Cervical dysplasia: early intervention - Cervical Dysplasia

Alternative Medicine Review, May, 2003 by Keri Marshall

Nutritional Intervention

Chemoprevention is an attempt to use natural and synthetic compounds to intervene in early pre-cancerous stages of carcinogenesis before invasive diseases begin. Cervical dysplasia is ideally suited to chemopreventive measures given its well-established pre-invasive state, its multi-step progression toward invasive disease, and the clinical diagnostic ease that allows practitioners to follow the lesion without significant invasive techniques. Nutritional intervention is ideally suited as a means of chemoprevention. Adjusting nutrient deficiencies ill women at risk of disease progression has been shown to prevent cancel from occurring.

Diet

Epidemiological studies suggest increased consumption of fruits and vegetables containing antioxidants is associated with lower risks for malignancies. (32-35) Fruits and vegetables are the primary dietary source of carotenoids, vitamin C, and folate, as well as other anticarcinogenic compounds, which may have synergistic effects. Results from a randomized controlled dietary intervention study of 53 premenopausal women demonstrated that dietary intervention could effectively promote increased fruit and vegetable intake. (36) The intervention improved status for both plasma carotenoids and folate in the target population, as well as a reduction in total plasma homocysteine. Participants were randomly assigned to a control group or a dietary intervention group and were followed for one year. The goal of the diet was to promote consumption of 8-10 servings of vegetables and fruits daily. A food-based nutritional cancer prevention strategy, compared to a single-nutrient intervention study, allows for the additive effect of multiple protective dietary factors and potential synergy of biological interactions that may further enhance protective effects. Although this study did not measure outcomes of disease regression, it set the stage for future studies evaluating dietary intervention and the reduction of cervical cancer.

Another study assessed dietary risk factors for women with invasive and in situ cervical carcinoma in Bangkok, Thailand. (37) Alter administering a food-frequency questionnaire, 50 in situ cases were compared to 125 controls, while a separate group of 134 invasive cases were compared to 384 controls. The study demonstrated that by increasing intake of foods rich in vitamin A, particularly high retinol foods, there may be a reduced risk of in situ disease, and at highest level of intake may inhibit progression to invasive disease. No significant associations were noted among high vitamin C-, folate-, vitamin E-, or beta carotene-foods, or cruciferous vegetables with regard to risk of either in situ or invasive cervical cancer. Currently underway is a randomized trial of 326 women with biopsy proven CIN II to determine if a change in dietary pattern can promote regression of cervical dysplasia. The primary locus of the dietary change is on carotenoids.

Vitamin A

All-trans retinoic acid and 9-cis retinoic acid are metabolites of vitamin A (retinol) in vivo. Interest in retinoic acid as a chemopreventive agent stems from laboratory research that indicates retinoids are potent modulators of epithelial cell growth and differentiation. (38) Additionally, epidemiological studies report retinol intake and serum retinol levels have been found to be 4.5-times lower among women with cervical dysplasia who progress to in situ or invasive disease when compared to those whose disease regresses. (39)