Evaluación clínica y análisis económico de las tecnologías para el tamizaje de las lesiones precursoras del cáncer del cuello uterino / Clinical evaluation and economic analysis of technologies for screening cervical cancer precursor lesions

CONTEXTO: A nivel mundial, el cáncer del cuello uterino (CCU) ocupa el 4to lugar entre las neoplasias más frecuentes en las mujeres, con una incidencia estimada de 604,127 casos nuevos y 341,831 muertes en 2020; aproximadamente el 90% de los nuevos casos y muertes tuvieron lugar en países de ingresos medios y bajos. En México, se estima que cada año se diagnostican 9439 nuevos casos de CCU siendo la segunda causa de cáncer en mujeres de forma general y el tercer cáncer más común en mujeres de 15 a 44 años. El CCU es un problema global de salud pública, con una carga particularmente alta en muchos países de medios y bajos ingresos. La eficacia comprobada de las medidas de intervención, como la vacunación contra los tipos más oncogénicos del VPH, hacen que éste tipo de cáncer sea una enfermedad prevenible en gran medida. Se ha observado una reducción de la incidencia y mortalidad del CCU predominantemente en países con un índice de Desarrollo Humano Alto, donde los servicios de detección de alta calidad, tratamiento oportuno y atención de seguimiento están disponibles de forma rutinaria. Más del 85% de las afectadas son generalmente mujeres jóvenes, con un nivel educativo bajo que viven en los países más pobres del mundo. Muchas son también madres de niños pequeños cuya supervivencia se ve afectada posteriormente por la muerte prematura de sus madres. Por lo tanto, el CCU representa una enorme carga de salud para las mujeres, sus familias y las comunidades. Dado que la enfermedad afecta principalmente a las mujeres en sus mejores años de edad adulta, la enfermedad y la muerte por éste tipo de cáncer ejerce una presión emocional y financiera sobre las familias, las comunidades y los sistemas de salud. A pesar de ser una enfermedad prevenible y curable si se detecta a tiempo y se trata oportunamente, sigue siendo uno de los cánceres más comunes y causa de muerte en las mujeres de todo el mundo. La mayoría de las lesiones precancerosas (99.8%) y CCU se atribuyen al virus del papiloma humano (VPH). Esta infección es muy común porque se transmite fácilmente a través del contacto sexual y la mayoría de las personas la adquieren poco después de iniciar su actividad sexual. En lo general, más del 90% de las infecciones por el VPH se eliminan por el sistema inmunitario. EVALUACIÓN CLÍNICA: La prueba de tamizaje más eficaz para NIC2+ es la detección del VPH, con una sensibilidad de 89.9% a 94%, comparada con la citología agrupada (incluye CC y CBL), CC, CBL y la inspección visual con ácido acético (IVAA) que tienen sensibilidades más bajas (70% a 72.9%, 62.5%, 72.9% y 69%, respectivamente). Además, es importante considerar que la prueba de detección del VPH es objetiva mientras que las otras son operador-dependientes y subjetivas (Koliopoulos 2017) (Mustafa 2016). Respecto de la especificidad agrupada de las pruebas de tamizaje para NIC2+, la detección del VPH es la menos específica (89.9% a 90%) comparada con la citología agrupada (90.3% a 95%), CC (96.6%), CBL (90.3%). De igual manera, al compararse con la IVAA es menos específica (84% vs. 87%) (Koliopoulos 2017) (Mustafa 2016). En general, las pruebas de tamizaje para la detección de lesiones precancerosas del cuello uterino son seguras (Melnikow 2018). EVALUACIÓN ECONÓMICA: A nivel internacional en países de altos y medianos ingresos la prueba de ADN del VPH es la opción más costo ­ efectiva, pero en países con recursos limitados la prueba de IVAA es la mejor alternativa. Por otro lado, la citología posee una limitada costo ­ efectividad ocasionada en parte por la necesidad de infraestructura y recursos humanos capacitados. Por lo anterior, en México se sugiere utilizar la prueba de ADN. En el caso de la citología, se deben considerar las implicaciones organizacionales y de costos asociadas a su sustitución como tamizaje primario. Un Análisis de Impacto Presupuestal (AIP) a 5 años, encontró que al utilizar la prueba del VPH (PCR para identificación de ADN viral) en mujeres de 25 a 64 años, alcanzando la cobertura del 70% en el último año del análisis, se requieren $520 Millones de Pesos (MDP) en promedio anual, lo que se traduce en la necesidad de incrementar los recursos asignados a tamizaje del VPH en un 51.7% en promedio anual. En un escenario donde el costo de la prueba se reduzca en 20% o 30% (lo cual es probable) el gasto adicional sería de $354 MDP y de $271 MDP respectivamente, ambos en promedio anual; lo que equivale al 40.8% y 33.9% en promedio anual de recursos adicionales (comparados con los recursos actuales destinados al tamizaje del CCU) para llevar a cabo la prueba del VPH. MÉTODOS: Para identificar la evidencia de la precisión y seguridad de las pruebas de tamizaje para la detección del CCU, se buscaron revisiones sistemáticas existentes relevantes y de alta calidad. Se realizó una búsqueda de estudios en las bases de datos de Medline (PubMed) y Cochrane Library incluyendo tanto términos controlados MeSH como términos libres. Se limitó a documentos publicados desde el 1 de enero de 2016 a mayo del 2023 y en idioma inglés o español. La selección de estudios y extracción de los datos fueron realizados por un revisor y verificados por otro. Los datos se resumieron y clasificaron en función de los resultados. La revisión sistemática de la evidencia económica se concentró en evaluaciones completas, publicadas a febrero de 2023, las cuales abordan tanto los costos como los beneficios en salud12 asociados al uso de pruebas de ADN del VPH comparado con IVAA, citología convencional y en base líquida en mujeres de los 25 a los 69 años de edad, obtenidas de las bases de datos Pubmed, Value in Health y University of York Centre of Reviews and Dissemination. RESULTADOS: Los resultados del AIP mostraron que el escenario actual del tamizaje del CCU tiene un costo de $1,006 MDP mientras que en el escenario futuro el costo es de $1,527 MDP, ambos en promedio anual; lo que implicaría un gasto adicional de $520 MDP y en términos porcentuales representaría la necesidad de un incremento del 51.7% (ambos montos en promedio anual) en los recursos asignados para el tamizaje del VPH. El análisis de sensibilidad encontró que al reducir el costo en un 20% de la prueba el gasto adicional se reduciría a los $354 MDP (lo que representaría la necesidad de un incremento del 40.8% en los recursos asignados al tamizaje del VPH) en promedio anual. En el mismo sentido, si el costo se redujera en un 30%, el gasto adicional sería de $271 MDP lo que en términos porcentuales representaría la necesidad de un incremento del 33.9% en los recursos asignados al tamizaje del VPH. CONCLUSIONES: La evidencia clínica analizada, de moderada calidad, mostró que la detección del VPH es la prueba más sensible, aunque menos específica, que otras pruebas de tamizaje para la identificación de lesiones precancerosas del cuello uterino como la citología cervical y la IVAA, con un perfil de seguridad adecuado. Tomando en consideración los resultados obtenidos en el presente trabajo, así como las recomendaciones emitidas por la Organización Mundial de la Salud (OMS), 26 es de suma importancia adoptar medidas de salud pública necesarias que permitan la implementación de la detección del VPH como la prueba estándar de tamizaje de lesiones precancerosas del cuello uterino en lugar de la citología cervical o la IVAA ya que tiene una alta sensibilidad y es objetiva, lo cual podría coadyuvar en el cumplimiento de las metas de la Estrategia Mundial para Acelerar la Eliminación del Cáncer del Cuello Uterino como Problema de Salud Pública en nuestro país, específicamente para que el 70% de las mujeres mexicanas sean examinadas mediante una prueba de alta precisión antes de los 35 años. Dos revisiones sistemáticas de evaluaciones económicas concluyeron que la prueba de ADN o la IVAA serían alternativas costo ­ efectivas en comparación con la citología. Cuál de las dos primeras es la mejor opción, depende del costo de la prueba de ADN, el rendimiento de la prueba de IVAA o la cantidad de recursos financieros disponibles. En este sentido, una revisión que incluyó en su mayoría evaluaciones de países de altos y medianos ingresos concluyó que la prueba de ADN es la opción más costo efectiva.

HPV Genotype Prevalence and Success of Vaccination to Prevent Cervical Cancer.

BACKGROUND: Nearly 500,000 new cases of cervical cancer are estimated annually worldwide. Three vaccines are currently licensed to prevent cervical cancer. The success of vaccination depends mainly on the prevalence of HPV genotypes, and many cases of HPV infection have been diagnosed after vaccination. Our aim was to search for HPV genotyping in cervical samples to verify the proportion of women that remain susceptible to infection even after vaccination. METHODS: 21,017 liquid-based cervical (LBC) specimens were received for cytology and HPV detection from 2015 to 2018. Before slide preparations for cytology, a 1,000-µL aliquot was taken from the LBC fixative and subjected to automated DNA extraction and multiplex PCR followed by capillary electrophoresis to detect and classify HPV. RESULTS: HPV was detected in 895 (4.3%) specimens. The most prevalent genotype was HPV-16, followed by HPV-58 and HPV-66. A total of 258 (28.8%) cases were positive for high-risk (HR)-HPV types (66, 59, 39, 56, 30, 35, 53, 51, 68, 82, and 70) that are not covered by the HPV vaccines. CONCLUSION: A significant proportion of HPV types detected in cytological specimens are representative of HR-HPV not covered by the available vaccines. The health system should be aware of the considerable percentage of women who are not being immunized and will continue to need cervical cancer screening.

Recent Trends in HPV Infection and Type Distribution in Greece.

BACKGROUND/AIM: This study gives an insight into recent trends for Human papillomavirus (HPV)-specific infection and its fluctuation over the years 2011-2016. MATERIALS AND METHODS: A total of 2,417 Caucasian women between the age of 18 and 71 years underwent their annual gynaecologic examination at the Outpatient Gynaecological Clinic in the study period. RESULTS: Overall HPV prevalence was 43.9%, and high-risk HPV accounted for 31.3%. HPV16 was the most common high-risk type followed by HPV51 and HPV31. HPV positivity was higher in those with low- and high-grade squamous intraepithelial lesions (HSILs) than in women with a normal cytological test. HPV infection was highest in 2011.The prevalence of single infections remained higher than multiple infections over the entire study period. HPV16 prevalence was very high in the first years of the study and HPV18 exhibited highest prevalence in 2011. Younger women exhibited a significant increase in HPV infection from 2014. Overall HPV infection decreased over the study period. CONCLUSION: These data suggest that HPV vaccination might reduce the frequency of HSILs and cervical cancer and are useful for the development of a national screening programme.

Identifying populations most susceptible to get benefit from broadening the scope for prevention of cervical cancer: Example from Uruguay.

OBJECTIVES: To identify factors associated with high-risk human papillomavirus (HPV) infection and high grade squamous intraepithelial lesion (HSIL) among a high-risk group of HPV-unvaccinated women in Montevideo. METHODS: Participants completed a questionnaire on socio-demographics, sexual behavior and gynecological history and received a gynecological examination. HPV DNA was detected by PCR using MY09/11 primers. Logistic regression analyses were performed to identify factors associated with high-risk HPV infection and HSIL. RESULTS: A total of 469 women with HPV DNA and cytological results completed the questionnaire. Among women older than 30 years, those with high number of sexual partners and regular housing conditions were more likely to be positive for high-risk HPV infection (adjusted OR: 2.94, 95%CI: 1.01-8.51 and 2.68, 95%CI: 1.01-7.21, respectively). A marginally non-statistically significant association between getting a HSIL and having a high number of sexual partners was also observed (adjusted OR: 3.22, 95%CI: 0.97-10.75). CONCLUSIONS: In an era of development of new strategies for accelerating the reduction of cervical cancer incidence and mortality, our results may contribute to identify populations most susceptible to get benefit from broadening the scope for prevention of cervical cancer and could be used with other triage strategies.

Human papilloma virus infection in HIV-infected women in Belgium: implications for prophylactic vaccines within this subpopulation.

Although high-risk (HR) human papilloma virus (HPV) infection is the primary causative factor for cervical squamous intraepithelial lesions and invasive cervical cancer, the epidemiology of potentially HR (pHR) and low-risk HPV still remains to be elucidated in HIV-infected women. In addition, the synergistic potential of the multiplicity of HPV infections harboured renders it difficult to model the impact of vaccines. This cross-sectional analysis of HIV-infected women explores the epidemiology of abnormal cytology, thereby profiling and pairing pHR/HR HPV genotypes. This cross-sectional analysis reports the findings of 593 HIV-infected women, who underwent a cytological examination and HPV genotyping. A logistic regression model was fitted to adjust for age and coinfection with pHR/HR HPV genotypes. In the 143 women with abnormal cytology, a multiple pHR/HR HPV genotype prevalence of 64.1% [95% confidence interval (CI): 44.6-57.6%] was observed. A combined prevalence of HPV 16 and HPV 18 of 29.6% (95% CI: 22.2-37.8%) was found. HPV 6 and HPV 66 were found in two cases of low-grade squamous intraepithelial lesions as stand-alone genotypes and HPV 53 in a high-grade squamous intraepithelial lesion case. Pairing involving HPV 31 with HPV 16 and HPV 58 was found in high-grade squamous intraepithelial lesion cases. Significant associations were observed between abnormal cytology, multiple HPV, HPV 39 and HPV 53 [adjusted odds ratio (aOR): 2.02; P=0.01; 95% CI: 1.2-3.5; aOR: 3.8; P=0.01; 95% CI: 1.4-10.7; and aOR: 0.5; P=0.03; 95% CI: 0.2-0.9, respectively]. Coinfection with pHR/HR HPV genotypes HPV 39 and 53 was significantly associated with abnormal cytology. Research into the imputed role of HPV 31 in pairings, low-risk and pHR HPV genotypes in HIV-infected women is warranted.

Clinical management and risk reduction in women with low-grade squamous intraepithelial lesion cytology: A population-based cohort study.

We analyzed the management and risk of subsequent cervical intraepithelial neoplasm 3 (CIN3) and invasive cervical cancer in women with low-grade squamous intraepithelial lesion (LSIL) cytology. A total of 53,293 women with a new diagnosis of cytologic LSIL were identified in Taiwan's national cervical screening registration database. Based on the retrieved clinical management data, the incidence of subsequent CIN3+ lesions was determined, and the hazard ratios (HRs) were estimated using a Cox proportional hazards model. The average follow-up was 5.02 years. A total of 988 women developed CIN3+ lesions during this period, with an overall incidence of 369.3 women per 100,000 person-years. Cryotherapy and conization/loop electrosurgical excision procedure (LEEP) decreased the subsequent risk of CIN3+ lesions in women younger than 50 years (HR 0.49, 95% confidence interval [CI] 0.37-0.64, p<0.0001 for cryotherapy; HR 0.39, 95% CI 0.27-0.55, p<0.0001 for LEEP). Cryotherapy and conization/LEEP were two significant protective factors for developing CIN3+ lesions, especially in women with biopsy-proven CIN1 (HR 0.55, 95% CI 0.37-0.82, p = 0.003 for cryotherapy; HR 0.43, 95% CI 0.24-0.77, p = 0.005 for LEEP). These results suggest that when women are first screened LSIL and lack prior abnormal cervical cytology, cryotherapy should be one of the treatment options. Younger women with a histological biopsy diagnosis of CIN1 were most likely to benefit from cryotherapy.

Beneficial Effects of Human Papillomavirus Vaccine for Prevention of Cervical Abnormalities in Miyagi, Japan.

Prevention of cervical cancer has been unsuccessful in Japan because of low rates of cancer screening and vaccination. The Vaccine Adverse Review Committee of the Japanese Government investigated 2,475 adverse events and reported 617 (6.9/100,000) severe cases and 176 (2.0/100,000) cases with chronic pain. The proactive recommendation for human papillomavirus (HPV) vaccination has been suspended since June 2013. In this study, we examined vaccination rate and incidence of abnormal cervical cytology in women aged 20 to 24 years attending cancer screening in Miyagi. Among the 3,272 women who underwent a health check in the fiscal year 2014 (April 2014-March 2015), 332 (10.2%) received a HPV vaccination. The HPV vaccination rates were 42.3%, 10%, 17.5%, 3.8% and 4.0% in women aged 20, 21, 22, 23 and 24 years, respectively. The rates of atypical squamous cells of undetermined significance (ASC-US) or worse were 2.41% (8/332) in women with HPV vaccination and 5.03% (148/2,940) in those without HPV vaccination, indicating a significant decrease in vaccinated women (p = 0.03). ASC-US cases were referred to HPV DNA tests. In addition, the rates of high grade squamous intraepithelial lesion (HSIL) or worse were 0.30% (1/332) in women with HPV vaccination and 0.82% (24/2,940) in those without HPV vaccination, showing the marginal decrease in women who were vaccinated (p = 0.3). Thus, this study indicates that HPV vaccination is associated with a reduction in the incidence of cervical abnormalities, suggesting a need for scientific discussion of reinstatement of proactive recommendation for HPV vaccine in Japan.

HPV immunisation and cervical screening--confirmation of changed performance of cytology as a screening test in immunised women: a retrospective population-based cohort study.

BACKGROUND: To document the effect of bivalent HPV immunisation on cervical cytology as a screening test and assess the implications of any change, using a retrospective analysis of routinely collected data from the Scottish Cervical Screening Programme (SCSP). METHODS: Data were extracted from the Scottish Cervical Call Recall System (SCCRS), the Scottish Population Register and the Scottish Index of Multiple Deprivation. A total of 95 876 cytology records with 2226 linked histology records from women born between 1 January 1988 and 30 September 1993 were assessed. Women born in or after 1990 were eligible for the national catch-up programme of HPV immunisation. The performance of cervical cytology as a screening test was evaluated using the key performance indicators used routinely in the English and Scottish Cervical Screening Programmes (NHSCSP and SCSP), and related to vaccination status. RESULTS: Significant reductions in positive predictive value (16%) and abnormal predictive value (63%) for CIN2+ and the mean colposcopy score (18%) were observed. A significant increase (38%) in the number of women who had to be referred to colposcopy to detect one case of CIN2+ was shown. The negative predictive value of negative- or low-grade cytology for CIN2+ increased significantly (12%). Sensitivity and specificity, as used by the UK cervical screening programmes, were maintained. CONCLUSIONS: The lower incidence of disease in vaccinated women alters the key performance indicators of cervical cytology used to monitor the quality of the screening programme. These findings have implications for screening, colposcopy referral criteria, colposcopy practice and histology reporting.

Outcome of Nonpersonalized Human Papillomavirus Vaccinations During Postconization Follow-up: A Report of Two Cases.

BACKGROUND: The human papillomavirus (HPV) vaccine was conceived to prevent new HPV infections among uninfected young women. From the initial intentions, its use has been extended to older women and also tested as a therapeutic tool. We report two HPV vaccination outcomes during postconization follow-up. CASES: Two young women, with different clinical histories, were subjected to HPV vaccine after a loop electrosurgical excision procedure for high-grade cervical intraepithelial neoplasia (CIN) and persisting low-grade CIN. During follow-up both women experienced a worsening of cervical lesions, which resulted in invasive cervical cancer and severe dysplasia, respectively. CONCLUSION: Limited to our experience, a nonpersonalized HPV vaccine administration during postconization follow-up was expensive and unnecessary.

Critical Analyses of the Introduction of Liquid-Based Cytology in a Public Health Service of the State of São Paulo, Brazil.

OBJECTIVE: The aim of this study was to compare the performance of the current conventional Pap smear with liquid-based cytology (LBC) preparations. STUDY DESIGN: Women routinely undergoing their cytopathological and histopathological examinations at Fundação Oncocentro de São Paulo (FOSP) were recruited for LBC. Conventional smears were analyzed from women from other areas of the State of São Paulo with similar sociodemographic characteristics. RESULTS: A total of 218,594 cases were analyzed, consisting of 206,999 conventional smears and 11,595 LBC. Among the conventional smears, 3.0% were of unsatisfactory preparation; conversely, unsatisfactory LBC preparations accounted for 0.3%. The ASC-H (atypical squamous cells - cannot exclude high-grade squamous intraepithelial lesion) frequency did not demonstrate any differences between the two methods. In contrast, the incidence of ASC-US (atypical squamous cells of undetermined significance) was almost twice as frequent between LBC and conventional smears, at 2.9 versus 1.6%, respectively. An equal percentage of high-grade squamous intraepithelial lesions were observed for the two methods, but not for low-grade squamous intraepithelial lesions, which were more significantly observed in LBC preparations than in conventional smears (2.2 vs. 0.7%). The index of positivity was importantly enhanced from 3.0% (conventional smears) to 5.7% (LBC). CONCLUSIONS: LBC performed better than conventional smears, and we are truly confident that LBC can improve public health strategies aimed at reducing cervical lesions through prevention programs.

30 years of preventive studies of uterine cervical cancer 1982-2012.

The studies for the prevention of uterine cervical cancer in Panama City began in a private institute, impelled by the high incidence of cancer. The preventive programs were initiated with the support of the Obstetrics and Gynecology Institute of the University of Padua in Italy. In these studies, we applied the methodological diagnostics of this Institute with certain modifications adapted to our needs. The diagnosis, treatment, and follow-up were carried out under the protocol of the University of Padua. We achieved a diagnosis of oncogenic risk (OR) in 6,411 patients which corresponded to 5,498 cases of human papillomavirus (HPV), 1,150 cases of dysplasia, 210 cases of cancer, and 794 cases of OR. From 2011, polymerase chain reaction (PCR) was also applied with the aim to improve the accuracy of the diagnosis. With this method the prevalence of pathologies were HPV infections both in healthy patients or in patients cured from HPV. Patients were treated by means of local destructive treatments (LDT), basically with cryotherapy and cauterization. We can consider these results as successful prevention and suggest to extend a preventive program to all the population.

Detection of High-Risk Human Papillomaviruses in the Prevention of Cervical Cancer in India.

Human papillomaviruses (HPVs) are small, non-enveloped, double-stranded DNA viruses that infect epithelial tissues. Specific genotypes of human papillomavirus are the single most common etiological agents of cervical intraepithelial lesions and cervical cancer. Cervical cancer usually arises at squamous metaplastic epithelium of transformation zone (TZ) of the cervix featuring infection with one or more oncogenic or high-risk HPV (HR- HPV) types. A hospital- based study in a rural set up was carried out to understand the association of HR-HPV with squamous intraepithelial lesions (SILs) and cervical cancer. In the present study, HR-HPV was detected in 65.7% of low-grade squamous intraepithelial lesions (LSILs), 84.6% of high-grade squamous intraepithelial lesions (HSILs) and 94% of cervical cancer as compared to 10.7% of controls. The association of HPV infection with SIL and cervical cancer was analyzed with Chi square test (p<0.001). The significant association found confirmed that detection of HR-HPV is a suitable candidate for early identification of cervical precancerous lesions and in the prevention of cervical cancer in India.

Topical application of trichloroacetic acid is efficacious for the treatment of internal anal high-grade squamous intraepithelial lesions in HIV-positive men.

OBJECTIVES: To assess the efficacy of topical 80% trichloroacetic acid (TCA) to treat internal anal high-grade squamous intraepithelial lesions (HSILs) in HIV-positive individuals. METHODS: All patients who attended the University of Pittsburgh Anal Dysplasia Clinic for treatment of biopsy-proven internal anal HSIL with topical TCA between July 1, 2009, and June 30, 2012, and who had 1 or more follow-up visits to assess treatment efficacy were included in the analysis. Recurrence of HSIL was assessed in July 1, 2013. RESULTS: A total of 98 HSILs from 72 patients were treated, and 77 (78.6%) resolved to normal epithelium or low-grade SIL during follow-up. Forty-eight (49.0%) and 27 (27.6%) of lesions resolved with 1 and 2 TCA treatments, respectively, whereas 1 lesion (1%) each resolved with 3 and 4 TCA treatments. Twenty-one (21.4%) lesions in 20 patients remained without resolution after TCA treatments. These patients were offered an alternative treatment. During follow-up, 8 (15.1%) of 53 patients had a lesion that recurred at the index site (11/53 [20.8%], inclusive of adjacent lesions) and 17 patients had new lesions diagnosed. CONCLUSIONS: Topical TCA is an efficacious treatment of internal anal HSIL in an anal dysplasia clinic setting with high-resolution anoscopy capacity. Advantages of TCA for this recurrent disease process include the following: low cost, no requirement for special equipment beyond that for high-resolution anoscopy, and painless application procedure. A larger prospective comparative study would better define efficacy and patient acceptability between treatment methods.