Point-of-care test for cervical cancer in LMICs

An Overview of HPV Screening Tests to Improve Access to Cervical Cancer Screening Amongst Underserved Populations: From Development to Implementation

Cervical cancer is the most common human papillomavirus (HPV)-related disease. Knowledge of the natural history and aetiology of cervical cancer offers unique opportunities for its prevention, and the development of HPV screening tests is one of the most effective strategies. The current HPV diagnostics detect HPV DNA or E6/E7 mRNA in cervical/vaginal samples using molecular-based technologies. HPV screening tests are more sensitive than cytology or visual inspection with acetic acid (VIA) as a primary screening method and are even more clinically valuable in triaging mild cytological abnormalities as a hybrid test. As technical and laboratory resources are grossly limited in marginalized or underserved settings which thus require that women travel long distances for screening and treatment. The practical implementation of an HPV-based screening programme may face many challenges and measures should be instituted to overcome these challenges without compromising disease detection. These measures may include a reduction in screening frequency using the WHO global strategy of offering HPV screening tests at 35 and 45 years of age, adoption of a high throughput testing technology, and improved access to vaginal HPV self-sampling screening tests to women in remote settings or those who are reluctant to undergo gynecologic examination. Another important strategy is the implementation of a "see-and-treat" approach using a point-of-care platform that requires limited skills of laboratory technicians. In addition, the development and large-scale incorporation of more specific HPV testing technologies that are much cheaper and easier to use in non-laboratory settings than the currently available options should be prioritized for underserved settings. At the same time, there is a need to develop and commence the implementation of an affordable and readily available intermediate or secondary test with optimal specificity for triaging or segregating clinically unimportant HPV infections that do not require colposcopy.

Colorimetric Paper-Based Sensors against Cancer Biomarkers

Cancer is a major cause of mortality and morbidity worldwide. Detection and quantification of cancer biomarkers plays a critical role in cancer early diagnosis, screening, and treatment. Clinicians, particularly in developing countries, deal with high costs and limited resources for diagnostic systems. Using low-cost substrates to develop sensor devices could be very helpful. The interest in paper-based sensors with colorimetric detection increased exponentially in the last decade as they meet the criteria for point-of-care (PoC) devices. Cellulose and different nanomaterials have been used as substrate and colorimetric probes, respectively, for these types of devices in their different designs as spot tests, lateral-flow assays, dipsticks, and microfluidic paper-based devices (μPADs), offering low-cost and disposable devices. However, the main challenge with these devices is their low sensitivity and lack of efficiency in performing quantitative measurements. This review includes an overview of the use of paper for the development of sensing devices focusing on colorimetric detection and their application to cancer biomarkers. We highlight recent works reporting the use of paper in the development of colorimetric sensors for cancer biomarkers, such as proteins, nucleic acids, and others. Finally, we discuss the main advantages of these types of devices and highlight their major pitfalls.

Self-collection for HPV-based cervical screening: a qualitative evidence meta-synthesis

Background

Cervical cancer is the fourth most common cancer affecting women worldwide, with 85% of the burden estimated to occur among women in low and middle-income countries (LMICs). Recent developments in cervical cancer screening include a novel self-collection method for the detection of oncogenic HPV strains in the collected samples. The purpose of this review is to synthesise qualitative research on self-collection for HPV-based testing for cervical screening and identify strategies to increase acceptability and feasibility in different settings, to alleviate the burden of disease.

Methods

This review includes qualitative studies published between 1986 and 2020. A total of 10 databases were searched between August 2018 and May 2020 to identify qualitative studies focusing on the perspectives and experiences of self-collection for HPV-based cervical screening from the point of view of women, health care workers and other key stakeholders (i.e., policymakers). Two authors independently assessed studies for inclusion, quality, and framework thematic synthesis findings. The Socio-Ecological Model (SEM) was used to synthesize the primary studies.

Results

A total of 1889 publications were identified, of which 31 qualitative studies were included. Using an adapted version of SEM, 10 sub-themes were identified and classified under each of the adapted model’s constructs: (a) intrapersonal, (b) interpersonal, and (c) health systems/public policy. Some of the themes included under the intrapersonal (or individual) construct include the importance of self-efficacy, and values attributed to self-collection. Under the intrapersonal construct, the findings centre around the use of self-collection and its impact on social relationships. The last construct of health systems focuses on needs to ensure access to self-collection, the need for culturally sensitive programs to improve health literacy, and continuum of care.

Conclusion

This review presents the global qualitative evidence on self-collection for HPV-based testing and details potential strategies to address socio-cultural and structural barriers and facilitators to the use of self-collection. If addressed during the design of an HPV-based cervical cancer screening testing intervention program, these strategies could significantly increase the acceptability and feasibility of the intervention and lead to more effective and sustainable access to cervical screening services for women worldwide.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11554-6.

Addressing cervical cancer screening disparities through advances in artificial intelligence and nanotechnologies for cellular profiling

Almost all cases of cervical cancer are caused by the human papilloma virus (HPV). Detection of pre-cancerous cervical changes provides a window of opportunity for cure of an otherwise lethal disease when metastatic. With a greater understanding of the biology and natural course of high-risk HPV infections, screening methods have shifted beyond subjective Pap smears toward more sophisticated and objective tactics. This has led to a substantial growth in the breadth and depth of HPV-based cervical cancer screening tests, especially in developed countries without constrained resources. Many low- and middle-income countries (LMICs) have less access to advanced laboratories and healthcare resources, so new point-of-care (POC) technologies have been developed to provide test results in real time, improve the efficiency of techniques, and increase screening adoption. In this Review, we will discuss how novel decentralized screening technologies and computational strategies improve upon traditional methods and how their realized promise could further democratize cervical cancer screening and promote greater disease prevention.

Qualitative Evidence Synthesis on Self-Collection for Human Papillomavirus-Based Cervical Screening: Protocol for Systematic Review

Background

Cervical cancer is the fourth most common cancer affecting women worldwide. In the 1980s, it was found that the sexually transmitted disease human papillomavirus causes over 90% of all cervical cancer cases. Since that discovery, diagnostic technologies have been developed for the detection of human papillomavirus DNA in cervical samples. However, significant sociocultural and structural barriers remain. Considerable strides have taken place in recent years to address these barriers, such as the self-collection for human papillomavirus–based cervical screening method.

Objective

The purpose of this review is to synthesize qualitative evidence around the self-collection method and identify strategies to increase acceptability and feasibility in different settings. This qualitative synthesis will be used to better understand how to conceptualize and implement more effective, accessible, and socially and culturally acceptable cervical screening programs and policies globally.

Methods

A systematic search will be conducted in Global Health, Cochrane, CINAHL (Cumulative Index to Nursing and Allied Health Literature), ProQuest, ScienceDirect, EMBASE, EMCARE, Medline (OVID), Scopus, and Web of Science. Published and peer-reviewed articles will be included. Two reviewers will independently screen and assess the studies. The data will be coded and analyzed using a thematic synthesis process. The socioecological model will be used to organize emergent themes at the micro and macro levels. The results will be presented in narrative and tabular form.

Results

The article search and data extraction were completed in May 2020. The data were analyzed in June 2020. The review will be submitted for publication in Fall 2020.

Conclusions

This review will present the global evidence of the perspectives and experiences of various key stakeholders and how these perspectives and experiences impact their decision-making process to perform or accept self-collection for human papillomavirus–based cervical screening. The review will provide guidance to implementation researchers as well as implications for future research.

Trial Registration

PROSPERO International Prospective Register of Systematic Reviews CRD42019109073; https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=109073

International Registered Report Identifier (IRRID)

DERR1-10.2196/21093

Cervical cancer risk profiling: molecular biomarkers predicting the outcome of hrHPV infection

INTRODUCTION

Cervical cancer affects half a million women worldwide annually. Given the association between high-risk human papillomavirus (hrHPV) infection and carcinogenesis, hrHPV DNA testing became an essential diagnostic tool. However, hrHPV alone does not cause the disease, and, most importantly, many cervical lesions regress to normal in a year because of the host immune system. Hence, the low specificity of hrHPV DNA tests and their inability to predict the outcome of infections have triggered a further search for biomarkers.

AREAS COVERED

We evaluated the latest viral and cellular biomarkers validated for clinical use as primary screening or triage for cervical cancer and assessed their promise for prevention as well as potential use in the future. The literature search focused on effective biomarkers for different stages of the disease, aiming to determine their significance in predicting the outcome of hrHPV infections.

EXPERT OPINION

Biomarkers such as p16/Ki-67, hrHPV genotyping, hrHPV transcriptional status, and methylation patterns have demonstrated promising results. Their eventual implementation in the screening programs may support the prompt diagnosis of hrHPV infection and its progression to cancer. These biomarkers will help in making clinical management decisions on time, thus, saving the lives of hrHPV-infected women, particularly in developing countries.

Point of care testing for infectious diseases

Infectious diseases are caused by pathogenic microorganisms and can be transmitted between individuals and populations thus threatening the general public health and potentially the economy. Efficient diagnostic tools are needed to provide accurate and timely guidance for case identification, transmission disruption and appropriate treatment administration. Point of care (POC) tests provide actionable results near the patient and thereby serve as a personal "radar". In this review, we review clinical needs for POC testing for several major pathogens, including malaria parasites, human immunodeficiency virus (HIV), human papillomavirus (HPV), dengue, Ebola and Zika viruses and Mycobacterium tuberculosis (TB). We compare different molecular approaches, including pathogen nucleic acid and protein, circulating microRNA and antibodies, used in the POC tests. Finally, we review recent advances in novel POC technologies focusing on microfluidic and plasmonic-based approaches.

Magnetic Focus Lateral Flow Sensor for Detection of Cervical Cancer Biomarkers

We report on a magnetic focus lateral flow biosensor (mLFS) for ultrasensitive detection of protein biomarkers in a practical format. With valosin-containing protein as a target protein, we show that the developed mLFS concept could detect as low as 25 fg/mL with magnetic focus to enhance target capture efficiency to deliver a 10⁶-fold improvement in sensitivity compared to that of conventional lateral flow (LF) systems. The conceptualized strategy utilizes a simple magnet placed beneath the three-dimensional printed LF device to concentrate the targets at the signal zone without any additional instrumentation. In addition, protein mixtures extracted from the tissue of cervical cancer patients was also utilized to validate the sensor. To investigate the effect of magnetic focus on sensitivity, surface-enhanced Raman spectroscopy and dark-field imaging was utilized to characterize the distribution and movement of Fe₃O₄ core-Au shell nanoprobes in a model LF strip. Our experiments show that the magnetic focus results in an increased interaction time between the magnetic probe-labeled targets and the capture antibody, yielding a higher capture efficiency, allowing for ultrasensitive detection of the target not possible before with LF. The proposed mLFS can be utilized to detect a range of trace protein biomarkers for early diagnosis and can be combined with diverse pretreatment and signal amplification steps to query complex samples.

LXR/RXR pathway signaling associated with triple-negative breast cancer in African American women

Background

Triple-negative breast cancer (TNBC) is more prevalent in African and African American (AA) women compared to European American (EA) women. African and AA women diagnosed with TNBC experience high frequencies of metastases and less favorable outcomes. Emerging evidence indicates that this disparity may in fact be the result of the uniquely aggressive biology of African and AA disease.

Purpose

To understand the reasons for TNBC in AA aggressive biology, we designed the present study to examine the proteomic profiles of TNBC and luminal A (LA) breast cancer within and across patients’ racial demographic groups in order to identify proteins or molecular pathways altered in TNBC that offer some explanation for its aggressiveness and potential targets for treatment.

Materials and methods

Proteomic profiles of TNBC, LA tumors, and their adjacent normal tissues from AA and EA women were obtained using 2-dimensional gel electrophoresis and bioinformatics, and differentially expressed proteins were validated by Western blot and immunohistochemistry. Our data showed that a number of proteins have significantly altered in expression in LA tumors compared to TNBC, both within and across patients’ racial demographic groups. The differentially overexpressed proteins in TNBC (compared to LA) of AA samples were distinct from those in TNBC (compared to LA) of EA women samples. Among the signaling pathways altered in AA TNBC compared to EA TNBC are innate immune signaling, calpain protease, and pyrimidine de novo synthesis pathways. Furthermore, liver LXR/RXR signaling pathway was altered between LA and TNBC in AA women and may be due to the deficiency of the CYP7B1 enzyme responsible for cholesterol degradation.

Conclusion

These findings suggest that TNBC in AA women enriched in signaling pathways that are different from TNBC in EA women. Our study draws a link between LXR/RXR expression, cholesterol, obesity, and the TNBC in AA women.

Interleukin-6 induced overexpression of valosin-containing protein (VCP)/p97 is associated with androgen-independent prostate cancer (AIPC) progression

Though Androgen deprivation therapy (ADT) is effective initially, numerous patients become resistant to it and develop castration resistant PCa (CRPC). Cytokines promotes ligand independent activation of AR. Interleukin-6 (IL-6) levels are elevated in CRPC patients and regulate AR activity. However, progression to CRPC is not fully understood. In this study, we analyzed differential protein expression in LNCaP cells treated with IL-6 using proteomics. Results revealed altered expression of 27 proteins and Valosin-containing protein (VCP)/p97 plays a predominant role in co-regulation of altered proteins. Interestingly, IL-6 induced VCP expression through Pim-1 via STAT3 is AR independent there by suggesting a role for VCP in CRPC. Transfection of LNCaP cells for VCP overexpression showed an increased cell proliferation, migration, and invasion where as its inhibition by NMS-873 showed the reverse effect causing cell death. Mechanistic studies demonstrate that cell death occurs due to apoptosis by endoplasmic reticulum (ER) stress, elevated cell cycle inhibitors p21, p27kip1, and active PARP and reduced Bcl-2. VCP promotes cell invasion and migration by altering E-cadherin and Vimentin levels inversely triggering EMT of PCa cells. VCP immunostaining revealed no staining in BPH but strong staining in PCa. This study determines VCP may play an important role in progression to CRPC and it can be a favorable target with to develop new therapies to treat ADT resistant prostate cancer.

Technical advances in global DNA methylation analysis in human cancers

Prototypical abnormalities of genome-wide DNA methylation constitute the most widely investigated epigenetic mechanism in human cancers. Errors in the cellular machinery to faithfully replicate the global 5-methylcytosine (5mC) patterns, commonly observed during tumorigenesis, give rise to misregulated biological pathways beneficial to the rapidly propagating tumor mass but deleterious to the healthy tissues of the affected individual. A growing body of evidence suggests that the global DNA methylation levels could serve as utilitarian biomarkers in certain cancer types. Important breakthroughs in the recent years have uncovered further oxidized derivatives of 5mC - 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC), thereby expanding our understanding of the DNA methylation dynamics. While the biological roles of these epigenetic derivatives are being extensively characterized, this review presents a perspective on the opportunity of innovation in the global methylation analysis platforms. While multiple methods for global analysis of 5mC in clinical samples exist and have been reviewed elsewhere, two of the established methods - Liquid Chromatography coupled with mass spectrometry (LC-MS/MS) and Immunoquantification have successfully evolved to include the quantitation of 5hmC, 5fC and 5caC. Although the analytical performance of LC-MS/MS is superior, the simplicity afforded by the experimental procedure of immunoquantitation ensures it’s near ubiquity in clinical applications. Recent developments in spectroscopy, nanotechnology and sequencing also provide immense promise for future evaluations and are discussed briefly. Finally, we provide a perspective on the current scenario of global DNA methylation analysis tools and present suggestions to develop the next generation toolset.

Feasibility of thermocoagulation in a screen-and-treat approach for the treatment of cervical precancerous lesions in sub-Saharan Africa

BACKGROUND

The use of thermocoagulation for the treatment of cervical precancerous lesions has recently generated a great deal of interest. Our aim was to determine the feasibility of this outpatient procedure in the context of a cervical cancer (CC) screen-and-treat campaign in sub-Saharan Africa.

METHODS

Between July and December 2015, women living in the area of Dschang (Cameroon) aged between 30 and 49 years, were enrolled in a CC screening study. HPV self-sampling was performed as a primary screening test and women who were either "HPV 16/18/45-positive" or "positive to other HPV types and to VIA" were considered screen-positive, thus requiring further management. The primary outcome was the percentage of screen-positive patients who met the criteria to undergo thermocoagulation. The secondary outcome was the assessment of the procedure's side effects immediately after treatment and at the 1-month follow-up visit.

RESULTS

A total of 1012 women were recruited in the study period. Among 121 screen-positive women, 110 of them (90.9%) were eligible to be treated with thermocoagulation. No patients discontinued treatment because of pain or other side effects. The mean ± SD (Standard Deviation) score measured on the 10-point Visual Analogue Scale (VAS) was 3.0 ± 1.6. Women having less than 2 children were more likely to report a higher pain score than those with more than two (4.2 ± 2.0 versus 2.9 ± 1.5, respectively; p value = 0.016). A total of 109/110 (99.1%) patients came to the 1-month follow-up visit. Vaginal discharge was reported in 108/109 (99.1%) patients throughout the month following treatment. Three patients (2.8%) developed vaginal infection requiring local antibiotics. No hospitalizations were required.

CONCLUSION

The majority of screen-positive women met the criteria and could be treated by thermocoagulation. The procedure was associated to minor side effects and is overall feasible in the context of a CC screen-and-treat campaign in sub-Saharan Africa.

TRIAL REGISTRATION

The trial was retrospectively registered on November 11, 2015 with the identifier: ISRCTN99459678 .