John Beard, the British embryologist and histologist, first proposed his trophoblast model of cancer in 1902. The model has subsequently been expanded by Kelley, and in current times, Gonzalez and Isaacs. The trophoblast model of cancer can be stated as a specified, scientifically testable model, including its core predictions that 1) adult stem cells are ectopic trophoblasts that have migrated to other tissues early in embryogenesis; 2) pancreatic enzymes are the key signal that converts the trophoblast into the stable placenta; 3) cancer arises from trophoblasts that have escaped regulatory control; and 4) pancreatic enzymes can be used to treat cancer. The author reviewed the literature on the trophoblast model of cancer and the use of pancreatic enzymes for the treatment of cancer and organized its key tenets into a set of specified scientific hypotheses. The trophoblast model of cancer can be stated as a set of 11 core predictions and 3 adjunctive or nonessential components. The trophoblast model of cancer is a detailed, testable model that should be investigated within an overlapping set of fields including oncology, histology, physiology, molecular biology, and embryology.