Curcumin chemoprevention: the long road to clinical translation.

Curcumin exhibits significant antitumorigenic activity in various preclinical models; data supporting its chemopreventive activity in humans, however, are lacking. To our knowledge, the first published results of a phase II chemoprevention study of curcumin are reported in this issue of the journal by Carroll and colleagues (beginning on page 354), who examined the effects of oral curcumin on various putative biomarkers of colonic tumorigenesis in smokers. This perspective discusses the potential significance and limitations of the current study findings in addressing the question of whether curcumin is clinically active as a chemopreventive agent.