Study Links Decrease in Cervical Cancer Incidence to Screening, HPV Vaccination

Other HPV-associated cancers were found to have increased over the study period, linking this trend to lack of guidelines and other resources.

A review of data for more than 650,000 patients with human papillomavirus (HPV)-associated cancers found the incidence of cervical cancer has decreased annually by 1% over a period of 17 years. However, investigators also found certain other types of cancers associated with the HPV had increased significantly during the same period between 2001 and 2017.1-3

The study authors reviewed data from the US Cancer Statistics program, with the results from the study being presented at the virtual 2021 American Society of Clinical Oncology (ASCO) Annual Meeting from June 4 to 8, 2021.1

The study’s lead author Cheng-I Liao, MD, Kaohsiung Veterans General Hospital, in Kaohsiung, Taiwan, said in an ASCO webcast that HPV is associated with more than 90% cervical and anal cancers, as well as 60 to 75% of oropharyngeal, vulvar, vaginal, and penile cancers. According to investigators, 52% of all HPV-associated cancers were incidence of cervical cancer during the study period.2

“It is likely that the significant decrease in cervical cancer incidence results from clear guidelines for cervical cancer screening and may also reflect promotion and acceptance of [HPV] vaccination, particularly in younger women,” Liao said in a press release.1

The HPV vaccine was first approved in 2006 for girls and young women ages 9 to 26 years as prevention against HPV infection and the development of cervical cancer lesions. Recommendations for HPV vaccination were later extended to boys ages 11 to 12 years, and for everyone up to age 45 years.1

In their study, investigators analyzed cervical cancer incidence in patients aged 20 to 24 years. Compared to older cohorts, women in the 20 to 24 years age group were found to have a disproportionately greater decrease in the incidence of cervical cancer at 4.63% per year, suggesting a potential effect of vaccination, according to the study authors.1

However, although data found that cervical cancer incidence continues to decrease in the United States, the investigators also found increasing incidence of oropharyngeal, anal and rectal, and vulvar squamous cell carcinoma during the same study period at annual percent changes of 0.77%, 2.75%, and 1.27%, respectively. According to the study authors, the increase in cancer types among women is projected to surpass that of cervical cancer by 2025 in every age group over 50 years.3

Additionally, the study found an overall annual increase in HPV-related cancers in men—2.36% annually— with the highest increase in oropharyngeal cancer.3 In fact, 81% of all HPV-related cancers in men were incidences of oropharyngeal cancer, which was approximately 5 times more likely than incidence in women.1,3

According to the study’s investigators, there are no clear guidelines nor standardized screening that exist for certain HPV-related cancers, including oropharyngeal, vulvar, vaginal, penile, anal, and rectal cancers.1

“In order to reduce these trends and achieve success comparable to what we’re seeing with cervical cancer, we must develop effective screening strategies and determine vaccine efficacy in these patient populations,” Liao said in the press release.1

In a prepared statement, ASCO President Lori J. Pierce, MD, FASTRO, FASCO applauded the study’s finding around the decrease in cervical cancer incidence and said it may reflect efforts to increase screenings and vaccinations of patients at risk.1

“Clearly, this study shows that we still have a great deal of work to do in order to reverse the increasing incidence rates of other HPV-related cancers,” Pierce said in the press release.1

According to investigators, they plan to analyze the rates of HPV testing and vaccination from other databases to obtain additional information. They also noted that additional resources and research are still needed to address the lack of disease screening as well as vaccination recommendations for HPV- associated cancers outside of cervical cancer.1,3


  1. With Strong Screening and Vaccination Guidelines, Cervical Cancer Rates Drop; Other HPV-Related Cancers Are on the Rise [news release]. May 19, 2021; American Society of Clinical Oncology. Accessed May 26, 2021.
  2. HPV Associated cancers in the US over the last 17 years‑Has screening or vaccination made any difference? Presented at: 2021 American Society of Clinical Oncology (ASCO) Annual Meeting Presscast. May 14, 2021. Accessed May 26, 2021.
  3. Liao CI, Caesar MAP, Chan C, et al. HPV-associated cancers in the United States over the last 15 years: Has screening or vaccination made any difference? J Clin Oncol 39, 2021 (suppl 15; abstr 107) doi: 10.1200/JCO.2021.39.15_suppl.107