The p16/ki-67 assay is a safe, effective and rapid approach to triage women with mild cervical lesions

Comparison of HPV 16/18 Genotyping and p16/Ki67 Dual Staining for Detection of High-Grade Cervical Lesion in Patients with Low-Grade Cervical Smears

Objective

To triage low-grade cervical smears (ASCUS/LSIL) by HPV 16/18 genotyping and dual staining with p16/Ki67 and to compare the sensitivity and specificity of these two triage methods for detection of high-grade cervical intraepithelial neoplasia (HGCIN).

Methods

In this prospective cross-sectional study, we evaluated a total of 89 women with low-grade smears (54 ASCUS, 35 LSIL) recruited from a tertiary care hospital. All patients underwent colposcopy guided cervical biopsy. Histopathology was used as gold standard. All samples were subjected to HPV 16/18 genotyping (excluding 9) using DNA PCR and p16/Ki67 dual staining (excluding 4) using Roche® kit. We then compared the two triage methods to detect high-grade cervical lesions.

Results

Overall, in all low-grade smears sensitivity, specificity and accuracy of HPV 16/18 genotyping, was found to be 66.7%, 77.1% and 76.2% respectively (p = 0.03). In low-grade smears sensitivity, specificity and accuracy of dual staining, was found to be 66.7%, 84.8% and 83.5% respectively (p = 0.01).

Conclusions

Overall, in all low-grade smears the sensitivity of the two tests was comparable. However, dual staining had a higher specificity and accuracy than HPV 16/18 genotyping. It was concluded that both are effective triage methods but dual staining had a better performance than HPV 16/18 genotyping.

Novel In Situ Hybridization Assay for Chromogenic Single-Molecule Detection of Human Papillomavirus E6/E7 mRNA

RNA plays a vital role in the physiological and pathological processes of cells and tissues. However, RNA in situ hybridization applications in clinical diagnostics are still limited to a few examples. In this study, we developed a novel in situ hybridization assay for human papillomavirus (HPV) E6/E7 mRNA by taking advantage of specific padlock probing and rolling circle amplification, combined with chromogenic readout. We designed padlock probes for 14 types of high-risk HPV and demonstrated that E6/E7 mRNA could be visualized in situ as discrete dot-like signals using bright-field microscopy. Overall, the results are consistent with the clinical diagnostics lab's hematoxylin and eosin (H&E) staining and p16 immunohistochemistry test results. Our work thus shows the potential applications of RNA in situ hybridization for clinical diagnostics using chromogenic single-molecule detection, offering an alternative technical option to the current commercially available kit based on branched DNA technology. IMPORTANCE In situ detection of viral mRNA expression in tissue samples is of great value for pathological diagnosis to access viral infection status. Unfortunately, conventional RNA in situ hybridization assays lack sensitivity and specificity for clinical diagnostic purposes. Currently, the commercially available branched DNA technology-based single-molecule RNA in situ detection method offers satisfactory results. Here, we present our padlock probe- and rolling circle amplification-based RNA in situ hybridization assay for detecting HPV E6/E7 mRNA expression in formalin-fixed paraffin-embedded tissue sections, providing an alternative yet robust method for viral RNA in situ visualization that is also applicable to different types of diseases.

Significance of Triple Detection of p16/ki-67 Dual-Staining, Liquid-Based Cytology and HR HPV Testing in Screening of Cervical Cancer: A Retrospective Study

In addition to liquid-based cytology (LBC) and HR HPV testing, p16/ki-67 dual-staining is another method for cervical cancer screening. The combination of any two methods can improve the accuracy of screening, but some cervical lesions are still missed or misdiagnosed. In this retrospective study, the significance of LBC, HR HPV testing and especially p16/ki-67 dual-staining in cervical lesion screening was evaluated with reference to histological diagnosis. At the same time, we tried to explore the value of p16/ki-67 dual-staining combined with LBC and HR HPV testing (triple detection) in improving the diagnostic specificity of CIN2+ and reducing the missed diagnosis of CIN2+ lesions. We found that p16/ki-67 dual-staining was valuable in identifying cervical CIN2+ lesions and reducing the missed diagnosis of CIN2+ in HPV negative patients. More than 96% of CIN2+ patients were positive for two or three tests of triple detection. Whole positive triple detection can effectively predict high grade cervical lesions. In conclusion, the triple detection can distinguish almost all cervical CIN2+ lesions. Our data put forward and highlight the feasibility and significance of triple detection in cervical lesion screening.