Methods of selecting a chemotherapy regimen for treatment of cancer in a patient are disclosed. A patient genetic sample from a bilary cancer such as cholangiocarcinoma is analyzed for a mutation in ERRFI1 and a chemotherapeutic agent is selected as a result of the analysis. If a mutation in ERRFI1 is present, treatment with an inhibitor of Epidermal Growth Factor Receptor (EGFR) is shown to have inhibitory effects on tumor growth. In this manner, the chemotherapy regimen is targeted to a given mutation in a patients cancer.
