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

Performance of an affordable urine self-sampling method for human papillomavirus detection in Mexican women

Introduction: Urine self-sampling for human papillomavirus (HPV)-based cervical cancer screening is a non-invasive method that offers several logistical advantages and high acceptability, reducing barriers related to low screening coverage. This study developed and evaluated the performance of a low-cost urine self-sampling method for HPV-testing and explored the acceptability and feasibility of potential implementation of this alternative in routine screening. Methods: A series of sequential laboratory assays examined the impact of several pre-analytical conditions for obtaining DNA from urine and subsequent HPV detection. Initially, we assessed the effect of ethylaminediaminetetraacetic acid (EDTA) as a DNA preservative examining several variables including EDTA concentration, specimen storage temperature, time between urine collection and DNA extraction, and first-morning micturition versus convenience sample collection. We further evaluated the agreement of HPV-testing between urine and clinician-collected cervical samples among 95 women. Finally, we explored the costs of self-sampling supplies as well as the acceptability and feasibility of urine self-sampling among women and healthcare workers. Results: Our results revealed higher DNA concentrations were obtained when using a 40mM EDTA solution, storing specimens at 25°C and extracting DNA within 72 hrs. of urine collection, regardless of using first-morning micturition or a convenience sampling. We observed good agreement (Kappa = 0.72) between urine and clinician-collected cervical samples for HPV detection. Furthermore, urine self-sampling was an affordable method (USD 1.10), well accepted among cervical cancer screening users, healthcare workers, and decision-makers. Conclusion: These results suggest urine self-sampling is feasible and appropriate alternative for HPV-testing in HPV-based screening programs in lower-resource contexts

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field