Barriers and innovative interventions for early detection of cervical cancer / Barreras e intervenciones innovadoras para la detección temprana del cáncer cervicouterino

Abstract: Cervical cancer has decreased significantly over the past 30 years in some countries. However, it remains among the leading causes of cancer deaths in low-income, and racial/ethnic minority women. Cervical cancer prevention technologies are not always available. Laboratories are often not well equipped to use them. HPV information has not been widely disseminated. WHO guidelines, and US and Latin American data provide context for strategies on effective interventions to reduce cervical cancer disparities. Systemic, personal and cultural barriers, combined with decision-making guidelines, and impactful messaging can accelerate reductions in cervical cancer health inequities in the Americas.

Resumen: El cáncer cervicouterino ha disminuido significativamente en los últimos 30 años, pero sigue siendo una de las principales causas de muerte entre mujeres de bajos recursos y minorías raciales/étnicas. Las tecnologías preventivas del cáncer cervicouterino no están siempre disponibles y los laboratorios no están siempre bien equipados para utilizarlas. La información sobre el VPH no ha sido difundida ampliamente. La OMS y datos de EEUU y Latinoamérica ofrecen estrategias para reducir el cáncer cervicouterino. El entendimiento de las barreras sistémicas, personales y culturales, dentro de un marco de toma de decisiones, y mensajes innovadores puede reducir las barreras asociadas con el cáncer cervicouterino en las Américas.

Triage strategies in cervical cancer detection in Mexico: methods of the FRIDA Study / Estrategias de triage en la detección de cáncer cervical: métodos del estudio FRIDA

Abstract Objective: This paper describes the study design and baseline characteristics of the study population, including the first 30 829 women who enrolled in the Forwarding Research for Improved Detection and Access for Cervical Cancer Screening and Triage (FRIDA Study). This is a large population based study that is evaluating the performance and cost-effectiveness of different triage strategies for high-risk HPV (hrHPV) positive women in Mexico. Materials and methods: The target population is more than 100 000 women aged 30 to 64 years who attend the Cervical Cancer Screening Program in 100 health centers in the state of Tlaxcala, Mexico. Since August 2013, all women in the region have been invited to enroll in the study. The study participants are evaluated to determine hrHPV infection using the Cobas 4800 HPV test. The HPV-16/18 genotyping and cytology triage strategies are performed as reflex tests in all hrHPV-positive participants. Women with a positive HPV-16/18 test and/or abnormal cytology (atypical squamous cells of undetermined significance or worse, ASCUS+) are referred for colposcopy evaluation, where a minimum of four biopsies and an endocervical sample are systematically collected. Histologic confirmation is performed by a standardized panel of pathologists. Results: Among the 30 829 women who have been screened, the overall prevalence of hrHPV is 11.0%. The overall prevalence of HPV16 and HPV18 are 1.5% and 0.7%, respectively. Cytological abnormalities (ASCUS+) were detected in 11.8% of the hrHPV-positive women. A total of 27.0% (920/3,401) of the hrHPV-positive women were referred to colposcopy because of a positive HPV16/18 test and/or abnormal reflex cytology, (31.6% had only ASCUS+, 53.6% were HPV16/18 positive with a normal cytology result, and 9.5% were positive to both triage tests). Conclusion: The results of this study will help policy makers and health service providers establish the best practices for triage in cervical cancer screening in Mexico and other countries.

Resumen Objetivo: El objetivo de este artículo es describir el diseño del estudio FRIDA y las características basales de las primeras 30 829 mujeres tamizadas. El estudio FRIDA (Forwarding Research for Improved Detection and Access for Cervical Cancer Screening and Triage) es un estudio de demostración con base poblacional diseñado para evaluar el desempeño y costo-efectividad de diferentes alternativas de triage en mujeres VPH de alto riesgo (VPHar) positivas bajo condiciones reales de un programa de tamizaje para cáncer cervical en México. Material y métodos: La población objetivo la conforman poco más de 100 000 mujeres de 30 a 64 años que asisten al programa de detección oportuna de cáncer cervical en alguno de los 100 centros de salud de la jurisdicción sanitaria 1 de Tlaxcala. Desde agosto de 2013, todas las mujeres son invitadas al estudio. Las participantes del estudio son tamizadas para determinar la infección con VPHar mediante la prueba VPHar Cobas 4800. Se realizan las pruebas de triage de tipificación de VPH16/18 y citología en todas las mujeres con resultados VPHar positivos. Las mujeres con un resultado positivo a VPH16/18 y/o citología anormal (células escamosas atípicas de resultado incierto o peor: ASCUS+) son referidas a evaluación colposcópica, seguida de una colección sistemática de un mínimo de cuatro biopsias cervicales y un cepillado endocervical. La confirmación histológica se lleva a cabo por un panel de patólogos. Resultados Un total de 30 829 mujeres han sido tamizadas, con una prevalencia de VPHar del 11.0%. La prevalencia global de VPH16 y VPH18 es 1.5% y 0.7%, respectivamente. Se detectó un 11.8% de anormalidades citológicas (ASCUS+). Entre las mujeres VPHar positivas, la prevalencia de un resultado de triage positivo (VPH16/18 o citología anormal) fue 27.0%, distribuido de la siguiente forma, 31.6% de éstos fueron sólo ASCUS+ VPH16/18 negativo, 53.6% fueron VPH 16/18 positivos y citología normal, y 9.5% positivos a ambas pruebas de triage. Conclusión: Los resultados de este estudio ayudarán tanto a los tomadores de decisiones como a los proveedores de servicios de salud a establecer la mejor estrategia de triage en programas de tamizaje de cáncer cervical basados en VPHar en México y en otros países.

Evaluation of adjunctive tests for cervical cancer screening in low resource settings.

BACKGROUND: Visual inspection of cervix after application of acetic acid (VIA) is an effective screening tool for cervical cancer in low resource settings, but its low specificity leads to high referral rates. Adjunctive testing may overcome this drawback. AIMS: This pilot study was aimed to assess test performances of VIA, human papillomavirus (HPV) testing and Pap smear, individually and in simulated combinations, to determine the probable best screening option. SETTING AND DESIGN: Gynecology outpatient department (OPD); cross-sectional study. MATERIALS AND METHODS: One hundred women with complaints of irregular vaginal bleeding or discharge, post coital bleeding or unhealthy cervix on examination underwent Pap smear, HPV testing, VIA, colposcopy and biopsy, if indicated, in this screening order. STATISTICAL ANALYSIS: Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for each of the tests with a biopsy result of > or =HSIL taken as the gold standard. Simulated parallel and sequential combinations for VIA/Pap, VIA/HPV and HPV/Pap were calculated and compared with individual test performance. RESULTS: Prevalence of abnormal Pap smears was 5%, VIA positive 51% and HPV positive 16%. Sensitivity and specificity of VIA were 100% and 53.3% respectively. For HPV and Pap tests corresponding figures were 85.7%, 89.7% and 50%, 98.9% respectively. The best simulated combination with a balance of sensitivity and specificity was of VIA followed by HPV testing (sensitivity 85.7%, specificity 95.4%). CONCLUSION: Addition of HPV testing to VIA can increase the specificity of VIA, thereby reducing the referral rates without compromising the sensitivity of the test.