladder cancer in biliary tract cancer trials (eligibility and subgroups)](https://onco.cc/terms/gallbladder-cancer-in-biliary-trials/)

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