Molecular Profiling of Advanced Biliary Tract Cancers

Inclusion Criteria: * Patients must have a histological or radiological diagnosis of inoperable or metastatic biliary tract cancer (BTC). * Patient must have a tumor lesion that is amenable to a core needle biopsy as judged by a staff radiologist. * Patients must have a measurable lesion by RECIST 1.1 in addition to the lesion that is going to be biopsied. * Patients must be fit enough to safely undergo a tumor biopsy as judged by the investigator. * Eastern Cooperative Group (ECOG) performance status ≤ 1 (Karnofsky ≥60%). * Life expectancy of greater than 90 days, as judged by the investigator. * Within 14 days of the proposed biopsy date, patients must have normal organ and marrow function. * Patients must undergo systemic treatment with gemcitabine or 5-FU based regimens as first line standard systemic palliative treatment with or without other investigational agents within a clinical trial. * Ability to understand and willing to sign a written informed consent document. Exclusion Criteria: * Patients with one or more contraindications to tumor biopsy. * Patients who have had prior systemic treatment (chemotherapy or any other anti-cancer agent) in the advanced setting. * Patients who are currently on anti-cancer treatment including chemotherapy. * Patients with known brain metastases are excluded from participation in this clinical study. * Uncontrolled inter-current illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements. * Any other condition that would, in the Investigator's judgment, contraindicate the patient's participation in the clinical study due to safety concerns or compliance with clinical study procedures