A method of treating a cancer in a subject in need thereof is disclosed. The cancer can be an esophageal cancer, a uterine cancer, a liver cancer, or a cholangiocarcinoma. The method comprises administering to the subject an effective amount of an anti-Dkk-1 antibody or antigen binding-fragment thereof, wherein the subject is determined to have a constitutively activating mutation of the beta-catenin protein.