Drug addiction is not an independent risk factor for oncogenic human papillomavirus infections or high-grade cervical intraepithelial neoplasia: case-control study nested within the Latin American Screening study cohort.

Drug abuse (addiction) has been listed among the risk factors for human papillomavirus (HPV) infections, but no case-control studies exist to rule out sexual behaviour and other potential confounders. The aim of this study is to evaluate the role of drug addiction as an independent predictor of HR-HPV infections and (cervical intraepithelial neoplasia) CIN2+ in an age-matched case-control (1:4) study nested within the prospective Latin American Screening (LAMS) study cohort. All 109 women in the LAMS cohort (n=12,114) reporting drug abuse/addiction were matched with four controls (n = 436) of non-abusers strictly by age. Conditional logistic regression analysis was used to estimate the co-variates of drug abuse, and the whole series (n=545) was analysed for predictors of HR-HPV and CIN2+ using univariate and multivariate regression models. Oncogenic HPV infections were significantly (P=0.019) more prevalent among abusers (37.7%) than in controls (21.9%), but there was no difference in high-grade squamous intraepithelial lesions (P=0.180) or CIN2+ lesions (P=0.201). In multivariate conditional logistic regression, number of lifetime sexual partners (P=0.0001), ever smokers (P=0.0001), non-use of OCs (P=0.013), ever having sexually transmitted diseases (STD) (P=0.041) and no previous Pap smear (P=0.027) were independent co-variates of drug addiction. Drug abuse was not an independent risk factor of high-risk (HR)-HPV infection, which was significantly predicted by (1) age below 30 years (P=0.045), (2) more than five lifetime sexual partners (P=0.046) and (3) being current smoker (P=0.0001). In multivariate model, only HR-HPV infection was an independent risk factor of CIN2+ (P=0.031), with adjusted OR=11.33 (95% CI 1.25-102.50). These data indicate that drug addiction is not an independent risk factor of either HR-HPV infections or CIN2+, but the increased prevalence of HR-HPV infections is explained by the high-risk sexual behaviour and smoking habits of these women.

Comparing PAP smear cytology, aided visual inspection, screening colposcopy, cervicography and HPV testing as optional screening tools in Latin America. Study design and baseline data of the LAMS study.

OBJECTIVES: This is a European Commission (EC)-funded ongoing study known as the LAMS (Latin American Screening) study, where PAP smear/liquid-based cytology and screening colposcopy were compared with i) three optional screening tools [visual inspection with acetic acid (VIA), or Lugol's iodine (VILI), cervicography] and with ii) Hybrid Capture II from a) conventional samples and from b) self-samples, in women at different risk for cervical cancer in Brazil and Argentina. STUDY DESIGN: During 2002-2003, a cohort of 12,107 women attending four clinics: Campinas (CA), Sao Paulo (SP), Porto Alegre (PA) and Buenos Aires (BA), were interviewed for risk factors, and examined using the 8 diagnostic arms. Colposcopy was performed for women positive in any test and for 5% of women with baseline PAP-negative and 20% of HCII-negatives. All high-grade lesions (CIN2/3) were treated, and low-grade CIN are prospectively followed-up. RESULTS: Of the 12,107 women, the following baseline data are available: epidemiological data (n=11,996), conventional PAP smears (n=10,363), LBC, SurePATH (n=320), LBC, DNA-Citoliq (n=1,346), VIA (n=12.067), VILI (n=3,061), cervicography (n=279), screening colposcopy (n=3,437), HCII conventional (n=4,710), HCII self-sampling (n=246) and cervical biopsies (n=1,524). The four sub-cohorts differ significantly in all their baseline data on the implicated risk factors of cervical cancer, consonant with their origin from regions with different cancer incidence. Around 95% of all PAP smears were negative, with slight variations in the prevalence of LSIL and HSIL between the four centers. Significant differences were found in the detection rates of abnormal findings in VIA, VILI and colposcopy between the four centers (p=0.0001). The prevalence of HPV was practically identical (16.5-18.8%) in all four cohorts (p=0.486), with no differences in the relative viral loads. Biopsy results were different depending on whether the women underwent screening colposcopy (BA) or elective colposcopy (others). CONCLUSION: Four cohorts with significantly different baseline data are available, and prospective follow-up of these women permits analysis of whether variations in cervical cancer incidence in these regions is due to i) different natural history of the precursor lesions, or ii) due to different levels of exposure to the known risk factors.