Chemoprevention of cervical cancer with folic acid: a phase III Southwest Oncology Group Intergroup study.
Several epidemiological reports and experimental investigations have suggested a preventive role for folic acid in the etiology of cervical cancer. The effect of p.o. folic acid supplementation on the natural history of cervical intraepithelial neoplasia (CIN) was evaluated in a multiinstitutional prospective, randomized, double-blind, placebo-controlled trial. Three hundred thirty-one women with biopsy-proven koilocytic atypia, mild CIN, or moderate CIN were randomized to receive oral folic acid (5 mg) or a similar-appearing placebo daily for 6 months following a 1-month run-in placebo period. Colposcopy, Papanicolaou smear, and serum vitamin levels (folate, retinol, alpha-tocopherol, beta-carotene, and retinyl palmitate) were monitored every 3 months. Demographic, medical, dietary, and sexual history data were obtained from personal interviews. The primary end point of the study was improvement in both Papanicolaou smear and colposcopic picture after 3 and 6 months of treatment as compared to the start of treatment. After 6 months of treatment there was no significant difference between the two study groups in the percentage of patients improved. Median serum folate levels in the treatment arm at 3 and 6 months (29.0 and 20.0 micrograms/dl) were significantly higher than those in the placebo arm (7.8 and 7.1 micrograms/dl, respectively). Mean serum levels of retinol, retinyl palmitate, alpha-tocopherol, and beta-carotene did not differ significantly between the two treatment arms. Our data support the conclusion that supplementation with folic acid (5 mg/day) does not enhance the regression of early epithelial abnormalities of the cervix.(ABSTRACT TRUNCATED AT 250 WORDS)
Childers
J M
JM
University of Arizona Cancer Center, Tucson, USA.
Chu
J
J
Voigt
L F
LF
Feigl
P
P
Tamimi
H K
HK
Franklin
E W
EW
Alberts
D S
DS
Meyskens
F L
FL
D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D003127:Colposcopy; D004311:Double-Blind Method; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D065006:Papanicolaou Test; D010919:Placebos; D011230:Precancerous Conditions / Q000473:pathology / Q000517:prevention & control; D011446:Prospective Studies; D012074:Remission Induction; D015206:Southwestern United States; D002583:Uterine Cervical Neoplasms / Q000473:pathology / Q000517:prevention & control*; D014626:Vaginal Smears; D002578:Uterine Cervical Dysplasia / Q000473:pathology / Q000517:prevention & control*
D010919:Placebos; D005492:Folic Acid