Visual inspection with acetic acid as a cervical cancer test: accuracy validated using latent class analysis

Barriers to early diagnosis of cervical cancer: a mixed-method study in Côte d'Ivoire, West Africa

BACKGROUND

Cervical cancer, a major public health problem in many developing countries, is usually associated with a poor survival related to an advanced disease at diagnosis. In Côte d'Ivoire and other developing countries with high cervical cancer prevalence, little is known about factors associated with advanced cervical cancer stages in a context of limited access to screening services.

METHODS

From May to July 2019, we conducted a cross-sectional study using a mixed, quantitative and qualitative method. Information on socio-demographic and history of the disease was extracted from a rapid case ascertainement study performed by the cancer registry of Côte d'Ivoire that enrolled all women diagnosed with cervical cancer between July 2018 and June 2019. In-depth semi-structured interviews were conducted among a subset of these women (12 women) and six healthcare providers to further capture barriers to early cervical cancer diagnosis. Factors associated with an advanced stage III, IV (according to FIGO classification) were estimated by a logistic regression model. Qualitative data were analyzed using a thematic analysis technique guided by the treatment pathway model and triangulated with quantitative data.

RESULTS

In total, 95 women with cervical cancer [median age = 51 (IQR 42-59)] years, were included. Among them, 18.9% were living with HIV and only 9.5% were covered by a health insurance. The majority (71.5%) were diagnosed with advanced cervical cancer. Being HIV-uninfected (aOR = 5.4; [1.6-17.8], p = 0.006) and being uninsured (aOR = 13.1; [2.0-85.5], p = 0.007) were independently associated with advanced cervical cancer in multivariable analysis. Qualitative data raised additional factors potentially related to advanced cervical cancer stages at diagnosis, including the lack of patient information on cervical cancer by healthcare providers and inadequate national awareness and screening campaigns.

CONCLUSION

In a context of challenges in access to systematic cervical cancer screening in Côte d'Ivoire, access to health insurance or integrated healthcare program appear to be key determinants of early diagnosis of cervical cancer.

Outcomes from 8 years of cervical cancer screening at a rural screen-and-treat site in northern Tanzania

OBJECTIVE

To examine screening outcomes for a rural screen-and-treat site as well as the referral completion rate, outreach programming, and screening costs.

METHODS

A retrospective cross-sectional analysis of demographic information and screening outcomes for all women screened at a rural screen-and-treat site between August 2011 and December 2018 was conducted. Referral completion rate for women with suspected cervical cancer was calculated for 2018.

RESULTS

A total of 10 157 screenings were conducted during the study period. Median age was 35 years and median parity was 5. In all, 545 (5.35%) women were positive on visual inspection with acetic acid (VIA+), and 461 (91.1%) of 506 eligible women received cryotherapy. In 2018, 93 women were referred for suspected cancer to the zonal referral center, but only 10 (10.8%) presented for treatment. Mean screening cost was US$ 6.62 per person.

CONCLUSION

VIA+ rate was comparable to rates at urban sites in Tanzania, and outreach was an important component of screening. In contrast to other reports, few women suspected of having cancer reached treatment after being referred. Although the low cost of screening highlights the feasibility of rural screen-and-treat sites, additional research is needed to improve completion of referrals to a higher level of care.

Development and validation of a clinical prediction model for endocervical curettage decision-making in cervical lesions

Background

In the absence of practical and reliable predictors for whether the endocervical curettage (ECC) procedure should be performed, decisions regarding patient selection are usually based on the colposcopists’ clinical judgment instead of evidence. We aimed to develop and validate a practical prediction model that uses available information to reliably estimate the need to perform ECC in patients suspected of having cervical lesions.

Methods

In this retrospective study, 2088 patients who underwent colposcopy, colposcopically directed biopsy (CDB) and ECC procedures between September 2019 and September 2020 at the Second Hospital of Shanxi Medical University were included. The data were analyzed with univariate and multivariable logistic regression. Least absolute shrinkage and selection operator (LASSO) was used to select predictors for ECC positivity. The ECC prediction model was presented as a nomogram and evaluated in terms of discrimination and calibration. Furthermore, this model was validated internally with cross-validation and bootstrapping.

Results

Significant trends were found for ECC positivity with increasing age (P = 0.001), menopause (P = 0.003), Human papillomavirus (HPV) status (P < 0.001), severity of ThinPrep Cytological Test (TCT) (P < 0.001), original squamous epithelium ectopia (P = 0.037) and colposcopy impression (P < 0.001) by multivariable logistic regression analysis. The ECC prediction model was developed based on the following predictors: age, menopause, symptom of contact bleeding, severity of TCT, HPV status, cervix visibility, original squamous epithelium ectopia, acetowhite changes and colposcopic impression. This model had satisfactory calibration and good discrimination, with an area under the receiver operator characteristic curve (AUC) of 0.869 (95% confidence interval 0.849 to 0.889).

Conclusions

A readily applicable clinical prediction model was constructed to reliably estimate the probability of ECC positivity in patients suspicious of having cervical lesions, which may help clinicians make decisions regarding the ECC procedure and possibly prevent adverse effects.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08523-y.

A cross-sectional study exploring triage of human papillomavirus (HPV)-positive women by visual assessment, manual and computer-interpreted cytology, and HPV-16/18-45 genotyping in Cameroon

BACKGROUND

High-risk human papillomavirus (HPV)-positive women require triage to identify those at higher risk of cervical intraepithelial neoplasia grade 2 or worse (CIN2+). We aimed to compare visual assessment of the cervix, manual cytology and automated cytology as triage tests to screen HPV-positive women, and to assess over-treatment rates after visual assessment and over-referral rates to colposcopy after cytology.

METHODS

The present cross-sectional study is nested in a large prospective screening trial in Cameroon. Evaluations of the tests have been conducted individually and in combination with HPV-16/HPV-18/45 genotyping. For the evaluation of over-treatment and colposcopic over-referral, we simulated two screening scenarios: (1) one-visit scenario (test-triage-and-treatment); and (2) two-visit scenario (test-triage-and-colposcopy).

RESULTS

1582 women with a median age of 40 years (IQR 35-45) performed self-sampling for HPV testing, of which 294 (18.6%) were HPV-positive, and 12.2% had CIN2+. Sensitivities for CIN2+ detection were 77.1% for visual assessment, 80.0% for manual cytology, and 84.8% for automated cytology. Sensitivity of combined tests was higher compared with single tests. The highest sensitivity was obtained by the combination of genotyping and automated cytology (91.2%). In the one-visit scenario, the over-treatment rate was 83.9% in referred women, with a ratio of 6.2 treated women per CIN2+. In the two-visit scenario, the lowest over-referral rate would have been under manual cytology (45.0%), with a ratio of 1.8 referred women per CIN2+. Single and combined triage strategies by automated cytology gave rise to over-referral rates of 69.2% and 76.7%, respectively, and a ratio of 3.2 and 4.3 referred women per CIN2+, respectively.

DISCUSSION

Triage of HPV-positive women using a combination of genotyping and automated cytology for CIN2+ detection may provide public benefits in low- and middle-income countries.

Comparison of the Accuracy of Papanicolaou Test Cytology, Visual Inspection With Acetic Acid, and Visual Inspection With Lugol Iodine in Screening for Cervical Neoplasia in Southeast Nigeria

Purpose

This study aimed to compare the accuracy of Papanicolaou test cytology, visual inspection with 5% acetic acid (VIA), and visual inspection with Lugol iodine (VILI) in the detection of premalignant and malignant lesions of the cervix.

Materials and Methods

This was a cross-sectional comparative study of 200 consenting participants at the Federal Teaching Hospital, Abakaliki over a 6-month period. All the participants had Papanicolaou test cytology. Subsequently, they were classified into two groups of 100 each through systematic random sampling: group 1 had VIA and group 2 had VILI. Thereafter, all the participants had cervical punch biopsy at the 6 and 12 o’clock cervical positions. Cervical punch biopsy was also done on the suspicious lesions of the cervix irrespective of their positions. The tests of validity of the three methods were calculated using the histology of the biopsy specimen as the gold standard. P value ≤ .05 was considered to be statistically significant.

Results

Among the VIA group, 19 (19%) had cervical epithelial abnormalities on Papanicolaou test cytology, and VIA was positive in 14 (14%). Histology results showed cervical neoplasia in 15 (15%) of the participants. Among the VILI group, 15 (15%) had cervical epithelial abnormalities on Papanicolaou test cytology, and VILI was positive in 19 (19%). Histology results showed cervical neoplasia in 15 (15%) of the participants. There was no significant difference in overall accuracy of Papanicolaou test cytology, VIA, and VILI. The overall accuracy of the Papanicolaou test cytology plus VIA was significantly more than Papanicolaou test cytology alone.

Conclusion

VIA or VILI can be used as a stand-alone cervical cancer screening test when compared with Papanicolaou test cytology, particularly in resource-limited settings. VIA can also complement Papanicolaou test cytology.

Diagnostic accuracy and prediction increment of markers of epithelial-mesenchymal transition to assess cancer cell detachment from primary tumors

Background

Metastases play a role in about 90% of cancer deaths. Markers of epithelial-mesenchymal transition (EMT) measured in primary tumor cancer cells might provide diagnostic information about the likelihood that cancer cells have detached from the primary tumor. Used together with established diagnostic tests of detachment—lymph node evaluation and radiologic imaging—EMT marker measurements might improve the ability of clinicians to assess the patient’s risk of metastatic disease. Translation of EMT markers to clinical use has been hampered by a lack of valid analyses of clinically-informative parameters. Here, we demonstrate a rigorous approach to estimating the sensitivity, specificity, and prediction increment of an EMT marker to assess cancer cell detachment from primary tumors.

Methods

We illustrate the approach using immunohistochemical measurements of the EMT marker E-cadherin in a set of colorectal primary tumors from a population-based prospective cohort in North Carolina. Bayesian latent class analysis was used to estimate sensitivity and specificity in a setting of multiple imperfect diagnostic tests and no gold standard. Risk reclassification analysis was used to assess the extent to which addition of the marker to the panel of established diagnostic tests would improve mortality prediction. We explored how changing the latent class conditional dependence assumptions and definition of marker positivity would impact the results.

Results

All diagnostic accuracy and prediction increment statistics varied with the choice of cut point to define marker positivity. When comparing different definitions of marker positivity to each other, numerous trade-offs were observed in terms of sensitivity, specificity, predictive discrimination, and prediction model calibration. We then discussed several implementation considerations and the plausibility of analytic assumptions.

Conclusions

The approaches presented here can be extended to any EMT marker, to most forms of cancer, and to different kinds of EMT marker measurements, such as RNA or gene methylation data. These methods provide valid, clinically-informative assessment of whether and how to use a given EMT marker to refine tumor staging and consequent treatment decisions.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3964-3) contains supplementary material, which is available to authorized users.

A tailored within-community specimen collection strategy increased uptake of cervical cancer screening in a cross-sectional study in Ghana

Background

The implementation of cervical cancer screening strategies has reported different rates of success in different countries due to population specific factors that limit women’s participation. We report observations and the development of a community-based specimen collection strategy which resulted from interactions with women in the study communities, following an initial low response to a hospital based cervical cancer screening strategy.

Method

Women were recruited by a house survey and invited to report at a hospital either within a week or after a week for self and health-personnel specimen collections. However, due to the very low response and subsequent interactions with the women of the communities, another strategy was developed that required recruited women report at a central location within their respective communities for specimen collections at times that did not interfere with their daily routines.

Results

For specimen collection, of the 156 participants who opted to report after a week at the hospital, 60 (38.5%) reported. Of the 118 participants who opted to report within 1 week at the hospital, 55 (46.6%) reported. Of the 103 participants were invited to report at a specified location within the community, 98 (95.1%) reported. An overall response rate of 60.4% was attained. Almost 89.7% (226 of 253) of the women performed both self and health personnel sample collection.

Conclusion

The community-based strategy with self-specimen collection and HPV testing holds great potential for increasing women’s participation in cervical cancer screening in Ghana as compared to the hospital based strategy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-017-4631-y) contains supplementary material, which is available to authorized users.

Evaluation of multiple primary and combination screening strategies in postmenopausal women for detection of cervical cancer in China

As China's population ages, the importance of determining prevalence of cervical disease and accurate cervical cancer screening strategies for postmenopausal women is increasing. Seventeen population-based studies were analyzed to determine prevalence of cervical neoplasia in postmenopausal women. All women underwent HPV DNA testing, visual inspection with acetic acid (VIA) and cytology testing. Diagnostic values for primary and combinations screening methods included sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), referral rate and area under curve (AUC) were calculated using directed biopsy or four quadrants biopsy as reference standard. Premenopausal and postmenopausal women had equal HPV infection and cervical neoplasia rates (p > 0.05). HPV DNA testing CIN3+ sensitivity, specificity, PPV, NPV, referral rate and AUC were 97.9% (95% CI: 90.2-99.9%), 84.2% (95% CI: 82.8-85.5%), 9.9% (95% CI: 7.4-12.8%), 100% (95% CI: 99.8-100%), 17.2% (95% CI: 15.9-18.7%), 0.911, respectively. VIA values were 41.7% (95% CI: 28.4-55.9%), 94.5% (95% CI: 93.6-95.3%), 11.8% (95% CI: 7.5-17.3%), 98.9% (95% CI: 98.5-99.3%), 6.2% (95% CI: 5.3-7.1%) and 0.681, respectively. Values for VIA with HPV triage were 39.6% (95% CI: 26.6-53.8%), 99.2% (95% CI: 98.8-99.5%), 45.2% (95% CI: 30.8-60.4%), 98.9% (95% CI: 98.5-99.3%), 1.5% (95% CI: 1.1-2.0%) and 0.694, respectively. VIA and HPV DNA co-test values were 100% (95% CI: 94.0-100%), 79.5% (95% CI: 78.0-81.0%), 8.0% (95% CI: 6.0-10.3%), 100% (95% CI: 99.9-100%), 21.9% (95% CI: 20.4-23.4%) and 0.898, respectively. VIA sensitivity decreases significantly in postmenopausal women compared to premenopausal performance. HPV DNA testing maintains performance between pre- and postmenopausal women and is the most accurate primary modality for screening postmenopausal populations in low resource areas of China.

Web-based instrument to assess skills in visual inspection of the cervix among healthcare providers

OBJECTIVE

To validate a web-based instrument for assessing healthcare providers' skills in visual inspection with acetic acid or Lugol iodine (VIA/VILI) for the diagnosis and management of cervical intraepithelial neoplasia.

METHODS

An observational cross-sectional study enrolled healthcare providers in a web-based assessment of VIA/VILI skills between August and November 2014. Participants participated in a four-module training course, followed by a multiple-choice test with 70 questions based on cervical photographs of HPV-positive women participating in cervical screening. Logistic regression was used to identify relationships between independent variables and success on the test.

RESULTS

Overall, 255 participants completed the test and 99 (38.8%) passed. No correlation was found between age or sex and test performance. Compared with other healthcare workers, physicians (odds ratio [OR] 1.91, 95% confidence interval [CI] 1.01-3.63; P=0.048), and participants with more colposcopy experience (OR 3.62, 95% CI 1.91-6.85; P<0.001) and postgraduate VIA/VILI training (OR 1.95, 95% CI 1.16-3.29; P=0.012) were more likely to pass the test. Participants who repeated the test (31/255 [12.2%]) were five times more likely to succeed on their second repeat (OR 5.89, 95% CI 1.46-23.73; P=0.013).

CONCLUSION

Web-based training for VIA/VILI is feasible and can identify healthcare workers who are proficient in this technique.

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.

Effectiveness of a two-stage strategy with HPV testing followed by visual inspection with acetic acid for cervical cancer screening in a low-income setting

The World Health Organization recently advocated a two-stage strategy with human papillomavirus (HPV) testing followed by visual inspection of the cervix with acetic acid (VIA) as a suitable option for cervical cancer screening. However, its accuracy has never been directly assessed in the context of primary screening. To evaluate effectiveness of HPV testing on self-obtained specimens (self-HPV) followed by VIA (sequential testing) in a low-income setting, we recruited 540 women aged between 30 and 65 years in two Cameroonian periurban areas. Eligible women were counseled about cervical cancer and how to perform self-sampling. HPV positive and a random sample of HPV-negative women were called back for VIA and biopsy. Disease was defined by interpretation of cervical intraepithelial neoplasia Grade 2 or worse (CIN2+). Performances of VIA, self-HPV and sequential testing were determined after adjustment for verification bias. HPV prevalence was 27.0%. VIA positivity was 12.9% and disease prevalence was 5%. Sensitivity and specificity of VIA for CIN2+ were 36.4% [95% confidence interval (CI): 15.2-64.6%] and 90.4% (95% CI: 85.4-93.7%), respectively. Sensitivity of self-HPV [100.0% (95% CI: 79.6-100.0%)] was 66% higher than that of sequential testing [33.3% (95% CI: 15.2-58.3%)]. Meanwhile, specificity of self-HPV [74.5% (95% CI: 70.6-78.1%)] was 22% lower than that of sequential testing [96.7% (95% CI: 94.8-97.9%)]. A two-stage screening strategy with self-HPV followed by VIA improves specificity of cervical cancer screening, but at the cost of an important loss of sensitivity. Ways to improve VIA performance or other tools are needed to increase positive predictive value of HPV testing.

A qualitative assessment of the social cultural factors that influence cervical cancer screening behaviors and the health communication preferences of women in Kumasi, Ghana

Cervical cancer is the leading cause of cancer death among women in Ghana. Despite the availability of cervical cancer screening in healthcare facilities throughout the country, less than 4 % of Ghanaian women seek preventive cervical cancer screenings regularly. There is a lack of culturally relevant cervical cancer education material available in Ghana. The aims of this study were to assess the social cultural factors that influence cervical cancer screening behaviors and the health communication preferences of Ghanaian women. A focus group guide based on the constructs of the PEN-3 model was used to conduct six focus groups that were stratified by educational attainment. Thirty-four women participated in the study. The qualitative data revealed that most participants were not aware of cervical cancer or cervical cancer screening. However, many of the participants were willing to seek screening if they knew more about it. The most common sources of health information were television, radio, friends, and family. And the participants preferred inspirational cervical-cancer-screening messages that would be delivered by a doctor and a cancer survivor.

Accuracy of visual inspection with acetic acid to detect cervical cancer precursors among HIV-infected women in Kenya

Visual inspection with acetic acid (VIA) is becoming a more widely recommended and implemented screening tool for cervical cancer prevention programs in low-resource settings. Many of these settings have a high prevalence of HIV-infected women. We carried out a cross-sectional validation study to define the sensitivity, specificity and predictive values of VIA among HIV-infected women. Women enrolled in HIV care at the Family AIDS Care and Education Services clinic in Kisumu, Kenya, were recruited for participation. All participants underwent VIA followed by colposcopy performed by a second blinded clinician. At colposcopy, lesions suspicious for cervical intraepithelial neoplasia 2 or greater (CIN2+) were biopsied. Disease status was determined by final histopathologic diagnosis in women who underwent biopsies. A satisfactory colposcopy with no lesions was considered a negative result. From October 2010 to June 2012, 1,432 women underwent VIA and colposcopy. A total of 514 (35.7%) women had a positive VIA, and 179 (12.2%) had CIN2+ confirmed by colposcopically directed biopsy. Sensitivity, specificity, positive and negative predictive values of VIA for CIN2+ were 86.6, 71.6, 30.3 and 97.4%, respectively. Specificity, but not sensitivity, increased with older age. Among older women, sensitivity was affected by CD4+ count and use of antiretroviral therapy. Although they are impacted by age and immune status, test characteristics for VIA among HIV-infected women are similar to what has been reported for general populations. Recommendations to use VIA as a screening tool should not vary by HIV status.

Assessment of psychological barriers to cervical cancer screening among women in Kumasi, Ghana using a mixed methods approach

BACKGROUND

Cervical cancer is the leading cause of cancer death among women in Ghana, West Africa. The cervical cancer mortality rate in Ghana is more than three times the global cervical cancer mortality rate. Pap tests and visual inspection with acetic acid wash are widely available throughout Ghana, yet less that 3% of Ghanaian women get a cervical cancer screening at regular intervals.

OBJECTIVE

This exploratory study was to identify psychological barriers to cervical cancer screening among Ghanaian women with and without cancer using a mixed methods approach.

METHODS

Semi-structured interviews were conducted with 49 Ghanaian women with cancer and 171 Ghanaian women who did not have cancer.

RESULTS

The results of the quantitative analysis indicated that cancer patients where not more likely to have greater knowledge of cancer signs and symptoms than women without cancer. Analysis of the qualitative data revealed several psychological barriers to cervical cancer screening including, common myths about cervical cancer, misconceptions about cervical cancer screening, the lack of spousal support for screening, cultural taboos regarding the gender of healthcare providers, and the stigmatization of women with cervical cancer.

CONCLUSION

The results of this study can be used to inform the development of culturally relevant cervical cancer education interventions aimed at addressing the psychological barriers to cervical cancer screening perceived by Ghanaian women.

A modified Latent Class Model assessment of human papillomavirus-based screening tests for cervical lesions in women with atypical glandular cells: a Gynecologic Oncology Group study

PURPOSE

In the absence of gold standard diagnoses, we estimate age-specific false-positive and false-negative prediction rates of HPV-, cytology-, and histology-based tests for significant cervical lesions (SCL) in US women with AGC-NOS Pap smear diagnoses.

METHODS

Modified Latent Class Model (LCM) analyses, with prevalence of SCL modeled as a function of age, were applied to GOG-0171 study data (n = 122). The accuracies of several HPV-based tests, including Hybrid Capture II high-risk HPV (HC2 H-HPV); carbonic anhydrase IX (CA-IX); and invasive histological diagnosis, were compared. 1-PPV and 1-NPV were written as functions of sensitivity, specificity, and prevalence to obtain age-specific false-positive and false-negative rates.

RESULTS

The histology-based test was nearly perfect (sensitivity = 1.00, CI = 0.98-1.00; specificity = 0.99, CI = 0.96-1.00). Otherwise, HC2 H-HPV performed best (sensitivity = 1.00, CI = 1.00-1.00; specificity = 0.87, CI = 0.79-0.94). The false-positive detection rates (1-PPV) for HC2 H-HPV were high (>17 %) at each age, while those of the histological diagnoses were low (<5 % at ages ≤60 and <17 % overall ages). False-negative prediction rates (1-NPV) for HC2 H-HPV were <0.11 % at each age and were uniformly lower than those of other tests, including the histology-based test (<0.25 %). CA-IX together with HC2 H-HPV did not improve performance.

CONCLUSIONS

Women with negative HC2 H-HPV can safely forego invasive treatment (i.e., cone or LEEP biopsy, hysterectomy) in favor of observational follow-up. Additional biomarkers must be found for use in combination with HC2 H-HPV to reduce false-positive rates. This novel application of a modified LCM exemplifies methods for potential use in future cancer screening studies when gold standard diagnoses are not available.

How to evaluate emerging technologies in cervical cancer screening?

Excellent recommendations exist for studying therapeutic and diagnostic questions. We observe that good guidelines on assessment of evidence for screening questions are currently lacking. Guidelines for diagnostic research (STARD), involving systematic application of the reference test (gold standard) to all subjects of large study populations, are not pertinent in situations of screening for disease that is currently not yet present. A five-step framework is proposed for assessing the potential use of a biomarker as a screening tool for cervical cancer: i) correlation studies establishing a trend between the rate of biomarker expression and severity of neoplasia; ii) diagnostic studies in a clinical setting where all women are submitted to verification by the reference standard; iii) biobank-based studies with assessment in archived cytology samples of the biomarker in cervical cancer cases and controls; iv) prospective cohort studies with baseline assessment of the biomarker and monitoring of disease; v) randomised intervention trials aiming to observe reduced incidence of cancer (or its surrogate, severe dysplasia) in the experimental arm at subsequent screening rounds. The 5-phases framework should guide researchers and test developers in planning assessment of new biomarkers and protect clinicians and stakeholders against premature claims for insufficiently evaluated products.

A package of primary health care services for comprehensive family-centred HIV/AIDS care and treatment programs in low-income settings

Particularly in resource-limited settings, HIV/AIDS is a family concern. Separate services for children and adults may make accessing care more difficult for families than services where family members can be cared for together. Implicit in comprehensive, family-centred approaches to care are the broader notions of longitudinal primary care and linkages to other services, including those based in communities. As highly-active antiretroviral therapy becomes more available, and the direct burden of HIV-associated morbidity diminishes, HIV-infected individuals require primary care that goes beyond exclusive management of HIV and related conditions, including preventive services and the management of common medical issues. The prevention of tuberculosis, diarrhoea, and, in endemic regions, malaria; the addressing of debilitating depression; cervical screening; and the management of chronic cardiovascular disease and its risk factors are all of benefit to patients accessing HIV/AIDS care. Packaging such services is an effective means both of standardizing care within a program and of ensuring patients receives a full roster of available interventions. As family-centred care models develop in resource-limited settings, the availability of evidence-based service packages such as presented here will help program designers prioritize available human and materiel resources toward those interventions that improve patients' global health and well being.

Pooled analysis of the accuracy of five cervical cancer screening tests assessed in eleven studies in Africa and India

Cervical cancer is the main cancer among women in sub-Saharan Africa, India and other parts of the developing world. Evaluation of screening performance of effective, feasible and affordable early detection and management methods is a public health priority. Five screening methods, naked eye visual inspection of the cervix uteri after application of diluted acetic acid (VIA), or Lugol's iodine (VILI) or with a magnifying device (VIAM), the Pap smear and human papillomavirus testing with the high-risk probe of the Hybrid Capture-2 assay (HC2), were evaluated in 11 studies in India and Africa. More than 58,000 women, aged 25-64 years, were tested with 2-5 screening tests and outcome verification was done on all women independent of the screen test results. The outcome was presence or absence of cervical intraepithelial neoplasia (CIN) of different degrees or invasive cervical cancer. Verification was based on colposcopy and histological interpretation of colposcopy-directed biopsies. Negative colposcopy was accepted as a truly negative outcome. VIA showed a sensitivity of 79% (95% CI 73-85%) and 83% (95% CI 77-89%), and a specificity of 85% (95% CI 81-89%) and 84% (95% CI 80-88%) for the outcomes CIN2+ or CIN3+, respectively. VILI was on average 10% more sensitive and equally specific. VIAM showed similar results as VIA. The Pap smear showed lowest sensitivity, even at the lowest cutoff of atypical squamous cells of undetermined significance (57%; 95% CI 38-76%) for CIN2+ but the specificity was rather high (93%; 95% CI 89-97%). The HC2-assay showed a sensitivity for CIN2+ of 62% (95% CI 56-68%) and a specificity of 94% (95% CI 92-95%). Substantial interstudy variation was observed in the accuracy of the visual screening methods. Accuracy of visual methods and cytology increased over time, whereas performance of HC2 was constant. Results of visual tests and colposcopy were highly correlated. This study was the largest ever done that evaluates the cross-sectional accuracy of screening tests for cervical cancer precursors in developing countries. The merit of the study was that all screened subjects were submitted to confirmatory investigations avoiding to verification bias. A major finding was the consistently higher sensitivity but equal specificity of VILI compared with VIA. Nevertheless, some caution is warranted in the interpretation of observed accuracy measures, since a certain degree of gold standard misclassification cannot be excluded. Because of the correlation between visual screening tests and colposcopy and a certain degree of over-diagnosis of apparent CIN2+ by study pathologists, it is possible that both sensitivity and specificity of VIA and VILI were overestimated. Gold standard verification error could also explain the surprisingly low sensitivity of HC2, which contrasts with findings from other studies.