A Randomized, Double Blind, Phase III Trial Using Oral (cid:1) -Carotene Supplementation for Women with High-Grade Cervical Intraepithelial Neoplasia 1

To evaluate the effect of daily (cid:1) -carotene (30 mg) versus placebo over a 2-year period on cervical intraepithelial neoplasia (CIN) 2 and 3 lesions. Human papillomavirus (HPV) typing was done to determine whether lesion regression was related to HPV. Micronutrient levels were measured to determine whether levels were predictive of regression. Variables that influence the risk of HPV infection and CIN, such as cigarette smoking and sexual behavior, were evaluated. Women were randomized to (cid:1) -carotene or placebo, with cytology and colposcopy every 3 months. Cervical biopsies were performed before treatment and after 6 and 24 months to evaluate response. Persistence of or progression to CIN 3 resulted in removal from the study, whereas treatment continued for 2 years on all others. The presence and type of HPV was determined by PCR. Response was defined as an improvement in CIN by 2 grades. Mantel-Haenszel (cid:2) 2 test was used to analyze response to treatment. Fisher’s exact test was used to determine the effect of HPV and CIN grade on response Wilcoxon’s rank-sum tests were used to compare micronutrient levels between groups. Twenty-one of 124 enrolled women were not randomized because they either moved, became pregnant, voluntarily withdrew, or the pathological review of their initial cervical biopsies did not confirm CIN 2 or 3. Of the remaining 103 women, 33 experienced lesion regression, 45 had persistent or progressive disease, and 25 women did not complete the study and were considered nonresponders in the final analysis. The overall regression rate (32%) was similar between treatment arms and when stratified for CIN grade. Data on 99 women with HPV typing showed that 77% were HPV-positive and 23% HPV-negative at enrollment. HPV- positive lesions were subdivided into indeterminate-, low-, and high-risk categories; the response rate was highest for women with no HPV detected (61%), lower for indeterminate/low-risk (30%), and lowest for high-risk (18%; P (cid:3) . 001). CIN regression was negatively correlated with retinol levels. In conclusion, (cid:1) -carotene does not enhance the regression of high-grade CIN, especially in HPV-positive subjects. epithelial cell differen- tiation. HPV 16-induced in keratinocytes and the expression of E6 and E7 HPV oncoproteins, thereby uncon-trolled cell growth. In addition, (cid:1) -carotene itself has been shown to inhibit tumor cell proliferation by reducing epidermal growth factor receptor levels on keratinocytes that have been immortalized with HPV 16 (9). Given the promise of diet and micronutrient supplementation on cancer chemoprevention in numerous epidemiological trials, four randomized clinical trials using (cid:1) -carotene as a possible chemopreventative agent for cervical cancer have been completed to date with mixed results (10–13). These trials have evaluated the relationship between (cid:1) -carotene supplementation and the regression of CIN; the relationship of serum and tissue micronutrient levels on the regression rate of CIN; and the role of (cid:1) -carotene in modulating various intermediate biomarkers of cervical cancer risk, such as causing HPV to disappear from cervical tissue and CIN to regress. In addition to these con-trolled clinical trials using (cid:1) -carotene given p.o. , trans -retinoic acid has also been applied topically to the cervices of women with biopsy-proven CIN 2 and 3 (14). This agent has been shown to lead to regression of CIN 2, but not CIN 3, lesions. This report presents data from a 2-year, randomized, placebo-controlled, chemoprevention trial evaluating the effect of (cid:1) -carotene in the treatment of high-grade CIN (CIN 2 and 3). The regression rates of CIN by treatment arm were analyzed using a Mantel-Haenszel (cid:3) 2 test stratified by CIN status at baseline. A Breslow-Day test was used to test for homogeneity of the odds ratio in the two strata. Fisher’s exact test was used to analyze HPV subtypes by treatment, CIN, and response. Wilcoxon’s rank-sum tests were used to compare micronutrient levels between groups. The data were analyzed using the SAS statistical package. All P s reported are two-tailed.