Population-Based Incidence Rates of Cervical Intraepithelial Neoplasia in the Human Papillomavirus Vaccine Era

Abstract

IMPORTANCE A substantial effect of human papillomavirus (HPV) vaccines on reducing HPV-related cervical disease is essential before modifying clinical practice guidelines in partially vaccinated populations. OBJECTIVE To determine the population-based cervical intraepithelial neoplasia (CIN) trends when adjusting for changes in cervical screening practices that overlapped with HPV vaccination implementation. DESIGN, SETTING, AND PARTICIPANTS The New Mexico HPV Pap Registry, which captures population-based estimates of both cervical screening prevalence and CIN, was used to compute CIN trends from January 1, 2007, to December 31, 2014. Under New Mexico Administrative Code, the New Mexico HPV Pap Registry, a statewide public health surveillance program, receives mandatory reporting of all cervical screening (cytologic and HPV testing) and any cervical, vulvar, and vaginal histopathological findings for all women residing in New Mexico irrespective of outcome. MAIN OUTCOME MEASURES Prespecified outcome measures included low-grade CIN (grade 1 [CIN1]) and high-grade CIN (grade 2 [CIN2] and grade 3 [CIN3]). RESULTS From 2007 to 2014, a total of 13 520 CIN1, 4296 CIN2, and 2823 CIN3 lesions were diagnosed among female individuals 15 to 29 years old. After adjustment for changes in cervical screening across the period, reductions in the CIN incidence per 100 000 women screened were significant for all grades of CIN among female individuals 15 to 19 years old, dropping from 3468.3 to 1590.6 for CIN1 (annual percentage change [APC], −9.0; 95% CI, −12.0 to −5.8; P < .001), from 896.4 to 414.9 for CIN2 (APC, −10.5; 95% CI, −18.8 to −1.2; P = .03), and from 240.2 to 0 for CIN3 (APC, −41.3; 95% CI, −65.7 to 0.3; P = .05). Reductions in the CIN2 incidence were also significant for women 20 to 24 years old, dropping from 1027.7 to 627.1 (APC, −6.3; 95% CI, −10.9 to −1.4; P = .02). CONCLUSIONS AND RELEVANCE Population-level decreases in CIN among cohorts partially vaccinated for HPV may be considered when clinical practice guidelines for cervical cancer screening are reassessed. Evidence is rapidly growing to suggest that further increases in raising the age to start screening are imminent, one step toward integrating screening and vaccination.

Cervical adenocarcinoma in situ: Human papillomavirus types and incidence trends in five states, 2008–2015

“…Importantly, we report significant declines in AIS incidence rates among 21–24 year‐olds, overall and among screened women. Although numbers are small in this group, this reported decline among AIS cases is similar to recent reports of declines among all CIN2+ lesions in the US during the same time period . Revised cervical cancer screening recommendations have resulted in a smaller pool of women screened annually, and thus fewer are available to be diagnosed annually .…”

“…Although numbers are small in this group, this reported decline among AIS cases is similar to recent reports of declines among all CIN2+ lesions in the US during the same time period. 40,42,48 Revised cervical cancer screening recommendations have resulted in a smaller pool of women screened annually, and thus fewer are available to be diagnosed annually. 49 The decline we observed among screened women in this age group suggests that reductions are not entirely due to increased screening intervals and could result, at least in part, from vaccine impact.…”

Primary HPV testing recommendations of US providers, 2015

“…It is possible that providers familiar with HPV vaccination know that high coverage can result in less HPV infection of vaccine types and are aware that future screening can differentiate the most oncogenic types—HPV 16/18, the same types in the first generation vaccines—from other types. HPV vaccination has been associated with significant decreases in cervical pre-cancers in the US (Benard et al, 2016) and the Netherlands (Dijkstra et al, 2016). Similarly, high coverage of the HPV vaccine in Australia has resulted in a reduction in HPV 16/18 infections, genital warts, and cervical pre-cancers (Brotherton et al, 2016).…”

Cervical cancer screening research in the PROSPR I consortium: Rationale, methods and baseline findings from a US cohort

“…Across Research Centers, unstructured histopathology diagnoses were mapped to clinically meaningful categories, with the most severe diagnosis recorded for each procedure. Classification was by manual review of all pathology reports at KPWA, by natural language parsing algorithms at UNM-NMHPVPR, 23,24 and by electronic text analysis methods at KPNC, KPSC, and Parkland-UTSW. For validation, Parkland-UTSW manually reviewed at least 10% of each category; KPNC and KPSC performed several iterative reviews that included all cancer diagnoses and up to 100 records from other result categories; UNM-NMHPVPR reviewed all cancer diagnoses, and a randomly selected sample from other result categories.…”