Value of PAX1 Methylation Analysis by MS-HRM in the Triage of Atypical Squamous Cells of Undetermined Significance

Cytologic DNA methylation for managing minimally abnormal cervical cancer screening results

OBJECTIVES

To explore the role of a DNA methylation assay for managing minimally abnormal cervical cancer screening results in a prospective cohort undergoing opportunistic cervical cancer screening.

METHODS

In the cohort of the METHY2 and METHY3 screening studies of women undergoing opportunistic cervical cancer screening, cervical cytology samples were sent for high-risk human papillomavirus (hrHPV) DNA assays, cytologic pathology and methylation assays of PAX1/JAM3 (CISCER). This study evaluated the discriminative power of CISCER in managing women with minimally abnormal cervical cancer screening results for CIN3+. Absolute CIN3+ risks and colposcopy referrals within one screening round were calculated.

RESULTS

A total of 1857 women with minimally abnormal cervical cancer findings had cervical histologic outcomes and were included in the analysis. In women with a minimally abnormal cervical cancer result, the sensitivity and specificity of CISCER was 74.9% (95% confidence interval [CI], 68.3%-81.4%) and 89.1% (95% CI 87.6%-90.6%) for detecting CIN3+. CISCER analysis discriminated well for minimally abnormal cervical cancer results, yielding a CIN3+ risk of 40.5% (95% CI 34.9%-46.2%) after a positive result and a CIN3+ risk of 2.7% (95% CI 2.0%-3.6%) after a negative result.

CONCLUSIONS

In women with a minimally abnormal cervical cancer screening result, the CISCER provides excellent detection of CIN3+. The use of CISCER in women with a minimally abnormal cervical cancer screening result can lead to a substantial reduction in the number of direct colposcopy referrals.

A Predictive Model Using Six Genes DNA Methylation Markers to Identify Individuals With High Risks of High-Grade Squamous Intraepithelial Lesions and Cervical Cancer

Background

Cervical cancer is preceded by low-grade squamous intraepithelial lesions (LSIL) and high-grade squamous intraepithelial lesions (HSIL). Human papillomavirus (HPV) test is a sensitive method for cervical cancer screening, but it is less specific compared with cytological examination, leading to overtreatment and reduced patient compliance. Therefore, new detection methods that can improve the accuracy of cervical cancer screening are needed.

Methods

In the present study, cervical exfoliated cell samples were collected from 228 Chinese individuals, including 114 healthy control individuals, 46 patients with LSIL, 21 patients with HSIL and 47 patients with cervical cancer. The DNA methylation levels of 12 cervical cancer-related genes were detected using quantitative multiplex methylation-specific PCR. All individuals were divided into high- or low-risk groups. Patients with HSIL and cervical cancer were assigned to the high-risk group, whereas healthy controls and patients with LSIL were assigned to the low-risk group. The ability to predict cancer risks was evaluated using ROC curves and a predictive model for cancer risk was constructed by linear regression analysis.

Results

The methylation levels were significantly higher for all 12 genes in individuals with cervical cancer or HSIL, compared with those in LSIL or normal group. Family with sequence similarity 19 member A4 (FAM19A4), phosphatase and actin regulator 3 (PHACTR3), somatostatin (SST), Zic family member 1 (ZIC1), paired box 1 (PAX1) and zinc finger protein 671 (ZNF671) were used to construct a predictive model for cancer risk prediction, with a specificity of 89.6% and a sensitivity of 95.0%.

Conclusion

The present study demonstrated the methylation levels of 12 cervical cancer-related genes were higher in Chinese patients with HSIL or cervical cancer. Also, a predictive model was constructed to distinguish cervical cancer or HSCL from individuals with low risk.

The Role of Methylation of Host and/or Human Papillomavirus (HPV) DNA in Management of Cervical Intraepithelial Neoplasia Grade 2 (CIN2) Lesions

Cervical intraepithelial neoplasia grade 2 (CIN2) is an intermediate stage between CIN 1, which is a low-grade lesion, and CIN3, which is the immediate precursor of cervical cancer (CC). Traditionally, CIN2 was regarded as a high-grade lesion and was treated with conization or ablative methods. In recent years, there has been a shift in the management of younger patients, who are now more often being managed conservatively due to frequent spontaneous CIN2 regression and possible adverse effects of treatment on future pregnancies. Because the risk of progression to CC still exists with conservative management, a personalized approach is needed to identify patients with a higher probability of progression. In this regard, research has focused on the role of host and human papillomavirus (HPV) gene methylation. This systematic review summarizes the current knowledge regarding conservative CIN2 management focusing on the main methylation markers and its implementation in conservative CIN2 management, and it describes major ongoing longitudinal studies on the subject. The review showed that DNA methylation is an accurate predictor of disease progression and a valid triage tool for HPV-positive women, with CIN2 performing better than triage cytology. Because virtually all CCs are methylation-positive, methylation-negative women at baseline have an extremely low risk of CC.

The role of PAX1 methylation in predicting the pathological upgrade of cervical intraepithelial neoplasia before cold knife conization

Objective

To explore the ability of PAX1 methylation (PAX1^m) to predict the pathological upgrade of cervical intraepithelial neoplasia (CIN) before cold knife conization (CKC).

Methods

A total of 218 women that underwent colposcopy-directed biopsy (CDB) pathology for the confirmation of CIN2 and CIN3 between December 2020 to September 2021 were enrolled in this study. The methylation levels of PAX1 (ΔCp_PAX1) were determined by quantitative methylation-specific polymerase chain reaction (qMSP). Receiver operating characteristic curve was used to identify the optimal cut-off value of ΔCp_PAX1 for predicting the pathological upgrade of disease.

Results

In the CDB-confirmed CIN2 group, 36% of CIN2 was found to have pathologically upgraded to CIN3 and 30% regressed to low-grade squamous intraepithelial lesion (LSIL) and below, and none of CIN2 upgraded to early-stage cervical cancer (ESCC) after CKC. In the CDB-confirmed CIN3 group, 19.5% (23/118) of CDB-confirmed CIN3 were pathologically upgraded to ESCC after CKC. Regardless of CIN2 or CIN3, the ΔCp_PAX1 level of women with upgraded pathology after CKC was significantly lower than that of women with degraded pathology. The optimal △Cp_PAX1 cut-off value in predicting CIN3 to be upgraded to ESCC after CKC was 6.360 and the area under the curve (AUC) was 0.814, with similar sensitivity (78.3%) and higher specificity (84.2%) than cytology≥LSIL (Se:78.3%;Sp:58.9%) and HPV16/18 positive (Se:73.9%;Sp:46.3%) patients.

Conclusions

PAX1^m could be a promising auxiliary marker in predicting the pathological upgrade of CIN before CKC. We found that if the △Cp _PAX1 cut-off value is lower than 6.360, it is highly suggestive of invasive cervical cancer.

Association and Effectiveness of PAX1 Methylation and HPV Viral Load for the Detection of Cervical High-Grade Squamous Intraepithelial Lesion

Background: PAX1 methylation (PAX1m) and HPV viral load (VL) have been reported to detect cervical high-grade squamous intraepithelial lesions (HSIL), but the relationship between them is unclear. This study aimed to evaluate the correlation between HPV VL and PAX1m and its effectiveness in predicting cervical lesions. (2) Methods: A total of 476 women referred to colposcopy for abnormal cervical screening at the Peking University People’s Hospital between November 2020 and November 2021 were enrolled. PAX1m and HPV VL were determined by QMSP and BMRT-HPV reports type-specific VL/10,000 cells, respectively. (3) Results: PAX1m was significantly increased in HSIL, especially in cervical cancer, but there was no significant difference between cervical intraepithelial neoplasms 1(CIN1) and CIN2. However, HPV VL significantly differed between CIN1 and CIN2 but not between CIN3 and cervical cancer. In general, PAX1m positively correlated with all hrHPV VL, mainly in the HPV16/18 VL (p < 0.001), but had no relationship with the other 12 types of hrHPV VL. PAX1m had the highest specificity in diagnosing CIN2+, followed by HPV16/18 VL, which are higher than cytology ≥ASCUS. (4) Conclusions: Hypermethylation of PAX1 is associated with high HPV VL, especially HPV16/18, and both present advantageous specificity in detecting CIN2+.

Methylation of PAX1 gene promoter in the prediction of concurrent chemo-radiotherapy efficacy in cervical cancer

Objectives: Cervical cancer is the fourth leading cause of cancer death among women worldwide. In currently, aberrant methylation of PAX1 is found in variety of solid tumors, including cervical cancer. In addition, the role of PAX1 gene methylation in cervical cancer and precancerous lesions screening has been confirmed in previous study. Here, we evaluated the predictive value of PAX1 methylation in concurrent chemo-radiotherapy (CCRT) outcomes in cervical cancer.

Methods: This study enrolled 82 cervical cancer patients from August 2018 to August 2020. We compared the clinical results between different PAX1 methylation status. Hyper-methylation patients were subjects to MRI and quantitative methylation-specific PCR (QMSP) for PAX1 before, in the middle, immediately after, 1 month and 3 months after CCRT. The changes in PAX1 methylation during CCRT were analyzed.

Results: The lower PAX1 methylation status were related to a poor tumor response. Based on the MRI findings three months post-treatment, the hypermethylated patients were classified into the complete response (CR; n=50) and partial remission (PR; n=18) groups. The average PAX1 △Cp value of CR and PR groups before radiotherapy was 5.08±1.98 and 4.32±2.00 respectively, and after concurrent chemo-radiotherapy was significantly increased to 17.35±4.96 and 16.99±6.17, respectively (P<0.05). Furthermore, the PAX1 △Cp value between CR and PR groups were significantly different at mid-treatment and performed well in predicting short-term efficacy (AUC 0.84) in this period, and its sensitivity and specificity for predicting PR were 0.72 and 0.88, respectively.

Conclusion: The PAX1 methylation level may predict the sensitivity and efficacy of CCRT in cervical cancer.

Diagnostic value of high-risk human papillomavirus viral load on cervical lesion assessment and ASCUS triage

This study aims to evaluate HR‐HPV viral load in the cervical lesion assessment and its diagnostic value on the triage of ASCUS. The three‐step protocol for cervical cancer screening was carried out in 5171 patients from June 2017 to August 2019, and 1620 histopathological results were obtained. The positive rate of HR‐HPV and TCT increased with the aggravation of pathological grades of cervical lesions. The sensitivity and specificity of HR‐HPV (DH3) to detect CIN II+ were 91.91% and 84.46%, respectively. In comparison, the corresponding results of the cytology test were 80.51% and 83.12%. HPV16/18 viral load was positively correlated with the grade of cervical lesions (p < 0.001, r = 0.321). The diagnostic efficiency of AUC by applying HPV16/18 viral load was 0.682 for the diagnosis of CIN II+. The optimal HPV16/18 viral load for predicting CIN II+ was 6.80 RLU/CO (relative light units/cut‐off), with corresponding sensitivity of 48.6%, specificity of 79.7%, and Youden index of 0.283. In the ASCUS population, viral loads were statistically different in HPV16/18 and the other 12 HR‐HPV when compared cervicitis group with CIN I group and CIN II+ group (all p < 0.05). Statistical differences were detected concerning HPV16/18 viral load, contact bleeding status, and smoking status when compared cervicitis group with CIN I group and CIN II+ group (p < 0.05), with a corresponding odds ratio of 1.004, 1.533, and 5.513, respectively. Our findings suggest that HR‐HPV viral load can be regarded as a useful tool to predict the grade of cervical lesions for ASCUS triage.

ClinicalTrials.gov ID: NCT03178136.

Softepigen: Primers Design Web-Based Tool for MS-HRM Technique

Polymerase Chain Reaction (PCR) based techniques for DNA methylation techniques includes the MS-HRM technique. Methylation Sensitive High-Resolution Melting (MS-HRM) primer-design requires a set of necessary recommendations for such DNA methylation assessment. However, there were not any available software that allows an automatic design of this kind primers. We present Softepigen, the first complete MS-HRM primer design software. Softepigen allows to search for primers in a genomic region following Wojdacz's recommendations and targets primer binding regions with high linguistic complexity sequences that increase the specificity of the converted sequence of the human genome. We performed in-silico PCR analysis through BiSearch ePCR tool to validate the specificity of the of the primers designed using Softepigen. Softepigen for MS-HRM performance in our genomic regions of interest show satisfactory specificity measurements, and we implemented it for freely available use in the web-based interface at www.soft-epigen.com.

Performance of DNA methylation assays for detection of high-grade cervical intraepithelial neoplasia (CIN2+): a systematic review and meta-analysis

Background

To conduct a meta-analysis of performance of DNA methylation in women with high-grade cervical intraepithelial neoplasia (CIN2+).

Methods

Medline and Embase databases were searched for studies of methylation markers versus histological endpoints. Pooled sensitivity, specificity and positive predictive value (PPV) for CIN2+ were derived from bivariate models. Relative sensitivity and specificity for CIN2+ compared to cytology and HPV16/18 genotyping were pooled using random-effects models.

Results

Sixteen thousand three hundred thirty-six women in 43 studies provided data on human genes (CADM1, MAL, MIR-124-2, FAM19A4, POU4F3, EPB41L3, PAX1, SOX1) and HPV16 (L1/L2). Most (81%) studies evaluated methylation assays following a high-risk (HR)-HPV-positive or abnormal cytology result. Pooled CIN2+ and CIN3+ prevalence was 36.7% and 21.5%. For a set specificity of 70%, methylation sensitivity for CIN2+ and CIN3+ were 68.6% (95% CI: 62.9–73.8) and 71.1% (95% CI: 65.7–76.0) and PPV were 53.4% (95% CI: 44.4–62.1) and 35.0% (95% CI: 28.9–41.6). Among HR-HPV+ women, the relative sensitivity of methylation for CIN2+ was 0.81 (95% CI: 0.63–1.04) and 1.22 (95% CI: 1.05–1.42) compared to cytology of atypical squamous cells of undetermined significance, or greater (ASCUS+) and HPV16/18 genotyping, respectively, while relative specificity was 1.25 (95% CI: 0.99–1.59) and 1.03 (95% CI: 0.94–1.13), respectively.

Conclusion

DNA methylation is significantly higher in CIN2+ and CIN3+ compared to ≤CIN1. As triage test, DNA methylation has higher specificity than cytology ASCUS+ and higher sensitivity than HPV16/18 genotyping.

Over Expressed TKTL1, CIP-2A, and B-MYB Proteins in Uterine Cervix Epithelium Scrapings as Potential Risk Predictive Biomarkers in HR-HPV-Infected LSIL/ASCUS Patients

High oncogenic risk human papillomaviruses (HR-HPVs) promote cervical carcinoma development, the fourth most common feminine cancer. A slow oncodevelopmental phase—defined histopathologically as Cervical Intraepithelial Neoplasia (CIN) grades 1–3, or cytologically as Low- or High-grade Squamous Intraepithelial Lesions (LSIL or HSIL)—precedes the malignancy. Cervical carcinoma screenings through HR-HPV genotyping and Pap smears are regularly performed in Western countries. Faulty cytology screening or genotyping or patients' non-compliance with follow-ups can let slip an oncoprogression diagnosis. Novel biomarker tests flanking HR-HPV genotyping and cytology could objectively predict the risk of disease progression thus helping triage LSIL/ASCUS patients. Here, anonymized leftovers of fresh cervical epithelium scrapings from twice (LSIL/ASCUS and HR-HPV DNA)-positive and twice (Pap smear- and HR-HPV DNA)-negative (control) patients in a proteome-preserving solution served to assess the biomarker worth of three cervical carcinoma-related proteins, i.e., B-MYB (or MYBL2), Cancerous Inhibitor of PP2A (CIP-2a), and transketolase-like1 (TKTL1). Leftovers anonymity was strictly kept and storage at −80°C, protein extraction, immunoblotting, and band densitometry were blindly performed. Only after tests completion, the anonymous yet code-corresponding HR-HPV-genotyping and cytology data allowed to assign each sample to the twice-positive or twice-negative group. Descriptive statistics showed that the three proteins levels significantly increased in the twice-positive vs. twice-negative scrapings. Diagnostic ROC curve analysis identified each protein's Optimal Decision Threshold (OTD) showing that TKTL1 and CIP-2a are stronger risk predictive biomarkers (Sensitivity, 0.91–0.93; Specificity, 0.77–0.83) than B-MYB. Logistic Regression coupled with Likelihood-Ratio Tests confirmed that a highly significant relation links increasing TKTL1/CIP-2a/B-MYB protein levels in twice-positive cervical scrapings to the risk of HR-HPV-driven oncoprogression. Finally, a 3 year clinical follow-up showed that 13 patients (50% of total) of the twice-positive group with biomarker values over OTDs compliantly underwent scheduled colposcopy and biopsy. Of these, 11 (i.e., 84.7%) received a positive histological diagnosis, i.e., CIN1 (n = 5; 38.5%) or CIN2/CIN2+ (n = 6; 46,2%). Therefore, TKTL1/CIP-2a/B-MYB protein levels could objectively predict oncoprogression risk in twice (HR-HPV- and Pap smear)-positive women. Further studies will assess the translatability of these findings into clinical settings.

The promising role of PAX1 (aliases: HUP48, OFC2) gene methylation in cancer screening

Background

Paired‐box gene 1 (PAX1), a member of the PAX family, plays a role in pattern formation during embryogenesis, and might be essential for development of the vertebral column.

Methods

PAX1 is silenced by methylation in several cancers and is considered a tumor suppressor gene. Our previous studies reported PAX1 as hypermethylated in cervical cancer tissues, thereby suggesting it as a potential screening marker. Recently, an increasing number of studies have confirmed PAX1 methylation as a promising biomarker in cervical cancer based on its excellent discriminatory ability between high‐grade cervical lesions and normal tissues, resulting in a reduced necessity for referral for colposcopy and biopsy. Additionally, PAX1 is also hypermethylated in other tumors, including those associated with epithelial ovarian cancer, esophageal squamous cell carcinoma, head and neck squamous cell carcinoma, and endometrial carcinoma, and shows relatively good sensitivity and specificity for the detection of these tumors.

Results

This review summarizes reports of PAX1 methylation and its promising role in cancer screening, especially that associated with cervical cancer.

Conclusion

According to current evidence, combined testing for human papillomavirus and PAX1 methylation analysis represents an efficacious cervical cancer‐screening protocol.

Utility of human papillomavirus L1 capsid protein and HPV test as prognostic markers for cervical intraepithelial neoplasia 2+ in women with persistent ASCUS /LSIL cervical cytology

Objective: Efficient and highly predictive biomarkers reflecting the prognosis of persistent atypical squamous cells of unknown significance(ASCUS) and low grade squamous intraepithelial lesion(LSIL)s are unavailable and need to be developed urgently. We aimed to develop a predictive model for diagnosis of cervical intraepithelial neoplasia(CIN)2+ by analyzing the immunocytochemical expression of the HPV L1 capsid protein in patients with persistent ASCUS and LSIL with a high risk of HPV infection. Methods: Cervical cytology samples comprising (70 ASCUS and 215 LSIL Pap smears) were analyzed. Immunocytochemical identification of the HPV L1 capsid protein in cervical cytology samples was performed. Expression levels of HPV L1 capsid protein in cervical cytology samples were measured, and the correlation between HPV L1 expression and cervical pathologic diagnosis was evaluated. The risk for CIN2+ was calculated using the results of immunocytochemistry and the HPV DNA test. Results: Negative results for HPV L1 immunochemistry test were more frequently observed in CIN2+, and expression of the HPV L1 capsid protein was higher in CIN1 or cervicitis (Fisher's exact test, p<0.05). Diagnosis rates for CIN2+ were highest for the combination of HPV L1 capsid protein immunocytochemistry, cytology and HPV test when compared with other combinations (Akaike information criterion (AIC): 191.7, Schwarz criterion(SC): 206.3, p<0.001). Conclusion: Absence of HPV L1 capsid expression and presence of HPV type 16 or 18 infection are reliable predictors of progression to CIN2+ in patients showing persistent ASCUS and LSIL.

PAX1 Methylation as a Potential Biomarker to Predict the Progression of Cervical Intraepithelial Neoplasia: A Meta-analysis of Related Studies

OBJECTIVE

The methylation of paired box gene 1 (PAX1) has a great influence on the process of cervical lesion. However, available evidence for the association between PAX1 methylation and cervical intraepithelial neoplasia (CIN) are inconsistent. Here, we systematically reviewed and analyzed PAX1 methylation in progress of CIN.

METHODS

Two investigators independently searched eligible studies of PAX1 methylation and CIN that were published in PubMed, Cochrane Library, EMBASE, and Web of Science databases until November 30, 2016. We extracted clinicopathologic features of CIN and cervical cancel relevant to PAX1 methylation. Odds ratios (ORs) with their 95% confidence intervals (CIs) were used to assess the association between PAX1 methylation and progression of patients with CIN.

RESULTS

Seven studies composed of 1055 patients with various stages of CIN and cervical cancel were eventually included. The results revealed that PAX1 methylation was associated with transition of CIN I to CIN II/III (OR, 0.09; 95% CI, 0.04-0.19) and CIN II/III to cervical cancer (OR, 0.16; 95% CI, 0.05-0.46), and similar results were produced in sensitivity analysis. Also, we found that the OR value was associated with average age and number of patients, publication year, and study location of included articles.

CONCLUSIONS

PAX1 gene methylation was associated with the transition of CIN I to CIN II/III and CIN II/III to cervical cancer, so that it could be an auxiliary biomarker to estimate the risk of CIN progress. Moreover, PAX1 may help to determine appropriate reexaminations and treatment for patients with various stages of CIN.

Detection of cervical intraepithelial neoplasia with HPVE6/E7 mRNA among women with atypical squamous cells of unknown significance

OBJECTIVE

To compare E6/E7 mRNA and HPV DNA assays for evaluating women with atypical cells of undetermined significance (ASCUS).

METHODS

The present prospective study enrolled patients with ASCUS undergoing HPV testing at Third Affiliated Hospital of Zhengzhou University, China, between September 1, 2013, and January 31, 2016. Patients with positive HPV DNA test results underwent screening by E6/E7 mRNA assay, and the accuracy of HPV DNA and E6/E7 mRNA testing were compared, with histology used for definitive diagnoses.

RESULTS

In total, 591 patients with ASCUS underwent HPV DNA screening, with 455 and 136 having positive and negative results, respectively; 252 patients with positive results and 66 with negative results underwent biopsy and histology testing and were included in the study. The sensitivity of the E6/E7 mRNA assay was similar to that of HPV DNA testing (88.2%, 95% confidence interval [CI] 77.6-94.4 vs 90.7%, 95%CI 81.2-95.9; P=0.636) for the detection of cervical intraepithelial neoplasia grade 2+, and the specificity was higher (36.4%, 95%CI 29.6-43.9 vs 24.3%, 95%CI 19.1-30.3; P=0.006). The area under the receiver operating characteristic curve was greater for E6/E7 mRNA testing compared with HPV DNA testing (0.658 vs 0.588).

CONCLUSION

The higher specificity of the E6/E7 mRNA assay means it could be a promising technique in the management of women with ASCUS.

PAX1 and SOX1 methylation as an initial screening method for cervical cancer: a meta-analysis of individual studies in Asians

BACKGROUND

Epigenetic alterations of gene or DNA methylation have been highlighted as promising biomarkers for early cervical cancer screening. Herein, we evaluated the diagnostic performance of paired boxed gene 1 (PAX1) and sex determining region Y-box 1 (SOX1) methylation for cervical cancer detection.

METHODS

Eligible studies were retrieved by searching the electronic databases. Study quality was assessed according to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) checklist. The bivariate meta-analysis model was employed to plot the summary receiver operator characteristic (SROC) curve using Stata 12.0 software.

RESULTS

The pooled sensitivity of PAX1 methylation was estimated to be 0.73 [95% confidence interval (CI): 0.70-0.75] in differentiating patients with HSIL (high-grade squamous intraepithelial lesion) or CIN3+ (cervical intraepithelial neoplasia type III/worse) or cervical cancer from normal individuals, corresponding to a specificity of 0.87 (95% CI: 0.85-0.89) and area under the curve (AUC) of 0.91. The SOX1 methylation test yielded an AUC of 0.82, under which, the pooled sensitivity was 0.71 (95% CI: 0.67-0.74) and specificity was 0.64 (95% CI: 0.61-0.67). Notably, the stratified analysis suggested that combing parallel testing of PAX1 methylation and human papillomavirus (HPV) DNA (AUC, sensitivity, and specificity of 0.89, 0.75, and 0.81, respectively) achieved higher accuracy than single HPV DNA testing (AUC, sensitivity, and specificity of 0.77, 0.81, and 0.70, respectively).

CONCLUSIONS

PAX1 or SOX1 methylation has a prospect to be an auxiliary biomarker for cervical cancer screening, and parallel testing of PAX1 methylation and HPV DNA in cervical swabs confers an improved diagnostic accuracy than single HPV DNA testing.