Impact of Tumor Shrinkage Pattern with Biweekly Triplet Gemcitabine+Cisplatin+S-1 Regimen for Biliary Tract Cancers: Implications for Neoadjuvant Therapy from the Data of KHBO1401 (KHBO1401-1A Study)

The multicenter randomized phase III KHBO1401 study (gemcitabine+cisplatin+S-1 [GCS] vs. GC in biliary tract cancers [BTC]) demonstrated that GCS not only prolonged patient survival but also achieved a high response rate and that it should be good for neoadjuvant therapy. Therefore, to explore the possibilities of neoadjuvant therapy, we investigated the tumor shrinkage pattern.