Cervical cancer prevention: Feasibility of self-sampling and HPV testing in rural and urban areas of Bolivia: An observational study.

BACKGROUND: Cervical cancer is a major health problem in Latin America. In 2019, the Italian Agency for Development Cooperation (La Paz regional site) conducted a pilot study to estimate the prevalence of high-risk human papillomavirus (HPV) and the feasibility of HPV screening in Bolivia through self-sampling and portable and transportable laboratory instruments for HPV testing in urban and rural areas. METHODS: Women aged 20-65 years from La Paz (urban area), Toro Toro (rural area), and Acasio (rural area) were enrolled in local public health centers between Dec 1, 2019, and June 30, 2021. Self-sampling was carried out with the Viba-Brush system (Rovers, Oss, Netherlands) and samples were preserved in ThinPrep containers (Hologic Corporation, San Diego, CA, USA). The GeneXpert system (Cepheid, Sunnyvale, CA, USA) for high-risk HPV testing detects HPV E6 and E7 DNA via real-time PCR in a mobile system of easy execution requiring minimal manual intervention. The system provides results in about 1 h. The hr- HPV prevalence data, overall and partial genotyping, were analyzed considering the following age groups: 20-34, 35-44, and 45-65 years old. FINDINGS: 2168 women were enrolled: 614 (28.3%) in La Paz, 743 (34.3%) in Toro Toro, and 811 (37.4%) in Acasio. Only one sample was collected from each participant. 2043 (94.2%) of 2168 samples were adequate for HPV testing. 255 (12.5%) samples were positive for high-risk HPV. Comparing the urban area (La Paz) versus rural combined areas (Acasio+Toro Toro), using a logistic model, the HPV total rate was statistically significantly higher in the city of La Paz (15.0% vs 11.4%; OR:1.37;95% CI: 1.04-1.80). Furthermore, the HPV prevalence was declining by age, and the urban/rural odds ratio was 1.50; (95% IC 1.13-19). The overall HPV 16 positivity was 2.7% (55/2043) and for HPV 18/45 was 1.8% (37/2043) without any statistically significant differences between the three BHU enrolling centers. Only the prevalence of HPV group '39/56/66/68' was significantly higher in La Paz (p<0,001) in comparison to Acasio and Toro Toro. INTERPRETATION: The total and age-adjusted prevalence of high-risk HPV infection in rural and urban areas in Bolivia, as measured with a validated test for screening, is similar to that observed in Europe and the USA. Our study shows that a screening protocol for HPV testing with self-sampling would be feasible in urban and rural areas in Bolivia, and that the reported high occurrence of cervical cancer in Bolivia is not related to a higher rate of high-risk HPV infections. Carrying out HPV tests locally avoids the issues associated with transportation and storage of the collected material and allows the participant to wait in the clinic for the test result, overcoming the very long response time for screening test in Bolivia.

Liquid-based anal cytology as a screening tool for prevention of anal cancer in at-risk populations: a single-center retrospective analysis on 111 patients

Objective: Squamous cell carcinoma of the anus (SCCA) is associated with human papillomavirus (HPV) infection in almost 90% of the cases. Its incidence is alarmingly high among men who have sex with men (MSM) and continues to increase at an average rate of 2% per year. The objective of the present study is to evaluate the usefulness and performance of liquid-based anal cytology as a screening tool for prevention and early detection of SCCA in a cohort of at-risk men. Method: We conducted a retrospective study including 111 MSM, aged between 22 and 62 years old, who underwent anal cytological screening with a liquid-based Pap test at our sexually transmitted diseases (STDs) clinic from January 2015 to March 2017. Results: Out of 111 anal smears, 57 (51,4%) resulted negative, 42 (37,8%) abnormal, and 12 (10,8%) unsatisfactory for the cytological evaluation. Only patients with an abnormal cytology underwent anoscopy and subsequent biopsy. The histological results were as follows: negative for squamous intraepithelial lesion (SIL) in 5 cases, low-grade SIL (L-SIL) in 21, high-grade SIL (H-SIL) in 5, SCCA in 1. Five patients had a normal anoscopy and biopsy was not taken. Conclusion: Liquid-based cytology, reducing the "darkening factors" typical for the conventional smears, has a higher positive predictive value than the traditional technique. Moreover, a cytological diagnosis of atypical squamous cells of undetermined significance (ASC-US) or L-SILmay hide a severe dysplasia or even a carcinoma. Thus, all patients with an abnormal anal cytology at any grade should be considered for anoscopy. (AU)