Treatment of unexpectedly detected gallbladder cancer Complete resection is highly recommended for unexpected gallbladder cancers that show resectable stage T1b (invasion of the muscular layer) or larger after examination including laparoscopy. patients with stage T1a (invasion of the lamina propria) who have already undergone complete cholecystectomy do not benefit from re-excision and need only continued observation. In case of unexpected intraoperative finding of gallbladder cancer, simultaneous staging evaluation should be performed during surgery and decision to perform extended cholecystectomy (total hepatectomy + lymphatic dissection with ± bile duct resection) should be made based on resectability as well as physician opinion. Treatment of resectable tumors Complete surgical resection is the only possible curative treatment. Cholecystectomy includes extended cholecystectomy, including total hepatectomy and lymphatic drainage (hilar, hepatogastric ligament, retroduodenal) with or without bile duct resection. Major hepatic resection including caudate lobectomy, such as extended right lobe resection with hilar resection has improved the resectability and cure rate of stage 3 and 4 hilar cholangiocarcinoma and prolonged the 5-year survival rate of patients. Preoperative transarterial or venous embolization increased the volume of the residual liver in patients with an expected postoperative residual volume of <25% and may reduce postoperative liver dysfunction. Indications for biliary drainage should be systematically discussed preoperatively with an experienced surgeon. Even when patients receive aggressive surgical treatment, the 5-year survival rate is only 5% to 10% for gallbladder cancer and 10% to 40% for bile duct cancer. Adjuvant therapy Plus chemotherapy with 5-Fu may result in a small survival benefit after surgery for patients undergoing non-radical gallbladder cancer. Postoperative treatment of nonradical resection of bile duct cancer remains controversial, with both supportive therapy and palliative chemotherapy and/or radiation therapy. Local adjuvant therapy should be considered due to a 52% local recurrence rate after surgery for gallbladder and biliary tract tumors. Retrospective studies suggest that adjuvant and, more recently, neoadjuvant chemotherapy may provide a survival benefit for gallbladder and biliary tract tumors, and that postoperative radiotherapy may be considered an option. 5-Fu is most commonly used in radiotherapy for cholangiocarcinoma, and gemcitabine in combination with or without oxaliplatin may be used in radiotherapy for this disease. Treatment of unresectable tumors Relief of jaundice may be achieved by endoscopic or percutaneous biliary stenting or bile-intestinal bypass. Emergency biliary drainage and broad-spectrum antibiotics are essential for patients with obstructive jaundice causing cholecystitis. Studies have shown that palliative chemotherapy increases survival time and quality of life in patients with advanced cancer, but the overall survival benefit of chemotherapy is not yet clear, and gemcitabine combined with cisplatin therapy may have a significant survival advantage. Oxaliplatin may be an option for gemcitabine combination therapy in cases of cisplatin intolerance, and several phase II trials have demonstrated antitumor activity and good tolerability of gemcitabine in combination with oxaliplatin. 5-Fu or gemcitabine monotherapy should be administered in cases where neither gemcitabine in combination with cisplatin or oxaliplatin is available. The limiting toxicity of cisplatin may be renal or neurotoxicity, bone marrow suppression, or ototoxicity, while sensory neuropathy may limit the use of oxaliplatin. The biologic agent erlotinib showed clinical activity in a phase II trial with bevacizumab, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, and a vascular endothelial growth factor (VEGF) inhibitor. Because patients with this disease rarely experience grade 3 to 4 side effects, bevacizumab in combination with erlotinib may be a treatment option for cytostatic therapy. Simultaneous radiotherapy is an additional treatment option. After years of 5-Fu-based radiotherapy, gemcitabine and oxaliplatin have shown the feasibility of combined chemotherapy (see adjuvant therapy). High-dose iridium-19 radiation therapy may improve local control of the disease compared to 3-D conformal radiation therapy, and emphasized radiotherapy (IMRT) has recently been shown to increase the safe dose to higher levels, and later trials will test the efficacy of this approach. Neoadjuvant therapy is not a routine treatment option for biliary tract tumors. However, surgical resection should be considered if re-staging evaluation of patients with locally advanced cancer shows potentially resectable tumors.