It’s very difficult to get sufficient dosage into the bloodstream for therapeutic benefit. Transdermal patches have ben tried, very messy, pronounced yellowing. Sublingual liquid might be helpful being that it was oral cancer. State of the art appears to be liposomal curcuminoids but not certain if even that surmounts the problem of bioavailability.
As I recall, the patient put curcumin in their mouths, but I can’t remember if the article stated exactly the method. But my impression that it was topically applied to the tissue in the mouth.