Veerle M.H. Coupé

Evaluation of 14 triage strategies for HPV DNA-positive women in population-based cervical screening.

High‐risk human papillomavirus (hrHPV) testing has a higher sensitivity but lower specificity than cytology for detection of high‐grade intraepithelial neoplasia (CIN). To avoid over‐referral to colposcopy and overtreatment, hrHPV‐positive women require triage testing and/or followup. A total of 25,658 women (30–60 years) enrolled in a population‐based cohort study had an adequate baseline Pap smear and hrHPV test. The end‐point was cumulative two‐year risk of CIN grade 3 or worse (CIN3+). In a post‐hoc analysis, fourteen triage/followup strategies for hrHPV‐positive women (n = 1,303) were evaluated for colposcopy referral rate, positive (PPV) and negative predictive value (NPV). Five strategies involved triage testing without a repeat test and nine strategies involved triage testing followed by one repeat testing. The tests were cytology, hrHPV, HPV16/18 genotyping and HPV16/18/31/33/45 genotyping. Results were adjusted for women in the cohort study who did not attend repeat testing. Of the strategies without repeat testing, combined cytology and HPV16/18/31/33/45 genotyping gave the highest NPV of 98.9% (95%CI 97.6–99.5%). The corresponding colposcopy referral rate was 58.1% (95%CI 55.4–60.8%). Eight of the nine strategies with retesting had an estimated NPV of at least 98%. Of those, cytology triage followed by cytology at 12 months had a markedly lower colposcopy referral rate of 33.4% (95%CI 30.2–36.7%) than the other strategies. The NPV of the latter strategy was 99.3% (95%CI 98.1–99.8%). Triage hrHPV‐positive women with cytology, followed by repeat cytology testing yielded a high NPV and modest colposcopy referral rate and appear to be the most feasible management strategy.

Properties of Sensitivity Analysis of Bayesian Belief Networks

The assessments for the various conditional probabilities of a Bayesian belief network inevitably are inaccurate, influencing the reliability of its output. By subjecting the network to a sensitivity analysis with respect to its conditional probabilities, the reliability of its output can be investigated. Unfortunately, straightforward sensitivity analysis of a belief network is highly time-consuming. In this paper, we show that by qualitative considerations several analyses can be identified as being uninformative as the conditional probabilities under study cannot affect the output. In addition, we show that the analyses that are informative comply with simple mathematical functions. More specifically, we show that a belief networks output can be expressed as a quotient of two functions that are linear in a conditional probability under study. These properties allow for considerably reducing the computational burden of sensitivity analysis of Bayesian belief networks.

Combined Promoter Methylation Analysis of CADM1 and MAL: An Objective Triage Tool for High-Risk Human Papillomavirus DNA–Positive Women

Purpose: Screening women for high-grade cervical intraepithelial neoplasia or cervical cancer (CIN3+) by high-risk human papillomavirus (hrHPV) testing has as side-effect the detection of hrHPV-positive women without clinically relevant lesions. Here, we developed an objective assay assessing the methylation status of the promoter regions of CADM1 and MAL to triage hrHPV-positive women for CIN3+. Experimental Design: In a training set (51 women with CIN3+ and 224 without CIN2+), panels consisting of one to four quantitative methylation-specific PCR (qMSP) assays (CADM1-m12,CADM1-m18,MAL-m1,MAL-m2) were analyzed. Cross-validated receiver-operating characteristics (ROC) curves were constructed and the panel with highest partial cross-validated area under the curve (AUC) was used for validation in an independent set of 236 consecutive hrHPV-positive women from a screening cohort. In the validation set, the ROC curve of the panel was compared with CIN3+ sensitivity and specificity of cytology and of cytology combined with HPV16/18 genotyping. Results: In the training set, CADM1-m18 combined with MAL-m1 was the best panel (cross-validated partial AUC = 0.719). In the validation set, this panel revealed CIN3+ sensitivities ranging from 100% (95% CI: 92.4–100) to 60.5% (95% CI: 47.1–74.6), with corresponding specificities ranging from 22.7% (95% CI: 20.2–25.2) to 83.3% (95% CI: 78.4–87.4). For cytology these were 65.8% (95% CI: 52.3–79.0) and 78.8% (95% CI: 73.7–83.1) and for cytology/HPV16/18, these were 84.2% (95% CI: 72.0–92.7) and 54.0% (95% CI: 49.2–58.7), respectively. The point estimates of both cytology and cytology/HPV16/18 were equal to the values of the ROC curve of CADM1-m18/MAL-m1. Conclusions: We developed an objective methylation marker panel that was equally discriminatory for CIN3+ as cytology or cytology with HPV16/18 genotyping in hrHPV-positive women. This opens the possibility for complete cervical screening by objective, nonmorphological molecular methods. Clin Cancer Res; 17(8); 2459–65. ©2011 AACR.

Age-dependent prevalence of 14 high-risk HPV types in the Netherlands: implications for prophylactic vaccination and screening.

We determined the prevalence of type-specific hrHPV infections in the Netherlands on cervical scrapes of 45 362 women aged 18–65 years. The overall hrHPV prevalence peaked at the age of 22 with peak prevalence of 24%. Each of the 14 hrHPV types decreased significantly with age (P-values between 0.0009 and 0.03). The proportion of HPV16 in hrHPV-positive infections also decreased with age (OR=0.76 (10-year scale), 95% CI=0.67–0.85), and a similar trend was observed for HPV16 when selecting hrHPV-positive women with cervical intraepithelial neoplasia grade 2 or worse (CIN2+) (OR=0.76, 95% CI=0.56–1.01). In women eligible for routine screening (age 29–61 years) with confirmed CIN2+, 65% was infected with HPV16 and/or HPV18. When HPV16/18-positive infections in women eligible for routine screening were discarded, the positive predictive value of cytology for the detection of CIN2+ decreased from 27 to 15%, the positive predictive value of hrHPV testing decreased from 26 to 15%, and the predictive value of a double-positive test (positive HPV test and a positive cytology) decreased from 54 to 41%. In women vaccinated against HPV16/18, screening remains important to detect cervical lesions caused by non-HPV16/18 types. To maintain a high-positive predictive value, screening algorithms must be carefully re-evaluated with regard to the screening modalities and length of the screening interval.

HPV DNA testing in population-based cervical screening (VUSA-Screen study): results and implications.

Background:Human papillomavirus (HPV) testing is more sensitive than cytology for detecting high-grade cervical intraepithelial neoplasia (CIN). We evaluated the performance of high-risk HPV (hrHPV) testing in routine screening.Methods:In all, 25 871 women (29–61) enrolled in our population-based cohort study were offered both cytology and hrHPV testing. High-risk HPV-positive women with normal cytology and an age-matched subcohort of hrHPV-negative women with normal cytology were invited for repeat testing after 1 and/or 2 years and were referred for colposcopy if they presented with abnormal cytology and/or a positive hrHPV test. The hrHPV-positive women with borderline or mild dyskaryosis (BMD) and all women with moderate dyskaryosis or worse (>BMD) were directly referred for colposcopy. Women with BMD and an hrHPV-negative test were advised to repeat cytology at 6 and 18 months and were referred for colposcopy if the repeat cytology test was abnormal. The main outcome measure was CIN grade 3 or worse (CIN3+). Results were adjusted for non-attendance at repeat testing.Results:The hrHPV-positive women with abnormal cytology had a CIN3+ risk of 42.2% (95% confidence interval (CI): 36.4–48.2), whereas the hrHPV-positive women with normal cytology had a much lower risk of 5.22% (95% CI: 3.72–7.91). In hrHPV-positive women with normal cytology, an additional cytology step after 1 year reduced the CIN3+ risk to only 1.6% (95% CI: 0.6–4.9) if the repeat test was normal. The CIN3+ risk in women with hrHPV-positive normal cytology was higher among women invited for the first time (29–33 years of age) (9.1%; 95% CI: 5.6–14.3) than among older women (3.0%; 95% CI: 1.5–5.5).Conclusion:Primary hrHPV screening with cytology triage in women aged ⩾30 years is an effective way to stratify women on CIN3+ risk and seems a feasible alternative to cytological screening. Repeat cytology after 1 year for hrHPV-positive women with normal cytology is however necessary before returning women to routine screening.

Long-term impact of human papillomavirus vaccination on infection rates, cervical abnormalities, and cancer incidence.

Background: Vaccination against human papillomavirus (HPV) types 16/18 is being implemented in many countries. There may be indirect benefit of HPV vaccination to nonvaccinated women, who may experience a reduced risk of infection with vaccine-preventable types (herd immunity). We attempt to disentangle the direct and indirect effects of HPV vaccination, while accounting for 14 oncogenic HPV types in a dynamic modeling framework. Methods: On the basis of vaccine uptake among preadolescent girls in the Netherlands, we calculated how heterosexual transmission of HPV-16/18 is expected to change as a result of vaccination, and used these predictions in an individual-based simulation model of cervical carcinogenesis that considers 14 high-risk HPV types. Models were parameterized to match prevaccine data on type-specific HPV infection and cervical disease. Results: At 50% vaccine coverage, the estimated lifetime infection risk in nonvaccinated women dropped from 0.69 (95% credible interval = 0.50–0.85) to 0.49 (0.32–0.68) for HPV-16, and from 0.68 (0.46–0.79) to 0.43 (0.26–0.57) for HPV-18. For the whole population, we calculated an eventual 47% reduction in cervical cancer incidence, with 1 in 4 cases prevented among nonvaccinated women. The number of indirectly averted cancer cases was highest with vaccine coverage between 50% and 70%, approximating 70 cases per 100,000 women born from 2010 onward. Conclusions: HPV-16/18 vaccination of preadolescent girls will markedly lower infection rates among nonvaccinated women. Reduced transmission of vaccine-preventable HPV becomes a prominent aspect of cervical cancer control, especially in populations with moderate vaccine coverage.

Incidence of enteropathy -associated T-cell lymphoma : A nation-wide study of a population-based registry in The Netherlands

Objective. Enteropathy-associated T-cell lymphomas (EATLs) are T-cell non-Hodgkin lymphomas of the small bowel, which are specifically associated with coeliac disease (CD). To our knowledge no studies have previously reported on the overall incidence of EATLs in the general population. The aim of this study was to investigate the incidence of EATL and the demographic characteristics of patients with EATL in The Netherlands. Material and methods. A survey of the nation-wide network and registry of histo- and cytopathology reports in The Netherlands (PALGA) was performed. We included all T-cell lymphomas detected between January 2000 and December 2006 that initially presented in the small bowel. Crude and world standardized incidence rates were computed as well as gender- and age-specific incidence rates. Finally, the distribution of characteristics such as the localization, the Marsh classification and method of diagnosis are described. Results. Clinicopathological data were gathered for 116 cases of EATL. The mean age at primary presentation of EATL was 64 years. The crude incidence in the total Dutch population was 0.10/100,000 with an incidence of 2.08/100,000 in the over 50-year-olds. Age-specific incidences were 1.44/100,000 in the 50–59 years age group, 2.92/100,000 in the 60–69 years age group, and 2.53/100,000 in the 70–79 years age group. There was a significant predominance of males (64%, p=0.004, CI 54–72); above the age of 50 the gender-specific incidence was 2.95/100,000 in males versus 1.09/100,000 in females. Most EATLs were localized in the proximal small intestine and the diagnosis was made by surgical resection in the majority of cases. Conclusions. EATL is a rare disease with an incidence of 0.10 per 100,000 inhabitants per year, occurring in older age, with a peak incidence in the 7th decade. The tumour is mainly localized in the proximal small intestine. Although uncomplicated CD is twice as frequent in female patients, EATL is more prevalent in males.

Model-Based Estimation of Viral Transmissibility and Infection-Induced Resistance From the Age-Dependent Prevalence of Infection for 14 High-Risk Types of Human Papillomavirus

Viral transmissibility and natural resistance to infection are key determinants in assessing the population impact of human papillomavirus (HPV) vaccination, yet information on these parameters is scarce. Using data from 2 large-scale surveys on sexual behavior in the Netherlands (carried out in 2005-2006), the authors employed a Bayesian framework to fit a transmission model to the cross-sectional age-dependent prevalence of HPV DNA in cervical smears (data collected in 1992-2002), assuming that the prevaccine situation reflected an endemic equilibrium, and calculated type-specific estimates of transmissibility and infection-induced resistance. The posterior median transmission probability per heterosexual partnership covered a range of 0.43-0.94 among the 14 high-risk types of HPV. The transmission probability of HPV-16 was estimated at 0.80 (95% posterior interval: 0.60, 0.99) and that of HPV-18 at 0.93 (95% posterior interval: 0.72, 1). The model predicted that the decrease in HPV prevalence with age could not solely be explained by sexual activity and screening but also by resistance to reinfection, which is lost at a rate of 0.014-0.047 (1%-5%) per year. These results support the notion that HPV infection is highly transmissible, and they suggest a gradual loss of type-specific immunity over time. Because high transmission potential is associated with a low impact of herd immunity, extensive vaccination coverage will be required to substantially reduce cervical cancer incidence.

Colonoscopy-controlled intra-individual comparisons to screen relevant neoplasia: faecal immunochemical test vs. guaiac-based faecal occult blood test.

Aliment Pharmacol Ther 31, 432–439

The health and economic effects of HPV DNA screening in the Netherlands.

We studied the health and economic effects of human papillomavirus (HPV) DNA testing in cervical screening using a simulation model. The key data source was a Dutch longitudinal screening trial. We compared cytological testing with repeat cytology (for borderline/mildly abnormal smears) to HPV testing with cytology triage (for HPV‐positive smears), combination testing (combined HPV and cytology) and cytological testing with HPV triage (for borderline/mildly abnormal smears). We varied the screening interval from 5 to 10 years. The main outcome measures were the number of cervical cancer cases, the number of quality‐adjusted life years (QALYs), and the incremental cost‐effectiveness ratio (ICER). The base‐case estimates were accompanied with ranges across 118 calibrated parameter settings (calibration criteria: cervical intraepithelial neoplasia 2/3, cancer and mortality rates). In comparison to 5‐yearly cytology, 5‐yearly HPV testing with cytology triage gave a reduction in the number of cancer cases of 23% (range, 9–27%). The reduction was 26% (range, 10–29%) for combination testing and 3% (range, −1 to 8%) for cytology with HPV triage. For strategies with primary HPV testing, the model also estimated a reduction in cancer cases when the screening interval was extended to 7.5 years. Five‐yearly cytology with HPV triage and 5 to 7.5‐yearly HPV testing with cytology triage were cost effective for the base‐case settings and the majority of calibrated parameter settings (ICER below Dutch willingness‐to‐pay threshold of €20,000/QALY). Our model indicates that HPV testing with cytology triage is likely to be cost effective. An extension of the screening interval may be considered to control costs.