The disclosure relates to use of a compound of formula (IA) or (IIA) and optionally with at least one additional therapeutic agent, in the manufacture of a composition for treating or preventing colon cancer in a subject, wherein the variables are as defined in the specification. Also described are pharmaceutical compositions comprising compounds including 5-phenylpenta-2,4-dienoic acid, 3-methyl-3-butenyl caffeic acid, 1,1-dimethylallyl caffeic acid, pinobanksin-3-acetate, tectochrysin, pinostrobin chalcone, benzyl ferulate and benzyl isoferulate. The composition may include as additional therapeutic agent selected from an anti-tumour agent, preferably the anti-tumour agent is selected from an anti-tumour food factor, a chemotherapeutic agent, or an immunotherapeutic agent. These pharmaceutical compositions are also useful in the treatment or prevention of gastrointestinal cancers, and the resensitisation of gastrointestinal cancers.
