Cross sectional study of conventional cervical smear, monolayer cytology, and human papillomavirus DNA testing for cervical cancer screening

Cost-effectiveness analysis of human papillomavirus-vaccination programs to prevent cervical cancer in Austria

OBJECTIVE

The study predicts long-term cervical cancer related population health and economic effects of introducing the HPV-vaccination for 12-year-old girls (and boys) in addition to current screening compared with screening only.

METHOD

Health effects are predicted by a dynamic transmission model. Model results are used to calculate incremental cost-effectiveness ratios (ICER) in euro per life year gained (LYG) for a time-horizon between 2008 and 2060 from a public payer and a societal perspective.

RESULTS

Vaccination of girls results a discounted ICER of euro 64,000/LYG and euro 50,000/LYG from a payer's and societal perspectives respectively. The additional vaccination of boys increases the ICER to euro 311,000 and euro 299,000/LYG respectively. Results were most sensitive to vaccination price, discount rate and time-horizon.

CONCLUSION

HPV-vaccination for girls should be cost-effective when adopting a longer time-horizon and a societal perspective. Applying a shorter time frame and a payer's perspective or vaccinating boys may not be cost-effective without reducing the vaccine price.

Gain of 3q26: a genetic marker in low-grade squamous intraepithelial lesions (LSIL) of the uterine cervix

OBJECTIVE

Physicians have few resources for determining which LSIL will progress to HSIL or regress. Recently the chromosome 3q26 region was found to be amplified in patients with cervical cancer. The frequency of this 3q gain increased with severity of dysplasia. The primary objective of this study was to evaluate an automated FISH assay for detection of 3q gain in liquid cytology samples as a potential tool for risk stratification and triaging.

METHODS

Slides prepared from 257 liquid cytology specimens (97 Negative, 135 LSIL 25 HSIL) were hybridized with a single-copy probe for the chromosome 3q26 region and a probe for the centromeric alpha-repeat sequence of chromosome 7, using standard FISH methods. Using automated analysis, the total number of nuclei and the number of nuclei with >2 signals for 3q26 were determined, using a 20x objective. The nuclei were rank ordered based on number of 3q26 FISH signals. The 800 nuclei with the highest number of signals were scored using both FISH probes and nuclei with increased numbers of 3q signals were enumerated.

RESULTS AND CONCLUSIONS

Analysis of 257 specimens demonstrated that a fully automated FISH scoring system can detect 3q gain in liquid cytology samples. A fully automated method for determination of 3q gain in liquid cytology may be the assay necessary to implement routine testing. Additional studies to validate the utility of this technology are needed.

Cervical cancer screening in the early post vaccine era

The Pap test is the foundation of cervical cancer screening in North America and most industrialized countries. It has been widely used in the United States since the 1950s. But are our current screening guidelines still justified? In this article, the author reviews the current recommendations for cervical cancer screening by the American Cancer Society (ACS) and the American College of Obstetricians and Gynecologists (ACOG) and the evidence supporting them, reviews the relative efficacy of liquid-based cytology versus the conventional Pap smear, and discusses the role of HPV DNA testing in primary screening.

Superior performance of liquid-based versus conventional cytology in a population-based cervical cancer screening program

OBJECTIVE

Liquid-based cytology may offer improvements over conventional cytology for cervical cancer screening. The two cytology techniques were compared in a group of 86,469 women who participated in a population-based screening program. Using a nation-wide pathology database containing both cervical cytology and histology records for all patients, we compared the outcome of the two screenings methods with regard to the detection rate of histological proven abnormalities and the determination of the true false-negative rates for both methods.

METHODS

Two cohorts of women living in the same geographical region were used. Cohort 1 (n=51,154 women) was analysed using conventional cytology (conventional cohort) and cohort 2 (liquid cohort) (n=35,315 women) was analysed using liquid-based cytology (SurePath). The samples were processed in one laboratory. The results of histological follow up were available via a central database.

RESULTS

The rate of unsatisfactory slides was significantly lower using liquid-based cytology (0.13% vs. 0.89%, p<0.0001). Detection of ASCUS+ (Atypical squamous cells of unknown significance or higher abnormalities) was significantly higher using liquid-based cytology (2.97% vs. 1.64%, p<0.0001), mainly due to the increase in the ASCUS category. The percentage of histological abnormalities within the ASCUS samples was approximately equal in both cohorts, indicating that more true abnormal cases were detected using liquid-based cytology. The sensitivity for detection of a histological proven lesion is significantly higher in the liquid cohort compared to the conventional cohort (96.2% vs. 92.0%), with only a slight difference in specificity (97.8% vs. 98.2%).

CONCLUSION

This population study confirmed previous institution-based reports of decreased numbers of unsatisfactory samples based on liquid-based cytology and showed an increased sensitivity for the detection of cytological abnormalities that was validated by subsequent histological investigation.

The performance of human papillomavirus high-risk DNA testing in the screening and diagnostic settings

OBJECTIVE

We sought to evaluate the performance of the human papillomavirus high-risk DNA test in patients 30 years and older.

MATERIALS AND METHODS

Screening (n=835) and diagnosis (n=518) groups were defined based on prior Papanicolaou smear results as part of a clinical trial for cervical cancer detection. We compared the Hybrid Capture II (HCII) test result with the worst histologic report. We used cervical intraepithelial neoplasia (CIN) 2/3 or worse as the reference of disease. We calculated sensitivities, specificities, positive and negative likelihood ratios (LR+ and LR-), receiver operating characteristic (ROC) curves, and areas under the ROC curves for the HCII test. We also considered alternative strategies, including Papanicolaou smear, a combination of Papanicolaou smear and the HCII test, a sequence of Papanicolaou smear followed by the HCII test, and a sequence of the HCII test followed by Papanicolaou smear.

RESULTS

For the screening group, the sensitivity was 0.69 and the specificity was 0.93; the area under the ROC curve was 0.81. The LR+ and LR- were 10.24 and 0.34, respectively. For the diagnosis group, the sensitivity was 0.88 and the specificity was 0.78; the area under the ROC curve was 0.83. The LR+ and LR- were 4.06 and 0.14, respectively. Sequential testing showed little or no improvement over the combination testing.

CONCLUSIONS

The HCII test in the screening group had a greater LR+ for the detection of CIN 2/3 or worse. HCII testing may be an additional screening tool for cervical cancer in women 30 years and older.

A multi-type HPV transmission model

A prophylactic quadrivalent (types 6/11/16/18) vaccine against oncogenic and warts-causing genital Human papillomavirus (HPV) types was approved by the US Food and Drug Administration in 2006. This paper presents a nonlinear, deterministic, age-structured, mathematical model of the transmission dynamics of HPV and disease occurrence in a US population stratified by gender and sexual activity group. The model can assess both the epidemiologic consequences and cost effectiveness of alternative vaccination strategies in a setting of organized cervical cancer screening in the United States. Inputs for the model were obtained from public data sources, published literature, and analyses of clinical trial data. The results suggest that a prophylactic quadrivalent HPV vaccine can: (i) substantially reduce the incidence of disease, (ii) increase survival among females, (iii) improve quality of life for both males and females, (iv) be cost-effective when administered to females age 12-24 years, and (v) be cost-effective when implemented as a strategy that combines vaccination of both females and males before age 12 vaccination with a 12 to 24 years of age catch-up vaccination program.

Preventing cervical cancer: the Pap test and the HPV vaccine

Women look to their internists and other primary care physicians to provide preventive health care. Periodic Pap tests are as much a part of a woman's ongoing health care as periodic lipid assessments, mammograms, screening for colon cancer, or any of the other recommended screening assessments. This article provides primary care physicians with the information needed to perform Pap tests at the appropriate intervals, or if not set up to do Pap tests themselves, to make the appropriate referrals. Also provided is the necessary information to counsel women with abnormal Pap tests who may need colposcopy or other follow-up evaluation. Finally, the role of the HPV vaccine in the prevention of cervical cancer is summarized.

A methodological framework to distinguish spectrum effects from spectrum biases and to assess diagnostic and screening test accuracy for patient populations: application to the Papanicolaou cervical cancer smear test

BACKGROUND

A spectrum effect was defined as differences in the sensitivity or specificity of a diagnostic test according to the patient's characteristics or disease features. A spectrum effect can lead to a spectrum bias when subgroup variations in sensitivity or specificity also affect the likelihood ratios and thus post-test probabilities. We propose and illustrate a methodological framework to distinguish spectrum effects from spectrum biases.

METHODS

Data were collected for 1781 women having had a cervical smear test and colposcopy followed by biopsy if abnormalities were detected (the reference standard). Logistic models were constructed to evaluate both the sensitivity and specificity, and the likelihood ratios, of the test and to identify factors independently affecting the test's characteristics.

RESULTS

For both tests, human papillomavirus test, study setting and age affected sensitivity or specificity of the smear test (spectrum effect), but only human papillomavirus test and study setting modified the likelihood ratios (spectrum bias) for clinical reading, whereas only human papillomavirus test and age modified the likelihood ratios (spectrum bias) for "optimized" interpretation.

CONCLUSION

Fitting sensitivity, specificity and likelihood ratios simultaneously allows the identification of covariates that independently affect diagnostic or screening test results and distinguishes spectrum effect from spectrum bias. We recommend this approach for the development of new tests, and for reporting test accuracy for different patient populations.

Bayesian Estimation of Performance Measures of Cervical Cancer Screening Tests in the Presence of Covariates and Absence of a Gold Standard

In this paper we develop a Bayesian analysis to estimate the disease prevalence, the sensitivity and specificity of three cervical cancer screening tests (cervical cytology, visual inspection with acetic acid and Hybrid Capture II) in the presence of a covariate and in the absence of a gold standard. We use Metropolis-Hastings algorithm to obtain the posterior summaries of interest. The estimated prevalence of cervical lesions was 6.4% (a 95% credible interval [95% CI] was 3.9, 9.3). The sensitivity of cervical cytology (with a result of ≥ ASC-US) was 53.6% (95% CI: 42.1, 65.0) compared with 52.9% (95% CI: 43.5, 62.5) for visual inspection with acetic acid and 90.3% (95% CI: 76.2, 98.7) for Hybrid Capture II (with result of >1 relative light units). The specificity of cervical cytology was 97.0% (95% CI: 95.5, 98.4) and the specificities for visual inspection with acetic acid and Hybrid Capture II were 93.0% (95% CI: 91.0, 94.7) and 88.7% (95% CI: 85.9, 91.4), respectively. The Bayesian model with covariates suggests that the sensitivity and the specificity of the visual inspection with acetic acid tend to increase as the age of the women increases.

The Bayesian method proposed here is an useful alternative to estimate measures of performance of diagnostic tests in the presence of covariates and when a gold standard is not available. An advantage of the method is the fact that the number of parameters to be estimated is not limited by the number of observations, as it happens with several frequentist approaches. However, it is important to point out that the Bayesian analysis requires informative priors in order for the parameters to be identifiable. The method can be easily extended for the analysis of other medical data sets.

Liquid compared with conventional cervical cytology: a systematic review and meta-analysis

OBJECTIVE

To compare test performance characteristics of conventional Pap tests and liquid-based cervical cytology samples.

DATA SOURCES

Eligible studies, published between 1991 and 2007, were retrieved through PubMed/EmBase searching and completed by consultation of other sources.

METHODS OF STUDY SELECTION

Studies were selected if a conventional and a liquid-based sample were prepared from the same woman or when one or the other type of sample was taken from a separate but similar cohort. The current systematic review and meta-analysis is restricted to studies where all subjects were submitted to gold standard verification, based on colposcopy and histology of colposcopy-targeted biopsies, allowing computation of absolute and relative test validity for cervical intraepithelial neoplasia grade 2 or worse. Randomized trials were selected as well if all test-positive cases were verified with the same gold standard, allowing computation of the relative sensitivity. Impact of study characteristics on accuracy was assessed by subgroup meta-analyses, meta-regression, and summary receiver operating characteristic curve regression.

TABULATION, INTEGRATION, AND RESULTS

The relative sensitivity, pooled from eight studies, with complete gold standard verification and from one randomized clinical trial, did not differ significantly from unity. Also, the specificity, considering high-grade and low-grade squamous intraepithelial lesions as cutoff, was similar in conventional and liquid cytology. However, a lower pooled specificity was found for liquid-based cytology when presence of atypical squamous cells of undetermined significance was the cutoff (ratio 0.91, 95% confidence interval 0.84-0.98). Differences in study characteristics did not explain interstudy heterogeneity.

CONCLUSION

Liquid-based cervical cytology is neither more sensitive nor more specific for detection of high-grade cervical intraepithelial neoplasia compared with the conventional Pap test.

Bayesian estimation of performance measures of cervical cancer screening tests in the presence of covariates and absence of a gold standard

In this paper we develop a Bayesian analysis to estimate the disease prevalence, the sensitivity and specificity of three cervical cancer screening tests (cervical cytology, visual inspection with acetic acid and Hybrid Capture II) in the presence of a covariate and in the absence of a gold standard. We use Metropolis-Hastings algorithm to obtain the posterior summaries of interest. The estimated prevalence of cervical lesions was 6.4% (a 95% credible interval [95% CI] was 3.9, 9.3). The sensitivity of cervical cytology (with a result of >or= ASC-US) was 53.6% (95% CI: 42.1, 65.0) compared with 52.9% (95% CI: 43.5, 62.5) for visual inspection with acetic acid and 90.3% (95% CI: 76.2, 98.7) for Hybrid Capture II (with result of >1 relative light units). The specificity of cervical cytology was 97.0% (95% CI: 95.5, 98.4) and the specificities for visual inspection with acetic acid and Hybrid Capture II were 93.0% (95% CI: 91.0, 94.7) and 88.7% (95% CI: 85.9, 91.4), respectively. The Bayesian model with covariates suggests that the sensitivity and the specificity of the visual inspection with acetic acid tend to increase as the age of the women increases. The Bayesian method proposed here is an useful alternative to estimate measures of performance of diagnostic tests in the presence of covariates and when a gold standard is not available. An advantage of the method is the fact that the number of parameters to be estimated is not limited by the number of observations, as it happens with several frequentist approaches. However, it is important to point out that the Bayesian analysis requires informative priors in order for the parameters to be identifiable. The method can be easily extended for the analysis of other medical data sets.

Evaluation of agreement between conventional and liquid-based cytology in cervical cancer early detection based on analysis of 2,091 smears: experience at the Brazilian National Cancer Institute

The aim of this work was to evaluate the agreement between conventional cytology (CC) and liquid-based cytology (LBC) in cervical cancer early detection. The results of CC and LBC (DNACitoliq in 2,059 women aged 25-59 years were compared. The percent agreement, kappa coefficient, prevalence-adjusted bias-adjusted kappa coefficient (PABAK), and Chamberlain's percent positive agreement (PPA) were calculated. The percent agreement between the two methods was very good (80% and 79%, respectively, for normal versus ASCUS+; and normal versus ASCUS, AGUS and LSIL+ vs. HSIL+). The kappa coefficient indicates slight agreement (0.26 and 0.23, respectively), but when PABAK was used the agreement was good (0.61 and 0.68, respectively). PPA was high for normal results (79.2%) and low for the remaining categories. To conclude, in this study, agreement between LBC and CC was only good for normal results, which involves the majority of cases and positively influences the overall agreement rate.

Cost-effectiveness of quadrivalent human papillomavirus (HPV) vaccination in Mexico: a transmission dynamic model-based evaluation

We examined the potential health outcomes and cost-effectiveness of quadrivalent human papillomavirus (HPV) 6/11/16/18 vaccination strategies in the Mexican population using a multi-HPV type dynamic transmission model. Assuming similar cervical screening practices, with or without vaccination, we examined the incremental cost-effectiveness of vaccination strategies for 12 year-old females, with or without male vaccination, and temporary age 12-24 catch-up vaccination for females or both sexes. The most effective strategy therein was vaccination of 12-year-olds, plus a temporary 12-24-year-old catch-up program covering both sexes; whereby HPV 6/11/16/18-related cervical cancer, high-grade cervical precancer, and genital wart incidence was reduced by 84-98% during year 50 following vaccine introduction. Incremental cost-effectiveness ratios in the primary analyses ranged from approximately 3000 dollars (U.S.) per quality-adjusted life year (QALY) gained for female vaccination strategies to approximately 16000 dollars /QALY for adding male vaccination with catch-up.

Accuracy of liquid based versus conventional cytology: overall results of new technologies for cervical cancer screening: randomised controlled trial

OBJECTIVE

To compare the accuracy of conventional cytology with liquid based cytology for primary screening of cervical cancer.

DESIGN

Randomised controlled trial.

SETTING

Nine screening programmes in Italy.

PARTICIPANTS

Women aged 25-60 attending for a new screening round: 22 466 were assigned to the conventional arm and 22 708 were assigned to the experimental arm.

INTERVENTIONS

Conventional cytology compared with liquid based cytology and testing for human papillomavirus.

MAIN OUTCOME MEASURE

Relative sensitivity for cervical intraepithelial neoplasia of grade 2 or more at blindly reviewed histology, with atypical cells of undetermined significance or more severe cytology considered a positive result.

RESULTS

In an intention to screen analysis liquid based cytology showed no significant increase in sensitivity for cervical intraepithelial neoplasia of grade 2 or more (relative sensitivity 1.17, 95% confidence interval 0.87 to 1.56) whereas the positive predictive value was reduced (relative positive predictive value v conventional cytology 0.58, 0.44 to 0.77). Liquid based cytology detected more lesions of grade 1 or more (relative sensitivity 1.68, 1.40 to 2.02), with a larger increase among women aged 25-34 (P for heterogeneity 0.0006), but did not detect more lesions of grade 3 or more (relative sensitivity 0.84, 0.56 to 1.25). Results were similar when only low grade intraepithelial lesions or more severe cytology were considered a positive result. No evidence was found of heterogeneity between centres or of improvement with increasing time from start of the study. The relative frequency of women with at least one unsatisfactory result was lower with liquid based cytology (0.62, 0.56 to 0.69).

CONCLUSION

Liquid based cytology showed no statistically significant difference in sensitivity to conventional cytology for detection of cervical intraepithelial neoplasia of grade 2 or more. More positive results were found, however, leading to a lower positive predictive value. A large reduction in unsatisfactory smears was evident.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN81678807 [controlled-trials.com].

[French pathologist' implication in cervical cancer screening]

The cytological test issue mostly from individual opportunistic or for some department from organized screening programme, must benefit of the same quality in all the procedures. Pathologists are very implicated in. The purpose of this document is to summarize cytopathologists' initiatives and to present their specific tools for that. The French association for quality assurance in pathology (AFAQAP) has been validated by HAS in March 2006 for EPP. Commission 1 of AFAQAP organized an annual voluntary test for diagnostic evaluation since 2000 with the adoption of new technologies (CD-rom, virtual digital slides), and in 2005 a test of Pap Smear reporting quality concerning TBS 2001 use. A referring evaluation on this theme is in press. Furthermore pathologists made tools are available to codify lesions they diagnose (ADICAP), to collect and to study data (FCRISAP), to standardize the histological and cytological reports (CRFS), to evaluate the procedures and structural requirements and techniques. Pathologists participate in the elaboration of national guidelines (ANAES 1998 et 2002, DGS 2006) and performance indicators with InVS. The cervix cancer screening programme must take in account and valorises the role of pathologists according to assessment of efficacy and evaluation of the screening.

[Comparison of the ThinPrep monolayer technique and conventional cervical Pap smears in a high-risk population using the Munich II nomenclature]

OBJECTIVE

In this prospective study using the Munich II nomenclature for cervical cytology. Pap smear results obtained by the ThinPrep monolayer technique and those obtained by the conventional method were compared.

METHODS

Pap smears were obtained from 1,000 women using an Ayre spatula/endocervical brush combination. Following transfer of the cell sample onto a slide, the same collection devices were rinsed in a liquid medium and processed using ThinPrep-2000 processor (split-sample technique).

RESULTS

Specimen inadequacies due to drying artefacts, cell overlap or low number of epithelial cells were rare with both methods without any significant differences. However, ThinPrep slides were significantly less often compromised by red or white blood cells or by cytolysis. In contrast, endocervical cells were missing in 11.6% of slides compared to only 2.3% in conventional Pap smears. ThinPrep yielded results of unknown significance (Pap III) significantly less often (4.2 vs 6.3%).

CONCLUSIONS

ThinPrep slides are less frequently compromised by blood components or cytolysis. Inconclusive results of Pap III are slightly less frequent when using ThinPrep. However, there is a significant percentage of slides lacking the endocervical component. Using a combination of spatula and cytobrush, this may not necessarily be due to non-representative cell sampling.

Model for assessing human papillomavirus vaccination strategies

A prophylactic quadrivalent vaccine can cost-effectively reduce the incidence of cervical cancer, cervical intraepithelial neoplasia, and genital warts.

We present a transmission dynamic model that can assess the epidemiologic consequences and cost-effectiveness of alternative strategies of administering a prophylactic quadrivalent (types 6/11/16/18) human papillomavirus (HPV) vaccine in a setting of organized cervical cancer screening in the United States. Compared with current practice, vaccinating girls before the age of 12 years would reduce the incidence of genital warts (83%) and cervical cancer (78%) due to HPV 6/11/16/18. The incremental cost-effectiveness ratio (ICER) of augmenting this strategy with a temporary catch-up program for 12- to 24-year olds was US $4,666 per quality-adjusted life year (QALY) gained. Relative to other commonly accepted healthcare programs, vaccinating girls and women appears cost-effective. Including men and boys in the program was the most effective strategy, reducing the incidence of genital warts, cervical intraepithelial neoplasia, and cervical cancer by 97%, 91%, and 91%, respectively. The ICER of this strategy was $45,056 per QALY.

Liquid-based cytology for cervical cancer screening

In multiple studies during the last decade, liquid-based cytology for cervical cancer screening has been shown to increase the detection rate for preneoplastic squamous intraepithelial lesions equal to or greater than the conventional Papanicolaou (Pap) smear method. Liquid-based collection and processing provide more representative cervical sampling than conventional smearing of the specimen on a glass slide. Currently, there are two test methodologies that are widely marketed and available to clinical laboratories, health systems and clinicians that undertake cervical cytology. The purpose of this article is to provide an overview of the methodology and performance of SurePath Liquid-Based Pap Test in cervical cytology screening. The SurePath liquid-based Pap test significantly reduces the unsatisfactory rate of Pap test slides, and detects a significantly higher number of low- and high-grade squamous lesions when compared with the conventional Pap smear technique. Biopsy confirmation shows that this increased detection does not come at a cost of decreasing specificity, and sensitivity for histologic dysplasia is equal to or greater than the best available data for the conventional Pap method. The SurePath collection vial provides residual cellular material for adjunctive out-of-the-vial molecular testing, including sexually transmitted diseases and oncologic biomarkers associated with cervical carcinoma. Finally, SurePath slides can be placed on an automated cervical cytology screening device (FocalPoint), thus providing improved disease detection and enhanced laboratory productivity.

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.

Human Papillomavirus Testing and Liquid-Based Cytology: Results at Recruitment From the New Technologies for Cervical Cancer Randomized Controlled Trial

BACKGROUND

Although testing for human papillomavirus (HPV) has higher sensitivity and lower specificity than cytology alone for detecting cervical intraepithelial neoplasia (CIN), studies comparing conventional and liquid-based cytology have had conflicting results.

METHODS

In the first phase of a two-phase multicenter randomized controlled trial, women aged 35-60 years in the conventional arm (n = 16,658) were screened using conventional cytology, and women in the experimental arm (n = 16,706) had liquid-based cytology and were tested for high-risk HPV types using the Hybrid Capture 2 assay. Women in the conventional arm were referred to colposcopy with atypical cells of undetermined significance (ASCUS) or higher and those in the experimental arm were referred with ASCUS or higher cytology or with a positive (> or = 1 pg/mL) HPV test. Sensitivity and positive predictive value (PPV) for detection of cervical intraepithelial neoplasia grade 2 or higher (CIN2+) were calculated.

RESULTS

The screening methods and referral criterion applied in the experimental arm had higher sensitivity than that in the conventional arm (relative sensitivity = 1.47; 95% confidence interval [CI] = 1.03 to 2.09) but a lower PPV (relative PPV = 0.40; 95% CI = 0.23 to 0.66). With HPV testing alone at > or = 1 pg/mL and at > or = 2 pg/mL, the gain in sensitivity compared with the conventional arm remained similar (relative sensitivity = 1.43, 95% CI = 1.00 to 2.04 and relative sensitivity = 1.41, 95% CI = 0.98 to 2.01, respectively) but PPV progressively improved (relative PPV = 0.58, 95% CI = 0.33 to 0.98 and relative PPV = 0.75, 95% CI = 0.45 and 1.27, respectively). Referral based on liquid-based cytology alone did not increase sensitivity compared with conventional cytology (relative sensitivity = 1.06; 95% CI = 0.72 to 1.55) but reduced PPV (relative PPV = 0.57; 95% CI = 0.39 to 0.82).

CONCLUSIONS

HPV testing alone was more sensitive than conventional cytology among women 35-60 years old. Adding liquid-based cytology improved sensitivity only marginally but increased false-positives. HPV testing using Hybrid Capture 2 with a 2 pg/mL cutoff may be more appropriate than a 1 pg/mL cutoff for primary cervical cancer screening.

Long-term risk of invasive cervical cancer after treatment of squamous cervical intraepithelial neoplasia

Invasive cancer of the cervix after treatment for cervical intraepithelial neoplasia (CIN) is becoming more important, as screening reduces the incidence of invasive disease. The rate of invasive cervical or vaginal cancer following treatment for CIN in UK remains elevated for at least 8 years. The aim of our study was to determine from international data how long this rate remains elevated and whether the rate of invasive disease reflects the rate of posttreatment CIN. The aim was to determine why the rate of invasive disease does not fall. A search of Medline and a secondary search of cited references identified 1,848 articles referring to the success rate of the treatment of CIN. Only 26 cohorts from 25 articles met all the inclusion criteria. The policy in these was to perform at least annual smears. After the first year following treatment for CIN, the rate of invasive disease remained about 56 per 100,000 woman years until at least 20 years after treatment. This rate is approximately 2.8 times greater than expected. In contrast, the risk of posttreatment CIN declined steadily with time to about 190 per 100,000 women in the 10th year. Although the posttreatment rate of CIN falls with time, the rate of invasive disease remains static. It seems likely that this is due to diminishing compliance with follow-up. Women should be encouraged to persevere with annual smears for at least 10 years after their treatment as this may offer them the best chance of detecting recurrence at a treatable stage.

Direct comparison of liquid-based and conventional cytology in a South African screening trial

Our study directly compares the performance of liquid-based (LBC) and conventional cytology for detecting high-grade cervical intraepithelial neoplasia and cancer (CIN 2+) in high-risk, previously unscreened women. As part of a larger randomized clinical trial assessing the efficacy and safety of a "screen and treat" program for cervical cancer prevention, 5,652 South African women, aged 35 to 65 years, were screened using either ThinPrep or conventional Papanicolaou cytology. The cytology method used (i.e., ThinPrep or conventional) was rotated on a 6-month basis for the duration of the study. Directly following collection of the cytology specimen, all women underwent colposcopy with endocervical curettage and biopsy of all colposcopic abnormalities. Assessment of cytology and histology results was blinded and results were compared using histology-confirmed CIN as the "gold standard." The accuracy of LBC and conventional cytology was statistically equivalent, although the sensitivity of conventional cytology was at least 5 percentage points higher at all cutoff levels. For example, at a cytology cutoff level of low-grade squamous intraepithelial lesion, the sensitivity of LBC was 60.3% for CIN2+ vs. 69.1% for conventional cytology and specificity was 94.1% and 94.5%, respectively. LBC specimens were significantly less likely to be "satisfactory-but-limited-by" (6.5% vs. 27.9%) but significantly more likely to be unsatisfactory (2.2% vs. 0.8%). Thus, in this high-risk population, the sensitivity of LBC is no greater than the sensitivity of conventional cytology. Because of the higher unit cost of LBC, low resource settings should carefully consider the potential benefits and drawbacks of LBC before adopting this new technology.

Effect of study design and quality on unsatisfactory rates, cytology classifications, and accuracy in liquid-based versus conventional cervical cytology: a systematic review

BACKGROUND

Liquid-based cytology is reported to increase the sensitivity of cervical cytology and the proportion of slides that are satisfactory for assessment, in comparison with conventional cytology. Although some countries have changed to liquid-based cytology for cervical screening, controversy remains. We reviewed the published work to assess the performance of liquid-based cytology relative to conventional cytology in primary studies assessed to be of low, medium, or high methodological quality.

METHODS

56 primary studies were reviewed and assessed with strict methodological criteria. Liquid-based cytology and conventional cytology were compared in terms of the percentage of slides classified as unsatisfactory, the percentage of slides classified in each cytology category, and the accuracy of detection of high-grade disease. Data were examined for studies overall and in strata to examine the effect of study quality on results.

FINDINGS

The median difference in the percentage of unsatisfactory slides between liquid-based cytology and conventional cytology was 0.17%. Only one small study was a randomised controlled trial. The classification of high-grade squamous epithelial lesion varied according to study quality (p=0.04), with conventional cytology classifying more slides in this category than did liquid-based cytology in high-quality studies (n=3) only. In medium-quality (n=30) and high-quality studies, liquid-based cytology classified more slides as atypical squamous cells of unknown significance than did conventional cytology when compared with low-quality studies (n=17; p=0.05). Only four studies provided sufficient verified data to allow estimation of sensitivity and specificity and comparison of test accuracy.

INTERPRETATION

We saw no evidence that liquid-based cytology reduced the proportion of unsatisfactory slides, or detected more high-grade lesions in high-quality studies, than conventional cytology. This review does not lend support to claims of better performance by liquid-based cytology. Large randomised controlled trials are needed.

The comparative diagnostic accuracy of conventional and liquid-based cytology in a colposcopic setting

OBJECTIVE

This study was conducted to compare the performance of liquid-based cytology (LBC) and conventional cytology (CS) in the high prevalence setting of colposcopy clinic.

DESIGN

A split sample of matched ThinPrep (TP) and conventional smear from 563 patients were evaluated blindly. The performance of both techniques was compared with the gold standard of biopsy results or normal colposcopy examination in 441 cases.

SETTING

Colposcopy clinic of an inner city hospital for women and children.

SAMPLE

Five hundred and sixty-three women referred to colposcopy clinic over 14-month period.

METHODS

Cervical smears were taken from 563 women referred for colposcopy. Using the split-sample technique, the material was spread on a conventional (CS) slide and the remaining material rinsed in a PreservCyt solution. A T2000 processor was used to prepare LBC preparations. All women underwent colposcopy/biopsy according to local protocol. Four hundred and forty-one women met the diagnostic standard criteria of the study, which was either a normal colposcopy or histopathology result. Sensitivity, specificity and positive and negative predictive values were calculated for both methods of cytology preparations.

MAIN OUTCOME MEASURES

Matched TP and conventional smears, detection of abnormality, matched biopsies, sensitivity, specificity, and positive and negative predictive values.

RESULTS

Inadequate rates for CS and LBC (TP) were 4.3% and 0.68%, respectively. In 73% of cases, the CS and the LBC preparations showed exact agreement, whereas 77% agreement was seen when comparison was made for amalgamated low grade and high grade abnormalities. Low grade cytological abnormalities accounted for 44% of LBC slides versus 37% in CS slides. High grade cytological abnormalities accounted for 22% of LBC versus 17% seen in CS cases (P < 0.001). LBC showed increased sensitivity in the detection of CIN2 or worse than CS (92% and 83%, respectively) and CS showed greater specificity than LBC (82% and 76%, respectively).

CONCLUSIONS

In high prevalence setting, LBC performed at least as well as CS. The inadequate rate was significantly lower with LBC. The numbers are too small, however, to make confident comments about increased sensitivity and negative predictive value with LBC. Larger studies are required to verify these findings.

[Contribution of viral typing in cytological anomalies of the cervix]

Management practices for low-grade cervical lesions identified on screening swabs have been modified by research on the HPV. The appropriate approach for low-grade lesions is particularly difficult to determine due to the potential risk of malignant transformation coupled with the cost implications of treating lesions which will heal spontaneously in the majority of patients. The diagnosis of these low-grade lesions can be improved by thin layer swabs which have a greater sensitivity than conventional swabs. The current consensus is that swab results should be expressed according to the Bethesda classification. Routine tests for HPV (Hybrid Capture II) should be reserved for patients with an ASC-US swab. Colposcopy is indicated if the swab is positive for a low-grade lesion followed by cytology if the colposcopy is normal. If there is no evidence of HPV, search for oncogenes can lighten the treatment regimen due to the high specificity of the test. If a low-grade histological lesion (CIN1) is proven, cytocolposcopic surveillance should be proposed, surgical resection being undertaken in colposcopy cannot be performed. Here again search for HPV oncogenes at one year is an interesting alternative if the examination is negative. These practices are applicable in adolescents and HIV- positive patients who are particularly exposed to HPV.

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.

Cost-effectiveness of human papillomavirus DNA testing in the United Kingdom, The Netherlands, France, and Italy

BACKGROUND

European countries with established cytology-based screening programs for cervical cancer will soon face decisions about whether to incorporate human papillomavirus (HPV) DNA testing and what strategies will be most cost-effective. We assessed the cost-effectiveness of incorporating HPV DNA testing into existing cervical cancer screening programs in the United Kingdom, The Netherlands, France, and Italy.

METHODS

We created a computer-based model of the natural history of cervical carcinogenesis for each using country-specific data on cervical cancer risk and compared each country's current screening policy with two new strategies: 1) cytology throughout a woman's lifetime, using HPV DNA testing as a triage strategy for equivocal cytology results ("HPV triage"), as well as 2) cytology until age 30 years and HPV DNA testing in combination with cytology in women more than 30 years of age ("combination testing"). Outcomes included reduction in lifetime cervical cancer risk, increase in life expectancy, lifetime costs, and incremental cost-effectiveness ratios, expressed as cost per year of life saved. We explored alternative protocols and conducted sensitivity analysis on key parameters of the model over a relevant range of values to identify the most cost-effective options for each country.

RESULTS

Both HPV DNA testing strategies, HPV triage and combination testing, were more effective than each country's status quo screening policy. Incremental cost-effectiveness ratios for HPV triage were less than $13,000 per year of life saved, whereas those for combination testing ranged from $9800 to $75,900 per year of life saved, depending on screening interval. We identified options that would be very cost-effective (i.e., cost-effectiveness ratio less than the gross domestic product per capita) in each of the four countries.

CONCLUSIONS

HPV DNA testing has the potential to improve health benefits at a reasonable cost compared with current screening policies in four European countries.

Liquid-based cytologic specimen studies to screen for cervical dysplasia in rural El Salvador

OBJECTIVE

To evaluate an alternative tool (ThinPrep; Cytye Corporation, Boxborough, Mass, USA) for cervical cancer screening in rural El Salvador.

METHODS

Cervical samples were obtained from 471 women attending health fairs in rural El Salvador. The samples were read by American and Salvadoran pathologists after a 1-week training course in liquid-based cytologic studies in the United States.

RESULTS

The system evaluated detected a significantly higher number of high-grade and above lesions than conventional cytologic studies (P=0.01). There were 0.4% and 1.7% of high-grade lesions and above detected with conventionally prepared slides in the United States and El Salvador, respectively, and 3.2% and 3.8% of such lesions detected with liquid-based samples in the United States and El Salvador. Intra-observer agreement among the pathologists reading the samples was substantial for the ThinPrep system, with a kappa value of 0.6.

CONCLUSION

A short workshop is effective in training pathologists to use ThinPrep. In the studied population, liquid-based studies appear to offer significant advantages over conventional cytologic studies for detecting high-grade lesions.

Report of the 2003 pan-Canadian forum on cervical cancer prevention and control

OBJECTIVE

To develop evidence-based consensus recommendations on the delivery of cervical cancer screening, human papillomavirus (HPV) education, HPV testing, and the optimal tool for cervical cytology within the Canadian health system.

PARTICIPANTS

Leading up to a forum held in Ottawa on November 21 and 22, 2003, 254 registrants reviewed position papers through a Web-based discussion group. Experts in program management, clinical practice, epidemiology, public health, economics, and women's health, representing 48 organizations, then participated in the 2-day forum to develop consensus recommendations.

EVIDENCE

Writing groups prepared position papers on optimal methods for cervical cytology; education concerning HPV; HPV testing in primary screening; HPV testing as a triage tool in cytopathology; and delivery mechanisms for cervical screening. Systematic reviews were the primary source of evidence supplemented by literature searches.

CONSENSUS PROCESS

Feedback from Web-based discussions was incorporated into consecutive drafts of position papers. At the forum, recommendations and supporting evidence were presented, further debated in small-group sessions, and discussed in a plenary session. Despite divergent professional mandates and opinions, consensus was achieved on 15 recommendations across all areas. Final recommendations were posted to the Web for further input and circulated for written consensus by participants.

CONCLUSIONS

The recommendations cover the use of new evidence and technologies in cervical cancer prevention in Canada and provide a framework for provision of HPV education, planning the implementation of new cervical screening technologies in Canada, the development of evaluation plans, and new research areas.

Interobserver agreement in the interpretation of anal intraepithelial neoplasia

BACKGROUND

Anal carcinoma incidence is increasing, and is highest among men with human immunodeficiency virus (HIV) infection who have sex with men. Anal carcinoma and anal intraepithelial neoplasia (AIN) are ascertained on tissue histology, but requires invasive procedures. Screening for AIN using anal cytology was suggested. The authors evaluated agreement on cytologic and biopsy specimens from HIV-positive men undergoing anal carcinoma screening.

METHODS

One hundred twenty-nine HIV-positive men with a history of anal-receptive intercourse underwent anal cytology, anoscopy, and biopsy. Four pathologists independently assessed cytology and biopsy specimens and reached consensus for discordant cases.

RESULTS

Each pathologist evaluated 120 cytology and 155 biopsy specimens. The weighted kappa value for overall agreement was 0.54 (95% confidence interval [CI], 0.49-0.59) for cytology specimens and 0.59 (95%CI, 0.55-0.63) for biopsy specimens. The median kappa values for pairwise agreement among pathologists and for agreement with consensus were, respectively, 0.69 and 0.77 for cytology and 0.66 and 0.75 for biopsy. At least 3 pathologists were in agreement for 92 (76.7%) cytology and 134 (86.5%) biopsy specimens. Reliability for the Bethesda classification system was at least moderate, except for the cytologic category of atypical squamous cells of undetermined significance (kappa = 0.12). Fourteen of 29 (48.3%) cytology specimens and 36 of 47 (76.6%) biopsy specimens with consensus interpretation of high-grade squamous intraepithelial lesions (HSIL) were interpreted originally as HSIL by > or = 3 pathologists. The kappa value for agreement with consensus distinguishing HSIL from non-HSIL ranged from 0.55 to 0.88 for cytology specimens and from 0.76 to 0.94 for biopsy specimens.

CONCLUSIONS

Agreement for cytologic and biopsy interpretations was generally at least moderate. Nevertheless, these results supported the need for disease indicators with greater reliability.

Is there a role for colposcopy in the follow-up of treated low grade squamous intraepithelial lesions?

Is routine colposcopy justified in the follow up of treated low grade squamous intraepithelial lesions (LGSIL) of the cervix? This retrospective study analysed the notes of women treated at a public hospital colposcopy clinic over a 5-year period. Two hundred and fifty women fulfilled the inclusion criteria of whom 11 had persistent disease. Of these, only one case of LGSIL was detected by colposcopy in the absence of abnormal cytology. In the present study, routine colposcopy offered minimal additional benefit over cytology.

Significance of atypia in conventional Papanicolaou smears and liquid-based cytology: a follow-up study

The diagnosis of atypical squamous epithelial cells, borderline nuclear changes, is associated with some controversy, as it encompasses benign, reactive, as well as possible neoplastic conditions. The aim of this study was to evaluate the follow-up diagnoses of cytological atypia in conventional Papanicolaou smears (CP) and liquid-based samples by the ThinPrep Pap Test (TP). A total of 1607 CP smears from 1 January 2000 to 31 December 2000 and 798 TP samples from 1 January 2002 to 31 December 2002 diagnosed as atypia were included. The results show that the detection rate of atypia in cervical cytological samples was reduced by 41.3% (P < 0.001) in TP compared with CP. Cytological and histological follow-up data showed the presence of neoplastic lesions in 34.7% of patients screened by TP versus 22.3% of patients screened by CP, corresponding to a 55.6% increase in TP (P < 0.001). Follow-up diagnosis of mild dysplasia was seen more than twice as often in TP than in CP (12.8% versus 5.0%, P < 0.001). The prevalence of moderate and severe dysplasia was significantly increased with 26.7% in TP compared with CP (21.9% versus 17.2%, P < 0.01). In conclusion, the ThinPrep Pap Test yielded a significant decrease in atypia rates compared with the conventional Papanicolaou test. In subsequent follow-up the percentage of neoplastic lesions was significantly increased in the ThinPrep Pap Test samples.

Cytopathology in France

In France, organization of the cytopathology seems to be quite different from that specifically regulated in the USA and in some other European countries. The aim of this article is to underline these specificities and to describe the solutions we advocate concerning new technologies, teaching, quality assurance, national guidelines em leader, to make our current practice compatible with the international recommendations. Moreover, we highlight the peculiar status of French cytotechnologists' and comment on the recent dramatic decrease of the medical demography in France, the consequence of which may promote a controlled transfer of competence.

Cost-effectiveness of liquid-based cytology with or without hybrid-capture II HPV test compared with conventional Pap smears: A study by the French society of clinical cytology

Many articles concerning conventional Pap smears, ThinPrep liquid-based cytology (LBC) and Hybrid-Capture II HPV test (HC II) have been published. This study, carried out by the French Society of Clinical Cytology, may be conspicuous for several reasons: it was financially independent; it compared the efficiency of the conventional Pap smear and LBC, of the conventional Pap smear and HC II, and included an economic study based on real costs; for all the women, a "gold standard" reference method, colposcopy, was available and biopsies were performed whenever a lesion was detected; The conventional Pap smear, the LBC (split-sample technique), the colposcopy, and the biopsies were done at the same time. This study included 2,585 women shared into two groups: a group A of a high-risk population, a group B of a screening population. The statistical analysis of the results showed that conventional Pap smears consistently had superior or equivalent sensitivity and specificity than LBC for the lesions at threshold CIN-I (Cervical Intraepithelial Neoplasia) or CIN-II or higher. It underlined the low specificity of the HC II. Finally, the LBC mean cost was never covered by the Social Security tariff.

Crossing the quality chasm: a requirement for successful cervical cancer prevention in developing countries

Disease prevention requires sociopolitical change, which in turn requires the participation of those for whom the change is intended, including demographic groups at high risk for disease, appropriate governmental authorities, and essential health care personnel. Multiparous women of lowest socioeconomic status, the demographic group at highest risk for the development of cervical cancer, lack sociopolitical leverage almost by definition. Pap screening in developing countries is an idea whose time has come, but it is also an ethical imperative currently lacking a substantial sociopolitical constituency. Noncytologic screening methods currently benefit from sponsorship by corporate manufacturers and by donor organizations such as the Bill and Melinda Gates Foundation. Pap screening efforts in developing countries will benefit from the involvement of cytology organizations based in developed countries. Future assessments of the progress of cervical cancer prevention efforts in developing countries will benefit from additional examination of the interactions between quality and sociopolitical obstacles to change. Many of these obstacles will be elucidated by following the money, as well as the science, involved in cervical screening activities.

Pap test in a high-risk population comparison of conventional and liquid-base cytology

Liquid-based cytology (LBC) is believed to have better sensitivity than conventional smears (CSs) and offers the possibility to perform molecular assay. The goal of this work was to study the performance of CS and LBC in a high-risk population and to compare the results with the hybrid capture (HC) II for high-risk human papillomavirus (HPV). Samples were collected from selected women with clinical suspicions of low genital tract lesion at Pérola Biygnton Hospital (São Paulo, Brazil). After CS preparation, the brush was introduced in the endocervix and a new sample was collected and rinsed in the preservative medium of the system. The residual material was used to HC2. From 925 cases, LBC was unsatisfactory in 4 (1.51%) cases and CS was unsatisfactory in 100 cases (10.81%); among theses cases HC2(+) reactions was observed in 54 (54%) CSs and 3 (21.4%) LBCs. Considering cases with atypia of undetermined significance (squamous and glandular), 85 (77.27%) cases from LBC and 44 (86.4%) from CS were positive for HC2 assay for high-risk DNA-HPV. The difference among the methods was not significant (P < 0.38). The diagnosis improvement of LBC in comparison with CS was 86% in satisfactory samples, 92.76% in undetermined atypical lesions (including glandular), 83% in positive low-grade squamous intraepithelial lesions (LSIL(+)), and 86.84% in high-grade SIL(+) (HSIL(+)). HC2(+) reactions were observed in 144 CS cases and 266 LBC cases with abnormalities. Our results have showed that LBC was superior to CS in a high-risk population to detect lesions with high concordance with HC2(+) reactions; CSs also exhibit a high concordance with HC2 assay but with inferior performance to detect lesions.

An evaluation of liquid-based cytology and human papillomavirus testing within the UK cervical cancer screening programme

The aim of this study is to evaluate different options for introducing liquid-based cytology (LBC) and human papillomavirus (HPV) testing into the UK cervical cancer screening programme. These include options that incorporate HPV testing either as a triage for mild and borderline smear abnormalities or as a primary screening test. Outcomes include the predicted impact on resource use, total cost, life years and cost–effectiveness. Extensive sensitivity analysis has been carried out to explore the importance of the uncertainty associated with disease natural history and the impact of screening. Under baseline assumptions, the cost–effectiveness of different options for introducing LBC appears favourable, and these results are consistent under a range of assumptions for its impact on the diagnostic effectiveness of cytology. However, if we assume a higher marginal cost of LBC in comparison to conventional methods, primary smear testing options are predicted to be more cost-effective without LBC. Combined LBC primary smear and HPV testing with a 5-year interval is similar in both cost and effectiveness to the other 3-yearly options of primary smear testing or primary HPV testing alone. However, both primary HPV testing and combined options would give rise to a far greater risk of inappropriate colposcopy throughout a woman's lifetime.

Biomarkers for cancer diagnosis: implications for nutritional research

The biology of disease progression is a complex process that involves multiple sequential steps leading to cellular changes and metabolic events. These molecular events, which may serve as potential biomarkers, can be analyzed by laboratory methods and used to detect a disease such as cancer or indicate the biological exposure to environmental substances including dietary intake. Identification of the genetic, molecular, and clinical events involved in the disease process enables the development of effective therapeutic and preventive measures and the prediction of prognostic outcomes. This article describes various factors that influence nutritional and cancer biomarker research, draws similarities between them, and discusses the measures that have been adapted to validate cancer biomarkers that can potentially be applied to nutritional biomarker research. Nutritional research suffers from a lack of means to quantify relationships between diet and cancer. Biomarkers of dietary intake or metabolism, therefore, could have potential application in study designs for establishing a causal relationship between diet and disease.

Evidence Supporting the Current Management Guidelines for High-Grade Squamous Intraepithelial Lesion Cytology

OBJECTIVE

The study was undertaken to provide consensus guidelines for the management of women with a cytologic interpretation of high-grade squamous intraepithelial lesion (HSIL) on cytologic examination. This review article presents relevant literature supporting the proposed guidelines.

PARTICIPANTS

An independent panel of 121 experts in various aspects of the diagnosis and management of cervical cancer precursors, including representatives from 29 participating professional organizations, federal agencies, national and international health organizations, and others were invited by the American Society for Colposcopy and Cervical Pathology.

CONSENSUS PROCESS

Guidelines for the management of women with HSIL cytologic results were developed through a multistep process. Draft management guidelines were developed by the HSIL working group after formal literature reviews and obtained input from the professional community at large by way of an interactive internet-based bulletin board. At the American Society for Colposcopy and Cervical Pathology Consensus Conference, September 6 through 8, 2001, in Bethesda, Maryland, the guidelines were discussed, revised, and adopted by formal vote.

CONCLUSIONS

Evidence-based guidelines have been developed for the management of women with HSIL cytologic results.

ThinPrep versus conventional Papanicolaou smear in the cytologic follow-up of women with equivocal cervical smears

BACKGROUND

The purpose of the current study was to compare the efficacy of liquid-based cytology and conventional smears in the cytologic follow-up of cases with "atypical squamous cells, cannot exclude a high-grade lesion" (ASC-H) or "atypical glandular cells" (AGC).

METHODS

Cytologic follow-up was performed on 214 cases with ASC-H/AGC diagnosis an conventional smears using either ThinPrep (n = 100) or conventional Papanicoloau (Pap) tests (n = 114). Results were then compared with further histologic and/or cytologic follow-up.

RESULTS

Repetition on conventional smears enabled a definite diagnosis (within normal limits [WNL], squamous intraepithelial lesion [SIL] or carcinoma) in 58 cases (50.9%). ASC/AGC was confirmed in 50 cases (43.9%), and 6 of the smears (5.3%) were inadequate. WNL, SIL, or carcinoma was diagnosed in 82 (82.0%) cases by following the patients with ThinPrep cytology, whereas ASC or AGC was confirmed in 18 cases (18.0%). No inadequate specimens were found. A diagnosis of SIL or greater (SIL +) was confirmed histologically in 11 of 11 (100.0%) conventional smears and in 31 of 34 (91.2%) ThinPrep specimens. Of the 87 WNL specimens, 9 (8 conventional smears and 1 ThinPrep specimen) developed a histologically confirmed SIL during further follow-up. Specimen adequacy was significantly better in the ThinPrep specimens compared with conventional smears.

CONCLUSIONS

Because of better specimen adequacy, ThinPrep cervical cytology appears to significantly reduce the occurrence of ASC/AGC compared with conventional Pap smears.