Cervical Cancer and Antioxidants
Etiology of Cervical Cancer
Although the cause of cervical cancer is unknown, there has been association of the disease with two types of human papilloma virus (HPV), both of which are transmitted sexually. Evidence of HPV is found in nearly 80% of cervical carcinomas. Human immunodeficiency virus (HIV) infection reduces the immune system’s ability to combat infection, including HPV, and thus increases the likelihood of the disease.4-6 It also has been established that women who smoke are twice as likely to develop cervical cancer.7 The authors of this paper have suggested that cigarette byproducts may affect the early evolution of HPV-related lesions, possibly by increasing the rate of cell turnover. It is likely that the actual cause of the disease is multifactorial and that the presence of the HPV induces the development of premalignant cells, which under the influence of oxidative stress and perhaps genetic6 and nutritional8 factors will further evolve into malignant and eventually invasive lesions. Some of these enabling factors may be reversible by the use of appropriate antioxidants.8
Mechanisms of Action
Although there are a number of studies on the mechanistic role of antioxidants in the prevention of the evolution of precancerous cervical cells into frank malignancy, the entire relationship has yet to be elucidated. Epidemiologic nutritional studies suggest that higher dietary consumption and circulating levels of certain micronutrients may be protective against cervical cancer. Low levels of essential antioxidants in the circulation have been found to be associated with an increased risk of cancer.1 It is possible that the infection with HPV induces an oxidative stress in cervical cells which then in association with other factors proceeds to the development of premalignant cells including cervical intraepithelial neoplasia (CIN) and thence to frankly malignant dedifferentiation. Antioxidants are theorized to reverse this process by a variety of mechanisms.