Cervical cancer diagnoses and deaths related to cervical cancer have been declining in the U.S. since the early 1970’s. Experts worldwide are in agreement that screening women with the Pap test is responsible for this decrease. After several decades of leveling rates of cervical cancer in the 1980’s and 1990’s, a further decline in cervical cancer occurred with the introduction of liquid based cytology and testing for human papillomavirus (HPV), the causative agent of cervical cancer. Numerous studies in the U.S. and Europe confirm that adding HPV testing to the Pap test (Pap plus HPV) improves the detection of cervical pre-cancer and prevents the development of cervical cancer.
Recently, the U.S. Preventive Services Task Force (USPSTF) has made public a draft of their recommendations for cervical cancer screening. In this draft, the USPSTF removed co-testing (Pap plus HPV detection) as a level “A” recommendation. In its stead, the Task Force advocates for testing with a Pap test alone every three years or with an HPV test alone every five years. In so doing the Task Force based its decision almost entirely on data from European studies that relied on types of Pap tests no longer used in the U.S. and on HPV tests that are not FDA approved in the U.S.
The decision by the USPSTF is even more troublesome in light of unanimous consensus that co-testing with Pap and HPV at the same time is more effective than testing with either test alone. No study published to date finds superiority of either test over a combination of the two. Although arguments that increased testing increases adverse events is the major argument made by the USPSTF, we found that the use of HPV testing alone as recommended by the current screening guidelines increased the number of colposcopies and biopsies over co-testing as recommended in the same guidelines (1). We also showed, in the same study, that the cost of co-testing was no costlier than the cost of testing for HPV alone (1).
In a similarly vexing argument, the USPSTF made the case against co-testing stating that the psychological trauma incurred by women discovering that they tested positive for HPV exceeded that of discovering that they had a positive Pap test, yet then advocates for HPV testing alone as a grade “A” recommendation.
No doubt, the issue of cost was considered by the USPSTF. Prolonging screening intervals has universally been shown to lower costs. Prolonging screening intervals has also universally been shown to increase the rates of cervical cancer in women. In a large population of women in Northern California, extending screening intervals from 3 to 5 years doubled the number of cervical cancers in women tested with either HPV testing alone or co-testing with Pap plus HPV (2). In this study, the investigators made the case for the more frequent 3-year interval, particularly when screening with HPV testing alone. In another study of more than a quarter million U.S. women, HPV alone failed to detect more invasive cancers than the Pap test and, when used alone, detected far fewer precancerous lesions than Pap and HPV testing did combined (3).
The Cytopathology Education and Technology Consortium is an organization composed of thought leaders to the major societies in pathology and cytopathology. They acknowledged the flawed reasoning of the USPSTF, pointedly addressing the decrease in detection that would occur if their recommendations were adopted. I agree with the positions stated in their letter to the USPSTF dated October 2, 2017. In it, the Consortium advocates that testing with Pap and HPV detection should remain a recommended form of cervical cancer screening. Primary HPV testing should only take place using FDA approved testing platforms and if used alone, be used at a three-year interval until U.S. based longitudinal data shows that the interval can safely be extended to five years.
Knowingly allowing the rate of cervical cancer to increase in the U.S. is inexcusable, particularly when the vast majority of data from the U.S. does not support the assertions posed by the USPSTF in their draft statement on cervical cancer screening. It is unconscionable that a method advocated by virtually every medical society in the U.S. as the preferred method for screening be abandoned for a method proven to be less effective and with similar, if not increased adverse events, solely on the basis of European studies that would not be applicable in this country. The health and reproductive welfare of women in this country is too important to remain silent in this issue.
References
1. Felix J., et. al. (2016). The Clinical and Economic Benefits of Co-Testing Versus Primary HPV Testing for Cervical Cancer Screening: A Modeling Analysis. Journal of Women’s Health, 25(6): 606–616. doi: 10.1089/jwh.2015.57082.
2. Gage J., et.al. (2014). Reassurance against future risk of precancer and cancer conferred by a negative Human Papillomavirus test. J Natl Cancer Inst. 106(8): dju 153.
3. Blatt A., et.al. (2015). Comparison of cervical cancer screening results among 256,648 women in multiple clinical practices. Cancer Cytopathology 125(5):282-288.