The impact of new technologies in cervical cancer screening: results of the recruitment phase of a large randomised controlled trial from a public health perspective

Early detection and prevention

The rapidly increasing incidence and mortality of cancer calls for a focused effort to increase the effect of cancer‐prevention efforts. In the area of early detection, there are major differences in the preventive impact of implemented screening policies, even when solid, evidence‐based international recommendations are issued. Studies are needed to determine why evidence‐based interventions are not used and to investigate why effects are less than predicted by solid research on the subject. Currently, population‐based screening is recommended only for three forms of cancer (cervical, breast and colorectal cancer) but, given the increasing cancer burden, efforts are required to facilitate the discovery of new biomarkers for screening, as well as the identification of barriers to implementation of new cancer screening discoveries. The creation of a network of excellence in research on Cancer Prevention (Cancer Prevention Europe) is likely to significantly contribute to progress in these areas. In the present review, some possible strategies to ensure progress are discussed, with specific examples from the cervical cancer screening area.

Prevention of Cervical Cancer: Guideline of the DGGG and the DKG (S3 Level, AWMF Register Number 015/027OL, December 2017) - Part 1 with Introduction, Screening and the Pathology of Cervical Dysplasia

Aims Annual opportunistic screening for cervical carcinoma has been carried out in Germany since 1971. The creation of this S3 guideline meets an important need, outlined in the National Cancer Plan, with regard to screening for cervical cancer, as the guideline aims to provide important information and support for planned organized screening for cervical cancer in Germany. Methods With the financial support of German Cancer Aid, 21 professional societies developed evidence-based statements and recommendations (classified using the GRADE system) for the screening, management and treatment of precancerous conditions of the cervix. Two independent scientific institutes compiled systematic reviews for this guideline. Recommendations The first part of this short summary presents the pathological basis and considers various questions related to screening for cervical cancer. As also reported in earlier reviews, the meta-analysis by Kleijnen Systematic Reviews showed that HPV-based screening offers better protection against invasive cervical cancer compared to cytology-based screening. The authors of this guideline therefore recommend - in accordance with the guideline of the Joint National Committee of Germany (Gemeinsamer Bundesauschuss, G-BA) - that women aged 35 and above should be examined at regular intervals (at least every 3 years) and undergo HPV-based screening. Co-testing can also be carried out. Women between the ages of 20 and 35 should have cytological screening every 2 years.

Use of Cytology, E6/E7 mRNA, and p16INK4a-Ki-67 to Define the Management of Human Papillomavirus (HPV)-Positive Women in Cervical Cancer Screening

OBJECTIVES

We measured the accuracy of p16(INK4a)-Ki67 (CINtec PLUS, Roche, Mannheim, Germany), and E6/E7mRNA (types 16/18/31/33/45 NucliSENS easyQ, bioMérieux, Boxtel, The Netherlands) as triage test, alone and combined with cytology.

METHODS

Six thousand two hundred and seventy two women were recruited in a population-based screening using HPV DNA as primary test; 396 were positive and were tested for cytology and biomarkers. All tests were performed on the same sample. Cytology-positive women were referred to colposcopy; cytology-negative women were referred to one-year HPV re-testing. The endpoint was CIN2+ at baseline or follow up.

RESULTS

Sensitivity was 77.6% (95% confidence interval (CI) 65.3-86.7) and 53.2% (95%CI: 40.3-65.4) for cytology at atypical squamous cells of undetermined significance (ASC-US) and high-grade threshold, and 87.6% (95%CI:75.7-93.6), and 80.8% (95%CI: 67.6-89.8) for p16INK4a-Ki67, and E6/E7mRNA, respectively. Colposcopy referral was 36% (95%CI: 31.2-40.9) and 11.2% (95%CI: 7.8-14.1) for cytology at ASC-US and high-grade threshold, respectively, and 36.0% (95%CI: 29.9-29.6), and 47.5% (95%CI: 32.5-42.4) for p16(INK4a)-Ki67, and E6/E7mRNA, respectively. Strategies referring high-grade cytology or biomarker positive women to colposcopy reached sensitivity close to 100%, with modest increase in colposcopy referral.

CONCLUSIONS

The high sensitivity of combined strategies probably allows longer intervals in HPV-positive, triage-negative women.

HPV DNA testing with cytology triage in cervical cancer screening: Influence of revealing HPV infection status

BACKGROUND

Knowledge of cervical human papillomavirus (HPV) status might influence a cytotechnician's assessment of cellular abnormalities. The authors compared original cytotechnicians' Papanicolaou (Pap) readings for which HPV status was concealed with Pap rereads for which HPV status was revealed separately for 3 screening populations.

METHODS

Previously collected cervical Pap smears and clinical data were obtained from the Canadian Cervical Cancer Screening Trial (study A), the Democratic Republic of Congo Community-Based Screening Study (study B), and the Brazilian Investigation into Nutrition and Cervical Cancer Prevention (study C). Smears were reread with knowledge of HPV status for all HPV-positive women as well as a sample of HPV-negative women. Diagnostic performance of Pap cytology was compared between original readings and rereads.

RESULTS

A total of 1767 Pap tests were reread. Among 915 rereads for HPV-positive women, the contrast between "revealed" and "concealed" Pap readings demonstrated revisions from negative to positive results for 109 women (cutoff was atypical squamous cells of undetermined significance or worse) and 124 women (cutoff was low-grade squamous intraepithelial lesions [LSIL] or worse). For a disease threshold of cervical intraepithelial neoplasia of grade 2 or worse, specificity significantly declined at the atypical squamous cells of undetermined significance cutoff for studies A (86.6% to 75.3%) and C (42.5% to 15.5%), and at the LSIL cutoff for study C (61.9% to 37.6%). Sensitivity remained nearly unchanged between readings, except in study C, in which reread performance was superior (91.3% vs 71.9% for the LSIL cutoff).

CONCLUSIONS

A reduction in the diagnostic accuracy of Pap cytology was observed when revealing patients' cervical HPV status, possibly due to a heightened awareness of potential abnormalities, which led to more false-positive results.

Investigating the Generalizability of Economic Evaluations Conducted in Italy: A Critical Review

OBJECTIVES

To assess the methodological quality of Italian health economic evaluations and their generalizability or transferability to different settings.

METHODS

A literature search was performed on the PubMed search engine to identify trial-based, nonexperimental prospective studies or model-based full economic evaluations carried out in Italy from 1995 to 2013. The studies were randomly assigned to four reviewers who applied a detailed checklist to assess the generalizability and quality of reporting. The review process followed a three-step blinded procedure. The reviewers who carried out the data extraction were blind as to the name of the author(s) of each study. Second, after the first review, articles were reassigned through a second blind randomization to a second reviewer. Finally, any disagreement between the first two reviewers was solved by a senior researcher.

RESULTS

One hundred fifty-one economic evaluations eventually met the inclusion criteria. Over time, we observed an increasing transparency in methods and a greater generalizability of results, along with a wider and more representative sample in trials and a larger adoption of transition-Markov models. However, often context-specific economic evaluations are carried out and not enough effort is made to ensure the transferability of their results to other contexts. In recent studies, cost-effectiveness analyses and the use of incremental cost-effectiveness ratio were preferred.

CONCLUSIONS

Despite a quite positive temporal trend, generalizability of results still appears as an unsolved question, even if some indication of improvement within Italian studies has been observed.

Women's intentions to receive cervical cancer screening with primary human papillomavirus testing

We explored the potential impact of human papillomavirus (HPV) testing on women's intentions to be screened for cervical cancer in a cohort of Canadian women. Participants aged 25-65 years from an ongoing trial were sent a questionnaire to assess women's intentions to be screened for cervical cancer with HPV testing instead of Pap smears and to be screened every 4 years or after 25 years of age. We created scales for attitudes about HPV testing, perceived behavioral control, and direct and indirect subjective norms. Demographic data and scales that were significantly different (p < 0.1) between women who intended to be screened with HPV and those who did not intend were included in a stepwise logistic regression model. Of the 2,016 invitations emailed, 1,538 were received, and 981 completed surveys for a response rate of 63% (981/1,538). Eighty-four percent of women (826/981) responded that they intended to attend for HPV-based cervical cancer screening, which decreased to 54.2% when the screening interval was extended, and decreased further to 51.4% when screening start was delayed to age of 25. Predictors of intentions to undergo screening were attitudes (odds ratio [OR]: 1.22; 95% confidence interval [CI]: 1.15, 1.30), indirect subjective norms (OR: 1.02; 95% CI: 1.01, 1.03) and perceived behavioral control (OR: 1.16; 95% CI: 1.10; 1.22). Intentions to be screened for cervical cancer with HPV testing decreased substantially when the screening interval was extended and screening started at age of 25. Use of primary HPV testing may optimize the screening paradigm, but programs should ensure robust planning and education to mitigate any negative impact on screening attendance rates.

Screening for Cervical Cancer with the Human Papillomavirus Test in an Area of Central Italy with No Previous Active Cytological Screening Programme

Objective

We report performance indicators and costs of the first round of a cervical cancer screening programme based on the human papillomavirus (HPV)-DNA test.

Methods

We implemented a demonstration study using HPV as the primary test in Guidonia, Italy (90,000 inhabitants). All women aged 25-64 were invited to undergo a Hybrid Capture II high-risk HPV test. Two cervical samplings, smear and liquid, were taken. The smear was dyed and interpreted only for HPV-positive (HPV+) women. Women with a non-negative Pap smear were referred for colposcopy, women HPV+/cytology negative were referred to one-year follow-up with HPV. A cost-analysis indicated the price at which the HPV-based and cytological screening would cost the same per screened woman and per lesion found.

Results

Of 24,000 women invited, 7639 accepted and 427 (5.6%) were HPV+; 141 (34%) of these had a non-negative Pap test, and 20 cervical intraepithelial neoplasia (CIN) 2 or higher were found (positive predictive value 15%). Compliance to one-year follow-up was 58% (166/286); 90 (54%) were HPV-positive and five additional lesions were found (positive predictive value 9%; overall detection rate 3.4/1000). The cost analysis showed that at a price of 8.3 euros per HPV DNA test, the strategy using HPV as primary test followed by cytological triage would cost the same per screened woman, while at a price of 12.7 euros it would have the same cost per CIN2+ found.

Conclusion

The workload for management of positive women was similar to cytological screening. Low compliance to one-year follow-up was the main barrier to effectiveness. The price of HPV test should be about 9 euros to maintain the same screening budget, and can go as high as 13 euros per lesion found.

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.

New paradigms in cervical cancer prevention: opportunities and risks

Testing for the DNA of high-risk types of papilloma virus (HPV) is more sensitive than cytology in detecting pre-cancerous lesions. One of the main advantages will be the possibility of applying prolonged screening intervals. However adequate screening protocols (age of start and stop, screening intervals, management of HPV positive women) need to be applied in order to avoid over-referral to colposcopy and over-treatment and to maintain sustainable costs. Further follow-up of running trials and research on molecular markers will better define these parameters. The new situation will require organised screening programmes with rigorous protocols and monitoring. This will be even more needed when women vaccinated for HPV 16 and 18 will be screened. Research on how to best screen vaccinated women is a priority. This paper proposes an overview of the plausible impact of new technologies in cervical cancer screening in the near future and in the vaccinated cohorts.