Accuracy of conventional cytology: results from a multicentre screening study in India

Diagnostic accuracy for alternative cervical cancer screening strategies: A systematic review and meta-analysis

We performed a systematic review and meta-analysis to evaluate the accuracy of screening cervical cancer tests as alternative standalone methods. The combined estimates of sensitivity of visual inspection with acetic acid, visual inspection with lugol's iodine, conventional pap smear, liquid-based cytology, High risk HPV testing by clinician, High risk HPV testing by self- sampling, cervicography were 64%, 80%, 55%, 70%, 70% and 67% respectively; the combine values of specificity of these screening strategies were 88%, 88%, 96%, 59%, 94%, and 95% respectively. Our findings draw attention to an attractive opinion to facilitate the collection of specimens for DNA HPV by patients in settings where they don't have access to a regular screening programs.

Deep learning based cervical screening by the cross-modal integration of colposcopy, cytology, and HPV test

PURPOSE

To develop and evaluate the colposcopy based deep learning model using all kinds of cervical images for cervical screening, and investigate the synergetic benefits of the colposcopy, the cytology test, and the HPV test for improving cervical screening performance.

METHODS

This study consisted of 2160 women who underwent cervical screening, there were 442 cases with the histopathological confirmed high-grade squamous intraepithelial lesion (HSIL) or cancer, and the remained 1718 women were controls. Three kinds of cervical images were acquired from colposcopy including the saline image of cervix after saline irrigation, the acetic acid image of cervix after applying acetic acid solution, and the iodine image of cervix after applying Lugol's iodine solution. Each kind of image was used to build a single-image based deep learning model by the VGG-16 convolutional neural network, respectively. A multiple-images based deep learning model was built using multivariable logistic regression (MLR) by combining the single-image based models. The performance of the visual inspection was also obtained. The results of the cytology test and HPV test were used to build a Cytology-HPV joint diagnostic model by MLR. Finally, a cross-modal integrated model was built using MLR by combining the multiple-images based deep learning model, the cytology test results, and the HPV test results. The performances of models were tested in an independent test set using the area under the receiver operating characteristic curve (AUC).

RESULTS

The saline image, acetic acid image, and iodine image based deep learning models had AUC of 0.760, 0.791, and 0.840. The multiple-images based deep learning model achieved an improved AUC of 0.845. The AUC of the visual inspection was 0.751. The Cytology-HPV joint diagnostic model had an AUC of 0.837, which was higher than the cytology test (AUC = 0.749) and the HPV test (AUC = 0.742). The cross-modal integrated model achieved the best performance with AUC of 0.921.

CONCLUSIONS

Combining all kinds of cervical images were benefit for improving the performance of the colposcopy based deep learning model, and more accurate cervical screening could be achieved by incorporating the colposcopy based deep learning model, the cytology test results, and the HPV test results.

Cervical Cancer Care Continuum in South India: Evidence from a Community-based Screening Program

In India, cervical cancer screening is conducted at various levels; however, after screening, the adherence to the cancer care continuum is barely understood. This study evaluated a community-based cancer screening program conducted in a rural setting (Tirunelveli and Tuticorin districts) in South India and reviewed the completion of care continuum. In this longitudinal descriptive study involving secondary data collection, data from the case records of 2192 women who were consecutively screened between March 2015 and May 2016 were included. All women underwent conventional cytology-based screening (Pap smear) and Visual Inspection with Acetic Acid (VIA). Those for whom either test was positive were referred for histopathological confirmation. Patients with confirmed precancerous conditions and unsatisfactory Pap smears were referred for further management. In total, 2192 women were screened [age range, 17-69 years; mean (standard deviation), 39.2 (8.5)]. Common symptom and sign were white discharge per vaginum (34.9%) and cervical erosion (34.4%), respectively. The VIA was positive for 24% (523/2178; 14 women did not cooperate for VIA) and 113 (5.1%) had epithelial cell abnormality in the Pap smear test. Per histopathology findings, one woman had non-keratinizing squamous cell carcinoma. Seven, three, and four had cervical intraepithelial neoplasia I, II and III, respectively. Of 2192, 807 were eligible for referral (597 had positive results on either Pap or VIA). Among the 807 women referred, only 74 (9.2%) women visited the referral center. The follow-up rate was very poor accounting to fragmentation of care continuum. The success of the screening program depends on the completion of the care continuum.

Program organization rather than choice of test determines success of cervical cancer screening: Case studies from Bangladesh and India

The call for elimination of cervical cancer as a public health problem by the World Health Organization has led to intense focus on the burden of disease, available resources, and the possibility of introducing efficient systems for screening and treatment that allow effective cancer control in limited-resource settings. Presently, the focus is on the introduction of rapid, technologically less-demanding, affordable HPV testing. However, until such tests become widely available, the momentum that has been gained using visual inspection with acetic acid (VIA) should not be lost. Countries with limited resources and a heavy burden of cervical cancer, such as Bangladesh and India, introduced and scaled up VIA-based programs with varying degrees of programmatic organization and performance. Despite its limitations, VIA's simplicity and affordability has allowed these countries to build infrastructure, increase numbers of trained healthcare personnel, and develop a system of multilevel coordination within the health system. Such efforts will have long-term advantages provided that countries have access to an appropriate HPV test and build on their efforts to improve program organization through a strengthened health system, translating lessons learned in program implementation, logistics, and compliance with the new paradigm.

The value of microendoscopy in the diagnosis of cervical precancerous lesions and cervical microinvasive carcinoma

PURPOSE

Cervical cancer is still one of the main causes of death in females. Conventional diagnostic tools such as colposcopy are still unsatisfactory, so accurate diagnostic tools for cervical diseases are needed. Therefore, the purpose of this study was to perform a clinical study to evaluate the value of microendoscopic imaging systems in the diagnosis of cervical precancerous lesions and cervical microinvasive carcinoma (MIC).

METHODS

Totally 106 patients ranging in age from 23 to 67 years were recruited. All patients had abnormal thin-layer cytology (TCT) results (≥ low-grade squamous intraepithelial lesions) and high-risk human papillomavirus (HPV) positivity. Each patient was first subjected to ordinary colposcopy, followed by microendoscopy and biopsy. All results of the colposcopy and microendoscopy images were compared to the histopathological diagnosis.

RESULTS

Characteristics of pathological blood vessels were easily distinguished by microendoscopy compared with ordinary colposcopy. The diagnostic agreement rate of microendoscopy with the pathological diagnosis was higher (95.3%) than that of ordinary colposcopy (37.7%) (weighted kappa = 0.863, P < .01). When diagnosing HSIL and more advanced disease, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the microendoscopic diagnosis were significantly higher than those of ordinary colposcopy (97.6 and 38.1%), (95.5 and 63.6%), (98.8 and 80.0%), (91.3 and 21.2%) and (97.7 and 43.4%), respectively.

CONCLUSION

This study shows that microendoscopy has important value in the diagnosis of cervical lesions which can provide real-time diagnosis in vivo without staining, particularly for lesions that are not sensitive to acetic acid staining.

The Positive Predictive Value of High-Grade Squamous Intraepithelial Lesion on Cytology for the Histological Diagnosis of Cervical Intraepithelial Neoplasia 2 or Higher: A Systematic Review

Cervical cancer is a major worldwide health problem. Therefore, regular cervical screening in order to make an early diagnosis can help to prevent cervical cancer, through identifying and treating preinvasive cervical lesions. The aim of this review is to evaluate the correlation between the cytological screening result and the final gold standard histological outcome in the diagnosis of cervical lesions. More specifically, the correlation between high-grade intraepithelial lesion (HSIL) on cytology and histological cervical intraepithelial neoplasia grade 2 or higher (CIN2+) was intended, by calculating the positive predictive value (PPV). PPV is an important value from a clinical point of view. An electronic search was carried out in the electronic databases MEDLINE (through PubMed) and the Cochrane Library (last searched beginning of December 2017), supplemented with the related article feature in PubMed and snowballing. Article selection (predefined inclusion and exclusion criteria) and data extraction were evaluated by two independent reviewers (N.K. and A.V.L.). After identifying 1,146 articles, 27 articles were finally included in this systematic review, representing 28,783 cytological HSIL diagnoses in total. The PPV of HSIL was 77.5% (range: 45.4-95.2%) for the histological diagnosis of CIN2+ and 55.4% (range: 36.4-67.6%) for the diagnosis of CIN3+. In this systematic review, 77.5% of the HSIL-positive women eventually had a CIN2+ diagnosis. The diagnostic value of a cytological HSIL result (conventional or liquid-based cytology) in the diagnosis of CIN2+ lesions is good, but a combination of tests could raise this value.

Cancer screening and early diagnosis in low and middle income countries : Current situation and future perspectives

Limited health system capacities and competing health priorities in low and middle income countries (LMICs) necessitate a pragmatic approach to population-based cancer screening. Thus, the challenges faced by LMICs to implement a 'western' model of screening for common cancers and the possible means to overcome these challenges are presented. Breast cancer is the number one cancer with a rising trend in the majority of LMICs. Implementation of mass-scale mammography-based screening is not feasible and sustainable in most of them. While some LMICs have introduced breast cancer screening based on clinical breast examination (CBE), the programs need to be of appropriate quality. All LMICs should improve the capacity for early diagnosis of breast cancer along with other common cancers through community education, training of frontline health workers, facilitating prompt referrals and improving the infrastructure for cancer diagnosis and treatment. Resources permitting, the LMICs with high burden of cervical cancer may consider human papillomavirus (HPV) detection-based screening; a simple low-cost alternative is visual inspection with acetic acid (VIA). Regardless of the choice, a strong linkage should be established between screening and treatment with implementation of robust quality assurance. The few LMICs with a rising trend of colorectal cancers and adequate resources may implement demonstration projects to screen with fecal immunochemical tests (FIT). Oral cancer screening of habitual tobacco and/or alcohol users using oral visual examination (OVE) may be implemented in countries with high burden of the cancer, but primary prevention (i.e., tobacco/alcohol cessation) should be prioritized. Screenings for other cancers are not recommended for LMICs.

Optimizing secondary prevention of cervical cancer: Recent advances and future challenges

Although human papillomavirus (HPV) vaccines offer enormous promise for the ultimate control and possible elimination of cervical cancer, barriers to uptake and coverage of the vaccine both in high- and low/middle-income settings mean that advances in secondary prevention continue to be essential to prevent unnecessary deaths and suffering from cervical cancer for decades to come. While cytology (the Pap smear) has reduced cervical cancer incidence and prevalence in jurisdictions where it has been systematically implemented in population-based programs-mainly in high-income settings-limitations inherent to this method, and to program delivery, leave many women still vulnerable to cervical cancer. Recent evidence has confirmed that screening based on HPV testing prevents more invasive cervical cancer and precancerous lesions, and offers innovative options such as self-collection of specimens to improve screening uptake broadly. In this paper, we review key advances, future opportunities, and ongoing challenges for secondary prevention of cervical cancer using HPV-based testing.

Systematic Review and Meta-Analysis of Individual Patient Data to Assess the Sensitivity of Cervical Cytology for Diagnosis of Cervical Cancer in Low- and Middle-Income Countries

PURPOSE

To assess the sensitivity of cervical cytology to cancer by pooling individual patient cytology results from cancers diagnosed in studies that assessed cervical screening in low- and middle-income countries.

METHODS

Two authors reviewed studies identified through PubMed and Embase databases. We included studies that reported cervical cytology in which at least one woman was diagnosed with cervical cancer and in which abnormal cytology results were investigated at colposcopy and through a histologic sample (if appropriate). When cytology results were not reported in the manuscript, authors were contacted. Stratified analyses and meta-regression were performed to assess sources of heterogeneity between studies.

RESULTS

We included 717 cancers from 23 studies. The pooled sensitivity of cytology to cancer at a cutoff of a high-grade squamous intraepithelial lesion (HSIL) or worse was 79.4% (95% CI, 67.7% to 86.0%). Results from stratified analyses did not differ significantly, except among studies that recruited symptomatic women or women referred because of abnormal cytology, when the sensitivity of cytology was much higher (95.9%; 95% CI, 86.5% to 99.9%). The cutoff of an HSIL or worse detected 85% of the cancers that would have been detected at a cutoff of atypical squamous cells of undetermined significance or worse (relative sensitivity, 85.2%; 95% CI, 80.7% to 89.7%).

CONCLUSION

Cytology at a high cutoff could be an excellent tool for targeted screening of populations at high risk of cervical cancer with a view to diagnose cancer at an earlier stage.

Cytology versus HPV testing for cervical cancer screening in the general population

BACKGROUND

Cervical cancer screening has traditionally been based on cervical cytology. Given the aetiological relationship between human papillomavirus (HPV) infection and cervical carcinogenesis, HPV testing has been proposed as an alternative screening test.

OBJECTIVES

To determine the diagnostic accuracy of HPV testing for detecting histologically confirmed cervical intraepithelial neoplasias (CIN) of grade 2 or worse (CIN 2+), including adenocarcinoma in situ, in women participating in primary cervical cancer screening; and how it compares to the accuracy of cytological testing (liquid-based and conventional) at various thresholds.

SEARCH METHODS

We performed a systematic literature search of articles in MEDLINE and Embase (1992 to November 2015) containing quantitative data and handsearched the reference lists of retrieved articles.

SELECTION CRITERIA

We included comparative test accuracy studies if all women received both HPV testing and cervical cytology followed by verification of the disease status with the reference standard, if positive for at least one screening test. The studies had to include women participating in a cervical cancer screening programme who were not being followed up for previous cytological abnormalities.

DATA COLLECTION AND ANALYSIS

We completed a 2 x 2 table with the number of true positives (TP), false positives (FP), true negatives (TN), and false negatives for each screening test (HPV test and cytology) used in each study. We calculated the absolute and relative sensitivities and the specificities of the tests for the detection of CIN 2+ and CIN 3+ at various thresholds and computed sensitivity (TP/(TP + TN) and specificity (TN/ (TN + FP) for each test separately. Relative sensitivity and specificity of one test compared to another test were defined as sensitivity of test-1 over sensitivity of test-2 and specificity of test-1 over specificity of test-2, respectively. To assess bias in the studies, we used the Quality Assessment of Diagnostic test Accuracy Studies (QUADAS) tool. We used a bivariate random-effects model for computing pooled accuracy estimates. This model takes into account the within- and between-study variability and the intrinsic correlation between sensitivity and specificity.

MAIN RESULTS

We included a total of 40 studies in the review, with more than 140,000 women aged between 20 and 70 years old. Many studies were at low risk of bias. There were a sufficient number of included studies with adequate methodology to perform the following test comparisons: hybrid capture 2 (HC2) (1 pg/mL threshold) versus conventional cytology (CC) (atypical squamous cells of undetermined significance (ASCUS)+ and low-grade squamous intraepithelial lesions (LSIL)+ thresholds) or liquid-based cytology (LBC) (ASCUS+ and LSIL+ thresholds), other high-risk HPV tests versus conventional cytology (ASCUS+ and LSIL+ thresholds) or LBC (ASCUS+ and LSIL+ thresholds). For CIN 2+, pooled sensitivity estimates for HC2, CC and LBC (ASCUS+) were 89.9%, 62.5% and 72.9%, respectively, and pooled specificity estimates were 89.9%, 96.6%, and 90.3%, respectively. The results did not differ by age of women (less than or greater than 30 years old), or in studies with verification bias. Accuracy of HC2 was, however, greater in European countries compared to other countries. The results for the sensitivity of the tests were heterogeneous ranging from 52% to 94% for LBC, and 61% to 100% for HC2. Overall, the quality of the evidence for the sensitivity of the tests was moderate, and high for the specificity.The relative sensitivity of HC2 versus CC for CIN 2+ was 1.52 (95% CI: 1.24 to 1.86) and the relative specificity 0.94 (95% CI: 0.92 to 0.96), and versus LBC for CIN 2+ was 1.18 (95% CI: 1.10 to 1.26) and the relative specificity 0.96 (95% CI: 0.95 to 0.97). The relative sensitivity of HC2 versus CC for CIN 3+ was 1.46 (95% CI: 1.12 to 1.91) and the relative specificity 0.95 (95% CI: 0.93 to 0.97). The relative sensitivity of HC2 versus LBC for CIN 3+ was 1.17 (95% CI: 1.07 to 1.28) and the relative specificity 0.96 (95% CI: 0.95 to 0.97).

AUTHORS' CONCLUSIONS

Whilst HPV tests are less likely to miss cases of CIN 2+ and CIN 3+, these tests do lead to more unnecessary referrals. However, a negative HPV test is more reassuring than a negative cytological test, as the cytological test has a greater chance of being falsely negative, which could lead to delays in receiving the appropriate treatment. Evidence from prospective longitudinal studies is needed to establish the relative clinical implications of these tests.

Comparison of the Cervex-Brush® Combi and the Cytobrush+Ayres Spatula Combination for Cervical Sampling in Liquid-Based Cytology

OBJECTIVES

To compare the performance of two cervical collection devices (Cytobrush+Ayres spatula and Cervex-Brush® Combi) for cellular sampling, transformation zone representation and accuracy in diagnosing cervical intraepithelial neoplasia (CIN) 2+.

METHODS

Cervical samples were collected from patients referred to the colposcopy unit of the Barretos Cancer Hospital between September 2013 and October 2014 using one of the two sampling devices. Additionally, colposcopy was performed with or without cervical biopsy and/or endocervical curettage.

RESULTS

Biopsy was performed in 670 of the 1,235 patients submitted to colposcopy (54.2%). The Cervex-Brush® Combi was more effective than the Cytobrush with respect to endocervical cells sampling (82.7% versus 74.6%; p = 0.001). Sensitivity was also higher with the Cervex-Brush® Combi (48.6% versus 33.9%; p = 0.023) for predicting CIN2+ when high-grade squamous intraepithelial lesions were detected at cytology.

CONCLUSIONS

Cervex-Brush® Combi was more effective than Cytobrush+Ayres Spatula for endocervical cells sampling and also had a slightly higher accuracy in predicting histologically CIN2+ lesions in patients with diagnosis of HSIL in cytology.

Public awareness of human papillomavirus

Objectives

The main objective of this study was to review the evidence relating to the level of awareness of human papillomavirus (HPV) in the general population and the implications for the potential introduction of HPV vaccination and HPV testing as part of screening.

Methods

PubMed search performed on terms: ‘HPV education’, ‘HPV awareness’ ‘Genital Warts Awareness’

Results

Public awareness of HPV is generally very low, particularly with respect to its relation to abnormal smears and cervical cancer although knowledge levels vary to some extent according to sociodemographic characteristics. There is also much confusion around which types cause warts and the types that can cause cancer. The sexually transmissible nature of the infection is of major concern and confusion to women.

Conclusions

Due to the lack of current awareness of HPV, significant education initiatives will be necessary should HPV vaccination and/or HPV testing be introduced. Organized edification of healthcare workers and the media, who constitute the two most preferred sources of information, will be crucial.

Accuracy of Combined Visual Inspection with Acetic Acid and Cervical Cytology Testing as a Primary Screening Tool for Cervical Cancer: a Systematic Review and Meta-Analysis

BACKGROUND

The performance of combined testing visual inspection with acetic acid (VIA) and cervical cytology tests might differ from one setting to another. The average estimate of the testing accuracy across studies is informative, but no meta-analysis has been carried out to assess this combined method.

OBJECTIVE

The objective of this study was to estimate the average sensitivity and specificity of the combined VIA and cervical cytology tests for the detection of cervical precancerous lesions.

MATERIALS AND METHODS

We conducted a systematic review and a meta-analysis, according to the Cochrane Handbook for Systematic Review of Diagnostic Test Accuracy. We considered two cases. In the either-positive result case, a positive result implies positivity in at least one of the tests. A negative result implies negativity in both tests. In the both-positive case, a positive result implies having both tests positive. Eligible studies were identified using Pubmed, Embase, Website of Science, CINHAL and COCRANE databases. True positive, false positive, false negative and true negative values were extracted. Estimates of sensitivity and specificity, positive and negative likelihood (LR) and diagnostic odds ratios (DOR) were pooled using a hierarchical random effect model. Hierarchical summary receiver operating characteristics (HSROC) were generated and heterogeneity was verified through covariates potentially influencing the diagnostic odds ratio.

FINDINGS

Nine studies fulfilled inclusion criteria and were included in the analysis. Pooled estimates of the sensitivities of the combined tests in either-positive and both-positive cases were 0.87 (95% CI: 0.83-0.90) and 0.38 (95% CI: 0.29-0.48), respectively. Corresponding specificities were 0.79 (95% CI: 0.63-0.89) and 0.98 (95% CI: 0.96-0.99) respectively. The DORs of the combined tests in either-positive or both-positive result cases were 27.7 (95% CI: 12.5-61.5) and 52 (95% CI: 22.1-122.2), respectively. When including only articles without partial verification bias and also a high-grade cervical intraepithelial neoplasia as a threshold of the disease, DOR of combined test in both-positive result cases remained the highest. However, DORs decreased to 12.1 (95% CI: 6.05-24.1) and 13.8 (95% CI: 7.92-23.9) in studies without partial verification bias for the combined tests in the either-positive and both-positive result cases, respectively. The screener, the place of study and the size of the population significantly influenced the DOR of combined tests in the both-positive result case in restriction analyses that considered only articles with CIN2+ as disease threshold.

CONCLUSIONS

The combined test in the either-positive result case has a high sensitivity, but a low specificity. These results suggest that the combined test should be considered in developing countries as a primary screening test if facilities exist to confirm, through colposcopy and biopsy, a positive result.

Evaluation of stationary colposcope and the Gynocular, by the Swede score systematic colposcopic system in VIA positive women: a crossover randomized trial

Objective

This study aimed to evaluate cervical lesions by the Swede coloscopy system, histologic finding, liquid-based cytology, and human papillomavirus (HPV) in women who resulted positive for visual inspection of the cervix with acetic acid (VIA) by using a pocket-sized battery-driven colposcope, the Gynocular (Gynius AB, Sweden).

Methods

This study was a crossover, randomized clinical trial at the colposcopy clinic of Bangabandhu Sheikh Mujib Medical University in Dhaka, Bangladesh, with 540 VIA-positive women. Swede scores were obtained by the Gynocular and stationary colposcope, as well as samples for liquid-based cytology, HPV, and cervical biopsies. The Swede scores were compared against the histologic diagnosis and used as criterion standard. The percentage agreement and the κ statistic for the Gynocular and standard colposcope were also calculated.

Results

The Gynocular and stationary colposcope showed high agreement in Swede scores with a κ statistic of 0.998, P value of less than 0.0001, and no difference in detecting cervical lesions in biopsy. Biopsy detected cervical intraepithelial neoplasia (CIN) 2+ (CIN2, CIN3, and invasive cancer) in 38 (7%) of the women, whereas liquid-based cytology detected CIN2+ in 13 (2.5%) of the women. Forty-four (8.6%) women who were tested resulted positive for HPV; 20 (3.9%) women had HPV-16, 2 (0.4%) had HPV-18, and 22 (4.3%) had other high-risk HPV.

Conclusions

Our study showed that few VIA-positive women had CIN2+ lesions or HPV infection. Colposcopy by Swede score identified significantly more CIN2+ lesions than liquid-based cytology and could offer a more accurate screening and selection for immediate treatment of cervical lesions in low-resource settings.

Application of bethesda system for cervical cytology in unhealthy cervix

INTRODUCTION

Women presenting with unhealthy cervix needs to be evaluated with Papanicolaou (Pap) smear for epithelial abnormalities.

AIM

To detect epithelial cell abnormalities in unhealthy cervix using the 2001Bethesda system of reporting for cervical cytology and to confirm histopathologicaly the findings of Pap smear.

MATERIALS AND METHODS

In this study, 125 women with clinical diagnosis of unhealthy cervix underwent conventional cytology. Cervical biopsies were taken from abnormal areas seen on colposcopy and sent for histopathology.

RESULTS

Out of 125 Pap smears, 122 were satisfactory for evaluation (19 normal, 86 negative for intraepithelial lesion or malignancy and 17 with epithelial cell abnormality) and 3 were unsatisfactory (one hemorrhagic and two severe inflammation). Out of 17 (13.60%) cases with epithelial cell abnormality, ASC-US was seen in 6 (4.80%), LSIL in 7 (5.60%), HSIL in 1 (0.80%), squamous cell carcinoma in 1 (0.80%), AGC endocervical in 1 (0.80%) and adenocarcinoma in 1 (0.80%) patients. Cervical biopsy was taken in 67 women. Diagnostic accuracy of Pap smear for preinvasive and invasive disease was 81.15% with overall sensitivity and specificity 78.57% and 88.67% respectively and predictive value of 64.71%.

CONCLUSION

Women with clinical diagnosis of unhealthy cervix should be evaluated by cytology to detect any premalignant or malignant lesions. The Bethesda system for cervical cytology reporting should be used universally as it will give a standardized interpretation.

Optimizing technology for cervical cancer screening in high-resource settings

Although historically successful in reducing the burden of cervical cancer, Papanicolaou (Pap) testing faces numerous limitations. A growing body of evidence suggests that modern screening practice will benefit from primary screening for high-risk human papillomavirus (HPV) infection, the causative agent of cervical cancer. Molecular tests detecting the presence of HPV nucleic acids consistently demonstrate high sensitivity relative to Pap testing, and provide reliable, dichotomous results. Pap cytology is ideally suited to triage HPV-positive cases owing to its high test specificity, and the accuracy of cytological readings will be maximized in high-prevalence conditions. This algorithm of primary HPV testing with Pap triage has been shown to maintain the high sensitivity of HPV testing without compromising Pap cytology's strong ability to rule out falsely positive diagnoses. Given the anticipated decline of high-risk HPV-16 and -18 infections in the emergent post-HPV vaccination era, highly sensitive primary HPV testing is especially warranted. Novel screening technologies that identify HPV viral gene expression continue to emerge and seek to complement current HPV testing by identifying those women who may be at risk of progressive disease. How to best incorporate these new technologies into clinical practice presents our next great challenge. Implementation of novel algorithms for cervical screening is not a trivial task. Avoidance of exceedingly complex screening algorithms is an important priority.

Human papillomavirus and other genital infections in indigenous women from Paraguay: a cross-sectional analytical study

Background

The incidence of cervical cancer in Paraguay is among the highest in the world, with the human papillomavirus (HPV) being a necessary factor for cervical cancer. Knowledge about HPV infection among indigenous women is limited. This cross-sectional study analyzed the frequency of HPV and other genital infections in indigenous Paraguayan women of the Department of Presidente Hayes.

Methods

This study included 181 sexually active women without cervical lesions. They belonged to the following ethnicities: Maká (n = 40); Nivaclé (n = 23); Sanapaná (n = 33); Enxet Sur (n = 51) and Toba-Qom (n = 34). The detection of HPV and other gynecological infectious microorganisms was performed by either molecular methods (for Mycoplasma hominis, Ureaplasma urealyticum, Chlamydia trachomatis), gram staining and/or culture (for Gardnerella vaginalis, Candida sp, Trichomonas vaginalis, Neisseria gonorrhoeae), serological methods (for Treponema pallidum, human immunodeficiency virus [HIV]) or cytology (cervical inflammation).

Results

A high prevalence (41.4%) of women positive for at least one sexually transmitted infection (STI) was found (23.2% any-type HPV, 11.6% T pallidum, 10.5% T vaginalis, 9.9% C trachomatis and 0.6% HIV) with 12.2% having more than one STI. HPV infection was the most frequent, with 16.1% of women positive for high-risk HPV types. There was a statistically significant association observed between any-type HPV and C trachomatis (p = 0.004), which indicates that the detection of one of these agents should suggest the presence of the other. There was no association between any-type HPV and other genital infections or cervical inflammation, suggesting that other mechanism could exist to favor infection with the virus.

Conclusion

This multidisciplinary work suggests that STIs are frequent, making it necessary to implement control measures and improve diagnosis in order to increase the number of cases detected, especially in populations with poor access to health centers.

Cervical cancer screening and prevention in low-resource settings

Cervical cancer is both preventable and curable, yet it remains one of the leading causes of mortality in women worldwide. Approximately 88% of cervical cancer cases are diagnosed in low-resource countries, yet very few resources are allocated to prevention and treatment programs. In fact, it is estimated that only 5% of women in low-resources countries are screened appropriately for cervical cancer. Cytology-based programs are not feasible because of lack of healthcare infrastructure and cost, thus alternative methods of cancer screening, such as visual inspection with acetic acid and HPV-DNA testing, have been intensively studied and are reviewed in this article.

Evidence-based screening, early diagnosis and treatment strategy of cervical cancer for national policy in low- resource countries: example of India

Cervical cancer remains the most frequent cancer in women from the developing world. More than 88% of deaths occur in low-income countries, and it is predicted to climb to 91.5% by 2030. Although Pap-based screening programmes have shown to be effective in reducing the disease burden in high-resource countries, implementation and sustention of cytology-based programmes is quite challenging in low-resource settings. The present paper reviews evidence-based alternatives of screening methods, triaging algorithm, treatment of cervical precancerous lesions, and age-group at screening appropriate for low-income countries. Evidence shows that visual inspection methods using diluted acid acetic or Lugol's iodine, and HPV-DNA testing are more sensitive tests than the Pap-smear screening test. Visual inspection allows an immediate result and, when appropriate, may be immediately followed by cryotherapy, the so called "screen-and-treat" approach, achieved in a single visit, by trained nurses and midwives. Examples of cervical cancer prevention programmes in India and selected low-income countries are given.

Molecular Basis for Advances in Cervical Screening

Human papillomaviruses (HPVs) cause cervical lesions, which can, in some instances, progress to high-grade neoplasia and cancer. Around half a million cases of cervical cancer occur each year, with most occurring in developing countries where cervical cancer is a major cause of cancer-related death. The reduction in cervical cancer incidence in developed countries is largely attributed to the introduction of cervical screening. Cervical screening currently depends on the identification by cytology of abnormalities in cells taken from the surface of the cervix. The standard Pap test was developed >50 years ago, and despite modifications, still forms the basis of the test currently in use in most routine screening laboratories. Advances in our understanding of the molecular mechanisms that lead to the development of cervical cancer have been slow to impact on screening, despite the relatively high false-negative rates that can be associated with the conventional Pap smear. Improvements in screening strategies fall into a number of categories. Methods that improve cell presentation and attempt to eliminate artefacts/obscuring debris can be combined with image analysis systems in order to enhance diagnostic accuracy. Such approaches still rely on cytological evaluation and do not incorporate advances in our knowledge of how HPV causes cancer. By contrast, markers of virus infection or cell cycle entry, particularly those that offer some degree of prognostic significance, may be able to highlight abnormal cells more reliably than cytology, and could be combined with cytology to improve the detection rate. Our understanding of the molecular biology of HPV infection and the organization of the HPV life-cycle during cancer progression provides a rational basis for marker selection. The general assumption that persistent active infection by high-risk HPV types is the true precursor of cervical cancer provides the rationale for HPV DNA testing in conjunction with enhanced cytology, while the development of RNA-based approaches should allow active infections to be distinguished from those that are latent. The detection in superficial cells of marker combinations at the level of RNA or protein has the potential to predict disease status more precisely than the detection of markers in isolation. There is also a need for better prognostic markers if the predictive value of screening is to be improved. The potential to control infection by vaccination should reduce the incidence of HPV-associated neoplasia in the population, and this may cause a change in the way that screening is carried out. Nevertheless, the lack of a therapeutic vaccine, and the difficulties associated with eliminating infection by multiple high-risk HPV types, means that some form of screening will still be required as a preventive measure for the control of cervical cancer for the foreseeable future.

Accuracy of several cervical screening strategies for early detection of cervical cancer: a meta-analysis

OBJECTIVE

The objectives of this study were to assess the accuracy of 6 common cervical screening strategies, including visual inspection with acetic acid, with a magnifying device, or with Lugol iodine (VILI), human papillomavirus testing with Hybrid Capture 2 assay, conventional Papanicolaou smear, and thin liquid-based cytology (LBC), and then to compare data obtained by the aforementioned 6 strategies.

METHODS

PubMed, EMBASE, and The Cochrane Library were systematically searched for all original relevant studies about early detection of cervical cancer. A meta-analysis was performed to evaluate the accuracy of the 6 screening strategies covering sensitivity, specificity, diagnostic odds ratio, and the area under the receiver operating characteristic curve.

RESULTS

Fifteen articles containing 22 cross-sectional studies were finally identified. The combined estimates of sensitivity for visual inspection with acetic acid, magnified visual inspection with acetic acid, VILI, Hybrid Capture 2 assay, conventional Papanicolaou smear, and LBC were 77%, 64%, 91%, 74%, 59%, and 88%, respectively; the combined values of specificity of these screening strategies were 87%, 86%, 85%, 92%, 94%, and 88%, respectively; the diagnostic odds ratio were 22.43, 10.30, 57.44, 33.26, 22.49, and 51.56, respectively; and the area under the receiver operating characteristic curve were 0.8918, 0.7737, 0.9365, 0.9486, 0.9079, and 0.9418, respectively.

CONCLUSIONS

This meta-analysis suggests that LBC appeared to be promising in primary cervical cancer screening in resourced regions, and VILI might be a good choice to identify/exclude cervical cancerous and precancerous lesions in resource-constrained regions.

Accuracy of concurrent visual and cytology screening in detecting cervical cancer precursors in rural India

The high burden of cervical cancer and inadequate/suboptimal cytology screening in developing countries led to the evaluation of visual screening tests, like visual inspection with acetic acid (VIA) and Lugol's iodine (VILI). We describe the performance of VIA, VILI and cytology, carried out in a multinational project called "Screening Technologies to Advance Rapid Testing" in 5,519 women aged 30-49 years, in detecting cervical intraepithelial neoplasia (CIN). VIA, VILI and cytology were positive in 16.9%, 15.6% and 6.1% women, respectively. We found 57 cases of CIN2, 55 of CIN3 and 12 of cervical cancer; 90% of CIN3 and 43% CIN2 cases were positive for p16 overexpression and high-risk HPV infection, indicating a high validity of histological diagnosis. The sensitivity of VIA, VILI and cytology to detect high-grade CIN were 64.5%, 64.5% and 67.7%, respectively; specificities were 84.2%, 85.5% and 95.4%. A high proportion of p16 positive CIN 3 (93.8%) and 2 (76.9%) were positive on cytology compared with visual tests (68.8% and 53.8%, respectively) indicating a higher sensitivity of cytology to detect p16 positive high-grade CIN. However, the immediate availability of the results from the visual tests permits diagnosis and/or treatment to be performed in the same sitting, which can potentially reduce loss to follow-up when women must be recalled following positive cytology. Organizing visual screening services in low-resource countries may facilitate the gradual building of an infrastructure committed to screening allowing the eventual introduction of more sensitive, highly objective, reproducible and affordable human papillomavirus screening tests in future.

Visual inspection methods for cervical cancer prevention

The need for simple, cost-effective screening approaches for cervical cancer prevention in low-resource countries has led to the evaluation of visual screening with 3-5% acetic acid. The low reproducibility and wide variation in accuracy reflect the subjective nature of the test. Pooled sensitivity, specificity, positive and negative predictive values were 80%, 92%, 10% and 99%, respectively, for detecting cervical intraepithelial neoplasia grade 2 or worse lesions. Realistic sensitivity of a quality- assured single visual inspection with acetic acid is around 50%. A single round of visual inspection with acetic acid screening has been associated with a 25-35% reduction in cervical cancer incidence and the frequency of cervical intraepithelial neoplasia grade 2 or worse lesions in randomised-controlled trials. Despite all its limitations, implementing visual inspection with acetic acid screening in low-resource countries may provide a pragmatic approach to building up human resources and infrastructure that may facilitate the highly anticipated low-cost, rapid human papilloma virus testing in the near future.

An overview of prevention and early detection of cervical cancers

Cervical cancer still remains the most common cancer affecting the Indian women. India alone contributes 25.41% and 26.48% of the global burden of cervical cancer cases and mortality, respectively. Ironically, unlike most other cancers, cervical cancer can be prevented through screening by identifying and treating the precancerous lesions, any time during the course of its long natural history, thus preventing the potential progression to cervical carcinoma. Several screening methods, both traditional and newer technologies, are available to screen women for cervical precancers and cancers. No screening test is perfect and hence the choice of screening test will depend on the setting where it is to be used. Similarly, various methods are available for treatment of cervical precancers and the selection will depend on the cost, morbidity, requirement of reliable biopsy specimens, resources available, etc. The recommendations of screening for cervical cancer in the Indian scenario are discussed.

Smear patterns and spectrum of premalignant and malignant cervical epithelial lesions in postmenopausal Indian women: a hospital-based study

Cervical cancer is one of the leading causes of morbidity and mortality among women but can be prevented through simple cost-effective measures, such as creating awareness, and regular screening with the Pap smear, both in the premenopausal and postmenopausal age group. This study was carried out to study the cervical smear patterns and type of cervical epithelial lesions in a group of postmenopausal Indian females and the relationship with clinical profile of patients. Pap smears were taken from 320 postmenopausal Indian females and meticulously screened. Lesions were classified according to type of postmenopausal pattern. 120 smears showed varying degrees of premalignant and malignant changes, which were classified using the Bethesda system. The findings were correlated with duration of menopause, parity, and duration of sexual activity and significance was derived. Histopathological correlation was conducted in those cases where biopsies were available. It was found that as the age of the patients increased, the incidence of low-grade and high-grade squamous intraepithelial lesions and carcinoma also increased with the relationship being statistically significant. The occurrence of these lesions also showed an association with increasing parity and period of sexual activity. Thus, it can be concluded that it is important to create widespread awareness about the necessity of regular screening, including the postmenopausal period. Conventional cytology or the Pap smear is a cost-effective and efficient method for screening of patients but requires training and experience to minimize errors. It is suitable for developing regions where costlier techniques are not in routine use.

Comparison of Pap smear, visual inspection with acetic acid, and digital cervicography as cervical screening strategies

PURPOSE

To compare the sensitivity, specificity, positive and negative predictive values (PPV and NPV), and accuracy of Pap smear, visual inspection with acetic acid (VIA) and digital cervicography (DC).

METHODS

This is a cross-sectional study on 100 women in the age group of 20-60 years, sequentially using the Pap test, the VIA, and the DC for screening. All women underwent colposcopic biopsy as the gold standard in comparing the methods.

RESULTS

Of the total of 100 women with the mean age 36.0 years, 17 cases were recognized positive for abnormal cervical cell by gold standard. The sensitivity, specificity, PPV, NPV, and accuracy of the Pap test, the VIA, and the DC were 23.5, 100, 100, 86.5, and 87%; 62.5, 98.8, 90.9, 93.2, and 92.9%; and 46.7, 97.6, 77.8, 91, and 89.8%, respectively, for cervical neoplasia.

CONCLUSIONS

The Pap test had low sensitivity but high specificity, whereas VIA had a high sensitivity in addition to being easy and low-cost. Adjuvant methods of screening such as VIA can be a valuable alternative to the Pap test for cervical cancer screening in low-resource settings.

Evaluation of atypical squamous cells on conventional cytology smears: An experience from a screening program practiced in limited resource settings

BACKGROUND

The Bethesda system (TBS) 2001 has subdivided the category of atypical squamous cells (ASC) into: ASC-US (undetermined significance) and ASC-H (cannot exclude high-grade squamous intraepithelial lesion (HSIL)). The present study is an analysis of ASC-US and ASC-H cases diagnosed in a screening program practiced in limited resource settings.

METHODS

During the period January 2005 to December 2008, a total of 9190 smears were received, of which 568 were unsatisfactory. Cases initially diagnosed as ASC-US (n=74) and ASC-H (n=29) on conventional cytology smears were reviewed. Biopsy and human papilloma virus (HPV) results were available in limited cases.

RESULTS

On review, diagnosis of ASC-US was retained in 49 (66.2%) of the 74 initially diagnosed ASC-US cases. Remaining 12 cases were re-labeled as negative for intraepithelial lesion or malignancy (NILM), nine as low-grade squamous intraepithelial lesion (LSIL), three as ASC-H and one case as squamous carcinoma (SCC). Similarly, on review, diagnosis of ASC-H cases was retained in 17 of the 29 initially diagnosed ASC-H cases. Seven cases were re-labeled as NILM, three as HSIL and one case each as ASC-US and SCC. Overall, 8622 cases (96.6%) were diagnosed as NILM, 72 (0.83%) as LSIL, 121 (1.40%) as HSIL, 23 (0.26%) as SCC, 50 (0.57%) as ASC-US cases, 20 (0.23%) as ASC-H, five (0.05%) as atypical glandular cells (AGC) and two cases as adenocarcinomas. Out of 50 ASC-US cases, biopsy in 23 cases showed presence of CIN 1 in 16 cases (69.5%) and CIN 2 in one case (4.34%), while the remaining six cases were negative for CIN/malignancy. The remaining 20 cases with unavailable biopsy results were HPV-positive. Out of 20 ASC-H cases, biopsy in 15 revealed CIN 2 and above in 11 cases (73.3%). Three cases (20%) revealed CIN 1.

CONCLUSIONS

Critical review is helpful in further reducing the number of ASC cases. The percentage of cases with CIN 2 and above is higher with ASC-H cases. The reason for relative increase in HSILs in the present study included referral bias in the screening program.

An audit of cervicovaginal cytology in a teaching hospital: Are atypical glandular cells under-recognised on cytological screening?

BACKGROUND

Cervical cytology screening for carcinoma of the cervix in India is mainly opportunistic in nature and is practiced mainly in urban centres. The effectiveness of cervical cytology screening depends on various factors. The quality of cervicovaginal cytology service is assessed by various quality indices and by cyto-histology correlation, which is the most important quality assurance measure.

AIMS

To describe the cervical cytology diagnoses, estimate the quality indices, and evaluate the discrepant cases on cytohistological correlation.

SETTINGS AND DESIGN

Retrospective observational study from a tertiary care centre in South India.

MATERIALS AND METHODS

Using a database search, all the cervicovaginal cytology reported during the period of 2002-2006 was retrieved and various diagnoses were described. The data was analysed to assess the quality indices. The cytohistologically discrepant cases were reviewed.

RESULTS

A total of 10,787 cases were retrieved, of which 98.14% were labeled negative and 1.36% were unsatisfactory for evaluation. A few (0.81%) of the cases were labeled as squamous intraepithelial lesions and 0.38% as atypical squamous cells. The ASCUS: SIL ratio was 0.5. Cytohistological correlation revealed a total of ten cases with significant discrepancy. The majority of these were carcinomas that were misdiagnosed as atypical glandular cells. These cytology smears and the subsequent biopsies were reviewed to elucidate the reasons for the discrepancies.

CONCLUSIONS

The cervical cytology service at our centre is well within the accepted standards. An increased awareness of cytological features, especially of glandular lesions, a good clinician-laboratory communication and a regular cytohistological review would further improve the diagnostic standards.

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.

Cervical cancer prevention for all the world's women: Genuine promise resides in skilled quality management rather than novel screening approaches

The debate over the best route for cervical cancer prevention in developing countries may be considered part of a larger debate over whether the global health community has become enamored with the promise of new approaches at the expense of delivering available preventives today. Pap screening, which is feasible anywhere cervical screening is appropriate, is the only intervention currently available for the prevention of cervical cancer in developing countries, and the Pap test will be an essential component of future novel preventive approaches. Cervical cancer vaccination, the long-term effectiveness of which is uncertain, will not eliminate screening requirements and is currently not affordable in developing countries. Root cause analyses, which may appropriately inform the best routes for improving health in developing countries, document that failures of cervical cancer prevention efforts are not attributable to factors specific to the Pap test but to lapses in programmatic quality management to which all screening tests are vulnerable. The genuine promise of cervical cancer prevention for all the world's women therefore resides in skilled quality management rather than novel screening approaches. We propose a global consensus policy by which Pap screening services will be provided in any setting where cervical screening is appropriate but unavailable, with consideration given to novel preventive approaches as they mature. Opportunity costs, borne by the underserved, are associated with prioritizing research on new approaches in any setting where established preventives are feasible but unavailable.

Diagnostic accuracy of human papillomavirus testing in primary cervical screening: a systematic review and meta-analysis of non-randomized studies

OBJECTIVE

This is a meta-analysis of studies comparing HPV testing to cytology with regard to their accuracy in the detection of underlying high grade cervical intraepithelial neoplasia in primary cervical cancer screening.

METHODS

A systematic review was conducted following the Cochrane Collaboration Guidelines. A systematic search was performed in 8 electronic databases. Strict selection criteria were applied in terms of types of participants, types of interventions and methods to limit verification bias. Where possible we calculated the sensitivity, specificity, positive and negative predictive value of cytology and the HPV test, as well as sensitivity and specificity ratios for the detection of CIN2 or worse. Random effect models were used for pooling accuracy parameters. The results were displayed using forest plots.

RESULTS

We identified 25 studies fulfilling the inclusion criteria. The pooled sensitivity of HC2, PCR, cytology (ASCUS or worse) and cytology (LSIL or worse) was 90%, 80.9%, 72.7% and 61.6%, respectively, and the pooled specificity was 86.5%, 94.7%, 91.9% and 96.0%, respectively. The ratio of the sensitivity of HC2 to cytology (ASCUS) was 1.25 (95% CI=1.20-1.29), and the corresponding specificity ratio was 0.97 (95% CI=0.96-0.98). The ratio of the sensitivity of combination of HC2 and cytology (ASCUS) to HC2 alone was 1.05 (95% CI=1.04-1.06) and the ratio of the specificity 0.95 (95% CI=0.94-0.96). For women over 30 years, the sensitivity of HC2 was 94.8% and the specificity 86.0%.

CONCLUSIONS

Compared to cytology, the HC2 and PCR are substantially more sensitive for prevalent CIN2 or worse but significantly less specific. The combination of HC2 and cytology has the highest sensitivity and lowest specificity. However, reduction of the incidence of or mortality from invasive cervical cancer among HPV screened subjects compared to cytologically screened subjects has not yet been demonstrated.

Cervical cancer in the developing world

In developed countries, systematic screening programmes have reduced the morbidity and mortality resulting from cervical cancer. Cytological methods of screening have been the mainstay in these countries. Nevertheless, there is scant evidence that cytology-based screening has had any effect in reducing cervical cancer mortality in less-developed countries. In fact, the challenge in less-developed countries is surpassed by the complex array of problems that go far beyond the introduction of simplified technologies. Currently, there are two main issues on this subject: the assessment of simpler screening methods, and the evaluation of different strategies regarding which women to target and the screening interval. Achieving high rates of coverage and compliance of the target population through high-quality procedures has remained the most difficult goal to achieve. Nevertheless, it is believed that creativity, flexibility and well-focused use of resources can reduce the inequitable burden of cervical cancer borne by women in poor countries.

Systems analysis of real-world obstacles to successful cervical cancer prevention in developing countries

Papanicolaou screening is feasible anywhere that screening for cervical cancer, the leading cause of cancer-related death among women in developing countries, is appropriate. After documenting that the Vietnam War had contributed to the problem of cervical cancer in Vietnam, we participated in a grass roots effort to establish a nationwide cervical cancer prevention program in that country and performed root cause analyses of program deficiencies. We found that real-world obstacles to successful cervical cancer prevention in developing countries involve people far more than technology and that such obstacles can be appropriately managed through a systems approach focused on programmatic quality rather than through ideological commitments to technology. A focus on quality satisfies public health goals, whereas a focus on technology is compatible with market forces.

A critical assessment of screening methods for cervical neoplasia

The objective of cervical cancer screening is to reduce cervical cancer incidence and mortality by detecting and treating precancerous lesions. Conventional cytology is the most widely used cervical cancer screening test. Although cytology has been effective in reducing the incidence of and mortality from cervical cancer in developed countries in both opportunistic and--more dramatically--organized national programs, it has been less successful and largely ineffective in reducing disease burden in low-resource settings where it has been implemented. Liquid-based cytology, testing for infection with oncogenic types of human papillomaviruses, visual inspection with 3-5% acetic acid, magnified visual inspection with acetic acid, and visual inspection with Lugol's iodine have been evaluated as alternative tests. Their test characteristics, and the applications and limitations in screening, are discussed with an emphasis on the work of the Alliance for Cervical Cancer Prevention over the past 5 years.

Preventing cervical cancer in low-resource settings: how far have we come and what does the future hold?

The Alliance for Cervical Cancer Prevention (ACCP) came together in 1999 to answer key research questions and to advocate for greater global and national interest in reducing the heavy burden of morbidity and mortality caused by this preventable disease. Visual inspection with acetic acid (VIA), visual inspection with Lugol's iodine (VILI), and human papillomavirus (HPV) tests have been shown to be viable alternatives to traditional cytology. ACCP experience confirmed that cryotherapy is a safe and effective method that is acceptable to women and can be delivered by a range of health providers, including nonphysicians. Programs can maximize coverage by accommodating local needs and involving community leaders and women in planning and implementation. Advocacy efforts have led to significant policy changes and galvanized support for cervical cancer prevention. Despite the prospect of new HPV vaccines, screening will be needed for at least the next 30-40 years. Our experience has shown that with creativity, flexibility, and well-focused use of resources, the inequitable burden of cervical cancer borne by women in poor countries can be sharply reduced.

The role of human papillomavirus testing in cervical screening

Organised, cytology-based cervical screening has led to a reduction in deaths associated with cervical cancer. Human papillomavirus (HPV) is necessary for the development of cervical cancer and associated pre-cursor cervical intraepithelial neoplasia and accumulated evidence suggests that incorporation of HPV testing could further refine screening programmes. HPV testing is discussed in the context of primary screening, for triage, and as a test of cure of treatment and possible value in developing countries. The high negative predictive value of a "double negative" cytology and HPV result could allow considerable changes in policy such as increased intervals between screening rounds, adjustment of age ranges for testing and schedule for return to routine screening post treatment. HPV testing for the triage of women to colposcopy with borderline or atypical squamous cells of undetermined significance (ASCUS) cytology could be clinically effective, but may be limited in women with low-grade squamous intraepithelial lesions (LSIL) or mild dyskaryosis by high HPV prevalence. Markers of HPV persistence harbour enormous potential to identify women at greatest risk of disease progression. Due to the diversity of existing cytology-based screening programmes, full cost-effectiveness analyses of HPV testing should be performed and assessed within local contexts.

Accuracy of human papillomavirus testing in primary screening of cervical neoplasia: Results from a multicenter study in India

The knowledge that cervical neoplasia are caused by human papillomavirus (HPV) infection has led to the evaluation of its role in screening. We evaluated the accuracy of HPV testing by Hybrid capture II (HC II) method in detecting cervical intraepithelial neoplasia grade 2 and 3 (CIN 2 and 3) lesions in 4 cross-sectional studies with common protocol and questionnaire in 3 different locations (Kolkata, Mumbai and Trivandrum) in India. These studies involved 18,085 women aged 25-65 years. The reference standard for final diagnosis was a combination of colposcopy/biopsy. All women were investigated with colposcopy and 3,116 received directed biopsy. The sensitivity of HPV testing for detecting CIN 2-3 lesions varied from 45.7% to 80.9% across the study sites; the specificity varied from 91.7% to 94.6% and the positive predictive value from 6.7% to 13.7%. Retesting of 298 randomly chosen denatured samples in France revealed an agreement rate of 85.9% and a kappa-value of 0.72. Although HPV testing seems to be a promising approach for cervical cancer prevention, a large range in sensitivity was observed in our study, possibly due to variations in the quality of specimen collection and reference standards. A higher sensitivity was associated with the center performing the test well. Further developments in terms of more reproducible, less expensive and less sophisticated testing are essential to make the test feasible and effective in low-resource settings.