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The American Cancer Society (ACS) in new guidance enhances the role of human papillomavirus (HPV) testing and changes the age limit for starting cervical cancer screenings. Dispensing with cotesting as the preferred screening method, this new guideline recommends HPV testing alone in women ages 25-65, calling for a phaseout of screening options for Pap and cotesting once HPV testing becomes widely available.
“For the first time, ACS has issued guidelines that are transitional. Cotesting and cytology alone are acceptable options but will not be included in the next guideline. The intent is to allow time for labs and others to make the switch to primary HPV screening,” Debbie Saslow, PhD, a co-author of the guidance, told CLN Stat. Saslow is the ACS’s managing director for HPV and gynecologic cancers.
The recommendations apply to all asymptomatic women with a cervix. Women should begin testing at age 25 and undergo primary HPV testing every 5 years through age 65. If this option isn’t available, the society recommends that women ages 25 to 65 screen with cotesting (HPV plus Pap/cytology) every 5 years, or Pap alone every 3 years. This differs from previous guidance from 2012, which recommended that screening begin at age 21, and cotesting options at age 30 years.
Many things factored into ACS’s emphasis on HPV testing: the regulatory approval of primary HPV tests, new clinical evidence on screening, and the U.S. Preventive Services Task Force’s inclusion of HPV testing in its 2018 recommendation statement. “The update is based on decades of studies comparing the effectiveness of HPV testing compared to cytology and bolstered by evidence of the impact of HPV vaccination, including a dramatic decline in cervical precancers and, more recently, cervical cancers among young women,” said Saslow.
HPV testing for the past few years has gained currency as a screening method. In 2017, CLN Stat reported on a study that found little value in supplementing an HPV test with a Pap test. HPV proved superior in detecting precancerous lesions.
ACS raised the recommended start of screening age to 25 based on three factors:
- Less than 1% of cervical cancers are diagnosed before age 25, a number that’s decreasing due to HPV vaccination.
- Such cases have not decreased as a result of screening, and the numbers are similar in countries that start screening later. Screening is just not beneficial earlier than age 25.
- There are more harms from screening earlier, i.e., starting at age 21. The rate of false positive results is much higher in younger people, and the most serious harm of false positives is the potential effect on pregnancy.
Screening isn’t necessary in women over age 65 with a cervix who have had 10 years of normal screening results, and those who have had hysterectomies for noncancerous reasons.
“While the driving force of ACS guidelines is the scientific evidence, we hope that this streamlined guidance will improve screening rates, which despite decades of use are still not optimal. Screening those who have not previously been screened or have not been screened regularly will prevent more cervical cancers,” said Saslow.
The guideline evoked mixed reactions. Some in the field claim ACS is taking options away from women by downplaying the Pap test and eventually getting rid of it.
Research has shown that cotesting detects the most cancers and saves the most lives, according to Mark Spitzer, MD, an ob-gyn specialist in New York and clinical professor of obstetrics and gynecology at Hofstra/Northwell Zucker School of Medicine. A recent study that evaluated real-world data from 13.6 million U.S. women from 2010-2018 found that cotesting detected significantly more women who developed biopsy-confirmed adenocarcinomas (82.3%), compared to HPV testing (61.2%) and Pap testing alone (59.7%). Cotesting also detected more women who developed biopsy-confirmed precancers (95.6%) than HPV testing (92.6%) or Pap testing alone (77.9%). This study was conducted by researchers at Quest Diagnostics and the University of Pittsburgh Medical Center.
Laboratory professionals should be aware that healthcare providers continue to value Pap testing and cotesting, “so it’s important to retain and support these screening methods,” Spitzer told CLN Stat. “Pathologists who review cytology slides know firsthand that cancer cases can be missed and that cytology delivers value to the screening process. A shift away from cytology and cotesting would lead to missed cancers and would risk halting the progress made in fighting cervical cancer.”
Reacting to the new guidelines, the American College of Obstetricians and Gynecologists (ACOG) affirmed its own three-part screening strategy: high-risk HPV testing alone, Pap testing alone, and cotesting. “ACOG looks forward to comprehensively reviewing the ACS recommendations and the supporting evidence in order to determine whether a similar update to our clinical guidance document on cervical cancer screening is needed,” said Christopher M. Zahn, MD, FACOG, ACOG’s vice president of practice activities, in a statement.