By Rebecca B. Perkins, MD, MSc
Professor, Department of Obstetrics and Gynecology, Boston University School of Medicine/Boston Medical Center, Boston
This article outlines national consensus guidelines for the use of p16/Ki67 dual stain for triage of human papillomavirus-positive cervical cancer screening tests.
Clarke MA, Wentzensen N, Perkins RB, et al; Enduring Consensus Cervical Cancer Screening and Management Guidelines Committee. Recommendations for use of p16/Ki67 dual stain for management of individuals testing positive for human papillomavirus. J Low Genit Tract Dis 2024;28:124-130.
This article by Clarke et al describes national consensus guidelines for the use of p16/Ki67 dual stain for triage of human papillomavirus (HPV)-positive cervical cancer screening tests.1 The Enduring Consensus Cervical Cancer Screening and Management Guidelines Committee (hereafter referred to as Enduring Guidelines) is a standing committee to provide regular updates of the 2019 American Society for Colposcopy and Cervical Pathology Risk-Based Management Consensus Guidelines for Abnormal Cervical Cancer Screening Tests and Cancer Precursors (hereafter referred to as 2019 Guidelines) for new technologies and approaches that were not included in the 2019 guidelines process.2 The Enduring Guidelines effort includes experts in cervical cancer prevention as well as representatives from 19 national organizations, including federal organizations, professional medical societies, and patient advocacy groups.3
Guidelines for the use of p16/Ki67 dual stain (hereafter referred to as dual stain) are the first set of clinical guidelines released by the Enduring Guidelines process. Dual stain was approved by the U.S. Food and Drug Administration in March 2020 to inform management of individuals with positive HPV results from screening with primary HPV testing or with co-testing. The dual stain terminology refers to two stains applied to cytology specimens (i.e., those collected by cervical scraping, such as when collecting a Pap test). The stains detect a marker of HPV-related oncogene activity (p16) and a marker of cell proliferation (Ki67). The detection of both p16 and Ki67 together in the same cell is strongly associated with precancerous cellular changes (cervical intraepithelial neoplasia grade 3 or higher, [CIN3+]).4,5
Dual stain is intended for use in those testing HPV-positive on either a primary HPV screening test or a cytology/HPV co-test. The Enduring Guidelines process examined the risk of CIN3+ among HPV-positive patients with dual stain-positive and dual stain-negative results in two different populations: the Kaiser Permanente Northern California largely employer-based health system and the STRIDES study, which includes primarily rural and publicly insured women in Mississippi.1 They found that those testing HPV-positive and dual stain-positive always exceeded the threshold for colposcopy referral (> 4% risk of CIN3+) in both populations. For patients undergoing co-testing, for those testing HPV-positive with negative for intraepithelial lesion or malignancy (NILM), atypical squamous cells of undetermined significance (ASC-US), or low-grade squamous intraepithelial lesion (LSIL) cytology, the CIN3+ risks exceeded the colposcopy threshold when the patients also tested dual stain-positive but were below the colposcopy threshold when they tested dual stain-negative. The guidelines conclude that dual stain offers useful information on risk stratification and is an acceptable option for triaging HPV-positive results.
The guidelines for use of dual stain are summarized in Figure 1. In summary, colposcopy is recommended when any of the following results are found: dual stain-positive, HPV 16/18 positive, and/or high-grade cytology results (i.e., atypical squamous cells, cannot exclude a high-grade lesion [ASC-H]; high-grade squamous intraepithelial lesion [HSIL]; atypical glandular cells [AGC]; or carcinoma). For patients without HPV 16/18-positive or high-grade cytology results who test dual stain-negative, repeating the HPV test or co-test in one year is recommended. If they have any high-risk results at the one-year follow-up (i.e., HPV 16/18, dual stain-positive, or high-grade cytology), then colposcopy is recommended. If they remain HPV-positive and dual stain-negative, they may repeat the HPV test again the following year. For patients remaining HPV-positive, dual stain-negative for three consecutive tests, providers and patients can choose whether to perform colposcopy at that time or continue expectant management with repeat HPV testing and obtain colposcopy only if the patient develops a high-risk result.
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HPV: human papillomavirus; NILM: negative for intraepithelial lesion or malignancy; ASC-US: atypical squamous cells of undetermined significance; LSIL: low-grade squamous intraepithelial lesion; ASC-H: atypical squamous cells, cannot exclude a high-grade lesion; HSIL: high-grade squamous intraepithelial lesion; AGC: atypical glandular cells; CIN3+: cervical intraepithelial neoplasia grade 3 or higher |
COMMENTARY
Cervical cancer is almost entirely preventable with tools available today, yet more than 14,000 individuals were diagnosed with cancer in the United States in 2023. Nearly one-third of individuals diagnosed with cervical cancer in the United States die from their disease.6 Dual stain is an option to use instead of, or in addition to, cytology for management of HPV-positive results. Overall, those testing dual stain-positive have a higher CIN3+ risk than those with a minimally abnormal (ASC-US or LSIL) cytology result. This has two important consequences. First, past history of abnormal screening test results is no longer considered when managing a positive dual stain result — colposcopy is recommended for all dual stain-positive results. This simplifies management because, in the 2019 guidelines, the management of an ASC-US or LSIL result is affected by the past screening history, with colposcopy deferred in the case of a recent HPV-negative screening result or normal colposcopic biopsy result.2
Second, cytology results of negative NILM, ASC-US, or LSIL do not affect management when dual stain results are present. Therefore, obtaining both cytology and dual stain may not be an efficient use of resources compared to using either cytology or dual stain alone for managing HPV-positive results. Resource use metrics suggest that using dual stain to triage HPV-positive screening results requires fewer colposcopies and detects CIN3+ earlier compared to using cytology triage. Therefore, in a setting where colposcopy resources are restricted, dual stain triage may be preferred to cytology, since fewer patients will be referred to colposcopy, and those referred will be at higher risk of CIN3+.
However, dual stain results currently do not have the equivalent of a high-grade (HSIL) cytology result. In the 2019 guidelines, high-grade results (e.g., HPV-positive HSIL) have the option of direct referral for excisional treatment without the need for first obtaining a biopsy (termed expedited treatment). Performing expedited treatment can reduce the number of visits needed for high-risk patients and minimize loss to follow-up.
In addition, some settings may alter management of high-grade results in other ways, such as prioritizing colposcopy of high-grade cytology results or performing more intensive patient outreach. Therefore, in a setting that performs expedited treatment or uses high-grade cytology results to manage outreach, continuing to use cytology may be preferred.
REFERENCES
- Clarke MA, Wentzensen N, Perkins RB, et al. Recommendations for use of p16/Ki67 dual stain for management of individuals testing positive for human papillomavirus. J Low Genit Tract Dis 2024;28:124-130.
- Perkins RB, Guido RS, Castle PE, et al. 2019 ASCCP Risk-Based Management Consensus Guidelines for Abnormal Cervical Cancer Screening Tests and Cancer Precursors. J Low Genit Tract Dis 2020;24:102-131.
- Wentzensen N, Garcia F, Clarke MA, et al. Enduring Consensus Guidelines for Cervical Cancer Screening and Management: Introduction to the scope and process. J Low Genit Tract Dis 2024;28:117-123.
- Wentzensen N, Clarke MA, Bremer R, et al. Clinical evaluation of human papillomavirus screening with p16/Ki-67 dual stain triage in a large organized cervical cancer screening program. JAMA Intern Med 2019;179:881-888.
- Wright TC, Stoler MH, Ranger-Moore J, et al. Clinical validation of p16/Ki-67 dual-stained cytology triage of HPV-positive women: Results from the IMPACT trial. Int J Cancer 2022;150:461-471.
- American Cancer Society. Cancer Statistics Center. https://cancerstatisticscenter.cancer.org/?_ga=2.20975355.1746569515.1533055502-552426982.1496697483#!/cancer-site/Cervix