SERUM MICRONUTRIENTS AND THE SUBSEQUENT RISK OF CERVICAL-CANCER IN A POPULATION-BASED NESTED CASE-CONTROL STUDY

A nested case-control study was conducted in Washington County, MD, to determine whether low serum micronutrients are related to the subsequ ent risk of cervical cancer. Among the 15,161 women who donated blood for future cancer research during a serum collection campaign in 1974, 18 developed invasive cervical cancer and 32 developed carcinoma in s itu during the period January 1975 through May 1990. For each of these 50 cases, two matched controls were selected from the same cohort. Th e frozen sera of the cases and their matched controls were analyzed fo r a number of nutrients. The mean serum levels of total carotenoids, a lpha-carotene, beta-carotene, cryptoxanthin, and lycopene were lower a mong cases than they were among controls. When examined by tertiles, t he risk of cervical cancer was significantly higher among women in the lower tertiles of total carotenoids (odds ratio 2.7; 95% confidence l imit, 1.1-6.4), a-carotene (odds ratio, 3.1; 95% confidence limit, 1.3 -7.6), and beta-carotene (odds ratio, 3.1; 95% confidence limit, 1.2-8 .1) as compared to women in the upper tertiles and the trends were sta tistically significant. Cryptoxanthin was significantly associated wit h a lower risk of cervical cancer when examined as a continuous variab le. Retinol, lutein, alpha- and gamma-tocopherol, and selenium were no t related to cervical cancer risk. Smoking was also strongly associate d with cervical cancer. These findings are suggestive of a protective role for total carotenoids, alpha-carotene and beta-carotene in cervic al carcinogenesis and possibly for cryptoxanthin and lycopene as well.