The Role of p16/Ki67 Dual Staining in Cervical Cancer Screening

Comparative analysis of HPV testing versus cytology in Danish cervical cancer screening: Insights from a large-scale implementation study

OBJECTIVE

Human papillomavirus (HPV) testing is the recommended primary screening method against cervical cancer. Denmark started implementing HPV testing as a primary screening method in 2021, but no national data are yet available. We report the results of the first and second screening rounds in a large Danish pilot implementation study. The objective was to compare colposcopy referrals, identify high-grade cervical intraepithelial neoplasia (CIN) and cancer, and positive predictive value (PPV) between HPV-based and cytology-based screening.

METHOD

In the HPV SCREEN DENMARK cohort (established May 2017-December 2019), participants were assigned to HPV-based (n = 28,677) or cytology-based screening (n = 43,622) based on the municipality of residence.

RESULTS

The first round of screening showed higher colposcopy referrals in the HPV group (6.4 %) compared to cytology (2.3 %), with HPV screening detecting more CIN3+ (n = 306/28,677 (1.1 %)) than cytology (n = 241/43,622 (0.6 %)) (RR = 1.9 (95 %CI 1.6-2.3). In absolute terms, 41 additional colposcopy referrals resulted in the detection of 10 more cases of CIN2+ and five extra CIN3+ cases per 1000 women screened. The PPV for CIN3+ of a colposcopy initiated by routine screening was similar in the HPV group (24.1 %) and cytology group (25.7 %). Within the initial years of screening, the cumulative incidence of CIN3+ and cervical cancer showed a more rapid increase in the HPV group compared to the cytology group.

CONCLUSION

HPV-based cervical screening detects almost twice as many CIN3+ cases but at the expense of a more than two-fold increase in colposcopy referrals. Furthermore, we found that HPV-based screening detects cervical cancer earlier than cytology-based screening.

Self-sampling for HPV testing in cervical cancer screening: A scoping review

Cervical cancer is the third most common gynecological cancer worldwide. Its origin is linked to intraepithelial lesions caused by high-risk Human Papillomavirus (HPV) types, detected in 99.7% of cases. Early screening is essential to prevent cancer development from these lesions. Molecular methods are more specific and offer the possibility of being performed through a self-collected sample by the patient, thus contributing to increasing screening coverage for this pathology. This study aim was to map the medical-scientific literature on existing protocols for self-sampling for HPV testing in cervical cancer screening. A search strategy was developed using the following keywords and their synonyms: "self-sampling," "professional sampling," and "HPV", on the databases: MEDLINE, Cochrane Library, Virtual Health Library - BVS, Scopus, National Institute for Health Research NHS EED, Web of Science, and EMBASE. The search strategy was formulated to identify relevant studies and describe their main characteristics, such as patient acceptance of self-sampling, cost differences between the tests used, and the accuracy of self-sampling compared to the gold standard test. A total of 876 studies were found, and 33 of those studies were included in this review. Out of these, 10 studies were domized clinical trials involving 46,751 patients, and 23 observational studies included 142,795 patients. Regarding acceptance, most studies reported a preference for self-sampling. Sensitivity analyses from various studies also showed that the low cost of self-sampling kits generally increased cost-effectiveness. The study concluded that using HPV testing on self-collected samples is a viable strategy for monitoring women with HPV.

P16/Ki67 Dual Staining in Glandular Cell Abnormalities of the Uterine Cervix

Very limited information exists about the role of p16/Ki67 dual staining on glandular cells in detecting glandular precancerous lesions and cervical adenocarcinoma. In this study, we investigated the diagnostic accuracy of p16/Ki67 dual staining for the detection of glandular and squamous lesions on the uterine cervix and for cancer of the upper reproductive tract. We performed a retrospective analysis of prospectively collected data on 96 patients with glandular cell abnormalities. We analyzed the diagnostic accuracy of p16/Ki67 dual staining for atypical glandular cells, not otherwise specified (AGC-NOS); atypical glandular cells, favor neoplastic (AGC-FN); adenocarcinoma in situ (AIS); and A-CA (cervical adenocarcinoma). A separate analysis for the detection of squamous precancerous lesions and squamous-cell carcinoma (CIN3+) and for cancer of the upper reproductive tract (EC/OC) was performed. Among patients who had normal histology or a low-grade lesion on final analysis, only 8.5% had positive dual staining. On the other hand, 85.7% of patients with AIS+ on final histology had positive dual staining. The respective specificities of p16/Ki67 dual staining on AGC-NOS for the detection of AIS+ (adenocarcinoma in situ or cervical adenocarcinoma), CIN3+ and EC/OC were 91.5%, 88.7% and 86.4%. High specificity values of p16/Ki67 dual staining on cervical smears labelled as AGC-NOS for the detection of CIN3+ and AIS+ suggest that this method might be a useful addition in cervical cancer screening.

Enhancing Cervical Cancer Screening: Review of p16/Ki-67 Dual Staining as a Promising Triage Strategy

Cervical cancer, primarily caused by high-risk human papillomavirus (HR-HPV) types 16 and 18, is a major global health concern. Persistent HR-HPV infection can progress from reversible precancerous lesions to invasive cervical cancer, which is driven by the oncogenic activity of human papillomavirus (HPV) genes, particularly E6 and E7. Traditional screening methods, including cytology and HPV testing, have limited sensitivity and specificity. This review explores the application of p16/Ki-67 dual-staining cytology for cervical cancer screening. This advanced immunocytochemical method allows for simultaneously detecting p16 and Ki-67 proteins within cervical epithelial cells, offering a more specific approach for triaging HPV-positive women. Dual staining and traditional methods are compared, demonstrating their high sensitivity and negative predictive value but low specificity. The increased sensitivity of dual staining results in higher detection rates of CIN2+ lesions, which is crucial for preventing cervical cancer progression. However, its low specificity may lead to increased false-positive results and unnecessary biopsies. The implications of integrating dual staining into contemporary screening strategies, particularly considering the evolving landscape of HPV vaccination and changes in HPV genotype prevalence, are also discussed. New guidelines and further research are necessary to elucidate the long-term effects of integrating dual staining into screening protocols.

Chronic Viral Infections and Cancer, Openings for Therapies and Vaccines

Infections are responsible for approximately one out of six cases of cancer worldwide [...].