Background
Systematic review and meta-analysis. Evaluated adjuvant therapy (chemotherapy, radiotherapy, or chemoradiotherapy) vs surgery alone after curative-intent resection for biliary tract cancer (BTC) — including gallbladder cancer and bile duct cancers. Searched MEDLINE/EMBASE for studies published 1960–November 2010. 20 studies analyzed involving 6,712 patients.
Interventions and follow up
Arm A: Adjuvant chemotherapy (CT), radiotherapy (RT), or chemoradiotherapy (CRT) after R0/R1 resectio
Arm B: Surgery alone (curative resection)
Primary endpoint: Overall survival (odds ratio for death at 5 years)
mFollow up: Variable across 20 included studie
Arm B: Surgery alone (curative resection)
Primary endpoint: Overall survival (odds ratio for death at 5 years)
mFollow up: Variable across 20 included studie
Results
Any adjuvant therapy vs surgery alone: OR 0.74, P=.06 — trend but not significant (significant when registry analyses excluded)
CT or CRT benefit: OR 0.39 (CT) and 0.61 (CRT) vs OR 0.98 (RT alone), P=.02 for difference
LN-positive subgroup: OR 0.49, P=.004 — significant
R1 margin subgroup: OR 0.36, P=.002 — significant
CT or CRT benefit: OR 0.39 (CT) and 0.61 (CRT) vs OR 0.98 (RT alone), P=.02 for difference
LN-positive subgroup: OR 0.49, P=.004 — significant
R1 margin subgroup: OR 0.36, P=.002 — significant
Adverse events
Main adverse events: Pooled toxicity data not systematically assessed across heterogeneous studies. Chemotherapy and CRT toxicity profiles were consistent with the individual agents used (fluoropyrimidine/gemcitabine-based regimens).
Conclusions
Adjuvant therapy (particularly CT or CRT) shows a significant survival benefit for biliary tract cancer in patients with lymph node-positive and R1-resected disease, supporting adjuvant therapy for these high-risk subgroups and providing the rationale for prospective trials (e.g., BILCAP, ACTICCA-1) in this setting.
Key Limitations
Key Limitations: Pooled retrospective/observational data — no randomized controlled trials included. Heterogeneous tumor types (gallbladder vs bile duct cancer), adjuvant regimens, and patient populations. Publication bias likely, especially toward positive results. OR for death at 5 years is an unconventional endpoint. The effect size difference by modality (CT > CRT > RT alone) may reflect patient selection rather than true modality superiority. The BILCAP trial (capecitabine adjuvant, published 2019) subsequently provided higher-quality RCT evidence.
Clinical Context
This meta-analysis was the key evidence supporting adjuvant therapy for biliary tract cancer prior to the BILCAP RCT. Results particularly support treatment for LN-positive and R1 patients — the groups most likely to benefit. BILCAP subsequently confirmed adjuvant capecitabine improves OS vs observation after resection of cholangiocarcinoma and gallbladder cancer (HR 0.71 per-protocol analysis). Adjuvant capecitabine is now ESMO and NCCN category 1 recommendation after biliary resection.
References