Folic acid prevents the initial occurrence of sporadic colorectal adenoma in Chinese over 50 years of age: a randomized clinical trial
Mené sur 791 participants âgés de plus de 50 ans (durée de suivi : 3 ans), cet essai randomisé chinois montre qu'une supplémentation en acide folique peut réduire le risque d'adénome colorectal
Colorectal adenoma (CRA) is the precursor lesion of colorectal cancer (CRC). Several agents have been shown to be effective in the chemoprevention of CRA recurrence, but there has been little research on its primary prevention. Participants aged>50 years with no adenomas were recruited for our study and randomized to receive either 1 mg/d FA supplement or treatment without FA. After 3 years of follow-up, plasma folate and colonoscopy were evaluated. Seven-hundred and ninety-one participants (91.98%) completed the study. CRA occurred in 64 (14.88%) participants in the FA group and 132 (30.70%) in the control group (unadjusted RR,0.49; 95%CI:0.37-0.63; P<0.01); left-sided adenoma (unadjusted RR,0.54; 95%CI:0.38-0.76; P=0.001) and advanced CRA (unadjusted RR,0.36; 95%CI:0.16-0.81; P=0.01) were most common. There was no significance difference in the occurrence of three or more adenomas (unadjusted RR, 0.70; 95%CI: 0.36-1.77; P=0.38) or right-sided adenoma (unadjusted RR,0.55; 95%CI: 0.30-1.00; P=0.07) between the two groups. Participants with low plasma folate may had a high risk of CRA. In conclusion, primary prevention with 1mg/d FA supplementation could reduce the incidence of CRA, especially left-sided and advanced disease in those with no previous adenomas. People with differing baseline plasma folate levels should be given individualized treatment. Those with low plasma folate should be encouraged to take adequate supplements; plasma folate should be elevated to an effective therapeutic level, which may reduce the incidence of CRA.