USPSTF proposes new cervical cancer screening guidelines

While the method of cervical cancer screening is beginning to change worldwide, human papillomavirus (HPV) tests, Papanicolaou (Pap) tests, and co-testing are all effective and recommended by the U.S. Preventive Services Task Force (USPSTF), according to newly drafted cervical cancer screening guidelines published December 10.

The American Society for Clinical Pathology (ASCP), now headed by President Dr. Greg Sossaman from Ochsner Health in New Orleans, called the recommendations a major victory for women's health. The ASCP commended the USPSTF for maintaining grade A designations for the following:

• Screening for cervical cancer every three years with a cervical cytology Pap test for women 21-29 years of age.
• HPV primary testing every five years, or getting a combined cytology-based Pap screening and high-risk HPV (hrHPV) test (cotesting) every five years, or Pap test alone every three years for women aged 30-65.
• No screening for women under 21. 

The USPSTF's draft clarifies a Grade A recommendation for cervical cytology alone every three years for women ages 21 to 29 years; then every five years with clinician- or patient-collected hrHPV primary screening for women ages 30 to 65 years. "As an alternative to HPV primary screening for women ages 30 to 65 years, the USPSTF recommends continued screening every three years with cervical cytology alone or screening every five years with hrHPV testing in combination with cytology (cotesting)," USPSTF said. 

The Task Force also recommended against screening (grade D) for cervical cancer in women who have had a hysterectomy with removal of the cervix and do not have a history of a high-grade precancerous lesion (i.e., cervical intraepithelial neoplasia [CIN] grade 2 or 3) or cervical cancer.

For at least five years, clinical laboratory industry stakeholders have been watching signals of a potential shift away from cervical cytology to DNA-based testing, and, further, self-collection cervical cancer at-home screening. 

In its corresponding model-based decision analysis, the USPSTF noted sparse data on follow-up management and screening over time in its ability to evaluate HPV self-collection as part of routine screening. It was only in May that the U.S. Food and Drug Administration (FDA) expanded approvals of two HPV tests (Becton, Dickinson and Company [BD]'s Onclarity HPV and Roche Molecular Systems' cobas HPV) to offer women the option to collect a vaginal sample themselves for the testing.

The USPSTF did note, however, that a one-time screening with HPV self-collection has the potential to reduce lifetime risk of cervical cancer by 25% to 30% if the screening occurs between the ages of 35 and 45 (12% to 15% if screening occurs at 65), assuming perfect adherence to follow-up diagnosis and precancer treatment. 

"ASCP has long championed the patient’s right to choose the best healthcare options and preserve shared decision-making through our Patient and Provider Choice campaign," the organization said following the USPSTF's draft release. "The recommendations track very closely with our advocacy efforts in the campaign, therefore we believe that the Task Force made the right decision in ensuring all cervical cancer screening options are available to all women." 

The ASCP said it was concerned that raising the screening age to 25 and/or removing cotesting (a procedure in which an HPV test and a Pap test are done at the same time) would exacerbate disparities in cervical cancer screening and detection in already underserved and vulnerable populations that may not currently have hrHPV testing available to them.  

Modeling studies 

From the Task Force's modeling studies, several unifying themes emerged:

1. HPV alone was consistently identified as an efficient strategy by all models, cohorts, and metrics; start/switch age, interval, and end ages were influenced by vaccination status.
2. Cytology alone was not efficient across any models or cohorts, although the Task Force said it explored cytology differently than it did HPV testing and cotesting.
3. Cotesting tended to be the least efficient across all models and cohorts.
4. Overall, interval and screening start age were more influential on outcomes than screening end age. 

Current cervical cancer screening methods apply HPV-based testing and artificial intelligence-based screening systems that use digitalized cytology images, in an effort to optimize the accuracy and efficiency of the Pap test. 

At the same time, changing attitudes have been observed abroad. In 2017, Australia replaced the Pap test. Canadian governments also backed the launch of at-home cervical cancer screenings that started in January. Additionally, there are studies of negative downstream effects of screening, including higher incidence of preterm deliveries and false-positive results with cervical cytology in those vaccinated against HPV.

Signals abroad

One of the earliest adopters of primary HPV testing for cervical cancer screening is Australia, where in December 2017, the Australian National Cervical Screening Program (NCSP) replaced the Pap test. The Australian program also offers the option of self-collected vaginal samples.

Last year, a trial of portable screening and same day colposcopic assessment began in the Kimberley region of Australia. It allows eligible participants to collect their own screening sample, receive a test result within an hour of testing, and access a specialist doctor during the same visit. 

In Canada, the Society of Obstetricians and Gynaecologists of Canada predicted that take-home HPV tests will replace traditional Pap smears in every Canadian province within two years. CTVNews.ca reported late last year that Quebec, Ontario, and Prince Edward Island had formally announced the move to HPV tests as the primary mode of screening. However, doctors at St. Joseph's Healthcare in London, Ontario, have seen strong demand for cervical cancer screening with the launch of pop-up Pap test clinics, typically from women who do not have a family doctor. 

In September 2021, the World Health Organization (WHO) recommended DNA-based testing for HPV as a first-choice screening method for cervical cancer prevention. Australia has aligned with the WHO, according to its national plan dated November 2023.

Signals in the U.S. 

The USPSTF's new recommendations differ slightly from the American Cancer Society (ACS) cervical cancer screening guidelines. In July 2020, those guidelines changed to suggest primary hrHPV testing (done by itself for screening) as the preferred screening option every five years for average-risk individuals aged 25-65 years old. ACS added that if primary HPV testing is not available then screen with a cotest that combines an FDA-approved HPV test with a Pap test every five years or a Pap test alone every three years.

The American College of Obstetricians and Gynecologists (ACOG) reaffirmed in April 2024 its support for USPSTF guidelines expanding the recommended options for cervical cancer screening in average-risk individuals aged 30 years and older, with some exceptions. 

"Although cytology alone is the recommended screening method for individuals aged 21-29 years, ACOG, [American Society for Colposcopy and Cervical Pathology] ASCCP, and [Society of Gynecologic Oncology] SGO advise that primary hrHPV testing every five years can be considered for average-risk patients aged 25-29 years based on FDA-approved age for use and primary hrHPV testing’s demonstrated efficacy in individuals aged 25 years and older," stated ACOG in April.

The Task Force’s draft recommendation statement and draft evidence review have been posted for public comment on the Task Force website. Comments can be submitted from December 10, 2024, through January 13, 2025, at http://www.uspreventiveservicestaskforce.org/tfcomment.htm.