Methods of treating glioblastoma and pancreatic cancer are provided by the administration of a therapeutically effective amount of a iodo-hexose compound to a subject in need thereof. The subject disclosure includes methods of treating glioblastoma and pancreatic cancer comprising the administration of a therapeutically effective amount of a 2-deoxy-2-iodo-D-hexose compound including 2-deoxy-2-iodo-D-mannose, 2-deoxy-2-iodo-D-glucose, 2-deoxy-2-iodo-D-galactose, and/or 2-deoxy-2-iodo-D-talose to a subject in need thereof.