Performance of DNA methylation-based biomarkers in the cervical cancer screening program of northern Portugal: A feasibility study

DNA methylation markers for oral cancer detection in non- and minimally invasive samples: a systematic review

More than 50% of oral cancer (OC) patients are diagnosed with advanced-stage disease associated with poor prognosis and quality of life, supporting an urgent need to improve early OC detection. The identification of effective molecular markers by minimally invasive approaches has emerged as a promising strategy for OC screening. This systematic review summarizes and evaluates the performance of the DNA methylation markers identified in non- or minimally invasive samples for OC detection. PubMed's MEDLINE, Scopus, Embase, and Cochrane Library databases were systematically searched for studies that evaluated DNA methylation markers in non-invasive and/or minimally invasive samples (oral rinse/saliva, oral brush, and blood) from OC patients. Two investigators independently extracted data on study population characteristics, candidate methylation markers, testing samples, DNA methylation assay, and performance diagnostic outcomes. Methodological study quality was assessed with the Quality Assessment for Studies of Diagnostic Accuracy-2 tool. Thirty-one studies met the inclusion criteria for this systematic review. DNA methylation markers were evaluated in oral rinse/saliva (n = 17), oral brush (n = 9), and blood (n = 7) samples. Methylation-specific PCR (MSP) and quantitative-MSP were the most common DNA methylation assays. Regarding diagnostic performance values for salivary, oral brush, and blood DNA methylation markers, sensitivity and specificity ranged between 3.4-100% and 21-100%, 9-100% and 26.8-100%, 22-70% and 45.45-100%, respectively. Different gene methylation panels showed good diagnostic performance for OC detection. This systematic review discloses the promising value of testing DNA methylation markers in non-invasive (saliva or oral rinse) or minimally invasive (oral brush or blood) samples as a novel strategy for OC detection. However, further validation in large, multicenter, and prospective study cohorts must be carried out to confirm the clinical value of specific DNA methylation markers in this setting.

Performance of CADM1, MAL and miR124-2 methylation as triage markers for early detection of cervical cancer in self-collected and clinician-collected samples: an exploratory observational study in Papua New Guinea

OBJECTIVE

WHO recommends human papillomavirus (HPV) testing for cervical screening, with triage of high-risk HPV (hrHPV) positive women. However, there are limitations to effective triage for low-resource, high-burden settings, such as Papua New Guinea. In this exploratory study, we assessed the performance of host methylation as triage tools for predicting high-grade squamous intraepithelial lesions (HSIL) in self-collected and clinician-collected samples.

DESIGN

Exploratory observational study.

SETTING

Provincial hospital, same-day cervical screen-and-treat trial, Papua New Guinea.

PARTICIPANTS

44 hrHPV+women, with paired self/clinician-collected samples (4 squamous cell carcinomas (SCC), 19 HSIL, 4 low-grade squamous intraepithelial lesions, 17 normal).

PRIMARY AND SECONDARY OUTCOME MEASURES

Methylation levels of CADM1, MAL and miR124-2 analysed by methylation-specific PCRs against the clinical endpoint of HSIL or SCC (HSIL+) measured using liquid-based-cytology/p16-Ki67 stain.

RESULTS

In clinician-collected samples, MAL and miR124-2 methylation levels were significantly higher with increasing grade of disease (p=0.0046 and p<0.0015, respectively). miR124-2 was the best predictor of HSIL (area under the curve, AUC 0.819) while MAL of SCC (AUC 0.856). In self-collected samples, MAL best predicted HSIL (AUC 0.595) while miR124-2 SCC (AUC 0.812). Combined miR124-2/MAL methylation yielded sensitivity and specificity for HSIL+ of 90.5% (95% CI 69.6% to 98.8%) and 70% (95% CI 45.7% to 88.1%), respectively, in clinician-collected samples, and 81.8% (95% CI 59.7% to 94.8%) and 47.6% (95% CI 25.7% to 70.2%), respectively, in self-collected samples. miR124-2/MAL plus HPV16/HPV18 improved sensitivity for HSIL+ (95.2%, 95% CI 76.2% to 99.9%) but decreased specificity (55.0%, 95% CI 31.5% to 76.9%).

CONCLUSION

miR124-2/MAL methylation is a potential triage strategy for the detection of HSIL/SCC in low-income and middle-income country.

Preliminary outcomes of the Cervical Cancer Screening Program of Northern Portugal: A snapshot

BACKGROUND

Cervical cancer screening remains an essential preventive tool worldwide. First line high-risk Human Papillomavirus (HrHPV) genotyping became gold standard for cervical cancer screening, and has been adopted by several countries, including Portugal. Herein, we aimed to assess the early outcomes of the regional Cervical Cancer Screening Program of Northern Portugal.

METHODS

The analysis of a representative set of cases evaluated during a one-month period (January 2020), with adequate follow-up was performed. Descriptive analysis was performed.

RESULTS

Overall, 7278 samples were received, of which 15.2% were HrHPV positive, most of these disclosing a negative result in subsequent liquid-based cytology. Nearly half of the HrHPV-positive women were referred to colposcopy. Within this group, HPV16/18+ cases depicted the higher frequency of high-grade squamous intraepithelial lesion (HSIL) or worse, compared with abnormal cytology or persistent HrHPV infection. Among women with non-HPV16/18 HrHPV infection and negative cytology, which are eligible for repeat sampling in one year, 65% were re-tested. Importantly, nearly half of these cleared HrHPV infection. Furthermore, referral to colposcopy due to HPV16/18 infection and/or abnormal cytology results were associated with > 40% risk for HSIL or worse lesion.

CONCLUSIONS

Our study confirmed the reliability and effectiveness of first line HrHPV genotyping in the Cervical Cancer Screening Program of Northern Portugal. Nonetheless, it also raised concerns about excessive referral to colposcopy, with the inherent human and financial costs. Thus, further improvement and optimization are key to ensure the sustainability of the program.

DNA methylation as a triage marker for colposcopy referral in HPV-based cervical cancer screening: a systematic review and meta-analysis

BACKGROUND

Screening plays a key role in secondary prevention of cervical cancer. High-risk human papillomavirus (hrHPV) testing, a highly sensitive test but with limited specificity, has become the gold standard frontline for screening programs. Thus, the importance of effective triage strategies, including DNA methylation markers, has been emphasized. Despite the potential reported in individual studies, methylation markers still require validation before being recommended for clinical practice. This systematic review and meta-analysis aimed to evaluate the performance of DNA methylation-based biomarkers for detecting high-grade intraepithelial lesions (HSIL) in hrHPV-positive women.

METHODS

Hence, PubMed, Scopus, and Cochrane databases were searched for studies that assessed methylation in hrHPV-positive women in cervical scrapes. Histologically confirmed HSIL was used as endpoint and QUADAS-2 tool enabled assessment of study quality. A bivariate random-effect model was employed to pool the estimated sensitivity and specificity as well as positive (PPV) and negative (NPV) predictive values.

RESULTS

Twenty-three studies were included in this meta-analysis, from which cohort and referral population-based studies corresponded to nearly 65%. Most of the women analyzed were Dutch, and CADM1, FAM19A4, MAL, and miR124-2 were the most studied genes. Pooled sensitivity and specificity were 0.68 (CI 95% 0.63-0.72) and 0.75 (CI 95% 0.71-0.80) for cervical intraepithelial neoplasia (CIN) 2+ detection, respectively. For CIN3+ detection, pooled sensitivity and specificity were 0.78 (CI 95% 0.74-0.82) and 0.74 (CI 95% 0.69-0.78), respectively. For pooled prevalence, PPV for CIN2+ and CIN3+ detection were 0.514 and 0.392, respectively. Furthermore, NPV for CIN2+ and CIN3+ detection were 0.857 and 0.938, respectively.

CONCLUSIONS

This meta-analysis confirmed the great potential of DNA methylation-based biomarkers as triage tool for hrHPV-positive women in cervical cancer screening. Standardization and improved validation are, however, required. Nevertheless, these markers might represent an excellent alternative to cytology and genotyping for colposcopy referral of hrHPV-positive women, allowing for more cost-effective screening programs.

Advances in epigenetic modifications and cervical cancer research

Cervical cancer (CC) is an important public health problem for women, and perspectives and information regarding its prevention and treatment are quickly evolving. Human papilloma virus (HPV) has been recognized as a major contributor to CC development; however, HPV infection is not the only cause of CC. Epigenetics refers to changes in gene expression levels caused by non-gene sequence changes. Growing evidence suggests that the disruption of gene expression patterns which were governed by epigenetic modifications can result in cancer, autoimmune diseases, and various other maladies. This article mainly reviews the current research status of epigenetic modifications in CC based on four aspects, respectively DNA methylation, histone modification, noncoding RNA regulation and chromatin regulation, and we also discuss their functions and molecular mechanisms in the occurrence and progression of CC. This review provides new ideas for early screening, risk assessment, molecular targeted therapy and prognostic prediction of CC.

A systematic review and meta-analysis of the diagnostic effectiveness of human papillomavirus methylation biomarkers for detection of cervical cancer

Background: The aim of this systematic review and meta-analysis was to assess the evidence for the diagnostic effectiveness of human papillomavirus (HPV) methylation biomarkers for detection of cervical cancer. Methods: PubMed, Embase and Web of Science were searched. Nine articles focusing on HPV methylation for detection of precancerous and cancerous cervical lesions were included. The QUADAS-2 tool was used for quality assessment. The receiver operating characteristic (ROC) was the main diagnostic performance parameter extracted. Results: Of the nine articles included in this study, seven were of moderate quality and two were of high quality. A meta-analysis of the ROC for 27 HPV methylation biomarkers revealed an overall pooled ROC of 0.770 (95% CI: 0.720-0.819; I²: 98.4%; Q: 1537.4; p < 0.01). Four methylation biomarkers had strong diagnostic ability (ROC > 0.900), 17 were moderate (ROC: 0.7000-0.8999) and six were poor (ROC < 0.700). Conclusion: HPV methylation biomarkers hold significant promise as independent screening tests for the detection of cervical precancerous and cancerous lesions.

Triage performance and predictive value of the human gene methylation panel among women positive on self-collected HPV test: Results from a prospective cohort study

Triaging of women positive for high-risk human papillomavirus (hrHPV) on self-collected samples requires a molecular reflex test to avoid recall for cytology or visual tests. We assessed triage performance and predictive value of human gene methylation panel (ZNF671/ASTN1/ITGA4/RXFP3/SOX17/DLX1) alone and with combination of HPV16/18 genotyping in a longitudinal screening study. Out of 9526 women at baseline, 1758 women positive for hrHPV on self-collected samples followed up yearly were included in the current analysis. Satisfactory risk stratification to detect cervical intraepithelial neoplasia grade 2 or worse (CIN2+) was demonstrated by the methylation panel with an odds ratio (OR) of 11.3 among methylation-positive women compared to methylation-negative counterparts. Triaging with methylation panel reduced colposcopy referral rate by 67.2% with sensitivity and specificity of 83.0% and 69.9% to detect CIN2+. The corresponding values for the combining methylation and HPV 16/18 were 96.6% and 58.3%. The cumulative 3-year incident CIN2+ risk was 6.8% (95% CI: 4.9%-8.6%) for hrHPV positive women, which was reduced to 4.5% (95% CI: 2.7%-6.3%) and 2.9% (95% CI: 1.2%-4.5%) for women negative on methylation triaging alone and negative on the combined strategy. The corresponding risk for women positive for both methylation and HPV 16/18 reached 33.7% (95% CI: 19.0%-45.8%). Our study demonstrated the satisfactory triage performance and predictive value of the methylation panel, especially in combination with HPV 16/18 genotyping. The substantially lower risk of CIN2+ among the triage negative women over the next 3 years suggests that the interval for repeat HPV test can be safely extended to at least 2 years.

Combined Liquid Biopsy Methylation Analysis of CADM1 and MAL in Cervical Cancer Patients

Cervical cancer is the fourth most common cancer in women, which is associated in >95% with a high-risk human papillomavirus (HPV) infection. Methylation of specific genes has been closely associated with the progress of cervical high-grade dysplastic lesions to invasive carcinomas. Therefore, DNA methylation has been proposed as a triage for women infected with high-risk HPV. Methylation analyses of cervical cancer tissue have shown that cell adhesion molecule 1 (CADM1) and myelin and lymphocyte protein (MAL) methylation are present in over 90% of all cervical high-grade neoplasias and invasive cervical cancers. Here, we established a liquid biopsy-based assay to detect MAL and CADM1 methylation in cell free (cf)DNA of cervical cancer. Methylation of the target gene was validated on bisulfite converted smear-DNA from cervical dysplasia patients and afterward applied to cfDNA using quantitative real-time PCR. In 52 smears, a combined analysis of CADM1 and/or MAL (CADM1/MAL) showed methylation in 86.5% of the cases. In cfDNA samples of 24 cervical cancer patients, CADM1/MAL methylation was detected in 83.3% of the cases. CADM1/MAL methylation was detected already in 81.8% of stage I-II patients showing the high sensitivity of this liquid biopsy assay. In combination with a specificity of 95.5% towards healthy donors (HD) and an area under the curve (AUC) of 0.872 in the receiver operating characteristic (ROC) analysis, CADM1/MAL cfDNA methylation detection might represent a novel and promising liquid biopsy marker in cervical cancer.

Methylation quantitative locus rs3758653 in the DRD4 gene is associated with duration from first heroin exposure to addiction

Opioid addiction is a chronic brain disease with a high heritability. However, the genetic underpinnings remain uncertain. DNA methylation is involved in the adaptive changes in neuroplasticity after prolonged drug use. The dopamine receptor D4 (DRD4) has an essential role in the reward processes associated with addictive drugs. To further elucidate the potential role and mechanism of the DRD4 gene variants in heroin addiction, we detected the methylation level of 46 CpG sites in the promoter region and the genotypes of three SNPs in the DRD4 gene. Correlations between the SNPs and methylation levels of the CpG sites, i.e., the analysis of methylation quantitative trait loci (mQTLs) was conducted. Following the identification of mQTLs that are unique in the heroin addiction group, we performed an association study between the mQTLs and traits of heroin addiction. Our results revealed that there were several correlations of SNPs rs3758653 and rs11246226 with the methylation levels of some CpG sites in the DRD4 gene. Among these SNP-CpG pairs, rs3758653-DRD4_04, rs3758653-DRD4_05, rs3758653-DRD4_13 and rs3758653-DRD4_03 were unique in the heroin addiction group. Moreover, we found that mQTL rs3758653 was associated with duration from first heroin exposure to addiction, and the expression level of the DRD4 gene in human brain regions of the frontal cortex and hippocampus. Our findings suggested that some mQTLs in the genome may be associated with traits of opioid addiction through implicating the processes of DNA methylation and gene expression.