A comparison of human papillomavirus testing of clinician-collected and self-collected samples during follow-up after screen-and-treat

Accuracy of HPV testing on self-collected and clinician-collected samples for different screening strategies in African settings: A systematic review and meta-analysis

OBJECTIVES

Cervical cancer still poses a considerable threat to women in low- and middle-income countries, particularly on the African continent. Self-collection of a vaginal sample promises advantages over the established sampling by clinicians. We aimed to assess the accuracy of self-sampling compared to clinician sampling in order to inform its application in primary care in the African context.

METHODS

We searched Pubmed, Livivo, Web of Science, Cochrane Library and African Index Medicus on the 07th of February 2022. The eligibility criteria were: reporting (i) self-sampling against clinician-sampling, (ii) study location in Africa, (iii) relevant outcome-measures: (a) Cohen's kappa (b) sensitivity and specificity of self-sampling tests. We combined Cohen's kappa effects, additionally sensitivity and specificity estimates using random-effects models. The study is registered with PROSPERO (CRD42020218081).

RESULTS

We included 28 studies in the systematic review and 21 studies in the meta-analysis. Self-sampling was used to test for high-risk HPV infections. Two studies additionally tested for low-risk HPV infections. The pooled Cohen's kappa was 0.66 (95%CI: 0.61-0.71). Populations at risk yielded 0.63 (95%CI: 0.56-0.71). Target amplification tests based on PCR performed best with a kappa of 0.68 (95%CI: 0.63-0.73) compared to isothermal mRNA tests, 0.61 (95%CI: 0.51-0.71). Point of care tests performed exceptionally well, 0.73 (95%CI: 0.67-0.80). Sensitivities are close to 80% and specificities close to 90% of self-sampling to detect high-risk HPV.

CONCLUSIONS

Self-sampling agrees moderately to substantially with clinician sampling in the African context. Point of care tests might be particularly suited for application in cervical cancer primary screening in low- and middle-income countries. Populations at risk should get special attention while using self-sampling. Screening protocols should be established.

Prevalence and distribution of selected cervical human papillomavirus types in HIV infected and HIV uninfected women in South Africa, 1989-2021: A narrative review

Background

Human papillomavirus infection, a causative agent of cervical cancer, is of great concern, more so in populations with high HIV prevalence, such as South Africa.

Aim

This review aimed to examine the prevalence and distribution of selected cervical human papillomavirus (HPV) types in HIV infected and HIV uninfected women in South Africa.

Methods

PubMed and Web of Science databases were searched using key words. For data integrity, data was assessed by two authors independently. The study inclusion criteria comprised records on cervical HPV, HPV genotyping and HPV type distribution among South African women. Statistical analysis was performed using Social Science Statistics.

Results

Sixty-nine articles met the inclusion criteria for analysis. Data on cervical HPV prevalence and type distribution was available only for five of the nine provinces of South Africa. Only 4/69 studies used sequencing as an approach to identify HPV types. In a general population, HPV type 16 was the most frequent (8.80%), followed by types 35 (4.86%), 18 (4.14%), 58 and 52 with the frequency of 3.65% and 3.62%, respectively. Furthermore, the least frequent type was HPV 70 (0.74%). Both HIV infected and HIV uninfected populations had a higher prevalence of high-risk human papillomavirus (hrHPV) types 16, 18 and 35 than other HPV types; while HPV types 6, 11 and 70 were the least frequent types from these populations. Lastly, HPV 16 was the most predominant type among women with normal (2.03%) and abnormal cervical cytology (6.60%).

Conclusion

Expanding on HPV genotyping will improve the knowledge in patterns of HPV type distribution in South Africa that will further help in decision making to improve current diagnostics, and future vaccine development and assessment.

Prevention of Cervical Cancer: Guideline of the DGGG and the DKG (S3 Level, AWMF Register Number 015/027OL, December 2017) - Part 2 on Triage, Treatment and Follow-up

Aims Annual opportunistic screening for cervical carcinoma has been done in Germany since 1971. The creation of this S3 guideline meets an important need, outlined in the National Cancer Plan, with regard to screening for cervical cancer, as this guideline aims to provide important information and support for planned organized screening for cervical cancer in Germany. Methods With the financial support of German Cancer Aid, 21 professional societies developed evidence-based statements and recommendations (classified using the GRADE system) for the screening, management and treatment of precancerous conditions of the cervix. Two independent scientific institutes compiled systematic reviews for this guideline. Recommendations The second part of this short summary deals with the triage, treatment and follow-up care of cervical dysplasia. With regard to those women who do not participate in screening, the guideline authors recommend sending out repeat invitation letters or an HPV self-collection kit. Colposcopy should be carried out for further investigation if cytology findings are Pap II-p and HPV test results are positive or if the results of an HPV 16 or HPV 18 screening test are positive. A single abnormal Pap smear should be triaged and investigated using HPV testing or p16/Ki67 dual staining.

Clearance and persistence of the human papillomavirus infection among Cameroonian women

Objective:

Persistent infection with human papillomavirus is the prerequisite for the development of cervical precancerous and cancerous lesions. The aim of this study was to determine the time-to-viral clearance in a population of human papillomavirus–infected Cameroonian women and to examine the possible predictors of viral persistence.

Methods:

We conducted a prospective cohort study based on a population of human papillomavirus–positive women having previously been recruited in a self-human papillomavirus-based cervical cancer screening campaign, who were invited for a control visit at 6 and 12 months. We determined human papillomavirus clearance using self-sampling (Self-HPV) and physician-sampling (Dr-HPV), which were analyzed with a point-of-care assay (GeneXpert^® IV; Cepheid, Sunnyvale, CA, USA). Logistic regression was performed to assess the relationship between sociodemographic and clinical characteristics with HPV clearance according to the two sampling techniques.

Results:

A total of 187 participants were included in the study. At the 12 months follow-up, 79.5% (n = 104) and 65.3% (n = 86) had cleared their human papillomavirus infection according to Dr-HPV and self-HPV, respectively (p = 0.001). Only parity (>5 children) was statistically associated with viral persistence (p = 0.033). According to Dr-HPV, clearance of women treated with thermoablation at 12 months was of 84.1% versus 70.2% for non-treated women (p = 0.075).

Conclusion:

The human papillomavirus clearing rates found in our study are close to those found in other studies worldwide. Parity was significantly associated with human papillomavirus persistence. Larger, prospective studies are needed to confirm our results.

Detecting cervical precancer and reaching underscreened women by using HPV testing on self samples: updated meta-analyses

OBJECTIVE

To evaluate the diagnostic accuracy of high-risk human papillomavirus (hrHPV) assays on self samples and the efficacy of self sampling strategies to reach underscreened women.

DESIGN

Updated meta-analysis.

DATA SOURCES

Medline (PubMed), Embase, and CENTRAL from 1 January 2013 to 15 April 2018 (accuracy review), and 1 January 2014 to 15 April 2018 (participation review).

REVIEW METHODS

Accuracy review: hrHPV assay on a vaginal self sample and a clinician sample; and verification of the presence of cervical intraepithelial neoplasia grade 2 or worse (CIN2+) by colposcopy and biopsy in all enrolled women or in women with positive tests. Participation review: study population included women who were irregularly or never screened; women in the self sampling arm (intervention arm) were invited to collect a self sample for hrHPV testing; women in the control arm were invited or reminded to undergo a screening test on a clinician sample; participation in both arms was documented; and a population minimum of 400 women.

RESULTS

56 accuracy studies and 25 participation trials were included. hrHPV assays based on polymerase chain reaction were as sensitive on self samples as on clinician samples to detect CIN2+ or CIN3+ (pooled ratio 0.99, 95% confidence interval 0.97 to 1.02). However, hrHPV assays based on signal amplification were less sensitive on self samples (pooled ratio 0.85, 95% confidence interval 0.80 to 0.89). The specificity to exclude CIN2+ was 2% or 4% lower on self samples than on clinician samples, for hrHPV assays based on polymerase chain reaction or signal amplification, respectively. Mailing self sample kits to the woman's home address generated higher response rates to have a sample taken by a clinician than invitation or reminder letters (pooled relative participation in intention-to-treat-analysis of 2.33, 95% confidence interval 1.86 to 2.91). Opt-in strategies where women had to request a self sampling kit were generally not more effective than invitation letters (relative participation of 1.22, 95% confidence interval 0.93 to 1.61). Direct offer of self sampling devices to women in communities that were underscreened generated high participation rates (>75%). Substantial interstudy heterogeneity was noted (I²>95%).

CONCLUSIONS

When used with hrHPV assays based on polymerase chain reaction, testing on self samples was similarly accurate as on clinician samples. Offering self sampling kits generally is more effective in reaching underscreened women than sending invitations. However, since response rates are highly variable among settings, pilots should be set up before regional or national roll out of self sampling strategies.

Self- versus physician-collected samples for the follow-up of human papillomavirus-positive women in sub-Saharan Africa

Introduction

Human papillomavirus (HPV) testing is a suitable tool for primary cervical cancer (CC) screening and follow-up in low-resource settings. Vaginal samples taken by women themselves (Self-HPV) are an interesting alternative to physician-performed sampling (Dr-HPV). Our aim was to assess the performance of Self-HPV and Dr-HPV at 6 and 12 months following a CC screening campaign.

Methods

This study was carried out at the Dschang District Hospital, Cameroon. Women aged 30–49 years were recruited in a CC screening campaign. HPV-positive women, of whom 2/3 were treated with thermoablation because of abnormal results at baseline screening, were invited to participate in a follow-up study. Self- and Dr-HPV, as well as cytology, were performed at 6 and 12 months. HPV samples were analyzed using the Xpert HPV assay. Sensitivity and specificity for the detection of low-grade squamous intraepithelial lesion or worse and of high-grade squamous intraepithelial lesion or worse were calculated for Self-HPV and Dr-HPV, using cytology as the reference diagnosis.

Results

Overall, 188 HPV-positive women were invited to attend follow-up. The obtained follow-up visits’ attendance was 154 (81.9%) and 131 (69.7%) at 6 and 12 months, respectively. While the overall performance of Dr-HPV at 6 months was slightly superior, Self-HPV showed an improved sensitivity for HSIL+ detection at 12 months when compared with Dr-HPV (83.3% [95% CI 41.8–98.9] versus 71.4% [95% CI 21.5–95.8], respectively). The overall HPV positivity agreement between Self- and Dr-HPV at 6 and 12 months corresponded to a κ value of 0.62 and 0.52, respectively. Among women treated with thermoablation (n=121) at baseline screening, Self-HPV was as sensitive as Dr-HPV, although less specific (P=0.003).

Conclusion

Self-HPV is a valuable tool for the follow-up of HPV-positive women in low-resource settings. Larger, randomized trials are needed to confirm the validity of our findings.

Mailed Human Papillomavirus Self-Collection With Papanicolaou Test Referral for Infrequently Screened Women in the United States

BACKGROUND

Testing for high-risk human papillomavirus (HPV) infection using mailed, self-collected samples is a promising approach to increase screening in women who do not attend clinic screening at recommended intervals.

METHODS

To assess this intervention among high-risk women in the United States, 429 women without a Papanicolaou (Pap) test in 4 or more years (overdue by US guidelines) were recruited from the general population. Participants aged 30 to 65 years were mailed a kit to self-collect a cervicovaginal sample at home, return the sample by mail, and receive HPV results by telephone, with referral to follow-up cytological Pap testing at a local clinic. Cervicovaginal self-samples were collected with a Viba brush, stored in Scope mouthwash, and tested by Hybrid Capture 2. Data were collected in 2010 to 2011 and analyzed in 2017.

RESULTS

Two-thirds (64%) of participants returned a self-collected sample, of whom 15% tested HPV DNA positive. Human papillomavirus self-test-positive women reported higher rates of follow-up Pap tests (82%) than did those with self-test negative results (51%). No demographic differences were found in self-test return rate or HPV positivity. High acceptability was reported in participant surveys: most women (81%) had "mostly positive" overall thoughts about the self-test, and most reported being comfortable receiving the kit in the mail (99%), returning their self-collected sample by mail (82%), and receiving their test results by telephone (97%).

CONCLUSIONS

Conducting HPV self-testing through population-based recruitment, mailed kit delivery and return by mail, and results delivery by telephone has the potential to reach a broad segment of US underscreened women.

Cervical cancer prevention and treatment research in Africa: a systematic review from a public health perspective

BACKGROUND

Women living in Africa experience the highest burden of cervical cancer. Research and investment to improve vaccination, screening, and treatment efforts are critically needed. We systematically reviewed and characterized recent research within a broader public health framework to organize and assess the range of cervical cancer research in Africa.

METHODS

We searched online databases and the Internet for published articles and cervical cancer reports in African countries. Inclusion criteria included publication between 2004 and 2014, cervical cancer-related content pertinent to one of the four public health categories (primary, secondary, tertiary prevention or quality of life), and conducted in or specifically relevant to countries or regions within the African continent. The study design, geographic region/country, focus of research, and key findings were documented for each eligible article and summarized to illustrate the weight and research coverage in each area. Publications with more than one focus (e.g. secondary and tertiary prevention) were categorized by the primary emphasis of the paper. Research specific to HIV-infected women or focused on feasibility issues was delineated within each of the four public health categories.

RESULTS

A total of 380 research articles/reports were included. The majority (54.6 %) of cervical cancer research in Africa focused on secondary prevention (i.e., screening). The number of publication focusing on primary prevention (23.4 %), particularly HPV vaccination, increased significantly in the past decade. Research regarding the treatment of precancerous lesions and invasive cervical cancer is emerging (17.6 %), but infrastructure and feasibility challenges in many countries have impeded efforts to provide and evaluate treatment. Studies assessing aspects of quality of life among women living with cervical cancer are severely limited (4.1 %). Across all categories, 11.3 % of publications focused on cervical cancer among HIV-infected women, while 17.1 % focused on aspects of feasibility for cervical cancer control efforts.

CONCLUSIONS

Cervical cancer research in African countries has increased steadily over the past decade, but more is needed. Tertiary prevention (i.e. treatment of disease with effective medicine) and quality of life of cervical cancer survivors are two severely under-researched areas. Similarly, there are several countries in Africa with little to no research ever conducted on cervical cancer.

HPV testing in the context of post-treatment follow up (test of cure)

BACKGROUND

Women treated for cervical lesions are at higher risk of subsequent disease compared to the general population. Consequently, post treatment surveillance strategies are required to ensure the success of treatment, so called "test of cure". The high sensitivity and negative predictive value of HPV assays can enhance post-treatment strategies.

OBJECTIVES

To provide an overview of the current data on test of cure strategies with a particular focus on HPV testing and to identify knowledge gaps and areas for further research.

RESULTS

HPV testing is sensitive for the detection of residual or recurrent disease post treatment for CIN2+ and is more sensitive than cytology alone. Co-testing increases sensitivity, marginally and there is a lack of consensus regarding the efficiency and safety to release negative women. Most test of cure studies have applied HPV DNA tests and post treatment positivity rates vary widely depending on assay and potentially, treatment type.

CONCLUSIONS

Globally, an increasing number of test of cure algorithms now incorporate HPV testing although there is heterogeneity of practice with respect to assay, number of post treatment tests, testing intervals, follow up time. While type specific persistence identified through genotyping may identify those at greater risk of disease there is no consensus as to how this may be applied, clinically. Data on HPV testing in women treated for glandular lesions would be welcome as would the performance of different HPV assays and associated biomarkers in this context.

Follow-up strategies after treatment (large loop excision of the transformation zone (LLETZ)) for cervical intraepithelial neoplasia (CIN): Impact of human papillomavirus (HPV) test

BACKGROUND

Development of cancer of the cervix is a multi-step process as before cervical cancer develops, cervical cells undergo changes and become abnormal. These abnormalities are called cervical intraepithelial neoplasia (CIN) and are associated with increased risk of subsequent invasive cancer of the cervix. Oncogenic high-risk human papillomavirus (hrHPV), the causative agent of cervical cancer and its precursor lesions, is present in up to one-third of women following large loop excision of the transformation zone (LLETZ) treatment and is associated with increased risk of residual disease and disease recurrence. HPV testing may serve as a surveillance tool for identifying women at higher risk of recurrence. High-risk human papillomavirus testing will enable us to identify women at increased risk of residual or recurrent CIN and therefore will allow us to offer closer surveillance and early treatment, when indicated.

OBJECTIVES

• To evaluate the effectiveness and safety of hrHPV testing after large loop excision of the transformation zone (LLETZ) treatment• To determine optimal follow-up management strategies following LLETZ treatment according to hrHPV status

SEARCH METHODS

We searched the Cochrane Gynacological Cancer Review Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), PubMed and PsycINFO up to August 2013. We searched registers of clinical trials, abstracts of scientific meetings and reference lists of included studies, and we contacted experts in the field.

SELECTION CRITERIA

We searched for randomised control trials (RCTs) that compared follow-up management strategies following LLETZ treatment for CIN.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed whether potentially relevant studies met the inclusion criteria. No trials were found; therefore no data were analysed.

MAIN RESULTS

The search identified 813 references on MEDLINE, 418 on EMBASE, 22 on CINAHL, 666 on PubMed, 291 on PsycINFO and 145 on CENTRAL. When all references were imported into EndNote and duplications were removed, 1348 references remained. Initial screening of titles and abstracts of these references revealed that 42 references were potentially eligible for this review. After reading the full-text versions, we identified no relevant trials comparing hrHPV and cytology testing versus cytology testing alone for detecting residual or recurrent disease during follow-up to LLETZ treatment of adult women with CIN.We found no evidence on the effects of hrHPV and cytology testing on residual or recurrent CIN2 or higher lesions, anxiety and psychosexual morbidity outcomes in women undergoing colposcopy and treatment for CIN.

AUTHORS' CONCLUSIONS

We found no evidence from RCTs to inform decisions about the best surveillance strategy for women following treatment for CIN. A prognostic systematic review is needed to investigate the risk of developing recurrent cervical intraepithelial neoplasia 2+ (CIN2+) in women with a positive hrHPV test after large loop excision of the transformation zone (LLETZ) treatment.

The Peru Cervical Cancer Screening Study (PERCAPS): the design and implementation of a mother/daughter screen, treat, and vaccinate program in the Peruvian jungle

Peru struggles to prevent cervical cancer (CC). In the jungle, prevention programs suffer from significant barriers although technology exists to detect CC precursors. This study used community based participatory research (CBPR) methods to overcome barriers. The objective was to evaluate the utility of CBPR techniques in a mother-child screen/treat and vaccinate program for CC prevention in the Peruvian jungle. The CC prevention program used self-sampling for human papillomavirus (HPV) for screening, cryotherapy for treatment and the HPV vaccine Gardasil for vaccination. Community health leaders (HL) from around Iquitos participated in a two half day educational course. The HLs then decided how to implement interventions in their villages or urban sectors. The success of the program was measured by: (1) ability of the HLs to determine an implementation plan, (2) proper use of research forms, (3) participation and retention rates, and (4) participants' satisfaction. HLs successfully registered 320 women at soup kitchens, schools, and health posts. Screening, treatment, and vaccination were successfully carried out using forms for registration, consent, and results with minimum error. In the screen/treat intervention 100% of participants gave an HPV sample and 99.7% reported high satisfaction; 81% of HPV + women were treated, and 57% returned for 6-month followup. Vaccine intervention: 98% of girls received the 1st vaccine, 88% of those received the 2nd, and 65% the 3rd. CBPR techniques successfully helped implement a screen/treat and vaccinate CC prevention program around Iquitos, Peru. These techniques may be appropriate for large-scale preventive health-care interventions.

Accuracy of human papillomavirus testing on self-collected versus clinician-collected samples: a meta-analysis

BACKGROUND

Screening for human papillomavirus (HPV) infection is more effective in reducing the incidence of cervical cancer than screening using Pap smears. Moreover, HPV testing can be done on a vaginal sample self-taken by a woman, which offers an opportunity to improve screening coverage. However, the clinical accuracy of HPV testing on self-samples is not well-known. We assessed whether HPV testing on self-collected samples is equivalent to HPV testing on samples collected by clinicians.

METHODS

We identified relevant studies through a search of PubMed, Embase, and CENTRAL. Studies were eligible for inclusion if they fulfilled all of the following selection criteria: a cervical cell sample was self-collected by a woman followed by a sample taken by a clinician; a high-risk HPV test was done on the self-sample (index test) and HPV-testing or cytological interpretation was done on the specimen collected by the clinician (comparator tests); and the presence or absence of cervical intraepithelial neoplasia grade 2 (CIN2) or worse was verified by colposcopy and biopsy in all enrolled women or in women with one or more positive tests. The absolute accuracy for finding CIN2 or worse, or CIN grade 3 (CIN3) or worse of the index and comparator tests as well as the relative accuracy of the index versus the comparator tests were pooled using bivariate normal models and random effect models.

FINDINGS

We included data from 36 studies, which altogether enrolled 154 556 women. The absolute accuracy varied by clinical setting. In the context of screening, HPV testing on self-samples detected, on average, 76% (95% CI 69-82) of CIN2 or worse and 84% (72-92) of CIN3 or worse. The pooled absolute specificity to exclude CIN2 or worse was 86% (83-89) and 87% (84-90) to exclude CIN3 or worse. The variation of the relative accuracy of HPV testing on self-samples compared with tests on clinician-taken samples was low across settings, enabling pooling of the relative accuracy over all studies. The pooled sensitivity of HPV testing on self-samples was lower than HPV testing on a clinician-taken sample (ratio 0·88 [95% CI 0·85-0·91] for CIN2 or worse and 0·89 [0·83-0·96] for CIN3 or worse). Also specificity was lower in self-samples versus clinician-taken samples (ratio 0·96 [0·95-0·97] for CIN2 or worse and 0·96 [0·93-0·99] for CIN3 or worse). HPV testing with signal-based assays on self-samples was less sensitive and specific than testing on clinician-based samples. By contrast, some PCR-based HPV tests generally showed similar sensitivity on both self-samples and clinician-based samples.

INTERPRETATION

In screening programmes using signal-based assays, sampling by a clinician should be recommended. However, HPV testing on a self-sample can be suggested as an additional strategy to reach women not participating in the regular screening programme. Some PCR-based HPV tests could be considered for routine screening after careful piloting assessing feasibility, logistics, population compliance, and costs.

FUNDING

The 7th Framework Programme of the European Commission, the Belgian Foundation against Cancer, the International Agency for Research on Cancer, and the German Guideline Program in Oncology.

Through the glass darkly: intraepithelial neoplasia, top-down differentiation, and the road to ovarian cancer

It is currently hoped that deaths from extra-uterine high-grade serous cancer (HGSC) will be reduced via opportunistic salpingectomy in healthy women. Accumulated data implicate the fimbria as a site of origin and descriptive molecular pathology and experimental evidence strongly support a serous carcinogenic sequence in the Fallopian tube. Both direct and indirect ('surrogate') precursors suggest that the benign tube undergoes important biological changes after menopause, acquiring abnormalities in gene expression that are often shared with malignancy, including PAX2, ALDH1, LEF1, RCN1, RUNX2, beta-catenin, EZH2, and others. However, the tube can be linked to only some HGSCs, recharging arguments that nearby peritoneum/ovarian surface epithelium (POSE) also hosts progenitors to this malignancy. A major sticking point is the difference in immunophenotype between POSE and Müllerian epithelium, essentially requiring mesothelial to Müllerian differentiation prior to or during malignant transformation to HGSC. However, emerging evidence implicates an embryonic or progenitor phenotype in the adult female genital tract with the capacity to differentiate, normally or during neoplastic transformation. Recently, a putative cell of origin for cervical cancer has been identified in the squamo-columnar (SC) junction, projecting a model whereby Krt7+ embryonic progenitors give rise to immunophenotypically distinct progeny under stromal influences via 'top down' differentiation. Similar differentiation can be seen in the endometrium with a parallel in juxtaposed mesothelial and Müllerian differentiation in the ovary. Abrupt mesothelial-Müllerian transitions remain to be proven, but would explain the rapid evolution, short asymptomatic interval, and absence of a defined epithelial starting point in many HGSCs. Resolving this question will require accurately distinguishing progenitor from progeny tumour cells in HGSC and pinpointing where initial transformation and trans-differentiation occur, whether in the tube or POSE. Both will be critical to expectations from prophylactic salpingectomy and future approaches to pelvic serous cancer prevention.

Cervical cancer screening in high- and low-resource countries: implications and new developments

The implementation of cytology-based screening programs for precancerous lesions of the cervix has decreased the incidence of and mortality from cervical cancer in much of the developed world. Countries without the resources to install such frequent and laboratory-dependent screening programs have more and more options at their disposal. A screening program based on cytology analysis requires too much training, infrastructure, and repeated screening to be feasible. Visual inspection with acetic acid, often used throughout the world, is inexpensive and both sensitive and specific, but it lacks reproducibility. Although human papillomavirus (HPV) testing is too expensive for widespread use, its negative predictive value and sensitivity make it a promising method of screening. Utilizing HPV vaccines as a primary mode of prevention may not be financially feasible and does not obviate the need for screening. Cervical cancer has been considered an AIDS-defining illness, with HPV and HIV often coexisting, and screening methods have been shown to be as reliable for women with HIV as those without. Ultimately, the most clinically effective and cost-effective methods for reducing cervical cancer incidence are those that limit the number of visits that women are required to attend. Providing immediate cryotherapy for those with a positive screen, whether by visual inspection or HPV testing, is promising to have quite an impact, although the type of program implemented will depend on the needs and expectations of each country.

Alternative approaches to cervical cancer screening for developing countries

Cervical cancer remains the most common cancer among women living in developing countries, largely because of the failure either to initiate or sustain effective cervical-cancer screening programmes. This potentially preventable and curable cancer continues to cause high mortality among relatively young women residing in low-resource countries. Cytology as a screening test, linked with a robust healthcare infrastructure, has significantly affected cervical cancer prevention in countries that have had sufficient resources to establish and sustain well-conducted programmes. The failure to establish such programmes has stimulated a large body of research into alternative screening tests and approaches to cervical-cancer prevention. Two of the most recent research methods have been visual inspection with acetic acid and molecular testing for high-risk types of human papillomavirus deoxyribonucleic acid. Visual inspection with acetic acid has shown a great deal of promise in cross-sectional studies; however, in randomised-controlled trials, it has been shown to be significantly less effective in reducing cervical cancer or its precursors. The development of point-of-care human papillomavirus or other highly sensitive tests for the prevention of cervical cancer is imperative. It has also been clearly shown that linking testing or screening to treatment (so-called 'screen and treat') without the intervention of colposcopy or the need for sophisticated laboratories may potentially prevent cervical cancer in large numbers of women.

Human papillomavirus deoxyribonucleic acid testing in developed countries

Cervical cancer has been largely eliminated in developed countries with the implementation of cytology-based screening programmes that depend on a call-recall system, followed by colposcopy and biopsy, treatment of precancerous lesions and follow up. With the discovery that persistent infection with high-risk human papillomavirus types is necessary for the development of cervical cancer, several tests for human papillomavirus deoxyribonucleic acid have been developed that can identify women at risk. Human papillomavirus deoxyribonucleic acid testing is more sensitive and only slightly less specific than cytology for detecting cervical intraepithelial neoplasia. It is also more reproducible, with the potential for self-sampling. Human papillomavirus genotyping, messenger RNA analysis and other biomarkers can help to further stratify this group and diminish referrals to colposcopy. Initially, human papillomavirus testing was used as an adjunct to cytology for triage of borderline cases, but evidence has shown its superiority as a screening method and in the follow up of women treated for cervical intraepithelial neoplasia.