The IMPACT trial: human papillomavirus, cervical cytology and histopathological results from the baseline and 1-year follow-up phase

• Published in: American journal of obstetrics and gynecology
• Main Authors: Safaeian, Mahboobeh, Wright, Jr, Thomas C, Stoler, Mark H, Ranger-Moore, Jim, Rehm, Susanne, Aslam, Shagufta, Fang, Qijun, Volkir, Patrick, Ridder, Ruediger
• Format: Journal Article
• Language: English
• Published: United States 11.04.2021
• Subjects: IMPACT; Pap cytology; cervical cancer screening; IMproving Primary screening And Colposcopy Triage; real-time PCR; cervical intraepithelial neoplasia; HPV
• ISSN: 1097-6868

An increase in human papillomavirus (HPV) test volumes is expected in the near future as HPV-based screening protocols are expected to become more broadly adopted. The IMproving Primary screening And Colposcopy Triage (IMPACT) trial, a prospective, multicenter US cervical cancer screening trial, was conducted to obtain FDA approvals for the new high-throughput cobas HPV for use on the cobas 6800/8800 Systems (cobas HPV) for detecting cervical precancer and cancer (cervical intraepithelial neoplasia of grade 2 or worse [≥CIN2] and grade 3 or worse, [≥CIN3]). Here the baseline demographics, HPV, cervical cytology and histolpathologic results are presented. Additionally the baseline and 1-years risks of ≥CIN2 and ≥CIN3 associated with HPV results are reported. In total, 35,263 women aged 25-65 years undergoing routine screening were enrolled; liquid-based cytology and 2 high-risk HPV PCR-based tests were performed. Women with abnormal Pap cytology, women positive for high-risk HPV by either of the two HPV tests, and a random subset of women negative by Pap cytology and the 2 HPV tests were referred to colposcopy/cervical biopsy. Women who did not meet the study endpoint were eligible for the 1-year follow-up study phase. Verification bias-adjusted cervical disease prevalence and risks and 95% confidence intervals were computed. The prevalence of ASC-US and >ASC-US cytology were 6.5% and 3.2%, respectively. Prevalence of high-risk HPV, HPV16, and HPV18 base on the new cobas HPV test were 15.1%, 3.1%, and 1.4%, respectively. Both cytologic abnormalities and HPV positivity declined with increasing age. Among women who had a colposcopy/biopsy, prevalence of ≥CIN2 and ≥CIN3 were 8.8% and 3.6%, respectively. The baseline and 1-year cumulative risks for ≥CIN3 were 13.6% and 16.9%, respectively, in HPV16-postive women. HPV-negative women had the lowest 1-year cumulative risk for ≥CIN3 (0.06%). The contemporary age-specific prevalence of HPV (including HPV16 and HPV18), cytologic abnormalities, and CIN in a large U.S. cervical cancer screening population provides benchmarks for health care policy, screening programs, and for laboratories and clinicians.