Performance of cervical cytology and HPV testing for primary cervical cancer screening in Latin America: an analysis within the ESTAMPA study.

Background: Cervical cytology remains widely used as the initial tool in cervical cancer screening worldwide. WHO guidelines recommend replacing cytology with primary HPV testing to reach cervical cancer elimination goals. We assessed the performance of cytology and high-risk HPV testing to detect cervical precancer, cervical intraepithelial neoplasia (CIN) grade 3 or worse (CIN3+) among women aged 30-64 years participating in the ESTAMPA study. Methods: Women were screened with cytology and HPV across ESTAMPA study centres in Latin America. Screen-positives were referred to colposcopy with biopsy collection and treatment as needed. Those with no evident precancer were recalled at 18-months for a second HPV test to complete disease ascertainment. Performance indicators for cytology and HPV to detect CIN3+ were estimated. Findings: 30,606 participants with available cytology and HPV results were included in the analysis. A total of 440 histologically confirmed CIN3s and 30 cancers were diagnosed. Cytology sensitivity for CIN3+ was 48.5% (95% CI: 44.0-53.0), whereas HPV testing had a sensitivity of 98.1% (95% CI: 96.3-96.7). Specificity was 96.5% (95% CI: 96.3-96.7) using cytology and 88.7% (95% CI: 88.3-89.0) with HPV. Performance estimates varied substantially by study centre for cytology (ranging from 32.1% to 87.5% for sensitivity and from 89.2% to 99.5% for specificity) while for HPV results were more consistent across sites (96.7%-100% and 83.6-90.8%, respectively). Interpretation: The limited and highly variable sensitivity of cytology strongly supports transition to the more robust and reproducible HPV-based cervical screening to ensure progress towards global cervical cancer elimination targets in Latin America. Funding: IARC/WHO, UNDP, HRP/WHO, NCI and local funders.

Performance of standardised colposcopy to detect cervical precancer and cancer for triage of women testing positive for human papillomavirus: results from the ESTAMPA multicentric screening study.

BACKGROUND: Colposcopy, currently included in WHO recommendations as an option to triage human papillomavirus (HPV)-positive women, remains as the reference standard to guide both biopsy for confirmation of cervical precancer and cancer and treatment approaches. We aim to evaluate the performance of colposcopy to detect cervical precancer and cancer for triage in HPV-positive women. METHODS: This cross-sectional, multicentric screening study was conducted at 12 centres (including primary and secondary care centres, hospitals, laboratories, and universities) in Latin America (Argentina, Bolivia, Colombia, Costa Rica, Honduras, Mexico, Paraguay, Peru, and Uruguay). Eligible women were aged 30-64 years, sexually active, did not have a history of cervical cancer or treatment for cervical precancer or a hysterectomy, and were not planning to move outside of the study area. Women were screened with HPV DNA testing and cytology. HPV-positive women were referred to colposcopy using a standardised protocol, including biopsy collection of observed lesions, endocervical sampling for transformation zone (TZ) type 3, and treatment as needed. Women with initial normal colposcopy or no high-grade cervical lesions on histology (less than cervical intraepithelial neoplasia [CIN] grade 2) were recalled after 18 months for another HPV test to complete disease ascertainment; HPV-positive women were referred for a second colposcopy with biopsy and treatment as needed. Diagnostic accuracy of colposcopy was assessed by considering a positive test result when the colposcopic impression at the initial colposcopy was positive minor, positive major, or suspected cancer, and was considered negative otherwise. The main study outcome was histologically confirmed CIN3+ (defined as grade 3 or worse) detected at the initial visit or 18-month visit. FINDINGS: Between Dec 12, 2012, and Dec 3, 2021, 42 502 women were recruited, and 5985 (14·1%) tested positive for HPV. 4499 participants with complete disease ascertainment and follow-up were included in the analysis, with a median age of 40·6 years (IQR 34·7-49·9). CIN3+ was detected in 669 (14·9%) of 4499 women at the initial visit or 18-month visit (3530 [78·5%] negative or CIN1, 300 [6·7%] CIN2, 616 [13·7%] CIN3, and 53 [1·2%] cancers). Sensitivity was 91·2% (95% CI 88·9-93·2) for CIN3+, whereas specificity was 50·1% (48·5-51·8) for less than CIN2 and 47·1% (45·5-48·7) for less than CIN3. Sensitivity for CIN3+ significantly decreased in older women (93·5% [95% CI 91·3-95·3] in those aged 30-49 years vs 77·6% [68·6-85·0] in those aged 50-65 years; p<0·0001), whereas specificity for less than CIN2 significantly increased (45·7% [43·8-47·6] vs 61·8% [58·7-64·8]; p<0·0001). Sensitivity for CIN3+ was also significantly lower in women with negative cytology than in those with abnormal cytology (p<0·0001). INTERPRETATION: Colposcopy is accurate for CIN3+ detection in HPV-positive women. These results reflect ESTAMPA efforts in an 18-month follow-up strategy to maximise disease detection with an internationally validated clinical management protocol and regular training, including quality improvement practices. We showed that colposcopy can be optimised with proper standardisation to be used as triage in HPV-positive women. FUNDING: WHO; Pan American Health Organization; Union for International Cancer Control; National Cancer Institute (NCI); NCI Center for Global Health; National Agency for the Promotion of Research, Technological Development, and Innovation; NCI of Argentina and Colombia; Caja Costarricense de Seguro Social; National Council for Science and Technology of Paraguay; International Agency for Research on Cancer; and all local collaborative institutions.

Multicentric study of cervical cancer screening with human papillomavirus testing and assessment of triage methods in Latin America: the ESTAMPA screening study protocol.

INTRODUCTION: Human papillomavirus (HPV) testing is replacing cytology in primary screening. Its limited specificity demands using a second (triage) test to better identify women at high-risk of cervical disease. Cytology represents the immediate triage but its low sensitivity might hamper HPV testing sensitivity, particularly in low-income and middle-income countries (LMICs), where cytology performance has been suboptimal. The ESTAMPA (EStudio multicéntrico de TAMizaje y triaje de cáncer de cuello uterino con pruebas del virus del PApiloma humano; Spanish acronym) study will: (1) evaluate the performance of different triage techniques to detect cervical precancer and (2) inform on how to implement HPV-based screening programmes in LMIC. METHODS AND ANALYSIS: Women aged 30-64 years are screened with HPV testing and Pap across 12 study centres in Latin America. Screened positives have colposcopy with biopsy and treatment of lesions. Women with no evident disease are recalled 18 months later for another HPV test; those HPV-positive undergo colposcopy with biopsy and treatment as needed. Biological specimens are collected in different visits for triage testing, which is not used for clinical management. The study outcome is histological high-grade squamous intraepithelial or worse lesions (HSIL+) under the lower anogenital squamous terminology. About 50 000 women will be screened and 500 HSIL+ cases detected (at initial and 18 months screening). Performance measures (sensitivity, specificity and predictive values) of triage techniques to detect HSIL+ will be estimated and compared with adjustment by age and study centre. ETHICS AND DISSEMINATION: The study protocol has been approved by the Ethics Committee of the International Agency for Research on Cancer (IARC), of the Pan American Health Organisation (PAHO) and by those in each participating centre. A Data and Safety Monitoring Board (DSMB) has been established to monitor progress of the study, assure participant safety, advice on scientific conduct and analysis and suggest protocol improvements. Study findings will be published in peer-reviewed journals and presented at scientific meetings. TRIAL REGISTRATION NUMBER: NCT01881659.

Impact of operational factors on HPV positivity rates in an HPV-based screening study in Colombia.

OBJECTIVE: To assess the effect of operational factors on the positivity rates of three HPV assays. METHODS: Within the cross-sectional ESTAMPA study, women aged 30-64 years were recruited at healthcare centers from Soacha, Colombia, during 2012-2015. Cervical samples were collected for cotesting with Hybrid Capture 2 (HC2; Qiagen, Gaithersburg, MD, USA), and either Aptima (Hologic, Marlborough, MA, USA) or Cobas 4800 (Roche Diagnostics, Indianapolis, IN, USA). The effect of operational factors on assay performance was assessed using adjusted positivity rates obtained from logistic regression models. RESULTS: There were 4168 women included. For samples collected in assay-specific medium, positivity rate differences were associated with the expertise of the nurse collecting the sample (P=0.014 HC2; P=0.091 Aptima) and if sample collection occurred after an initial cytology (P=0.025 HC2; P=0.033 Aptima). If PreservCyt medium (Hologic) was used, HC2 positivity differences were observed depending on the time between sample collection and processing (P=0.026) and on the laboratory technician processing the samples (P=0.003). No differences were observed for PreservCyt samples processed with Aptima or Cobas. CONCLUSION: Nurse expertise, collection of previous cytology, processing time, and laboratory technician could influence HPV assay performance. Suitable quality assurance protocols for HPV-based screening programs are required. ClinicalTrials.gov: NCT01881659.