Human papillomavirus infection and cervical cancer precursor lesions in women living by Amazon rivers: investigation of relations with markers of oxidative stress.

Objective To investigate the relation between oxidative stress markers, human papillomavirus infection and cervical cancer precursor lesions. Methods The study comprised women aged 14 to 60 years living in communities located by Amazon rivers in the state of Pará (Itaituba, Limoeiro do Ajuru and Bragança, 126, 68 and 43 women respectively). Papanicolau smears and polymerase chain reaction tests for human papillomavirus DNA detection were performed. Blood samples were collected to test malondialdehyde, total and oxidized glutathione levels. Results Malondialdehyde, total and oxidized glutathione concentrations did not differ significantly (p>0.05) between women with and without low-grade squamous intraepithelial lesions across communities. Malondialdehyde levels (8.02nmols/mL) were almost five times higher in human papillomavirus-positive compared to human papillomavirus-negative women (1.70nmols/mL) living in Itaituba (statistically significant difference; p<0.05). Malondialdehyde levels did not differ significantly (p>0.05) between human papillomavirus-positive and human papillomavirus-negative women living in remaining communities. Significant (p<0.05) differences in total glutathione levels between human papillomavirus-positive and human papillomavirus-negative women (8.20μg/mL and 1.47μg/mL, respectively) were limited to those living in Bragança. Conclusion Malondialdehyde and total glutathione levels were significantly associated with human papillomavirus infection. However, lack of similar associations with squamous lesions suggest oxidative stress alone does not explain correlations with cervical carcinogenesis. Other factors may therefore be involved.