Human Papillomavirus and environmental factors predict treatment failure of cervical precancerous lesions among Brazilian women: a hospital based cohort

Cervical cancer is preventable through the detection and treatment of precancerous lesions. However treatment failure occurs around 5-35%, and there is no consensus about the risk factors involved. Although it has been indicated that HR-HPV in conjunction with cytology should be useful for monitoring women treated for CIN, few HPV infected women will develop (present a) persistent HPV infections and progress to cancer, suggesting that additional factors are necessary for treatment failure, such as tobacco smoking and oral contraceptive use. Aim: to evaluate the effect of HPV and selected environmental factors on the risk of CIN treatment failure. A prospective study was conducted on a cohort of 205 women histologically confirmed CIN1–3 who were treated at Brazilian National Cancer Institute from October/2004 to May/2006.  A questionnaire with epidemiological and clinical information was administered by two trained registered nurses. Women were followed for 24 months with cytological exams and cervical smears were taken for HPV tests. Mean age was 35(+11) years old; mean age at sexual onset was 17(+3) years old.  Current oral contraceptive use(HR=2.05;95%CI:1.08-3.88), current tobacco use(HR=1.87;95%CI:1.08-3.24), and a positive HPV result up to 6 months after treatment (HR=2.35;95%CI:1.39-3.97) were statistically associated with CIN treatment failure in 24 months.  Women who are current smokers, oral contraceptive users, and who are HPV positive in the first 3-6 months after treatment, are at higher risk of treatment failure.