Thao N. Hoang

Trends in HPV‐associated cancer incidence in Texas medically underserved regions

AbstractBackgroundWhile cervical cancer incidence rates (IR) in the United States have dropped in the last 20 years, non‐cervical human papillomavirus (HPV) associated cancers increased. Many people in Texas (TX) live in medically underserved areas and have higher risk of developing HPV‐associated cancers. Since previous studies of these regions focused on cervical cancer, we included other HPV‐associated cancers in our analysis of IR in East TX and the TX‐Mexico Border compared to other TX regions.MethodsCancer data from 2006 to 2019 were obtained from the TX Cancer Registry. Cases of HPV‐associated cervical, vaginal, vulvar, penile, anal, and oropharyngeal cancers and corresponding patient‐level demographic data were included. We calculated IR per 100,000 and drew heat maps to visualize cancer IR by county. To control potential confounders, we added county‐level risk factors: rates for smoking, excessive drinking, obesity, STIs, primary care provider availability and dentist availability, from the County Health Rankings and Roadmaps program. We reported IRs by region and time and estimated unadjusted and adjusted risk ratio (RR) for association of each type of cancer and region. Lastly, we created adjusted models for each cancer by period to see time trends of regional differences.ResultsRisk of anal, cervical, and oropharyngeal cancer was lower at parts of the Border than in the rest of TX in the adjusted model. We also observed increasing anal and oropharyngeal cancer risk and decreasing cervical and vaginal cancer risk over time.ConclusionPatient sociodemographics, behavioral risk factors, and access to care may contribute to some observed differences in cancer IR across regions. This indicates that targeted prevention efforts towards these regions, especially in low socioeconomic status communities, may benefit future generations.

Vulvar Cancer Incidence in the United States and its Relationship to Human Papillomavirus Vaccinations, 2001–2018

Abstract The human papillomavirus (HPV) vaccine was indicated for the prevention of vulvovaginal cancers in 2008, but its impact on the incidence of vulvar cancers within the US is unknown. To determine this, we conducted a secondary analysis of 88,942 vulvar cancer cases among women 20+ years old using the US Cancer Statistics 2001–2018 databases. Data were stratified by tumor behavior (in situ or invasive), age (20–44, 45–64, 65+ years old), race/ethnicity (non-Hispanic White, non-Hispanic Black, Hispanic), and US census region (Northeast, South, Midwest, West), and incidence rates and average annual percentage changes (AAPC) were calculated by group. Reversing previous trends, the incidence of vulvar carcinoma in situ significantly decreased between 2001 and 2018 among women from all age groups, races/ethnicities, and regions (combined AAPC,  −4.3; 95% confidence interval (CI), −4.7 to −3.8). The incidence of invasive vulvar squamous cell carcinoma decreased significantly among 20- to 44-year-old women (AAPC, −0.8; 95% CI, −1.3 to −0.3), but significantly increased among those 45 to 64 (AAPC, 2.3; 95% CI, 1.8–2.8) and 65+ years old (AAPC, 1.2; 95% CI, 1.1–1.4). Regardless of tumor behavior, incidence was highest among non-Hispanic Whites and the Midwest region. Overall, the significant declines in vulvar carcinoma in situ among all ages, as well as invasive vulvar cancer among younger women, are encouraging and complement other recent data suggesting HPV vaccinations are already reducing anal and cervical cancer incidence. Over time, further declines in vulvar carcinoma incidence are likely as uptake and completion rates of the HPV vaccine increase in the US. Prevention Relevance: We found evidence that HPV vaccinations likely contributed to a decrease in the incidences of vulvar carcinoma in situ and invasive vulvar carcinoma among 20- to 44-year-old women between 2001 and 2018. Our data add to the growing evidence that HPV vaccinations are reducing the incidence of HPV-related anogenital cancers.