Human papillomavirus (HPV) or Pap testing alone is less likely than the combination of both methods to detect cervical cancer, according to a Quest Diagnostics real-world study published online July 8 in the American Journal of Clinical Pathology.
Cotesting involves Pap and HPV screening using the same specimen. A new study of women 30 years or older by researchers at Quest Diagnostics and the University of Pittsburgh Medical Center found that cotesting outperformed HPV or Pap testing alone for detecting precancer or cancer. In the retrospective study, the researchers evaluated deidentified results for tests conducted between 2010 and 2018 by Quest in 13.6 million women; 8,059 had precancers and 1,259 were subsequently diagnosed with cervical cancer.
Dr. Harvey Kaufman, senior medical director of medical informatics at Quest, and colleagues compared cotesting with each of the components alone -- liquid-based cytology and HPV testing. Of 1,615 cotests performed prior to cancer diagnosis, 86.9% were positive by cotesting and about 13.1% were false negatives. False-negative rates with Pap testing alone and HPV alone were 26.4% and 28.4%, respectively, the company reported.
Cotesting also identified more women who developed biopsy-confirmed adenocarcinomas, an aggressive form of cervical cancer. Cotesting identified 82.3% of cases, compared with 61.2% for HPV testing alone and 59.7% for Pap tests alone.
Furthermore, the researchers reported that cotesting was better for identifying women who developed biopsy-confirmed precancers -- picking up 95.6% of precancers, compared with 92.6% for HPV testing and 77.9% for Pap testing.
A challenge to cotesting
Cotesting has been the preferred method for cervical cancer screening in women 30 years or older, and practice guidelines have reflected this, Kaufman and colleagues noted. However, cotesting has been questioned since the release of new risk-based management consensus guidelines from the American Society for Colposcopy and Cervical Pathology (ASCCP). Among other things, the new guidelines advise that with primary HPV screening, if an HPV test is positive, the specimen should then have reflex cytology from the same laboratory specimen (Journal of Lower Genital Tract Disease, April 2020, Vol. 24:2, pp. 87-89).
Quest noted that guidelines from the U.S. Preventive Services Task Force (USPSTF) give the following options for screening in women between the ages of 30 and 65 years:
- Pap every three years
- Primary HPV every five years
- Cotesting every five years
Kaufman et al contend that the ASCCP consensus risk-based guidelines were largely based on research conducted at Kaiser Permanente Northern California, which they described as a "relatively select geographic population with limited socioeconomic diversity." The authors contrasted this with their AJCP study, which they noted reflects the "largest and most diverse" cervical screening population reported to date in the U.S.
"Screening guidelines for a condition as serious as [cervical cancer] should be developed based on the most rigorous longitudinal assessment of current technologies applied to a large, heterogeneous, geographically distributed, and socioeconomically diverse population as possible, as such factors represent the conditions under which most care is provided throughout the United States," Kaufman and colleagues wrote.