Reference: CA Cancer J Clin. 2020 Jul 30
Deaths from cervical cancer have plummeted for women participating in Pap screening since it was introduced in the 1950s. We have learned in the last few decades that high-risk serotypes of human papillomavirus (HPV) infection cause almost all cervical cancer and that HPV testing is a more sensitive marker for cervical intraepithelial neoplasia (CIN) than cytology when using colposcopy and biopsy as the gold standard. Moreover, combining the two methods (co-testing) doesn’t add much to sensitivity or specificity. We also know that most young women who contract HPV in their late teens or early 20s will clear the virus within two years without intervention. For these reasons and others, the USPSTF announced guidelines in 2018 recommending cytology without HPV testing for women aged 21-30 every three years followed by HPV testing every five years (or cytology every three years or co-testing) for women aged ≥ 30 years. But now, the American Cancer Society (ACS) is recommending commencement of cervical cancer screening with HPV testing alone every 5 years from age 25 to 65. Cytology is an acceptable alternative, but is clearly considered to be not as predictive of cancer development.
This latest plan has a number of advantages and disadvantages. In our view, simplicity might be this guideline’s greatest strength. The existing guidelines from groups such as ACOG, USPSTF, and ASCCP are more complicated, which may be part of the reason for low adherence. These new guidelines from ACS reduce the frequency of false-positive testing for those under the age of 25 (< 1% of cervical cancer occurs in patients age < 25 years), and since some diagnostic cervical sampling methods can have adverse obstetric implications, may actually reduce the rate of miscarriages. Many women would likely appreciate receiving fewer pelvic exams, and the ACS model suggests this screening method is not only less unpleasant but more cost-effective. This guideline is a logical progression from 2012 ACS, 2018 USPSTF, and 2019 ACOG guidance recognizing that HPV testing alone can be adequate screening for most women.
On the other hand, many of the assumptions the ACS is making are based on surrogate markers and primarily stem from mathematical models and one systematic review. Because cervical cancer mortality is so low in the United States, they must assume a reduction in CIN translates to a reduction in mortality. HPV testing is not universally available, and fewer visits for cervical cancer screening may decrease opportunities for other preventative health services to be provided. Will fewer interactions with the health care system lead to increased health disparities?
We appreciate that the ACS explicitly regards their recommendations as iterative. The ACS also recognizes that this new approach is likely to make some people nervous and is open to misinterpretation. This is not intended for patients who are at higher risk of cancer, and as HPV vaccine recipients age, their cohort might need different guidelines. The ACS acknowledges that their approach may result in a higher rate of follow-up colposcopies, although they hold out hope that the recently developed self-administered tests for HPV may reduce the number of pelvic exams while improving screening rates.This is a bold new step in cervical cancer screening, but we will have to wait and see if other professional organizations such as the USPSTF and ACOG sign on to this approach.
For more information, see the topic Cervical Cancer Screening in DynaMed.
DynaMed EBM Focus Editorial Team
This EBM Focus was written by Dan Randall, MD, Deputy Editor for Internal Medicine at DynaMed. Edited by Alan Ehrlich, MD, Executive Editor at DynaMed and Associate Professor in Family Medicine at the University of Massachusetts Medical School, and Katharine DeGeorge, MD, MS, Associate Professor of Family Medicine at the University of Virginia and Clinical Editor at DynaMed.