Laurie W. Smith

Primary cervical cancer screening with HPV testing compared with liquid-based cytology: results of round 1 of a randomised controlled trial – the HPV FOCAL Study

Background:Round 1 data of human papillomavirus (HPV) FOCAL, a three-arm, randomised trial, which aims to establish the efficacy of HPV DNA testing as a primary screen for cervical cancer, are presented.Methods:The three arms are: Control arm – liquid based cytology with atypical squamous cells of unknown significance (ASC-US) triage with hrHPV testing; Intervention Arm – hrHPV at entry with liquid-based cytology (LBC) triage of hrHPV positives, with exit screen at 4 years; Safety check arm – hrHPV at entry with LBC triage of hrHPV positives with exit screen at 2 years.Results:A total of 6154 women were randomised to the control arm and 12 494 to the HPV arms (intervention and safety check). In the HPV arm, the baseline cervical intraepithelial neoplasia (CIN)2+ and CIN3+ rate was 9.2/1000 (95%CI; 7.4, 10.9) and 4.8/1000 (95%CI; 3.6, 6.1), which increased to 16.1/1000 (95%CI 13.2, 18.9) for CIN2+ and to 8.0/1000 (95%CI; 5.9, 10.0) for CIN3+ after subsequent screening of HPV-DNA-positive/cytology-negative women. Detection rate in the control arm remained unchanged after subsequent screening of ASC-US-positive/hrHPV DNA-negative women at 11.0/1000 for CIN2+ and 5.0/1000 for CIN3+.Conclusion:After subsequent screening of women who were either hrHPV positive/cytology negative or ASC-US positive/HPV negative, women randomised to the HPV arms had increased CIN2+ detection compared with women randomised to the cytology arm.

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

BackgroundIn 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 ≥ CIN3 as the outcome.Methods/DesignHPV-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 provinces 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 casesDiscussionTo 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 RegistrationInternational Standard Randomised Controlled Trial Number Register, ISRCTN79347302

HPV for cervical cancer screening (HPV FOCAL): Complete Round 1 results of a randomized trial comparing HPV‐based primary screening to liquid‐based cytology for cervical cancer

Complete Round 1 data (baseline and 12‐month follow‐up) for HPV FOCAL, a randomized trial establishing the efficacy of HPV DNA testing with cytology triage as a primary screen for cervical cancer are presented. Women were randomized to one of three arms: Control arm – Baseline liquid‐based cytology (LBC) with ASCUS results triaged with HPV testing; Intervention and Safety arms – Baseline HPV with LBC triage for HPV positives. Results are presented for 15,744 women allocated to the HPV (intervention and safety combined) and 9,408 to the control arms. For all age cohorts, the CIN3+ detection rate was higher in the HPV (7.5/1,000; 95%CI: 6.2, 8.9) compared to the control arm (4.6/1,000; 95%CI: 3.4, 6.2). The CIN2+ detection rates were also significantly higher in the HPV (16.5/1,000; 95%CI: 14.6, 18.6) vs. the control arm (10.1/1,000; 95%CI: 8.3, 12.4). In women ≥35 years, the overall detection rates for CIN2+ and CIN3+ were higher in the HPV vs. the control arm (CIN2+:10.0/1,000 vs. 5.2/1,000; CIN3+: 4.2/1,000 vs. 2.2/1,000 respectively, with a statistically significant difference for CIN2+). HPV testing detected significantly more CIN2+ in women 25–29 compared to LBC (63.7/1,000; 95%CI: 51.9, 78.0 vs. 32.4/1,000; 95%CI: 22.3, 46.8). HPV testing resulted in significantly higher colposcopy referral rates for all age cohorts (HPV: 58.9/1,000; 95%CI: 55.4, 62.7 vs. control: 30.9/1,000; 95%CI: 27.6, 34.6). At completion of Round 1 HPV‐based cervical cancer screening in a population‐based program resulted in greater CIN2+ detection of across all age cohorts compared to LBC screening.

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

We explored the potential impact of human papillomavirus (HPV) testing on womens 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 womens 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.

Projected Impact of HPV and LBC Primary Testing on Rates of Referral for Colposcopy in a Canadian Cervical Cancer Screening Program

OBJECTIVE To estimate the impact of implementing primary human papilloma virus liquid-based cytology (LBC) screening on four-year rates of referral for colposcopy in the British Columbia screening program. METHODS We used data on referral for colposcopy from an RCT (HPV FOCAL) comparing HPV testing every four years with LBC testing every two years. We also used data from population screening with conventional cytology among women aged 25 to 69. The predicted effect of adoption of either trial protocol on rates of referral for colposcopy was estimated using trial age-specific result and screening result-specific rates weighted by their screening program distribution. The cumulative age-specific rates of referral for colposcopy over four years were calculated. RESULTS Use of HPV testing initially increased rates of referral for colposcopy in the trial, but over four years the cumulative rates of referral were similar to those for LBC except in women aged 25 to 29, in whom a substantial excess persisted. Four-year rates of referral for colposcopy declined with age in women screened with HPV testing, LBC, and conventional cytology. Extrapolating the trial results to the distribution in the provincial screening program, implementation of either HPV or LBC throughout the provincial population would approximately double the current rates of referral for colposcopy. CONCLUSION Compared with LBC screening, primary screening for HPV increased rates of referral for colposcopy only among women aged 25 to 29. In contrast to current practice, referral for colposcopy was largely driven by the trial protocol recommendations for the management of abnormal results and not by which screening test was used.

Effect of Screening With Primary Cervical HPV Testing vs Cytology Testing on High-grade Cervical Intraepithelial Neoplasia at 48 Months: The HPV FOCAL Randomized Clinical Trial

Importance There is limited information about the relative effectiveness of cervical cancer screening with primary human papillomavirus (HPV) testing alone compared with cytology in North American populations. Objective To evaluate histologically confirmed cumulative incident cervical intraepithelial neoplasia (CIN) grade 3 or worse (CIN3+) detected up to and including 48 months by primary HPV testing alone (intervention) or liquid-based cytology (control). Design, Setting, and Participants Randomized clinical trial conducted in an organized Cervical Cancer Screening Program in Canada. Participants were recruited through 224 collaborating clinicians from January 2008 to May 2012, with follow-up through December 2016. Women aged 25 to 65 years with no history of CIN2+ in the past 5 years, no history of invasive cervical cancer, or no history of hysterectomy; who have not received a Papanicolaou test within the past 12 months; and who were not receiving immunosuppressive therapy were eligible. Interventions A total of 19 009 women were randomized to the intervention (n = 9552) and control (n = 9457) groups. Women in the intervention group received HPV testing; those whose results were negative returned at 48 months. Women in the control group received liquid-based cytology (LBC) testing; those whose results were negative returned at 24 months for LBC. Women in the control group who were negative at 24 months returned at 48 months. At 48-month exit, both groups received HPV and LBC co-testing. Main Outcomes and Measures The primary outcome was the cumulative incidence of CIN3+ 48 months following randomization. The cumulative incidence of CIN2+ was a secondary outcome. Results Among 19 009 women who were randomized (mean age, 45 years [10th-90th percentile, 30-59]), 16 374 (8296 [86.9%] in the intervention group and 8078 [85.4%] in the control group) completed the study. At 48 months, significantly fewer CIN3+ and CIN2+ were detected in the intervention vs control group. The CIN3+ incidence rate was 2.3/1000 (95% CI, 1.5-3.5) in the intervention group and 5.5/1000 (95% CI, 4.2-7.2) in the control group. The CIN3+ risk ratio was 0.42 (95% CI, 0.25-0.69). The CIN2+ incidence rate at 48 months was 5.0/1000 (95% CI, 3.8-6.7) in the intervention group and 10.6/1000 (95% CI, 8.7-12.9) in the control group. The CIN2+ risk ratio was 0.47 (95% CI, 0.34-0.67). Baseline HPV-negative women had a significantly lower cumulative incidence of CIN3+ at 48 months than cytology-negative women (CIN3+ incidence rate, 1.4/1000 [95% CI, 0.8-2.4]; CIN3+ risk ratio, 0.25 [95% CI, 0.13-0.48]). Conclusions and Relevance Among women undergoing cervical cancer screening, the use of primary HPV testing compared with cytology testing resulted in a significantly lower likelihood of CIN3+ at 48 months. Further research is needed to understand long-term clinical outcomes as well as cost-effectiveness. Trial Registration isrctn.org Identifier: ISRCTN79347302

Women's intentions to self-collect samples for human papillomavirus testing in an organized cervical cancer screening program

BackgroundMounting evidence affirms HPV testing as an effective cervical cancer screening tool, and many organized screening programs are considering adopting it as primary testing. HPV self-collection has comparable sensitivity to clinician collected specimens and is considered a feasible option in hard-to-reach women. We explored women’s intentions to HPV self-collect for cervical cancer screening from a cohort participating in a Canadian randomized controlled cervical cancer screening trial.MethodsWomen aged 25–65 were invited to complete an online survey assessing intentions to be screened with HPV testing instead of the Pap smear. The survey was based in the Theory of Planned Behaviour and questions were included to assess women’s intentions to self-collect for HPV. Demographic characteristics of women who intended to self-collect were compared with those who did not. Demographic and scale variables achieving a p-value <0.1 in the univariate and bivariate analyses were included in the stepwise logistic regression model. The final model was created to predict factors associated with women’s intentions to self-collect an HPV specimen for cervical cancer. Odds ratios were calculated with 95% confidence intervals to identify variables associated with a woman’s intention to self-collect for cervical cancer screening.ResultsThe overall survey response rate was 63.8% (981/1538) with 447 (45.6%) reporting they intended to self-collect, versus 534 (54.4%) reporting they did not. In the univariate analysis, women with more than high school education were more likely to self-collect. Women who intended to receive HPV testing versus the Pap smear were 1.94 times as likely to be in favour of self-collection and those who intended to self-collect had significantly higher attitudinal scores towards HPV self-collection. The adjusted odds ratio and 95% confidence interval from the multivariate analysis demonstrated attitude towards self-collection was the only significant variable predicting a woman’s intention to self-collect (OR 1.25; 95% CI: 1.22, 1.29).ConclusionsThe primary predictor of a woman’s intention to HPV self-collect for cervical cancer screening was her attitude towards the procedure. From a program planning perspective, these results indicate that education and awareness may be significant contributing factors to improving acceptance of self-collection and subsequently, improving screening attendance rates.

Aptima HPV Assay versus Hybrid Capture® 2 HPV test for primary cervical cancer screening in the HPV FOCAL trial

BACKGROUND Cervical cancer screening programs are switching from Pap screening to high-risk HPV testing. OBJECTIVES To compare the Aptima HPV Assay (AHPV) with the Hybrid Capture® 2 High-Risk HPV DNA Test® (HC2) for primary cervical screening. STUDY DESIGN HPV FOCAL is a randomized trial comparing HC2 to liquid-based cytology (LBC) for screening women aged 25-65. AHPV and HC2 were compared at the baseline screen (n=3473). Genotyping was by the Aptima HPV 16 18/45 Genotype Assay. We assessed HPV genotyping and reflex LBC for colposcopy triage. RESULTS AHPV/HC2 agreement was 96.5% (kappa 0.76); positive agreement was 77.4%. The AHPV positive rate was 7.2% vs. 8.4% for HC2 (p=0.06). Based on HC2 screening, round 1 CIN2 and CIN3+ rates were 9.2/1000 and 5.2/1000 respectively. Using HC2 as the comparator test, AHPV CIN2+ and CIN3+ relative sensitivities were 0.96 and 1.00 (p=1.00) respectively. High-grade reflex LBC and HPV 16 infection were significantly associated with CIN3+. AHPV specificity was 0.94 vs. 0.93 (p=0.05) for HC2. Compared with triage of HC2+ with abnormal cytology or HPV persistence for 12 months, colposcopy referral would be significantly reduced (38.3/1000 vs. 60.8/1000; p<0.001) if AHPV+ women with abnormal LBC and HPV 16/18/45 were referred at baseline. CIN2+ and CIN3+ detection rates were not significantly different for the two strategies. CONCLUSIONS AHPV vs. HC2 screening had equivalent CIN2+ and CIN3+ detection. Triage of AHPV+ by abnormal reflex LBC and the presence of HPV 16/18/45 would result in a significantly lower colposcopy referral rate with similar CIN2+ and CIN3+ detection rates as the overall HC2+ referral algorithm.

Disease detection and resource use in the safety and control arms of the HPV FOCAL cervical cancer screening trial.

Background:The HPV FOCAL Trial is a RCT comparing human papilloma virus (HPV) with Liquid Based Cytology (LBC) screening for cervical cancer. Results are presented for the comparison of the Safety and Control arms after two rounds.Methods:HPV FOCAL included randomisation of women aged 25–65 into the Safety arm, where they were initially screened with HPV and the Control arm, where they received entry screening with LBC, with both arms screened again with LBC at 24 months.Results:There are 6203 (Safety) and 6075 (Control) women included in this analysis. For the Safety vs Control arms, Round 1 screening resulted in increased detection of cervical intraepithelial neoplasia 2 or worse (CIN2+),15.3 vs 10.4 per 1000, RR=1.48 (95%CI=1.08–2.03) and higher colposcopy referral rates, 5.6% vs 3.2%. LBC screening at 24 months resulted in similar colposcopy referral rates, 1.5% vs 1.9%, and decreased CIN2+ detection, 2.0 vs 4.7 per 1000, RR=0.43 (95%CI=0.21–0.88) in the Safety vs Control arms. CIN2+ detection and colposcopy referral rates declined with increasing age in both arms. One round of HPV screening detected similar levels of CIN2+ as two rounds of LBC screening.Interpretation:CIN2+ detection at 2 years was lower in those screened by HPV, indicating an improved 2-year negative predictive value of the HPV test.

Recommendations for Implementing Human Papillomavirus-Based Cervical Cancer Screening: Lessons Learned from the HPV FOCAL Trial

Laurie Smith, RN, BN, MPH, Dirk van Niekerk, FRCPC, Andrew Coldman, PhD, Mel Krajden, MD, FRCPC, Eduardo L. Franco, DrPH, FRSC, FCAHS, Gina Ogilvie, MD, MSc, FCFP, DrPH Cancer Control Research, BC Cancer Agency, Vancouver BC Cervical Cancer Screening Program, BC Cancer Agency, Vancouver BC Faculty of Medicine, University of British Columbia, Vancouver BC Hepatitis Division, BC Centre for Disease Control, Vancouver BC Division of Cancer Epidemiology, McGill University, Montreal QC Women’s Health Research Institute, Vancouver BC