Carlos R. Oliveira (United States of America)
Yale school of medicine Pediatric Infectious Diseases and Global HealthPresenter of 3 Presentations
EPIDEMIOLOGY OF ANAL CANCER IN NEW HAVEN COUNTY, CONNECTICUT: 2006–2013 (ID 848)
Abstract
Introduction
HPV vaccine was introduced in the United States in 2006. Over 90% of anal cancers are potentially preventable with HPV vaccine. The objective of this study was to explore the potential impact of HPV vaccine on the epidemiology of anal cancer in the post-vaccine era.
Methods
Incident cases of anal cancer among residents of New Haven County (NHC) were identified from 2006–2013 using discharge diagnosis codes from the Yale-New Haven Health System, the largest healthcare provider in Connecticut and home to the only comprehensive cancer center in the state. The annual incidence rate (IR) was estimated by sex and age-groups (30-49, 50-64, and >65-years)using data from the US Census. Trends in the IR of anal cancer were characterized by the annual percentage change (APC) using Join-point regression.
Results
From 2006–2013 there were 246 newly diagnosed cases of anal cancer in NHC (median age= 58 years, IQR= 52-69 years). Most were women (58%) and were publicly insured (52%). During the 8-years, the age-adjusted annual IR increased from 3.7 to 6.7 per 100,000 population (average APC= 8.8, p<0.01). Changes in the IR of anal cancer were statistically significant only in women 50-64 and >65 years of age. Join-point analyses identified 2011 as a significant point of change (Figure 1), when the slope changed from an increasing trend (APC = 14.3; 95%CI = 12.4 to 14.3) to a decreasing trend (APC = -3.8; 95%CI: -3.6 to -3.9). The APC was significantly lower in the younger age-group (IRR=0.27, p<0.01).
Conclusions
The overall incidence of anal cancer continues to rise in the post-vaccine era, though most of the burden remains in older men and women who were least likely to have received HPV vaccine. Continued surveillanceis needed to determine whether the IR will continue to decrease as vaccine uptake increases.
EFFECTIVENESS OF HUMAN PAPILLOMAVIRUS VACCINE: A CASE-CONTROL STUDY WITH BAYESIAN MODEL AVERAGING (ID 401)
Abstract
Introduction
The full benefit of human papillomavirus (HPV) vaccines may not be realized in real-world settings due to delays in immunization. At older ages, many women will have already been exposed to HPV rendering this prophylactic vaccine less effective.This study aimed to determine the extent to which age at the time of immunization influences the vaccine’s effectiveness (VE) against HPV-attributable high-grade cervical lesions (HGCL).
Methods
We conducted a matched case-control study of women in New Haven County, Connecticut, where there is population-based surveillance for HGCL and genotyping of HPV from cervical specimens. Cases were vaccine-eligible women with a HGCL attributable to HPV 16 or 18. Controls were women with normal Pap smear results, matched to cases by age, medical practice, and date of Pap smear. Participants were interviewed and records were reviewed for immunization history and potential confounders. Matched odds ratios (mOR) from conditional logistic regression were estimated by age at time of immunization (<18 years, >19 years). The VE was estimated as 1-mOR. Multivariable models were used to adjust for potential confounding. Consensus estimates of the adjusted VE were calculated using Bayesian Model Averaging (BMA).
Results
A total of 312 women (108 cases and 204 controls) were included. Cases and controls were similar in age, race/ethnicity, marital status, level of education, income, use of contraception, and history of sexually transmitted diseases (Table 1). The adjusted effectiveness of >1 dose of the vaccine was 43%. When the first dose was given at <18 years of age, the VE was 77% (Figure 1).
Conclusions
These data quantify the clinical effectiveness of HPV vaccine and use real-world data to highlight the fact that the vaccine’s protective effect is greater when given <18 years of age. These empirical estimates provide evidence that can be used to promote timely immunization for adolescents.
TRENDS OF UNINDICATED CERVICAL CANCER SCREENING IN ADOLESCENT FEMALES: 2012–2018 (ID 852)
Abstract
Introduction
Cervical cancer is exceedingly rare in adolescents. In 2009, U.S. guidelines discouraged screening in young immunocompetent women <21 years of age. This study aims to ascertain the trends and factors associated with unindicated screening in adolescents.
Methods
Cervical cancer screening tests performed in females <21 years from 2012–2018 were reviewed from Yale New Haven Health System. The final diagnosis, the results of HPV testing, and the clinical indications for the procedure were extracted using Natural Language Processing. Each screening test was adjudicated as either indicated or unindicated based on the logic presented in the guidelines. The biannual rate of unindicated screening was calculated as the ratio of unindicated cases to the total number of <21 years patient visits completed by a given provider during a 6-month interval for the overall sample, for each practice setting, and for provider degrees.
Results
Data from 118 providers and 797 women (N=906 Paps) were included. Characteristics of patients are detailed in Table 1. The reasoning for performing screening was not given for 62% of the reports. The most common reasons listed were “routine clinical care” (63%) or “history of prior cervical abnormalities” (23%). Although most adolescents had an unindicated pap, 8% had a follow-up pap after receiving an abnormal result on a prior unindicated pap. During the study period, 49 colposcopies and 3 conizations were performed in women <21 years. Although the incidence of unindicated screening was more than twice as high among community-based providers, the rate of reduction was greater in the community than in the academic setting during the study period (Table 2).
Conclusions
Nearly a decade has passed since the release of the current cervical cancer screening guidelines in the US, yet unindicated screening of adolescents remains a challenge. More research is needed to identify better strategies to reduce the overutilization of screening.