Phase I of the DiaVACCS screening trial: Study design, methods, population demographics and baseline results
Background. Human papillomavirus (HPV)-based primary screening guidelines are based on screening test performance and prevalence data generated in high-resource areas with low HIV infection rates. There is an urgent need for local data on infection and disease prevalence, as well as screeni...
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| Format: | Article |
| Language: | English |
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South African Medical Association
2022-07-01
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| Series: | South African Medical Journal |
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| Online Access: | https://samajournals.co.za/index.php/samj/article/view/16 |
| _version_ | 1827365044178911232 |
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| author | G Dreyer L C Snyman F H van der Merwe K L Richter G J Dreyer C Visser M H Botha |
| author_facet | G Dreyer L C Snyman F H van der Merwe K L Richter G J Dreyer C Visser M H Botha |
| author_sort | G Dreyer |
| collection | DOAJ |
| description |
Background. Human papillomavirus (HPV)-based primary screening guidelines are based on screening test performance and prevalence data generated in high-resource areas with low HIV infection rates. There is an urgent need for local data on infection and disease prevalence, as well as screening test performance, among both HIV-positive and HIV-negative South African (SA) women, in order to inform updated screening guidelines.
Objectives. This study describes the baseline characteristics of participants in the cross-sectional phase of the multicentric DIAgnosis in Vaccine And Cervical Cancer Screen (DiaVACCS) screening trial. The objective was to determine the prevalence of positive screening and pre-invasive disease using different tests and strategies in the SA HIV-positive and HIV-negative population.
Methods. A total of 1 104 women aged 25 - 65 years and eligible for screening were included, 465 HIV positive and 639 HIV negative. Visual inspection and molecular and cytological screening tests were done on self-sampled and healthcare worker-collected specimens. All participants who screened positive and 49.1% of those who screened negative were invited for colposcopy and biopsy, and those qualifying for treatment were recalled for large loop excision of the transformation zone as part of the trial. The worst histology result for each participant was used, and for untested women, multiple imputation was used to estimate verification bias- adjusted histology values.
Results. Visual inspection was positive in 50.4% of HIV-positive v. 20.9% of HIV-negative women, cytology (atypical squamous cells of undetermined significance) in 39.9% v. 17.0%, and high-risk HPV DNA in 41.2% v. 19.6%. Overall, high-grade squamous intraepithelial lesion-positive cytology peaked in the age group 30 - 39 years at 16.7%. After adjustment for verification bias, histological diagnosis of cervical intraepithelial neoplasia (CIN)2+ was suspected in 44.7% v. 23.5% and CIN3+ in 23.3% v. 10.2% of HIV-positive and negative women, respectively. Invasive cancer was diagnosed in 15 women (1.95% of histological studies performed), and verification bias adjustment suggested 20 cases (1.8% of the study population).
Conclusion. The baseline findings from the DiaVACCS trial confirm a high prevalence of HPV-related cervical pathology in the SA HIV-negative screening population, showing a clear need to reach these women with a screening programme. Among HIV-positive women, prevalence values were almost doubled. The prevalence of existing invasive cervical cancer was 1 - 2% of all women. Further analysis of the performance of single and multiple screening tests between the two subgroups will contribute to the choice of the most effective strategies to identify women at risk of developing invasive cancer.
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| first_indexed | 2024-03-08T08:21:12Z |
| format | Article |
| id | doaj.art-5736bca0b9444767b1710ecfe411dfa2 |
| institution | Directory Open Access Journal |
| issn | 0256-9574 2078-5135 |
| language | English |
| last_indexed | 2024-03-08T08:21:12Z |
| publishDate | 2022-07-01 |
| publisher | South African Medical Association |
| record_format | Article |
| series | South African Medical Journal |
| spelling | doaj.art-5736bca0b9444767b1710ecfe411dfa22024-02-02T05:45:13ZengSouth African Medical AssociationSouth African Medical Journal0256-95742078-51352022-07-01112710.7196/SAMJ.2022.v112i7.16478Phase I of the DiaVACCS screening trial: Study design, methods, population demographics and baseline resultsG Dreyer0L C Snyman1F H van der Merwe2K L Richter3G J Dreyer4C Visser5M H Botha6epartment of Obstetrics and Gynaecology and Gynaecological Oncology Unit, Faculty of Health Sciences, University of Pretoria, South Africaepartment of Obstetrics and Gynaecology and Gynaecological Oncology Unit, Faculty of Health Sciences, University of Pretoria, South AfricaDepartment of Obstetrics and Gynaecology and Unit for Gynaecological Oncology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South AfricaDepartment of Medical Virology, Faculty of Health Sciences, University of Pretoria, South AfricaDepartment of Statistics and Actuarial Science, Faculty of Commerce, Stellenbosch University, Cape Town, South AfricaDepartment of Obstetrics and Gynaecology and Gynaecological Oncology Unit, Faculty of Health Sciences, University of Pretoria, South AfricaDepartment of Obstetrics and Gynaecology and Unit for Gynaecological Oncology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa Background. Human papillomavirus (HPV)-based primary screening guidelines are based on screening test performance and prevalence data generated in high-resource areas with low HIV infection rates. There is an urgent need for local data on infection and disease prevalence, as well as screening test performance, among both HIV-positive and HIV-negative South African (SA) women, in order to inform updated screening guidelines. Objectives. This study describes the baseline characteristics of participants in the cross-sectional phase of the multicentric DIAgnosis in Vaccine And Cervical Cancer Screen (DiaVACCS) screening trial. The objective was to determine the prevalence of positive screening and pre-invasive disease using different tests and strategies in the SA HIV-positive and HIV-negative population. Methods. A total of 1 104 women aged 25 - 65 years and eligible for screening were included, 465 HIV positive and 639 HIV negative. Visual inspection and molecular and cytological screening tests were done on self-sampled and healthcare worker-collected specimens. All participants who screened positive and 49.1% of those who screened negative were invited for colposcopy and biopsy, and those qualifying for treatment were recalled for large loop excision of the transformation zone as part of the trial. The worst histology result for each participant was used, and for untested women, multiple imputation was used to estimate verification bias- adjusted histology values. Results. Visual inspection was positive in 50.4% of HIV-positive v. 20.9% of HIV-negative women, cytology (atypical squamous cells of undetermined significance) in 39.9% v. 17.0%, and high-risk HPV DNA in 41.2% v. 19.6%. Overall, high-grade squamous intraepithelial lesion-positive cytology peaked in the age group 30 - 39 years at 16.7%. After adjustment for verification bias, histological diagnosis of cervical intraepithelial neoplasia (CIN)2+ was suspected in 44.7% v. 23.5% and CIN3+ in 23.3% v. 10.2% of HIV-positive and negative women, respectively. Invasive cancer was diagnosed in 15 women (1.95% of histological studies performed), and verification bias adjustment suggested 20 cases (1.8% of the study population). Conclusion. The baseline findings from the DiaVACCS trial confirm a high prevalence of HPV-related cervical pathology in the SA HIV-negative screening population, showing a clear need to reach these women with a screening programme. Among HIV-positive women, prevalence values were almost doubled. The prevalence of existing invasive cervical cancer was 1 - 2% of all women. Further analysis of the performance of single and multiple screening tests between the two subgroups will contribute to the choice of the most effective strategies to identify women at risk of developing invasive cancer. https://samajournals.co.za/index.php/samj/article/view/16DiaVACCS screening trial |
| spellingShingle | G Dreyer L C Snyman F H van der Merwe K L Richter G J Dreyer C Visser M H Botha Phase I of the DiaVACCS screening trial: Study design, methods, population demographics and baseline results South African Medical Journal DiaVACCS screening trial |
| title | Phase I of the DiaVACCS screening trial: Study design, methods, population demographics and baseline results |
| title_full | Phase I of the DiaVACCS screening trial: Study design, methods, population demographics and baseline results |
| title_fullStr | Phase I of the DiaVACCS screening trial: Study design, methods, population demographics and baseline results |
| title_full_unstemmed | Phase I of the DiaVACCS screening trial: Study design, methods, population demographics and baseline results |
| title_short | Phase I of the DiaVACCS screening trial: Study design, methods, population demographics and baseline results |
| title_sort | phase i of the diavaccs screening trial study design methods population demographics and baseline results |
| topic | DiaVACCS screening trial |
| url | https://samajournals.co.za/index.php/samj/article/view/16 |
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