Long term predictive values of cytology and human papillomavirus testing in cervical cancer screening: joint European cohort study

Factors associated with non-attendance, opportunistic attendance and reminded attendance to cervical screening in an organized screening program: a cross-sectional study of 12,058 Norwegian women

BACKGROUND

Cervical cancer incidence and mortality may be reduced by organized screening. Participant compliance with the attendance recommendations of the screening program is necessary to achieve this. Knowledge about the predictors of compliance is needed in order to enhance screening attendance.

METHODS

The Norwegian Co-ordinated Cervical Cancer Screening Program (NCCSP) registers all cervix cytology diagnoses in Norway and individually reminds women who have no registered smear for the past three years to make an appointment for screening. In the present study, a questionnaire on lifestyle and health was administered to a random sample of Norwegian women. The response rate was 68%. To address the predictors of screening attendance for the 12,058 women aged 25-45 who were eligible for this study, individual questionnaire data was linked to the cytology registry of the NCCSP. We distinguished between non-attendees, opportunistic attendees and reminded attendees to screening for a period of four years. Predictors of non-attendance versus attendance and reminded versus opportunistic attendance were established by multivariate logistic regression.

RESULTS

Women who attended screening were more likely than non-attendees to report that they were aware of the recommended screening interval, a history of sexually transmitted infections and a history of hormonal contraceptive and condom use. Attendance was also positively associated with being married/cohabiting, being a non-smoker and giving birth. Women who attended after being reminded were more likely than opportunistic attendees to be aware of cervical cancer and the recommended screening interval, but less likely to report a history of sexually transmitted infections and hormonal contraceptive use. Moreover, the likelihood of reminded attendance increased with age. Educational level did not significantly affect the women's attendance status in the fully adjusted models.

CONCLUSIONS

The likelihood of attendance in an organized screening program was higher among women who were aware of cervical screening, which suggests a potential for a higher attendance rate through improving the public knowledge of screening. Further, the lower awareness among opportunistic than reminded attendees suggests that physicians may inform their patients better when smears are taken at the physician's initiative.

Eurogin 2010 roadmap on cervical cancer prevention

The EUROGIN 2010 roadmap represents a continuing effort to provide and interpret updated information on cervical cancer screening and vaccination against the cause of the disease, high-risk human papillomavirus (HPV). Contrary to the two previous reports in 2008 and 2009, the present roadmap gives equal room to HPV-based screening and HPV vaccination, as a result of the recent strengthening of the evidence on the efficacy and feasibility of both approaches. The superiority of HPV testing in primary screening compared to cytology (in more developed countries) and to cytology or visual inspection methods (in less developed countries) has been demonstrated in several randomised trials. High vaccine efficacy has been confirmed up to 7 years after vaccination; school-based programmes in some countries have been able to reach over 70% coverage among adolescent girls. Demonstration projects have indicated that the delivery of HPV vaccines in less developed countries is feasible and favourably received by populations where cervical cancer is very common. HPV-based screening can diminish cervical cancer incidence more quickly than HPV vaccination, but vaccination can eventually facilitate screening efforts, especially if new vaccines against a greater number of HPV types are introduced. The availability of two highly complementary prevention tools such as HPV testing and HPV vaccination makes it possible to conceive integrated strategies for the elimination of cervical cancer that have no precedent in the cancer field. HPV tests and HPV vaccines remain, however, too expensive, and large-scale financing of screening and vaccination in less developed countries is sorely lacking.

Comparison of clinical and analytical performance of the Abbott Realtime High Risk HPV test to the performance of hybrid capture 2 in population-based cervical cancer screening

The clinical performance of the Abbott RealTime High Risk HPV (human papillomavirus) test (RealTime) and that of the Hybrid Capture 2 HPV DNA test (hc2) were prospectively compared in the population-based cervical cancer screening setting. In women >30 years old (n = 3,129), the clinical sensitivity of RealTime for detection of cervical intraepithelial neoplasia of grade 2 (CIN2) or worse (38 cases) and its clinical specificity for lesions of less than CIN2 (3,091 controls) were 100% and 93.3%, respectively, and those of hc2 were 97.4% and 91.8%, respectively. A noninferiority score test showed that the clinical specificity (P < 0.0001) and clinical sensitivity (P = 0.011) of RealTime were noninferior to those of hc2 at the recommended thresholds of 98% and 90%. In the total study population (women 20 to 64 years old; n = 4,432; 57 cases, 4,375 controls), the clinical sensitivity and specificity of RealTime were 98.2% and 89.5%, and those of hc2 were 94.7% and 87.7%, respectively. The analytical sensitivity and analytical specificity of RealTime in detecting targeted HPV types evaluated with the largest sample collection to date (4,479 samples) were 94.8% and 99.8%, and those of hc2 were 93.4% and 97.8%, respectively. Excellent analytical agreement between the two assays was obtained (kappa value, 0.84), while the analytical accuracy of RealTime was significantly higher than that of hc2. RealTime demonstrated high intralaboratory reproducibility and interlaboratory agreement with 500 samples retested 61 to 226 days after initial testing in two different laboratories. RealTime can be considered to be a reliable and robust HPV assay clinically comparable to hc2 for the detection of CIN2+ lesions in a population-based cervical cancer screening setting.

A comparison of HPV DNA testing and liquid based cytology over three rounds of primary cervical screening: extended follow up in the ARTISTIC trial

BACKGROUND

The additional sensitivity of HPV testing compared with cytology could permit extended cervical screening intervals. We wished to determine, through a further (third) round of screening in the ARTISTIC trial, the protection provided by a negative baseline HPV screen compared with that of cytology over a 6 year period.

METHODS

Cumulative rates of CIN2 or worse (CIN2+) and CIN3 or worse (CIN3+) were correlated with baseline HPV status and cytology. HPV was detected using the Hybrid Capture 2 (Qiagen) assay for high risk types and genotyped using the Linear Array (Roche) and Papillocheck (Greiner) assays. LBC was performed using ThinPrep (Hologic).

FINDINGS

Round 3 included 8,873 women of whom 6,337 had been screened in both rounds 1 and 2 and 2,536 had not been screened since round 1. The median duration of follow-up was 72.7 months. The cumulative rate of CIN2+ over three rounds was 3.88% (95%CI 3.59%, 4.17%) overall; 2.39% in round 1, 0.78% in round 2 and 0.74% in round 3. Cumulative rates by baseline status were 20.53% (95%CI 19.04%, 22.08%) for abnormal cytology, 20.12% (95%CI 18.68%, 21.61%) for HPV detection, 1.41% (95%CI 1.19%, 1.65%) for negative cytology and 0.87% (95%CI 0.70%, 1.06%) for a negative HPV test. In HPV negative women aged over 50 the cumulative rate was 0.16% (95%CI 0.07%, 0.34%). Women who were HPV positive/cytology negative at entry had a cumulative CIN2+ rate of 7.73% (95%CI 6.29%, 9.36%) over 6 years, twice the overall rate.

INTERPRETATION

A negative HPV test was significantly more protective than normal cytology over three rounds. The findings of this extension of ARTISTIC suggest that the screening interval could be extended to 6 years if HPV testing replaced cytology as the primary screening test.

Human papillomavirus testing in the prevention of cervical cancer

Strong evidence now supports the adoption of cervical cancer prevention strategies that explicitly focus on persistent infection with the causal agent, human papillomavirus (HPV). To inform an evidence-based transition to a new public health approach for cervical cancer screening, we summarize the natural history and cervical carcinogenicity of HPV and discuss the promise and uncertainties of currently available screening methods. New HPV infections acquired at any age are virtually always benign, but persistent infections with one of approximately 12 carcinogenic HPV types explain virtually all cases of cervical cancer. In the absence of an overtly persistent HPV infection, the risk of cervical cancer is extremely low. Thus, HPV test results predict the risk of cervical cancer and its precursors (cervical intraepithelial neoplasia grade 3) better and longer than cytological or colposcopic abnormalities, which are signs of HPV infection. The logical and inevitable move to HPV-based cervical cancer prevention strategies will require longer screening intervals that will disrupt current gynecologic and cytology laboratory practices built on frequent screening. A major challenge will be implementing programs that do not overtreat HPV-positive women who do not have obvious long-term persistence of HPV or treatable lesions at the time of initial evaluation. The greatest potential for reduction in cervical cancer rates from HPV screening is in low-resource regions that can implement infrequent rounds of low-cost HPV testing and treatment.

Promising strategies for cervical cancer screening in the post-human papillomavirus vaccination era

Human papillomavirus (HPV) vaccination is expected to reduce the burden of cervical cancer in most settings; however, it is also expected to interfere with the effectiveness of screening. In the future, maintaining Pap cytology as the primary cervical screening test may become too costly. As the prevalence of cervical dysplasias decreases, the positive predictive value of the Pap test will also decrease, and, as a result, more women will be referred for unnecessary diagnostic procedures and follow-up. HPV DNA testing has recently emerged as the most likely candidate to replace cytology for primary screening. It is less prone to human error and much more sensitive than the Pap smear in detecting high-grade cervical lesions. Incorporating this test would improve the overall quality of screening programs and allow spacing out screening tests, while maintaining safety and lowering costs. Although HPV testing is less specific than Pap cytology, this issue could be resolved by reserving the latter for the more labour-efficient task of triaging HPV-positive cases. Because most HPV-positive smears would contain relevant abnormalities, Pap cytology would be expected to perform with sufficient accuracy under these circumstances. HPV Pap triage would also provide a low-cost strategy to monitor long-term vaccine efficacy. Although demonstration projects could start implementing HPV testing as a population screening tool, more research is needed to determine the optimal age to initiate screening, the role of HPV typing and other markers of disease progression, and appropriate follow-up algorithms for HPV-positive and Pap-negative women.

Human papillomavirus DNA testing for cervical cancer screening: practical aspects in developing countries

Cervical cancer is the second most common cancer in women worldwide, and the most common cause of death from cancer in women in the developing world. Cervical cancer represents the only gynecologic cancer that can be prevented through regular screening. Although there are established screening programs in the Western world that have effectively reduced the burden of cervical cancer, these programs have relied on insensitive screening technologies that depend on the long preinvasive phase of cervical carcinogenesis. The developing world faces specific additional challenges in implementing a successful cervical cancer screening program. The association between cervical cancers and human papillomavirus (HPV) make testing for the presence of HPV DNA a valuable screening tool. This review focuses on practical aspects of the implementation and delivery of HPV testing as the primary cervical cancer screening strategy in the developing world, and attempts to offer some solutions to the real-world challenges faced in these regions.

Evaluation of oncogenic human papillomavirus RNA and DNA tests with liquid-based cytology in primary cervical cancer screening: the FASE study

The APTIMA HPV Assay (AHPV) allows detection of 14 high-risk human papillomavirus (HPV) RNA types in cervical specimens. Until present, the assay has been compared to HPV DNA tests only in triage settings. Herein, we compare AHPV with a DNA assay (Hybrid Capture 2; HC2) and liquid-based cytology (LBC; using PreservCyt ThinPrep liquid Pap) in a screening setting (French APTIMA screening evaluation [FASE] study). Women (N = 5,006) aged 20-65 were screened by gynecologists in 17 private practices in Paris, France. One cervical specimen was collected and tested with LBC, AHPV and HC2 assays. Women were referred to colposcopy if they were ASC-US+ in LBC or HPV positive in either HPV assay. To control for verification bias, a random group (14%) with normal LBC and dually HPV negative tests underwent colposcopy. Data from 4,429 women were analyzed. Sensitivity, specificity and predictive values were calculated for the three tests. AHPV and HC2 were highly sensitive for CIN2+ (92.0% and 96.7%) and CIN3+ (95.7% and 95.3%) detection and much more sensitive than LBC (69.1% for CIN2+ and 73.3% for CIN3+). Specificity of AHPV was higher than that of HC2, but similar to that of LBC (p < 0.001). Combining LBC with either HPV test slightly increased sensitivity but compromised specificity. AHPV assay is both specific and sensitive for the detection of high-grade precancerous lesions and may be considered as an option for routine cervical cancer screening for women over 20 years of age.

Cost-effectiveness analysis of human papillomavirus DNA testing and Pap smear for cervical cancer screening in a publicly financed health-care system

Objective:

To evaluate the long-term cost-effectiveness of different strategies for human papillomavirus (HPV) DNA testing combined with Pap smear for cervical cancer screening in Taiwan.

Methods:

This study adopts a perspective of Department of Health in cost-effectiveness analysis to compare a no-screening strategy with nine different screening strategies. These strategies comprise three screening tools (Pap smear alone, HPV DNA testing followed by Pap smear triage, and HPV DNA testing combined with Pap smear), and three screening intervals (annually, every 3 years, and every 5 years). Outcomes are life expectancy, quality-adjusted life years (QALYs), lifetime costs, and incremental cost-effectiveness ratios (ICERs). Probabilistic sensitivity analyses (PSAs) were conducted to assess parameter uncertainty.

Results:

When three times gross domestic product per capita is used as the decision threshold, all nine screening strategies were cost-effective compared with the no-screening strategy. Compared with the current screening strategy (an annual Pap smear), HPV DNA testing followed by Pap smear triage every 5 years and every 3 years were cost-effective. Results of PSA also indicated that a HPV DNA testing followed by Pap smear triage every 5 or every 3 years achieved the highest expected net benefits.

Conclusions:

Possible economic advantages are associated with extending the cervical cancer screening interval from one Pap smear annually to HPV DNA testing followed by Pap smear triage every 5 years with an ICER $1 247 000 per QALY gained, especially in a country with a publicly financed health-care system.

Quantitative analysis of methylation status of the PAX1 gene for detection of cervical cancer

OBJECTIVE

Although aided by high-risk human papillomavirus (HPV) DNA test, early detection of cervical cancer is still a challenge. Hypermethylation of the paired boxed gene 1 (PAX1) was recently reported as a characteristic of cervical cancer. This study designed a quantitative measure of PAX1 methylation and compared its efficacy to the currently available Hybrid Capture 2 (HC2) HPV test in detection of cervical cancer.

METHODS

Using real-time quantitative methylation-specific polymerase chain reaction, we measured the percentage of PAX1 methylation in cervical scrapings obtained from a hospital-based cohort of women with cervical neoplasia of different severities and compared the efficacy of diagnosis of cervical cancer to that of the HC2 HPV test.

RESULTS

From 73 cervical scrapings, with diagnoses of normal (n = 17), cervical intraepithelial neoplasm 1 (CIN1; n = 10), CIN2 (n = 18), CIN3 (n = 14), and invasive cancer (n = 14), the percentage of PAX1 methylation was determined. The percent of methylated reference of invasive cancer (mean [SE], 56.7 [7.1]) was significantly higher than CIN3 (6.5 [2.3]) and the other milder lesions (1.0 [0.3]; P < 0.0001). At a cutoff percent of methylated reference value of 4.5, PAX1 methylation was found in 100% of invasive cancer tissue as compared with 0% of normal tissue, 10% of CIN1, 11% of CIN2, and 43% of CIN3 (P < 0.0001). As a comparison, the HC2 HPV test result was positive in 5.9% of normal tissue, 70% of CIN1, 55.6% of CIN2, 71.4% of CIN3, and 100% of invasive cancer. In addition to cancer tissue, methylation of PAX1 was also found in normal tissue adjacent to the cancer lesion (9/11, 82%) but much less in the remote normal tissues (2/5, 40%), indicating a field methylation.

CONCLUSIONS

In this hospital-based study, quantitative measurement of PAX1 hypermethylation in cervical scrapings is highly sensitive and is more specific than HC2 in detection of cervical cancer.

Performance of high-risk human papillomavirus DNA testing as a primary screen for cervical cancer: a pooled analysis of individual patient data from 17 population-based studies from China

BACKGROUND

Controversy remains over whether high-risk human papillomavirus (HPV) DNA testing should be used as a primary screen for cervical cancer. The aims of our study were to assess whether HPV DNA testing could be applied to cervical-cancer screening programmes in China, as well as other similar developing countries.

METHODS

We did a pooled analysis of population-based cervical cancer screening studies done in mainland China from 1999 to 2008 with concurrent HPV DNA testing (Hybrid Capture 2 assay; Qiagen, Gaithersburg, MD, USA), liquid-based cytology (LBC), and visual inspection with acetic acid (VIA). Eligible women were sexually active, not pregnant, had an intact uterus, and had no history of cervical intraepithelial neoplasia (CIN), cervical cancer, or pelvic irradiation. All women positive for any test were referred for colposcopy and biopsy. Cervical lesions were diagnosed by directed or random biopsy. We assessed the diagnostic accuracy of HPV DNA testing for the detection of CIN grade 3 or greater.

FINDINGS

30,371 women from 17 cross-sectional, population-based studies in various parts of China were screened. 1523 women were subsequently excluded because of inadequate HPV DNA specimens or they did not have a biopsy taken, which included women with atypical squamous cells of undetermined significance; low-grade squamous intraepithelial lesion or worse; positive HPV, negative cytology, and missing or positive colposcopy results; and unsatisfactory cytology results. HPV DNA testing had a higher sensitivity of 97·5% (95% CI 95·7-98·7) for detection of CIN grade 3 or worse, and a lower specificity of 85·1% (82·3-87·9), compared with cytology (sensitivity 87·9% [95% CI 84·7-90·7], specificity 94·7% [93·5-96·0]) and VIA (54·6% [48·0-61·2], 89·9% [86·8-93·0]). Sensitivity did not vary by study or age (<35 years, 35-49 years, ≥50 years); however, specificity did vary with age (p<0·0001) and was highest in women younger than 35 years (89·4%; 95% CI 86·1-91·5). An increase in the positive cutoff point from the manufacturer recommended 1 pg/mL to 2 pg/mL led to a decrease in the overall HPV DNA positivity from 16·3% to 13·9% (p<0·0001), which could result in a decrease in referral rates, although sensitivity was slightly lower (97·5% to 95·2%). An increase in the cutoff point to 10 pg/mL in women younger than 35 years maintained a high sensitivity 97·7% (95% CI 87·7-99·9) and increased specificity to 93·5% (95% CI 91·9-94·6).

INTERPRETATION

HPV DNA testing is highly sensitive and moderately specific for CIN grade 3 or worse, with consistent results across study sites and age groups-including women younger than 35 years. A rise in the cutoff point might be beneficial for future screening programmes in China, especially when screening women younger than 35 years.

Correlation between hybrid capture II high-risk human papillomavirus DNA test chemiluminescence intensity from cervical samples with follow-up histologic results: a cytologic/histologic review of 367 cases

BACKGROUND

The Hybrid Capture II high-risk human papillomavirus (hrHPV) DNA test is a US Food and Drug Administration-approved nucleic acid hybridization assay using chemiluminescence for the semiquantitative detection of hrHPV in cervical samples. Patient samples and controls are used to calculate results as negative for hrHPV if <1.0, positive for hrHPV if >2.5, and "equivocal" if between 1.0 and 2.5.

METHODS

The authors reported on the cervical histologic results of 209 patients demonstrating "equivocal" results for hrHPV from SurePath (204 patients) or ThinPrep (5 patients) vials, and compared patients in this cohort with atypical squamous cells of undetermined significance (ASC-US) cytology on the index cervical Papanicolaou (Pap) test (Group 1; n = 148 patients) with a patient cohort demonstrating unequivocal positive hrHPV test results (Group 2; n = 148 patients). The chemiluminescence intensity of hrHPV tests from patients in Group 2 were correlated with the presence and severity of dysplasia on subsequent histologic results, and patients were thereby stratified for their subsequent risk of cervical intraepithelial neoplasia (CIN) types II/III.

RESULTS

Approximately 97% of hrHPV tests demonstrating "equivocal" results were found to be positive at the time of retesting, and 15% of biopsied cases demonstrated CIN II or III. Results of follow-up histology after an ASC-US diagnosis, expressed as a percentage of the biopsied cohort, were: CIN II/III: 16.5% in Group 1 and 22.4% in Group 2; CIN I: 27% in Group 1 and 23.5% in Group 2; and negative: 56.5% in Group 1 and 54.1% in Group 2. Chemiluminescence intensity did not appear to be correlated with the severity of dysplasia.

CONCLUSIONS

The percentage of high-grade CIN in the "equivocal" hrHPV cohort is highly significant and therefore the management of these patients should be similar to the unequivocally positive population. After an unequivocal positive hrHPV test, the hrHPV chemiluminescence intensity does not appear to further predict the rate of high-grade CIN.

Integrating novel primary- and secondary-prevention strategies: the next challenge for cervical cancer control

The advent of prophylactic vaccines against human papillomavirus (HPV) infection, the cause of cervical cancer, and of new molecular methods to screen for this disease have become key developments in cancer control in the last 5 years. Although Pap cytology has had a significant history as a key method for cervical cancer screening, not all countries have benefited from this technology or have been able to implement the necessary public health steps to manage and treat the precancerous lesions that are detected by the Pap test. Testing of cervical exfoliated cells for DNA of oncogenic HPV types has been proven to be more accurate than Pap cytology. The latter test’s high specificity makes it an ideal technique to triage women who are found to be HPV positive via a primary screen. HPV testing followed by Pap testing only for HPV-positive women is a promising strategy for screening women in the post-vaccination era.

Cost-effectiveness of high-risk human papillomavirus testing for cervical cancer screening in Québec, Canada

OBJECTIVES

Human papillomavirus (HPV) testing is not widely used for triage of equivocal Pap smears or primary screening in Québec, Canada. Our objective was to evaluate the cost-effectiveness of cervical cancer screening strategies utilizing HPV testing.

METHODS

We used a lifetime Markov model to estimate costs, quality of life, and survival associated with the following strategies: 1) cytology; 2) cytology with HPV testing to triage equivocal Pap smears; 3) HPV testing followed by colposcopy for HPV-positive women; 4) HPV testing with cytology to triage HPV-positive women; and 5) simultaneous HPV testing and cytology. Cytology was used in all strategies prior to age 30. Outcome measures included disease incidence, quality-adjusted life-years saved (QALYs), lifetime risk of cervical cancer, and incremental cost-effectiveness ratios.

RESULTS

All strategies incorporating HPV testing as a primary screening test were more effective and less expensive than annual cytology alone, while HPV testing to triage equivocal Pap smears annually was very cost-effective ($2,991 per QALY gained compared to annual cytology alone). When compared to cytology every three years, HPV-based strategies cost an additional $8,200 to $13,400 per QALY gained.

CONCLUSION

Strategies incorporating HPV testing are not only more effective than screening based on cytology alone but are also highly cost-effective. Provincial policy-makers should evaluate incorporating HPV-based strategies into current cervical cancer screening guidelines.

Long-term absolute risk of cervical intraepithelial neoplasia grade 3 or worse following human papillomavirus infection: role of persistence

BACKGROUND

Infection with high-risk human papillomavirus (HPV) is the main cause of high-grade cervical intraepithelial neoplasia (CIN) and cancer. It has been suggested that information about high-risk HPV type-specific infection might make cervical cancer screening more effective. Persistent HPV infection could also be a useful screening marker. We estimated the long-term risk of high-grade CIN after one-time detection of high-risk HPV DNA and after persistent infection with individual high-risk HPV types.

METHODS

A cohort of 8656 women from the general population of Denmark was examined twice, 2 years apart (first study examination: May 15, 1991, to January 31, 1993; second study examination: October 1, 1993, to January 31, 1995). The women underwent a gynecological examination and cervical cytology and had swabs taken for HPV DNA analysis by the Hybrid Capture 2 and line probe assays. The women were followed up through the nationwide Danish Pathology Data Bank for cervical neoplasia for up to 13.4 years. The absolute risk of developing cervical lesions before a given time was estimated as a function of time.

RESULTS

For women with normal cytological findings who were concurrently HPV16 DNA positive at the second examination, the estimated probability of developing CIN grade 3 (CIN3) or worse within 12 years of follow-up was 26.7% (95% confidence interval [CI] = 21.1% to 31.8%). The corresponding risks among those infected with HPV18 was 19.1% (95% CI = 10.4% to 27.3%), with HPV31 was 14.3% (95% CI = 9.1% to 19.4%), and with HPV33 was 14.9% (95% CI = 7.9% to 21.1%). The absolute risk of CIN3 or worse after infection with high-risk HPV types other than HPV16, HPV18, HPV31, or HPV33 was 6.0% (95% CI = 3.8% to 8.3%). The estimated absolute risk for CIN3 or cancer within 12 years of the second examination among women who were HPV16 DNA positive at both examinations was 47.4% (95% CI = 34.9% to 57.5%); by contrast, the risk of CIN3 or worse following a negative Hybrid Capture 2 test was 3.0% (95% CI = 2.5% to 3.5%).

CONCLUSION

HPV16, HPV18, HPV31, and HPV33 infection and especially HPV16 persistence were associated with high absolute risks for progression to high-grade cervical lesions. The results indicate the potential value of genotyping in cervical cancer screening. Given that HPV DNA-negative women retained their low risk of CIN3 or worse for many years, frequent screening of these women may be unnecessary.

Population fraction of cervical neoplasia attributable to high-risk human papillomaviruses

AIMS

The efficacy of human papillomavirus (HPV) type 16 and 18 vaccines against cervical intraepithelial neoplasia grade II (CIN2+) has been verified, but the active follow-up of studies with invasive cervical cancer or cervical intraepithelial neoplasia grade III (CIN3) as primary end points are ethically not possible. Furthermore, ongoing registry-based passive follow-up studies with invasive cervical cancer as the end point will take time.

MATERIALS & METHODS

To evaluate the feasibility of CIN3 as a surrogate end point, we compared high-risk (hr) HPV-associated relative risk and population attributable fraction (PAF) of CIN3 and/or squamous cell carcinoma (SCC) estimated in a large serological case-cohort HPV study. Our case-cohort comprised 83 SCC and 389 CIN3 cases and a subcohort of 7862 out of 230,998 Finnish women, who at baseline were under 32 years of age and had undergone a minimum of two pregnancies within 5 years during 1983-1997.

RESULTS

PAFs of the case-cohort, approach-based, serologically defined and misclassification-corrected HPV16 and hrHPV (HPV types 16, 18, 31 and 33) exposures in the SCC samples were 61% (95% CI: 18-85) and 73% (95% CI: 13-93), respectively. Considerably lower HPV16 and hrHPV PAF estimates in CIN3 of 6% (95% CI: -19-35) and 36% (95% CI: -5-65), respectively, were obtained. A meta-analysis-derived, PCR-based, hrHPV-associated relative risk estimate of 20.3 in CIN2/3+ yielded a PAF estimate for hrHPV in CIN2/3+ of 86% (90% CI: 63-95) in our study population. The former, hrHPV serology-based CIN3 PAF estimates were biased owing to low sensitivity of HPV16 and/or HPV16/18/31/33 serology, most notably in cervical cancer precursor lesions, but the latter estimate overlapped with our hrHPV serology-based cervical cancer PAF estimate.

CONCLUSION

CIN3 may be a valid surrogate efficacy end point for HPV vaccination studies, but the associated causality of multiple hrHPV exposures needs to be unambigously defined.

Cost-effectiveness of human papillomavirus vaccination and screening in Spain

BACKGROUND

In Spain, prophylactic vaccination against human papillomavirus (HPV) types 16 and 18 is being offered free-of-charge to one birth cohort of girls aged 11-14. Screening is opportunistic (annual/biannual) contributing to social and geographical disparities.

METHODS

A multi-HPV-type microsimulation model was calibrated to epidemiologic data from Spain utilising likelihood-based methods to assess the health and economic impact of adding HPV vaccination to cervical cancer screening. Strategies included (1) screening alone of women over age 25, varying frequency (every 1-5 years) and test (cytology, HPV DNA testing); (2) HPV vaccination of 11-year-old girls combined with screening. Outcomes included lifetime cancer risk, life expectancy, lifetime costs, number of clinical procedures and incremental cost-effectiveness ratios.

RESULTS

After the introduction of HPV vaccination, screening will need to continue, and strategies that incorporated HPV testing are more effective and cost-effective than those with cytology alone. For vaccinated girls, 5-year organised cytology with HPV testing as triage from ages 30 to 65 costs 24,350€ per year of life saved (YLS), assuming life-long vaccine immunity against HPV-16/18 by 3 doses with 90% coverage. Unvaccinated girls would benefit from organised cytology screening with HPV testing as triage; 5-year screening from ages 30 to 65 costs 16,060€/YLS and 4-year screening from ages 30 to 85 costs 38,250€/YLS. Interventions would be cost-effective depending on the cost-effectiveness threshold and the vaccine price.

CONCLUSIONS

In Spain, inequitable coverage and overuse of cytology make screening programmes inefficient. If high vaccination coverage among pre-adolescent girls is achieved, organised cytology screening with HPV triage starting at ages 30 to at least 65 every 4-5 years represents the best balance between costs and benefits.

Evaluation of the performance of the novel PapilloCheck HPV genotyping test by comparison with two other genotyping systems and the HC2 test

The novel PapilloCheck genotyping test was compared with SPF10 PCR LiPav1 and PGMY09/11 on hybrid capture 2 (HC2)-pretested samples. From results of 826 cervical samples detection rates and kappa values for the tests were calculated using a HPV type consensus definition. With PapilloCheck HPV types 53, 56, and 33 were found with a sensitivity of 100%. The lowest detection rate was observed for HPV 35 (72.2%). The SPF10 PCR LiPav1 was found to be 100% positive for HPV 18, 31, 53, 56, and 35 and lowest for HPV 59 (81%). The PGMY09/11 system detected only HPV 59 at 100% detection rate and showed lowest sensitivity for HPV 56 (40.5%). Multiple infection rates ranged from 25.8% (PGMY09/11 PCR-LBA), over 39.5% (PapilloCheck) to 55.9% (SPF10 PCR LiPav1). In samples with higher viral DNA load detection rates and concordance between the genotyping tests increases. The kappa values in comparison to the HPV consensus type ranged from k = 0.21 to k = 0.82 for comparing SPF10 PCR with the HPV consensus type, while values for PGMY09/11 PCR ranged from k = 0 to k = 0.96 and were best for the PapilloCheck (k = 0.49-0.98). Detection rates for the identification of high-grade cervical intraepithelial neoplasia (CIN2+) ranged from 93.7% (PGMY09/11 PCR) to 98.4% (PapilloCheck, SPF10 PCR, HC2). In conclusion, this study shows that the PapilloCheck give comparable results to established PCR methods. However, these results also show a necessity for the standardization of genotype-specific HPV detection assays.

Cost-effectiveness of high-risk human papillomavirus testing for cervical cancer screening in Québec, Canada

OBJECTIVES

Human papillomavirus (HPV) testing is not widely used for triage of equivocal Pap smears or primary screening in Québec, Canada. Our objective was to evaluate the cost-effectiveness of cervical cancer screening strategies utilizing HPV testing.

METHODS

We used a lifetime Markov model to estimate costs, quality of life, and survival associated with the following strategies: 1) cytology; 2) cytology with HPV testing to triage equivocal Pap smears; 3) HPV testing followed by colposcopy for HPV-positive women; 4) HPV testing with cytology to triage HPV-positive women; and 5) simultaneous HPV testing and cytology. Cytology was used in all strategies prior to age 30. Outcome measures included disease incidence, quality-adjusted life-years saved (QALYs), lifetime risk of cervical cancer, and incremental cost-effectiveness ratios.

RESULTS

All strategies incorporating HPV testing as a primary screening test were more effective and less expensive than annual cytology alone, while HPV testing to triage equivocal Pap smears annually was very cost-effective ($2,991 per QALY gained compared to annual cytology alone). When compared to cytology every three years, HPV-based strategies cost an additional $8,200 to $13,400 per QALY gained.

CONCLUSION

Strategies incorporating HPV testing are not only more effective than screening based on cytology alone but are also highly cost-effective. Provincial policy-makers should evaluate incorporating HPV-based strategies into current cervical cancer screening guidelines.

Rate of cervical cancer, severe intraepithelial neoplasia, and adenocarcinoma in situ in primary HPV DNA screening with cytology triage: randomised study within organised screening programme

OBJECTIVE

To assess the performance and impact of primary human papillomavirus (HPV) DNA screening with cytology triage compared with conventional cytology on cervical cancer and severe pre-cancerous lesions.

DESIGN

Randomised trial.

SETTING

Population based screening programme for cervical cancer in southern Finland in 2003-5.

PARTICIPANTS

58 076 women, aged 30-60, invited to the routine population based screening programme for cervical cancer.

INTERVENTIONS

Primary HPV DNA test (hybrid capture II) with cytology triage if the result was positive or conventional cytological screening (reference).

MAIN OUTCOME MEASURES

Rate of cervical cancer, cervical intraepithelial neoplasia (CIN) grade III, and adenocarcinoma in situ (as a composite outcome referred to as CIN III+) during 2003-7 through record linkage between files from the screening registry and the national cancer registry.

RESULTS

In the HPV and conventional arms there were 95 600 and 95 700 woman years of follow-up and 76 and 53 cases of CIN III+, respectively (of which six and eight were cervical cancers). The relative rate of CIN III+ in the HPV arm versus the conventional arm was 1.44 (95% confidence interval 1.01 to 2.05) among all women invited for screening and 1.77 (1.16 to 2.74) among those who attended. Among women with a normal or negative test result, the relative rate of subsequent CIN III+ was 0.28 (0.04 to 1.17). The rate of cervical cancer between arms was 0.75 (0.25 to 2.16) among women invited for screening and 1.98 (0.52 to 9.38) among those who attended.

CONCLUSIONS

When incorporated into a well established organised screening programme, primary HPV screening with cytology triage was more sensitive than conventional cytology in detecting CIN III+ lesions. The number of cases of cervical cancer was small, but considering the high probability of progression of CIN III the findings are of importance regarding cancer prevention.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN23885553.

What is the role of HPV typing in the United States now and in the next five years in a vaccinated population?

OBJECTIVE

To review the current state of HPV typing of the vaccinated population in the United States and potential for typing of this population over the next 5 years.

METHODS

An expert forum conducted on September 12-13, 2008, by the Society of Gynecologic Oncologists including 56 experts in cervical cancer and titled "Future strategies of cervical cancer prevention: what do we need to do now to prepare?"

RESULTS

In principle, screening with HPV DNA testing for oncogenic genotypes followed by cytologic triage has attractive features that may serve well the screening needs of a post-vaccination era in the US. Particularly in light of the recent FDA approval of a HPV genotyping test, the group focused on how typing could be used to assist clinical decisions and whether its implementation would be cost-effective. Furthermore, it was agreed upon that HPV typing should not be used to determine who should be vaccinated against HPV. There was considerable discussion regarding the potential misuse and overuse of HPV typing in low risk women among healthcare providers.

CONCLUSIONS

As HPV typing technologies gain traction in the United States, its appropriate use will depend on the evolving natural history of the vaccinated cohort, continued educational efforts of healthcare providers, and most importantly, creating an integrated approach to cervical cancer prevention that will lead to a greater decrease in the incidence of cervical disease in the US while allowing for cost equipoise. On September 12-13, 2008, the Society of Gynecologic Oncologists (SGO) convened a symposium of 56 cervical cancer experts titled "Future strategies of cervical cancer prevention: what do we need to do now to prepare?" to discuss evidence-based strategies in cervical cancer prevention and control, including HPV vaccination. This paper is the second in a series of manuscripts which highlight concepts, information, obstacles and approaches discussed during the Forum's sessions and focuses on the current state of HPV typing of the vaccinated population in the United States and typing of this population over the next 5 years.

Long-term follow-up of cervical disease in women screened by cytology and HPV testing: results from the HART study

Background:

Several studies have shown that testing for high-risk human papillomavirus (HPV) types results in an improved sensitivity for CIN2+, compared with cytology, although with a somewhat lower specificity.

Methods:

We obtained follow-up results, with at least one smear after participation in the HART study, which compared HPV testing (HC-II) with cytology as a primary screening modality.

Results:

With a median follow-up of 6 years, 42 additional cases of CIN2+ were identified; women who were HPV positive at baseline were more likely to develop CIN2+ than those who were HPV negative (hazard ratio (HR) 17.2; 95% confidence interval (CI) (9.3–31.6)) and the risk increased with increasing viral load. Compared with HPV-negative women (relative light unit (RLU) <1), the HR (95% CI) was 5.4 (1.6, 18.2) for 1–10 RLU and 25.5 (13.6, 47.9) for RLU ⩾10. Positive cytology (borderline or worse compared with negative) was also predictive of developing CIN2, although to a lesser extent (HR 8.7; 95% CI (4.5–17.1)). Only one case of CIN3 and three cases of CIN2 were found in women who showed a positive cytology result but were HPV negative at baseline.

Conclusion:

After 5 years of follow-up, CIN2+ occurred in 0.23% of women who were HPV negative at baseline compared with 0.48% of women who showed a negative cytology result, indicating a much longer low-risk interval for CIN2+ after HPV testing.

A randomized controlled trial of Human Papillomavirus (HPV) testing for cervical cancer screening: trial design and preliminary results (HPV FOCAL Trial)

BACKGROUND

In the HPV FOCAL trial, we will establish the efficacy of hr-HPV DNA testing as a stand-alone screening test followed by liquid based cytology (LBC) triage of hr-HPV-positive women compared to LBC followed by hr-HPV triage with > or = CIN3 as the outcome.

METHODS/DESIGN

HPV-FOCAL is a randomized, controlled, three-armed study over a four year period conducted in British Columbia. It will recruit 33,000 women aged 25-65 through the province's population based cervical cancer screening program. Control arm: LBC at entry and two years, and combined LBC and hr-HPV at four years among those with initial negative results and hr-HPV triage of ASCUS cases; Two Year Safety Check arm: hr-HPV at entry and LBC at two years in those with initial negative results with LBC triage of hr-HPV positives; Four Year Intervention Arm: hr-HPV at entry and combined hr-HPV and LBC at four years among those with initial negative results with LBC triage of hr-HPV positive cases

DISCUSSION

To date, 6150 participants have a completed sample and epidemiologic questionnaire. Of the 2019 women enrolled in the control arm, 1908 (94.5%) were cytology negative. Women aged 25-29 had the highest rates of HSIL (1.4%). In the safety arm 92.2% of women were hr-HPV negative, with the highest rate of hr-HPV positivity found in 25-29 year old women (23.5%). Similar results were obtained in the intervention arm HPV FOCAL is the first randomized trial in North America to examine hr-HPV testing as the primary screen for cervical cancer within a population-based cervical cancer screening program.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number Register, ISRCTN79347302.

[Cervical screening: toward a new paradigm?]

OBJECTIVES

Analysis of the trials which compare the virologic testing (HPV testing) and the cytology in the cervical screening.

MATERIAL AND METHODS

The MedLine database was consulted using the Keywords: "cervical screening", "pap smear", "liquid based cytology", "HPV testing", "adults", "adolescents", "cervical intraepithelial neoplasia (CIN)", "uterine cervix cancer". Articles were selected according their concern about the debate of the uterine cervix cancer screening in France.

RESULTS

The HPV testing seems interesting allowing a decreasing delay in the diagnosis of CIN (more diagnosis of CIN2+ in the first round and less during the second one). But, when the two rounds are added, the number of CIN2+ are identical in the two arms (cytology and HPV testing) in all the trials (except the Italian NTCC trial). A negative HPV testing protects the women much longer than cytology can do: a delay of five years between two rounds seems ideal. The HPV testing alone increases the detection rate of cervical lesions, which could regress spontaneously and may induce an overtreatment, especially in the youngest population: a triage is necessary and the cytology appears to be the best way to select the candidates for colposcopy in case of positive HPV testing and cytology. The HPV infection presents some particularities in adolescent females: for this reason, the HPV testing should not be used in this special population. In vaccinated women, a consensus for the screening is necessary.

CONCLUSION

The health care providers in France have to understand the characteristics of the HPV testing: its advantages compared to the cytologic screening are only evident in case of an organization of the screening in France and even in Europe.

Predicted impact of vaccination against human papillomavirus 16/18 on cancer incidence and cervical abnormalities in women aged 20-29 in the UK

Background:

Human papillomavirus (HPV) vaccination has been approved in more than 90 countries and is being implemented in many of these. In the UK, vaccination for girls aged 12–13 with catch-up for girls up to age 18 was introduced in 2008, using the bivalent GSK vaccine (Cervarix).

Methods:

We modelled the proportion of abnormal smears, cervical intraepithelial neoplasia grade 3 (CIN3) and invasive cancer, which will be prevented in women aged 20–29 in the UK as a result of HPV vaccination.

Results:

It will take many years for the full benefit of vaccination to be achieved. The earliest effects will be seen in women aged 20–29. With 80% coverage in women aged 12–13, we project an eventual 63% reduction in invasive cancer, a 51% reduction in CIN3 and a 27% reduction in cytological abnormalities before age 30. The full effect in this age group will not be seen until 2025, although half of the benefit will be seen by 2019 in England, where screening starts at age 25. However in Scotland and Wales, where screening starts at age 20, 50% of the benefit for CIN3 and abnormal smears (but not cancer) will be seen earlier.

Conclusion:

Substantial reductions in disease can be anticipated by vaccination, but most of the benefit will not be apparent for at least another decade. High vaccine coverage is the key factor for achieving these benefits.

Efficacy of human papillomavirus testing for the detection of invasive cervical cancers and cervical intraepithelial neoplasia: a randomised controlled trial

BACKGROUND

Human papillomavirus (HPV) testing is known to be more sensitive, but less specific than cytology for detecting cervical intraepithelial neoplasia (CIN). We assessed the efficacy of cervical-cancer screening policies that are based on HPV testing.

METHODS

Between March, 2004, and December, 2004, in two separate recruitment phases, women aged 25-60 years were randomly assigned to conventional cytology or to HPV testing in combination with liquid-based cytology (first phase) or alone (second phase). Randomisation was done by computer in two screening centres and by sequential opening of numbered sealed envelopes in the remaining seven centres. During phase one, women who were HPV-positive and aged 35-60 years were referred to colposcopy, whereas women aged 25-34 years were referred to colposcopy only if cytology was also abnormal or HPV testing was persistently positive. During phase two, women in the HPV group were referred for colposcopy if the HPV test was positive. Two rounds of screening occurred in each phase, and all women had cytology testing only at the second round. The primary endpoint was the detection of grade 2 and 3 CIN, and of invasive cervical cancers during the first and second screening rounds. Analysis was done by intention to screen. This trial is registered, number ISRCTN81678807.

FINDINGS

In total for both phases, 47,001 women were randomly assigned to the cytology group and 47,369 to HPV testing. 33,851 women from the cytology group and 32,998 from the HPV-testing group had a second round of screening. We also retrieved the histological diagnoses from screening done elsewhere. The detection of invasive cervical cancers was similar for the two groups in the first round of screening (nine in the cytology group vs seven in the HPV group, p=0.62); no cases were detected in the HPV group during round two, compared with nine in the cytology group (p=0.004). Overall, in the two rounds of screening, 18 invasive cancers were detected in the cytology group versus seven in the HPV group (p=0.028). Among women aged 35-60 years, at round one the relative detection (HPV vs cytology) was 2.00 (95% CI 1.44-2.77) for CIN2, 2.08 (1.47-2.95) for CIN3, and 2.03 (1.60-2.57) for CIN2 and 3 together. At round two the relative detection was 0.54 (0.23-1.28) for CIN2, 0.48 (0.21-1.11) for CIN3, and 0.51 (0.28-0.93) for CIN2 and 3 together. Among women aged 25-34 years, there was significant heterogeneity between phases in the relative detection of CIN3. At round one the relative detection was 0.93 (0.52-1.64) in phase one and 3.91 (2.02-7.57) in phase two. At round two the relative detection was 1.34 (0.46-3.84) in phase one and 0.20 (0.04-0.93) in phase two. Pooling both phases, the detection ratio of CIN2 for women aged 25-34 years was 4.09 (2.24-7.48) at round one and 0.64 (0.23-1.27) at round two.

INTERPRETATION

HPV-based screening is more effective than cytology in preventing invasive cervical cancer, by detecting persistent high-grade lesions earlier and providing a longer low-risk period. However, in younger women, HPV screening leads to over-diagnosis of regressive CIN2.

FUNDING

European Union, Italian Ministry of Health, Regional Health Administrations of Piemonte, Tuscany, Veneto and Emilia-Romagna, and Public Health Agency of Lazio.

Age-specific evaluation of primary human papillomavirus screening vs conventional cytology in a randomized setting

BACKGROUND

Human papillomavirus (HPV) DNA testing has shown higher sensitivity than cytology for detecting cervical lesions, but it is uncertain whether the higher sensitivity is dependent on the age of the woman being screened. We compared the age-specific performance of primary HPV DNA screening with that of conventional cytology screening in the setting of an organized population-based cervical cancer screening program in Finland.

METHODS

From January 1, 2003, to December 31, 2005, randomized invitations were sent to women aged 25-65 years for routine cervical cancer screening by primary high-risk HPV DNA testing (n = 54 207) with a Hybrid Capture 2 assay followed by cytology triage for women who were HPV DNA positive or by conventional cytology screening (n = 54 218). In both screening arms, cytology results of low-grade squamous intraepithelial lesion or worse triggered a referral for colposcopy. Relative rates (RRs) of detection to assess test sensitivity, specificity, and positive predictive values (PPVs) with 95% confidence intervals (CIs) were calculated for the histological endpoints of cervical intraepithelial neoplasia (CIN) grade 1 or higher (CIN 1+), CIN grade 2 or higher (CIN 2+), and CIN grade 3 or higher (CIN 3+). All statistical tests were two-sided.

RESULTS

The overall frequency of colposcopy referrals was 1.2% in both screening arms. Women younger than 35 years were referred more often in the HPV DNA screening vs the conventional screening arm (RR = 1.27, 95% CI = 1.01 to 1.60). The prevalence of histologically confirmed CIN or cancer was 0.59% in the HPV DNA screening arm vs 0.43% in the conventional screening arm. The relative rates of detection for CIN 1, CIN 2, and CIN 3+ for HPV DNA screening with cytology triage vs conventional screening were 1.44 (95% CI = 0.99 to 2.10), 1.39 (95% CI = 1.03 to 1.88), and 1.22 (95% CI = 0.78 to 1.92), respectively. The specificity of the HPV DNA test with cytology triage was equal to that of conventional screening for all age groups (99.2% vs 99.1% for CIN 2+, P = .13). Among women aged 35 years or older, the HPV DNA test with cytology triage tended to have higher specificity than conventional screening. The PPVs for HPV DNA screening with cytology triage were consistently higher than those for conventional screening. In both screening arms, the test specificities increased with increasing age of the women being screening, whereas the highest PPVs were observed among the youngest women being screened. Overall, 7.2% of women in the HPV DNA screening arm vs 6.6% of women in the conventional screening arm were recommended for intensified follow-up, and the percentages were highest among 25- to 29-year-olds (21.9% vs 10.0%, respectively).

CONCLUSIONS

Primary HPV DNA screening with cytology triage is more sensitive than conventional screening. Among women aged 35 years or older, primary HPV DNA screening with cytology triage is also more specific than conventional screening and decreases colposcopy referrals and follow-up tests.

EUROGIN 2008 roadmap on cervical cancer prevention

The EUROGIN 2008 Roadmap represents a continuing effort to provide updated information on primary and secondary prevention of cervical cancer. The report addresses several areas including the progress made toward global implementation of currently licensed human papillomavirus (HPV) vaccines, the possibilities and value of future-generation HPV vaccines, endpoints under consideration for evaluation of candidate HPV vaccines, and monitoring impact of HPV vaccination programmes that can be implemented within developed and less-developed countries. For the sake of completeness, a short update on the evolution of HPV testing in primary screening programmes at present and after HPV vaccine introduction has also been included. The report is available on the EUROGIN website (www.eurogin.com).

Human papillomavirus testing for cervical cancer screening: results from a 6-year prospective study in rural China

Long-term follow-up evaluations of cervical screening approaches are limited in low-resource areas. This prospective study assessed the risk of future cervical intraepithelial neoplasia grade 2 or worse (CIN2+) associated with baseline human papillomavirus (HPV) and cytologic status. In rural China, 1,997 women were screened with 6 screening tests, including colposcopic evaluations, and underwent biopsies in 1999. In December 2005, 1,612 women with cervical intraepithelial neoplasia grade 1 or less at baseline were rescreened by visual inspection, liquid-based cytology, and HPV-DNA testing. All women underwent colposcopy at follow-up, with biopsies taken from women with visually apparent lesions or cytologic abnormalities. Twenty women developed incident CIN2+. The crude relative risk of CIN2+ for baseline HPV-positive women was 52 (95% confidence interval: 12.1, 222.5). The crude relative risk of CIN2+ was 167 (95% confidence interval: 21.9, 1,265) for baseline and follow-up repeatedly HPV-positive women compared with repeatedly HPV-negative women. Among 1,374 baseline HPV-negative women, 2 and no incident CIN2+ cases were detected in baseline cytologically normal and abnormal subgroups, respectively. Among 238 baseline HPV-positive women, 6 of 18 incident cases of CIN2+ developed in the cytologically normal group. This study demonstrates that a single oncogenic HPV-DNA test is more effective than cytology in predicting future CIN2+ status.