Subjects using NSAIDs on a regular basis for longer than 2 years had significantly more protection, compared with those using them for less time. "Two years or longer of continuous regular use is required before realization of any chemoprevention effect on colorectal cancer," Dr. Huang said.
He noted that their study had several limitations, namely that the extent of NSAID exposure, which included dosage, dose frequency, and treatment duration, varied considerably among the studies. Control populations also varied, and statistical adjustment was not possible for these variations.
