A new study reports that a type of cervical cancer that is less amenable to Pap testing is increasing in several subpopulations of women, pointing to the growing importance of human papillomavirus (HPV) testing and vaccination. The study appears early online in Preventive Medicine.

Overall trends in cervical cancer incidence have been driven by declines in squamous cell carcinoma, which account for the majority of cervical cancers. Most of the rest are adenocarcinomas, for which Pap testing is less sensitive. While overall cervical cancer rates have been dropping for decades, cervical adenocarcinomas seem to have become more common in the past 20 to 30 years. But there has been limited reporting on recent trends.

To learn more, investigators led by Farhad Islami, MD, PhD, analyzed recent cervical cancer incidence trends by histology and age in the United States. They examined trends in squamous cell carcinoma and adenocarcinoma incidence rates in the United States by age group, race/ethnicity, and stage at diagnosis using data from the US Cancer Statistics Incidence Analytic Database.

They found squamous cell carcinoma incidence rates continued to decrease in all racial/ethnic groups except among non-Hispanic whites, in whom rates stopped dropping in the 2010s. For adenocarcinoma, after being stable between 1999 and 2002, incidence rates among non-Hispanic whites rose 1.3% per year during 2002–2015. Those increases were driven by steeper increases in women ages 40 to 49, among whom cervical adenocarcinoma rates rose 4.4% per year since 2004, and women 50 to 59?years, among whom rates rose 5.5% per year since 2011. Adenocarcinoma incidence decreased in blacks and Hispanics during 1999–2015 and was stable in Asian/Pacific Islanders.

“Increasing or stabilized incidence trends for [adenocarcinoma] and attenuation of earlier declines for [squamous cell carcinoma] in several subpopulations underscore the importance of intensifying efforts to reverse the increasing trends and further reduce the burden of cervical cancer in the US,” write the authors.

The authors state that “more efforts are needed to increase screening utilization according to guidelines and appropriate follow-up of positive results” to further reduce the burden of cervical cancer. They note that increasing the use of HPV testing may improve early detection of adenocarcinoma, but they also recommend research to further improve screening strategies to reduce overdiagnosis, which may be more common with HPV testing. HPV vaccination is an effective tool to prevent cervical cancer because virtually all these cancers are caused by HPV infection. “Our results also underscore the importance of HPV vaccination. Concerted efforts are needed to increase its use, which remains suboptimal,” said Dr. Islami.