← Return to [[Biliary Tract Cancer Clinical Trials]] ---- Phase II | Intergroup prospective single-arm trial | n=79 eligible patients | Resected EHCC + gallbladder carcinoma | JCO 2015 **Ben-Josef et al.** Published in Journal of Clinical Oncology, 2015 Enrollment: 2008–2012 [PubMed Link](https://pubmed.ncbi.nlm.nih.gov/25964250/) --- ### Essential Takeaway SWOG S0809 established the modern reference regimen for **adjuvant chemoradiation in resected extrahepatic cholangiocarcinoma and gallbladder carcinoma**. The study demonstrated encouraging survival, low locoregional recurrence rates, and unexpectedly similar outcomes between R0 and R1 resections using adjuvant gemcitabine/capecitabine followed by capecitabine-based chemoradiation. Although not randomized, the trial became one of the most influential studies supporting postoperative radiation in biliary tract cancer and remains heavily cited in multidisciplinary decision-making for margin-positive or node-positive disease. --- ### Clinical Question Can adjuvant gemcitabine/capecitabine followed by chemoradiation improve outcomes after resection of high-risk extrahepatic cholangiocarcinoma or gallbladder carcinoma? --- ### Population Included: - Extrahepatic cholangiocarcinoma (EHCC) - Gallbladder carcinoma (GBCA) - pT2-4 disease - Node-positive disease - R1 resections allowed - M0 disease - ECOG 0-1 Excluded: - Intrahepatic cholangiocarcinoma - Ampullary carcinoma - Prior treatment --- ### Study Design Single-arm prospective phase II intergroup study. #### Systemic Therapy Phase 4 cycles: - Gemcitabine 1000 mg/m² days 1 and 8 - Capecitabine 1500 mg/m²/day days 1-14 - 21-day cycles #### Chemoradiation Phase Concurrent capecitabine: - 1330 mg/m²/day Radiation: - 45 Gy regional nodal RT - Boost to 54-59.4 Gy tumor bed - IMRT allowed and commonly used Target volumes included: - retropancreaticoduodenal nodes - celiac nodes - portal vein nodes --- ### Endpoints #### Primary Endpoint 2-year overall survival (OS) #### Secondary Endpoints - Disease-free survival (DFS) - Local recurrence - Toxicity - Pattern of relapse - Outcomes stratified by R0 vs R1 status --- ### Key Results #### Overall Survival ##### Entire Cohort - 2-year OS: 65% - Median OS: 35 months #### By Margin Status ##### R0 Resection - 2-year OS: 67% - Median OS: 34 months ##### R1 Resection - 2-year OS: 60% - Median OS: 35 months The relatively similar outcomes between R0 and R1 patients became one of the most discussed findings of the study. --- ### Disease-Free Survival - 2-year DFS: 52% - Median DFS: ~26 months --- ### Local Control #### 2-Year Local Recurrence - Overall: 11% - R0: 9% - R1: 16% This low locoregional failure rate strongly supported the biologic rationale for adjuvant radiation. Patients with RT protocol deviations had substantially higher local recurrence rates: - 42% vs 11% - p = 0.02 --- ### Toxicity #### Grade 3 Toxicity Most common: - neutropenia (35%) - hand-foot syndrome (13%) - diarrhea (8%) #### Grade 4 Toxicity - 11% #### Treatment-Related Mortality - 1 death from GI hemorrhage Overall treatment completion rate: - 86% --- ### Important Observations ### R1 Outcomes Historically, R1 resections in BTC are associated with significantly worse survival. SWOG S0809 demonstrated surprisingly similar outcomes between R0 and R1 groups, suggesting a potential benefit of aggressive adjuvant chemoradiation in margin-positive disease. This finding became one of the strongest practical arguments for postoperative RT in EHCC. --- ### Pattern of Failure The study also challenged assumptions that: - EHCC is primarily a local disease - GBCA is primarily metastatic Both diseases demonstrated similar recurrence patterns and similar local control rates. --- ### Interpretation SWOG S0809 became the foundational modern study supporting adjuvant chemoradiation for: - R1 resections - node-positive disease - locally advanced EHCC - high-risk gallbladder carcinoma Importantly, however, the trial was not randomized and therefore cannot prove that radiation improved survival compared with chemotherapy alone. Its true contribution was establishing: - feasibility of national BTC adjuvant trials - a reproducible multidisciplinary adjuvant regimen - prospective benchmark local control data The low local recurrence rates and encouraging R1 outcomes strongly influenced subsequent NCCN recommendations and multidisciplinary practice patterns. --- ### Important Limitations #### Single-Arm Design No chemotherapy-alone comparison arm. Interpretation depends heavily on historical controls. --- ### Mixed Disease Population Combined: - distal EHCC - hilar EHCC - gallbladder carcinoma which complicates disease-specific conclusions. --- ### Predates Modern BTC Standards The trial preceded: - BILCAP - TOPAZ-1 - modern molecular profiling - contemporary systemic BTC regimens --- ### Not Applicable to Intrahepatic Cholangiocarcinoma ICC was excluded and should not be extrapolated from this dataset. --- ### Relationship to BILCAP Following publication of BILCAP, adjuvant capecitabine became the standard systemic backbone in resected BTC. SWOG S0809 is therefore often interpreted in the modern era as evidence supporting **selective addition of radiation** on top of systemic therapy rather than defining systemic therapy itself. --- ### Current Practice Relevance SWOG S0809 remains highly relevant for postoperative multidisciplinary discussions involving: - R1 resections - close margins - node-positive disease - perihilar cholangiocarcinoma - concern for locoregional recurrence The regimen is still commonly referenced when considering adjuvant chemoradiation in high-risk EHCC. --- ### Practice Impact SWOG S0809 substantially increased acceptance of: - postoperative chemoradiation for EHCC - aggressive local therapy in margin-positive disease - multidisciplinary adjuvant management in BTC Despite lacking randomized evidence, it remains one of the most influential adjuvant radiation studies in biliary tract cancer. ```