Vitamin A and cervical squamous intraepithelial lesions

Abstract

Sir, The vast majority of women who come into contact with Human Papilloma Virus (HPV) do not develop any cervical lesions 1. Among those who do, few still present with a high-grade squamous intraepithelial lesion (HSIL) of the cervix. Brazil has a high incidence of cervical cancer, mostly in the northeast region where poverty and malnutrition rates are high 2. Previous studies have shown a high prevalence of low vitamin A levels in this population, which has been considered a public health problem 3. The progression of the disease may be multifactorial, presenting many co-factors, which associated with HPV infection could lead to an increased risk of developing HSIL. Nutritional factors are gradually taking on an important role in understanding the pathophysiology of HPV infection and may help to explain the mechanisms that result in the progression of intraepithelial lesions in some women 1. Although still uncertain, the hypothesis has been advanced that an adequate intake of vitamin A could protect individuals against the development of squamous intraepithelial lesions. Experiments in animals have shown that vitamin A deficiency predisposes to the development of these lesions 4. The deficit of retinoids in turn, was associated with an increased risk of gastrointestinal tract, genito-urinary and skin cancer 5. We have carried out a cross-sectional pilot study to assess the levels of Vitamin A by means of the Bessey–Lowrey method, modified by Araujo & Flores 3 in 40 women aged between 14 and 48 years who had colposcopy directed biopsy of the cervix in the Cervical Pathology and Colposcopy Service in the Federal University of Ceara (UFC) in Fortaleza, Brazil, between July 2004 and July 2005. Of these women, 17 (42.5%) had negative results for squamous intraepithelial lesions (SILs). In 23 (57.5%) cases, the histological diagnosis pointed to SIL, and 18 (45%) had low-grade (LSIL), while five (12.5%) had high grade (HSIL). The serum levels of vitamin A ranged from 9.1 g/dl to 108.4 mg/dl. Vitamin A levels below 20 μg/dl (low) were found in only 1/17 (6%) women without a cervical lesion, but 4/18 (22%) among those with LSIL and 5/5 (100%) of HSIL. There was no significant difference between serum vitamin A levels for women with negative biopsies and with low-grade SIL, but there may be still lower levels in women with high-grade lesions. Vitamin A can perhaps be an important co-factor in the development of SILs, but more comprehensive studies and intervention trials with vitamin supplementation are necessary to evaluate this.