Brain Metastases from Biliary Tract Cancers: A Case Series and Review of the Literature in the Genomic Era

Background: Biliary tract cancers (BTCs) are highly fatal malignancies that make up less than 1% of all cancers. BTC is often diagnosed at an unresectable stage; surgical resection remains the only definitive treatment. Brain metastases (BMs) from BTC are extremely rare, and few studies on patients with BMs from BTC exist. The aim of this study was to identify clinical characteristics associated with poor prognosis for patients with BMs from BTC. Materials and Methods: We performed a retrospective review of electronic medical records for patients with BMs from BTC managed at Mount Sinai Hospital from 2000 to 2017. Data on patient characteristics, magnetic resonance imaging findings, treatment regimens, and clinical outcomes were analyzed. Results: We identified 1,910 patients with BTC. Nine patients developed BMs, with an incidence of 0.47%. Of these nine patients, six had intrahepatic cholangiocarcinoma, two had extrahepatic cholangiocarcinoma, and one had gallbladder cancer. Six (66.7%) patients had one BM, one (11.1%) patient had two BMs, and two (22.2%) patients had three or more BMs. Four (44.4%) patients underwent BM resection, and seven (77.8%) received BM radiation. Median overall survival from time of BM diagnosis was 3.8 months (95% confidence interval 0.1–16.9). Conclusion: Development of BMs from BTC is rare; however, prognosis is less than 4 months. BM diagnosis can occur within 2 years of primary diagnosis. As targeted therapeutics emerge, future studies ought to focus on identifying genomic BM markers associated with BTC subtypes. Implications for Practice: In the largest retrospective study of biliary tract cancer brain metastases, the clinical presentation and outcomes are reported of nine patients with an extremely rare clinical entity. The genomic literature and potential therapeutic targets for these patients with limited treatment options is comprehensively and exhaustively discussed.