Abstract: A method of treating cancer, comprising the step of administering to a subject in need thereof an effective amount of a compound or compounds which increase or supplement the intracellular levels of endogenous aldehyde, prior to, together with, or subsequent to the administration of a therapeutically-effective amount of a chemotherapeutic agent such as anthracyclines and anthracenediones, wherein the efficacy of the chemotherapeutic agent is enhanced relative to the efficacy of the chemotherapeutic agent alone. The compound may be an aldehyde-releasing compound (preferably formaldehyde), including known aldehyde-releasing compounds and two new classes of aldehyde-releasing compounds.