Noninvasive genomic detection of melanoma

Tape strips detect molecular alterations and cutaneous biomarkers in skin of patients with hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) has a high unmet need for better treatments. Biopsies are considered the gold standard for studying molecular alterations in skin. A reproducible, minimally invasive approach is needed for longitudinal monitoring in trials and in pediatric populations.

OBJECTIVE

To determine whether skin tape strips can detect molecular alterations in HS and identify biomarkers of disease activity.

METHODS

We performed RNA sequencing on tape strips collected from lesional and healthy-appearing (nonlesional) HS skin (n = 22) and healthy controls (n = 21). We correlated the expression of skin biomarkers between tape strips and a previously published gene-signature of HS biopsies.

RESULTS

Tape strips detected upregulation of known HS biomarkers (eg, Interleukin[IL]-17A) in nonlesional and/or lesional skin and also identified novel clinically actionable targets, including OX40 and JAK3. The expression of Th17 and tumor necrosis factor-α pathways were highly correlated between tape strips and biopsies. HS clinical severity was significantly associated with expression of biomarkers (eg tumor necrosis factor-α , IL-17 A/F, OX40, JAK1-3, IL-4R) in HS lesional and/or nonlesional skin.

LIMITATIONS

Sample size. Tape stripping is limited in depth.

CONCLUSION

This study validates tape strips as a minimally-invasive approach to identify cutaneous biomarkers in HS. This provides a novel avenue for monitoring treatment efficacy and a potential step toward individualized therapy in HS.

Mind the Gap: A Questionnaire on the Distance between Diagnostic Advances and Clinical Practice in Skin Cancer Treatment

Background and Objectives: Significant progress has been made in skin cancer diagnosis, with a surge in available technologies in recent years. Despite this, the practical application and integration of these technologies in dermatology and plastic surgery remain uneven. Materials and Methods: A comprehensive 20-question survey was designed and distributed using online survey administration software (Google Forms, 2018, Google, Mountain View, CA, USA) from June 2023 to September 2023. The survey aimed to assess the knowledge and utilization of dermatologic diagnostic advancements among plastic surgeons in various European countries. Results: Data were obtained from 29 plastic surgeons across nine European countries, revealing a notable gap between diagnostic technologies and their routine use in surgical practice. The gap for some technologies was both cognitive and applicative; for electrical impedance spectroscopy (EIS) and multispectral imaging, only 6.9% of the sample knew of the technologies and no surgeons in the sample used them. In the case of other technologies, such as high-frequency ultrasound (HFUS), 72.4% of the sample knew about them but only 34.5% used them, highlighting a more significant application problem. Conclusions: Spotlighting this discrepancy provides a valuable foundation for initiating collaborative efforts between units and facilitating knowledge exchange among diverse specialists. This, in turn, contributes to advancing clinical practice by integrating the innovative opportunities presented by ongoing research.

A noninvasive method for whole-genome skin methylome profiling

BACKGROUND

Ageing, disease and malignant transformation of the skin are associated with changes in DNA methylation. So far, mostly invasive methodologies such as biopsies have been applied in collecting DNA methylation signatures. Tape stripping offers a noninvasive option for skin diagnostics. It enables the easy but robust capture of biologic material in large numbers of participants without the need for specialized medical personnel.

OBJECTIVES

To design and validate a methodology for noninvasive skin sample collection using tape stripping for subsequent DNA -methylation analysis.

METHODS

A total of 175 participants were recruited and provided tape-stripping samples from a sun-exposed area; 92 provided matched tape-stripping samples from a sun-protected area, and an additional 5 provided matched skin-shave biopsies from the same area. Using -enzymatic conversion and whole-genome Illumina sequencing, we generated genome-wide DNA methylation profiles that were used to evaluate the feasibility of noninvasive data acquisition, to compare with established sampling approaches and to investigate biomarker identification for age and ultraviolet (UV) exposure.

RESULTS

We found that tape-stripping samples showed strong concordance in their global DNA methylation landscapes to those of conventional invasive biopsies. Moreover, we showed sample reproducibility and consistent global methylation profiles in skin tape-stripping samples collected from different areas of the body. Using matched samples from sun-protected and sun-exposed areas of the body we were able to validate the capacity of our method to capture the effects of environmental changes and ageing in a cohort covering various ages, ethnicities and skin types. We found DNA methylation changes on the skin resulting from UV exposure and identified significant age-related hypermethylation of CpG islands, with a pronounced peak effect at 50-55 years of age, including methylation changes in well-described markers of ageing.

CONCLUSIONS

These data demonstrate the feasibility of using tape stripping combined with whole-genome sequencing as a noninvasive approach to measuring DNA methylation changes in the skin. In addition, they outline a viable experimental framework for the use of skin tape stripping, particularly when it is performed in large cohorts of patients to identify biomarkers of skin ageing, UV damage and, possibly, to track treatment response to therapeutic interventions.

Molecular Classifiers in Skin Cancers: Challenges and Promises

Skin cancers are common and heterogenous malignancies affecting up to two in three Australians before age 70. Despite recent developments in diagnosis and therapeutic strategies, the mortality rate and costs associated with managing patients with skin cancers remain high. The lack of well-defined clinical and histopathological features makes their diagnosis and classification difficult in some cases and the prognostication difficult in most skin cancers. Recent advancements in large-scale "omics" studies, including genomics, transcriptomics, proteomics, metabolomics and imaging-omics, have provided invaluable information about the molecular and visual landscape of skin cancers. On many occasions, it has refined tumor classification and has improved prognostication and therapeutic stratification, leading to improved patient outcomes. Therefore, this paper reviews the recent advancements in omics approaches and appraises their limitations and potential for better classification and stratification of skin cancers.

RNA analysis of tape strips to rule out melanoma in lesions clinically assessed as cutaneous malignant melanoma: A diagnostic study

BACKGROUND

Distinguishing cutaneous malignant melanoma (CMM) from nevi can be clinically challenging. Suspicious lesions are therefore excised, resulting in many benign lesions being removed surgically to find 1 CMM. It has been proposed to use tape strip derived ribonucleic acid (RNA) to distinguish CMM from nevi.

OBJECTIVE

To develop this technique further and validate if RNA profiles can rule out CMM in clinically suspicious lesions with 100% sensitivity.

METHODS

Before surgical excision, 200 lesions clinically assessed as CMM were tape stripped. Expression levels of 11 genes on the tapes were investigated by RNA measurement and used in a rule-out test.

RESULTS

Histopathology showed that 73 CMMs and 127 non-CMMs were included. Our test correctly identified all CMMs (100% sensitivity) based on the expression levels of 2 oncogenes, PRAME and KIT, relative to a housekeeping gene. Patient age and sample storage time were also significant. Simultaneously, our test correctly excluded CMM in 32% of non-CMM lesions (32% specificity).

LIMITATIONS

Our sample contained a very high proportion of CMMs, perhaps due to inclusion during COVID-19 shutdown. Validation in a separate trial must be performed.

CONCLUSION

Our results demonstrate that the technique can reduce removal of benign lesions by one-third without overlooking any CMMs.

Skin drug delivery using lipid vesicles: A starting guideline for their development

Lipid vesicles can provide a cost-effective enhancement of skin drug absorption when vesicle production process is optimised. It is an important challenge to design the ideal vesicle, since their properties and features are related, as changes in one affect the others. Here, we review the main components, preparation and characterization methods commonly used, and the key properties that lead to highly efficient vesicles for transdermal drug delivery purposes. We stand by size, deformability degree and drug loading, as the most important vesicle features that determine the further transdermal drug absorption. The interest in this technology is increasing, as demonstrated by the exponential growth of publications on the topic. Although long-term preservation and scalability issues have limited the commercialization of lipid vesicle products, freeze-drying and modern escalation methods overcome these difficulties, thus predicting a higher use of these technologies in the market and clinical practice.

Detection of cutaneous malignant melanoma by tape stripping of pigmented skin lesions - A systematic review

BACKGROUND

Cutaneous malignant melanoma (MM) is potentially aggressive, and numerous clinically suspicious pigmented skin lesions are excised, causing unnecessary mutilation for patients at high healthcare costs, but without histopathological evidence of MM. The high number of excisions may be lowered by using more accurate diagnostics. Tape stripping (TS) of clinically suspicious lesions is a non-invasive diagnostic test of MM that can potentially lower the number needed to biopsy/excise.

MATERIALS AND METHODS

The aim is to determine the diagnostic accuracy of TS in detecting MM in clinically suspicious pigmented skin lesions. This systematic review following PRISMA guidelines searched PubMed, Web of Science, and Embase (September 2022) using melanoma combined with tape stripping, adhesive patch(es), pigmented lesion assay, or epidermal genetic information retrieval.

RESULTS

Ten studies were included. Sensitivity ranged from 68.8% (95% confidence interval [CI] 51.5, 82.1) to 100% (95% CI 91.0, 100). Specificity ranged from 69.1% (95% CI 63.8, 74.0) to 100% (95% CI 78.5, 100). A pooled analysis of five studies testing the RNA markers LINC00518 and PRAME found a sensitivity of 86.9% (95% CI 81.7, 90.8) and a specificity of 82.4% (95% CI 80.8, 83.9).

CONCLUSION

Overall quality of studies was low, and the reliability of sensitivity and specificity is questionable. However, TS may supplement well-established diagnostic methods as pooled analysis of five studies indicates a moderate sensitivity. Future studies are needed to obtain more reliable data as independent studies with no conflict of interest.

Molecular Skin Cancer Diagnosis: Promise and Limitations

Skin cancer is a significant and increasing global health burden. Although the current diagnostic workflow is robust and able to provide clinically actionable results, it is subject to notable limitations. The training and expertise required for accurate diagnoses using conventional skin cancer diagnostics are significant, and patient access to this workflow can be limited by geographic location or unforeseen events, such as coronavirus disease 2019 (COVID-19). Molecular biomarkers have transformed diagnostics and treatment delivery in oncology. With rapid advancements in molecular biology techniques, understanding of the underlying molecular mechanism of cancer pathologies has deepened, yielding biomarkers that can be used to monitor the course of malignant diseases. Herein, commercially available, clinically validated, and emerging skin cancer molecular biomarkers are reviewed. The qualities of an ideal molecular biomarker are defined. The potential benefits and limitations of applying molecular biomarker testing over the course of skin cancer from susceptibility to treatment are explored, with a view to outlining a future model of molecular biomarker skin cancer diagnostics.

Detection of cutaneous malignant melanoma using RNA sampled by tape strips: A study protocol

Background

Cutaneous malignant melanoma (CMM) is curable if detected in its early stages. However, the clinical recognition of CMM is challenging. An American research group has shown promising results in detecting CMM based on RNA profiles sampled from suspicious lesions with tape strips. We aim to further develop this technique and validate if RNA profiles sampled with tape strips can detect CMM.

Methods

This prospective cohort study will include approximately 200 lesions clinically suspected of CMM requiring surgical removal. Tape stripping of the lesions will be performed just before surgical excision. Subsequently, RNA on the tape strips is analyzed using quantitative real-time polymerase chain reaction with TaqMan technology. The results are combined into a binary outcome where positive indicates CMM and negative indicates no CMM. The histopathological diagnosis of the lesions will be used as the gold standard. The main outcome is the results of the RNA test and the histopathological diagnosis, which, combined, provide the sensitivity and specificity of the test.

Discussion

The accuracy of the clinical examination in CMM diagnostics is limited. This clinical trial will explore the ability to use RNA analysis to improve the management of suspicious lesions by enhancing early diagnostic accuracy. Hopefully, it can reduce the number of benign lesions being surgically removed to rule out CMM and decrease patient morbidity.

Trial registration

The project was approved by The Committee on Health Research Ethics of the Capital Region of Denmark (H-15010559) and registered at the Danish Data Protection Agency (BFH-2015-065).

NAD/NAMPT and mTOR Pathways in Melanoma: Drivers of Drug Resistance and Prospective Therapeutic Targets

Malignant melanoma represents the most fatal skin cancer due to its aggressive behavior and high metastatic potential. The introduction of BRAF/MEK inhibitors and immune-checkpoint inhibitors (ICIs) in the clinic has dramatically improved patient survival over the last decade. However, many patients either display primary (i.e., innate) or develop secondary (i.e., acquired) resistance to systemic treatments. Therapeutic resistance relies on the rewiring of multiple processes, including cancer metabolism, epigenetics, gene expression, and interactions with the tumor microenvironment that are only partially understood. Therefore, reliable biomarkers of resistance or response, capable of facilitating the choice of the best treatment option for each patient, are currently missing. Recently, activation of nicotinamide adenine dinucleotide (NAD) metabolism and, in particular, of its rate-limiting enzyme nicotinamide phosphoribosyltransferase (NAMPT) have been identified as key drivers of targeted therapy resistance and melanoma progression. Another major player in this context is the mammalian target of rapamycin (mTOR) pathway, which plays key roles in the regulation of melanoma cell anabolic functions and energy metabolism at the switch between sensitivity and resistance to targeted therapy. In this review, we summarize known resistance mechanisms to ICIs and targeted therapy, focusing on metabolic adaptation as one main mechanism of drug resistance. In particular, we highlight the roles of NAD/NAMPT and mTOR signaling axes in this context and overview data in support of their inhibition as a promising strategy to overcome treatment resistance.

Adjunctive Diagnostic Methods for Skin Cancer Detection: A Review of Electrical Impedance-Based Techniques

Skin cancer is among the fastest-growing cancers with an excellent prognosis, if detected early. However, the current method of diagnosis by visual inspection has several disadvantages such as overlapping tumor characteristics, subjectivity, low sensitivity, and specificity. Hence, several adjunctive diagnostic techniques such as thermal imaging, optical imaging, ultrasonography, tape stripping methods, and electrical impedance imaging are employed along with visual inspection to improve the diagnosis. Electrical impedance-based skin cancer detection depends upon the variations in electrical impedance characteristics of the transformed cells. The information provided by this technique is fundamentally different from other adjunctive techniques and thus has good prospects. Depending on the stage, type, and location of skin cancer, various impedance-based devices have been developed. These devices when used as an adjunct to visual methods have increased the sensitivity and specificity of skin cancer detection up to 100% and 87%, respectively, thus demonstrating their potential to minimize unnecessary biopsies. In this review, the authors track the advancements and progress made in this technique for the detection of skin cancer, focusing mainly on the advantages and limitations in the clinical setting. © 2022 Bioelectromagnetics Society.

Tape Stripping: Investigational, Diagnostic and Therapeutic Uses in Dermatology

Adhesive tape has been used in the scientific study of human skin for over 90 years. Using the tape stripping method in dermatology has aided in the research and diagnose of different skin diseases. Basic science, identification, and therapeutic interventions in skin diseases such as psoriasis, atopic dermatitis, non-melanoma skin cancer, and melanoma have been studied using this technique. Among many promising applications that will be discussed throughout this paper, the Pigmented Lesion Assay (PLA) will be discussed in depth in relation to melanoma. This product carries considerable and significant research towards early detection of melanoma. Tape stripping is unique and advantageous in its ability to provide a non-surgical approach to evaluating the human epidermis. The cellular and molecular components of the skin are used to diagnose different skin conditions without invasive skin biopsy.

Melanoma: How and When to Consider Clinical Diagnostic Technologies

In response to rising rates of melanoma worldwide, novel non-invasive melanoma detection techniques are emerging to facilitate the early detection of melanoma and decrease unnecessary biopsies of benign pigmented lesions. Because they often report similar study findings, it may be difficult to determine how best to incorporate these technologies into clinical practice based on their supporting studies alone. As an expansion of the recent article by Fried et al.¹, which reviewed the clinical data supporting these non-invasive melanoma detection techniques, the first article in this continuing medical education series provides practical advice on how and when to use various non-invasive melanoma detection techniques into clinical practice.

Non-invasive diagnostic techniques in pigmentary skin disorders and skin cancer

BACKGROUND

Diagnosis of pigmentary skin disorders, pre-cancerous and cancerous skin diseases is traditionally relied on visual assessment. The most widely applied invasive diagnostic technique is the skin biopsy. There have been significant technological advances in non-invasive diagnostic methods for skin disorders.

OBJECTIVE

The objective of this article is to discuss different non-invasive diagnostic modalities, used in the diagnosis of pigmentary skin disorders and cutaneous cancers.

METHODS

Comprehensive literature search was performed to screen articles related to non-invasive diagnostic techniques in pigmentary skin disorders and cutaneous cancers. Articles published in journals indexed in PubMed were searched along with those in Google Scholar. Clinical trials, review articles, case series, case reports and other relevant articles were considered for review. References of relevant articles were also considered for review.

RESULTS

Dermoscopy and ultrasonography were the only non-invasive diagnostic and imaging techniques available to dermatologists for many years. The advent of computed tomography (CT) and magnetic resonance imaging (MRI) augmented the visualization of deeper structures. Confocal laser microscopy (CLM) and reflectance spectrophotometers have showed promising results in the non-invasive detection of pigmented lesions. Optical coherence tomography (OCT), electrical impedance spectroscopy (EIS), multispectral imaging, high frequency ultrasonography (HFUS) and adhesive patch biopsy aid in the accurate diagnosis of benign, as well as neoplastic skin diseases.

CONCLUSION

There have been significant advancements in non-invasive methods for diagnosis of dermatological diseases. These techniques can be repeatedly used in a comfort manner for the patient, and may offer an objective way to follow the course of a disease.

Emerging Minimally Invasive Technologies for the Detection of Skin Cancer

With the increasing incidence of skin cancer, many noninvasive technologies to detect its presence have been developed. This review focuses on reflectance confocal microscopy (RCM), optical coherence tomography (OCT), high-frequency ultrasound (HFUS), electrical impedance spectroscopy (EIS), pigmented lesion assay (PLA), and Raman spectroscopy (RS) and discusses the basic principle, clinical applications, advantages, and disadvantages of each technology. RCM provides high cellular resolution and has high sensitivity and specificity for the diagnosis of skin cancer. OCT provides lower resolution than RCM, although its evaluable depth is deeper than that of RCM. RCM and OCT may be useful in reducing the number of unnecessary biopsies, evaluating the tumor margin, and monitoring treatment response. HFUS can be mainly used to delineate tumor depths or margins and monitor the treatment response. EIS provides high sensitivity but low specificity for the diagnosis of skin malignancies. PLA, which is based on the genetic information of lesions, is applicable for the detection of melanoma with high sensitivity and moderate-to-high specificity. RS showed high accuracy for the diagnosis of skin cancer, although more clinical studies are required. Advances in these technologies for the diagnosis of skin cancer can lead to the realization of optimized and individualized treatments.

Pigmented Lesion Assay for Suspected Melanoma Lesions: A Health Technology Assessment

BACKGROUND

Early detection of melanoma is key, as survival rates are substantially better when the cancer is detected in its early stages. Currently, the standard of care is to biopsy any lesion suspected of melanoma for diagnostic confirmation by histopathology. As a result, most people who undergo biopsy receive negative melanoma results. If effective, a non-invasive alternative, such as pigmented lesion assay, could minimize the number of unnecessary biopsies performed. We conducted a health technology assessment of pigmented lesion assay for people with suspected melanoma lesions, which included an evaluation of diagnostic accuracy, clinical utility, the budget impact of publicly funding pigmented lesion assay, and the preferences and values of people who have undergone biopsy for suspected melanoma.

METHODS

We performed a systematic literature search of the clinical evidence. We assessed the risk of bias of each included study using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) and the Risk of Bias Assessment Tool for Non-randomized Studies (RoBANS). We assessed the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic literature search of the economic evidence. We also analyzed the budget impact of publicly funding pigmented lesion assay in adults with suspected melanoma in Ontario. To contextualize the potential value of pigmented lesion assay, we spoke with people who had undergone skin biopsy for melanoma. We also used the qualitative research synthesis from a report by the Canadian Agency for Drugs and Technologies in Health to provide context for the preferences and values of those with suspected melanoma.

RESULTS

We included seven studies in the clinical evidence review. Pigmented lesion assay has a sensitivity of 79% (95% confidence interval [CI] 58%-93%) and a specificity of 80% (95% CI 73%-85%; GRADE: Low). We found one published cost-effectiveness study with potentially serious limitations. Therefore, the cost-effectiveness of pigmented lesion assay compared with the standard care pathway is currently uncertain. Assuming a very low uptake, we estimated that the budget impact of publicly funding pigmented lesion assay in Ontario over the next 5 years is about $3.44 million if the test is used exclusively by primary care providers, or about $2.56 million if it is used exclusively by specialists. The people with whom we spoke who had experienced biopsy for suspected melanoma responded positively to the potential benefits of pigmented lesion assay, emphasizing its ease-of-use, potential increase in early detection of melanoma, and reduction in physical and emotional burden of unnecessary biopsies. Participants also felt that the accuracy of this tool was essential to ensure minimal false negatives.

CONCLUSIONS

There is uncertainty because of the low-quality evidence for the diagnostic accuracy of pigmented lesion assay. The cost-effectiveness of pigmented lesion assay compared with standard care is also uncertain. We estimated that publicly funding pigmented lesion assay in Ontario over the next 5 years would result in additional costs of $3.44 million (if used exclusively by primary care providers) or $2.56 million (if used exclusively by specialists). For people who had experienced biopsy for suspected melanoma, it was felt that pigmented lesion assay could represent an effective tool to increase early detection and avoid unnecessary biopsies, if the tool was accurate.

Metabolic Interplay between the Immune System and Melanoma Cells: Therapeutic Implications

Malignant melanoma represents the most fatal skin cancer due to its aggressive biological behavior and high metastatic potential. Treatment strategies for advanced disease have dramatically changed over the last years due to the introduction of BRAF/MEK inhibitors and immunotherapy. However, many patients either display primary (i.e., innate) or eventually develop secondary (i.e., acquired) resistance to systemic treatments. Treatment resistance depends on multiple mechanisms driven by a set of rewiring processes, which involve cancer metabolism, epigenetic, gene expression, and interactions within the tumor microenvironment. Prognostic and predictive biomarkers are needed to guide patients’ selection and treatment decisions. Indeed, there are no recognized clinical or biological characteristics that identify which patients will benefit more from available treatments, but several biomarkers have been studied with promising preliminary results. In this review, we will summarize novel tumor metabolic pathways and tumor-host metabolic crosstalk mechanisms leading to melanoma progression and drug resistance, with an overview on their translational potential as novel therapeutic targets.

Melanoma Progression under Obesity: Focus on Adipokines

Simple Summary

Obesity is a rapidly growing public health problem and the reason for numerous diseases in the human body, including cancer. This article reviews the current knowledge of the effect of molecules secreted by adipose tissue-adipokines on melanoma progression. We also discuss the role of these factors as markers of incidence, metastasis, and melanoma patient survival. Understanding the functions of adipokines will lead to knowledge of whether and how obesity promotes melanoma growth.

Abstract

Obesity is a growing problem in the world and is one of the risk factors of various cancers. Among these cancers is melanoma, which accounts for the majority of skin tumor deaths. Current studies are looking for a correlation between obesity and melanoma. They suspect that a potential cause of its development is connected to the biology of adipokines, active molecules secreted by adipose tissue. Under physiological conditions, adipokines control many processes, including lipid and glucose homeostasis, insulin sensitivity, angiogenesis, and inflammations. However, when there is an increased amount of fat in the body, their secretion is dysregulated. This article reviews the current knowledge of the effect of adipokines on melanoma growth. This work focuses on the molecular pathways by which adipose tissue secreted molecules modify the angiogenesis, migration, invasion, proliferation, and death of melanoma cells. We also discuss the role of these factors as markers of incidence, metastasis, and melanoma patient survival. Understanding the functions of adipokines will lead to knowledge of whether and how obesity promotes melanoma growth. Further studies may contribute to the innovations of therapies and the use of adipokines as predictive and/or prognostic biomarkers.

RNA tape sampling in cutaneous lupus erythematosus discriminates affected from unaffected and healthy volunteer skin

Objective

Punch biopsy, a standard diagnostic procedure for patients with cutaneous lupus erythematosus (CLE) carries an infection risk, is invasive, uncomfortable and potentially scarring, and impedes patient recruitment in clinical trials. Non-invasive tape sampling is an alternative that could enable serial evaluation of specific lesions. This cross-sectional pilot research study evaluated the use of a non-invasive adhesive tape device to collect messenger RNA (mRNA) from the skin surface of participants with CLE and healthy volunteers (HVs) and investigated its feasibility to detect biologically meaningful differences between samples collected from participants with CLE and samples from HVs.

Methods

Affected and unaffected skin tape samples and simultaneous punch biopsies were collected from 10 participants with CLE. Unaffected skin tape and punch biopsies were collected from 10 HVs. Paired samples were tested using quantitative PCR for a candidate immune gene panel and semi-quantitative immunohistochemistry for hallmark CLE proteins.

Results

mRNA collected using the tape device was of sufficient quality for amplification of 94 candidate immune genes. Among these, we found an interferon (IFN)-dominant gene cluster that differentiated CLE-affected from HV (23-fold change; p<0.001) and CLE-unaffected skin (sevenfold change; p=0.002), respectively. We found a CLE-associated gene cluster that differentiated CLE-affected from HV (fourfold change; p=0.005) and CLE-unaffected skin (fourfold change; p=0.012), respectively. Spearman’s correlation between per cent area myxovirus 1 protein immunoreactivity and IFN-dominant mRNA gene cluster expression was highly significant (dermis, rho=0.86, p<0.001). In total, skin tape-derived RNA expression comprising both IFN-dominant and CLE-associated gene clusters correlated with per cent area immunoreactivity of some hallmark CLE-associated proteins in punch biopsies from the same lesions.

Conclusions

A non-invasive tape RNA collection technique is a potential tool for repeated skin biomarker measures throughout a clinical trial.

Tape strips in dermatology research

Tape strips have been used widely in dermatology research as a minimally invasive method to sample the epidermis, avoiding the need for skin biopsies. Most research has focused on epidermal pathology, such as atopic eczema, but there is increasing research into the use of tape strips in other dermatoses, such as skin cancer, and the microbiome. This review summarizes the technique of tape stripping, and discusses which dermatoses have been studied by tape stripping and alternative minimally invasive sampling methods. We review the number of tape strips needed from each patient and the components of the epidermis that can be obtained by tape stripping. With a focus on protein and RNA extraction, we address the techniques used to process tape strips. There is no optimal protocol to extract protein, as this depends on the abundance of the protein studied, its level of expression in the epidermis and its solubility. Many variables can alter the amount of protein obtained from tape strips, which must be standardized to ensure consistency between samples. No study has compared different RNA extraction techniques, but our own experience is that RNA yield is optimized by using 20 tape strips and the use of a cell scraper.

Cutaneous Malignant Melanoma: A Review of Early Diagnosis and Management

Cutaneous melanoma (CM) is a malignant tumor formed from pigment-producing cells called melanocytes. It is one of the most aggressive and fatal forms of skin malignancy. In the last decades, CM's incidence has gradually risen, with 351,880 new cases in 2015. Since the 1960s, its incidence has increased steadily, in 2019, with approximately 96,000 new cases. A greater understanding of early diagnosis and management of CM is urgently needed because of the high mortality rates due to metastatic melanoma. Timely detection of melanoma is crucial for successful treatment, but diagnosis with histopathology may also pose a significant challenge to this objective. Early diagnosis and management are essential and contribute to better survival rates of the patient. To better control this malignancy, such information is expected to be particularly useful in the early detection of possible metastatic lesions and the development of new therapeutic approaches. This article reviews the available information on the early diagnosis and management of CM and discusses such information's potential in facilitating the future prospective.

Technical Note: Noninvasive mid-IR fiber-optic evanescent wave spectroscopy (FEWS) for early detection of skin cancers

PURPOSE

Melanoma is the most lethal of the three primary skin cancers, including also basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), which are less lethal. The accepted diagnosis process involves manually observing a suspicious lesion through a Dermascope (i.e., a magnifying glass), followed by a biopsy. This process relies on the skill and the experience of a dermatologist. However, to the best of our knowledge, there is no accepted automatic, noninvasive, and rapid method for the early detection of the three types of skin cancer, distinguishing between them and noncancerous lesions, and identifying each of them. It is our aim to develop such a system.

METHODS

We developed a fiber-optic evanescent wave spectroscopy (FEWS) system based on middle infrared (mid-IR) transmitting AgClBr fibers and a Fourier-transform infrared spectrometer (FTIR). We used the system to perform mid-IR spectral measurements on suspicious lesions in 90 patients, before biopsy, in situ, and in real time. The lesions were then biopsied and sent for pathology. The spectra were analyzed and the differences between pathological and healthy tissues were found and correlated.

RESULTS

Five of the lesions measured were identified as melanomas, seven as BCC, and three as SCC. Using mathematical analyses of the spectra of these lesions we were able to tell that all were skin cancers and we found specific and easily identifiable differences between them.

CONCLUSIONS

This FEWS method lends itself to rapid, automatic and noninvasive early detection and characterization of skin cancers. It will be easily implemented in community clinics and has the potential to greatly simplify the diagnosis process.

A Review of Noninvasive Techniques for Skin Cancer Detection in Dermatology

As a result of increasing melanoma incidence and challenges with clinical and histopathologic evaluation of pigmented lesions, noninvasive techniques to assist in the assessment of skin lesions are highly sought after. This review discusses the methods, benefits, and limitations of adhesive patch biopsy, electrical impedance spectroscopy (EIS), multispectral imaging, high-frequency ultrasonography (HFUS), optical coherence tomography (OCT), and reflectance confocal microscopy (RCM) in the detection of skin cancer. Adhesive patch biopsy provides improved sensitivity and specificity for the detection of melanoma without a trade-off of higher sensitivity for lower specificity seen in other diagnostic tools to aid in skin cancer detection, including EIS and multispectral imaging. EIS and multispectral imaging provide objective information based on computer-assisted diagnosis to assist in the decision to biopsy and/or excise an atypical melanocytic lesion. HFUS may be useful for the determination of skin tumor depth and identification of surgical borders, although further studies are necessary to determine its accuracy in the detection of skin cancer. OCT and RCM provide enhanced resolution of skin tissue and have been applied for improved accuracy in skin cancer diagnosis, as well as monitoring the response of nonsurgical treatments of skin cancers and the determination of tumor margins and recurrences. These novel approaches to skin cancer assessment offer opportunities to dermatologists, but are dependent on the individual dermatologist's comfort, knowledge, and desire to invest in training and implementation of noninvasive techniques. These noninvasive modalities may have a role in the complementary assessment of skin cancers, although histopathologic diagnosis remains the gold standard for the evaluation of skin cancer.

Technological advances for the detection of melanoma: Advances in molecular techniques

The growth of molecular technologies analyzing skin cells and inherited genetic variations has the potential to address current gaps in both diagnostic accuracy and prognostication in patients with melanoma or in individuals who are at risk for developing melanoma. In the second article in this continuing medical education series, novel molecular technologies are reviewed. These have been developed as adjunct tools for melanoma management and include the Pigmented Lesion Assay, myPath Melanoma, and DecisionDx-Melanoma tests, and genetic testing in patients with a strong familial melanoma history. These tests are commercially available and marketed as ancillary tools for clinical decision-making, diagnosis, and prognosis. We review fundamental principles behind each test, discuss peer-reviewed literature assessing their performance, and highlight the utility and limitations of each assay. The goal of this article is to provide a comprehensive, evidence-based foundation for clinicians regarding the management of patients with difficult pigmented lesions.

Expert-Level Diagnosis of Nonpigmented Skin Cancer by Combined Convolutional Neural Networks

Importance

Convolutional neural networks (CNNs) achieve expert-level accuracy in the diagnosis of pigmented melanocytic lesions. However, the most common types of skin cancer are nonpigmented and nonmelanocytic, and are more difficult to diagnose.

Objective

To compare the accuracy of a CNN-based classifier with that of physicians with different levels of experience.

Design, Setting, and Participants

A CNN-based classification model was trained on 7895 dermoscopic and 5829 close-up images of lesions excised at a primary skin cancer clinic between January 1, 2008, and July 13, 2017, for a combined evaluation of both imaging methods. The combined CNN (cCNN) was tested on a set of 2072 unknown cases and compared with results from 95 human raters who were medical personnel, including 62 board-certified dermatologists, with different experience in dermoscopy.

Main Outcomes and Measures

The proportions of correct specific diagnoses and the accuracy to differentiate between benign and malignant lesions measured as an area under the receiver operating characteristic curve served as main outcome measures.

Results

Among 95 human raters (51.6% female; mean age, 43.4 years; 95% CI, 41.0-45.7 years), the participants were divided into 3 groups (according to years of experience with dermoscopy): beginner raters (<3 years), intermediate raters (3-10 years), or expert raters (>10 years). The area under the receiver operating characteristic curve of the trained cCNN was higher than human ratings (0.742; 95% CI, 0.729-0.755 vs 0.695; 95% CI, 0.676-0.713; P < .001). The specificity was fixed at the mean level of human raters (51.3%), and therefore the sensitivity of the cCNN (80.5%; 95% CI, 79.0%-82.1%) was higher than that of human raters (77.6%; 95% CI, 74.7%-80.5%). The cCNN achieved a higher percentage of correct specific diagnoses compared with human raters (37.6%; 95% CI, 36.6%-38.4% vs 33.5%; 95% CI, 31.5%-35.6%; P = .001) but not compared with experts (37.3%; 95% CI, 35.7%-38.8% vs 40.0%; 95% CI, 37.0%-43.0%; P = .18).

Conclusions and Relevance

Neural networks are able to classify dermoscopic and close-up images of nonpigmented lesions as accurately as human experts in an experimental setting.

A review of microsampling techniques and their social impact

Conventional skin and blood sampling techniques for disease diagnosis, though effective, are often highly invasive and some even suffer from variations in analysis. With the improvements in molecular detection, the amount of starting sample quantity needed has significantly reduced in some diagnostic procedures, and this has led to an increased interest in microsampling techniques for disease biomarker detection. The miniaturization of sampling platforms driven by microsampling has the potential to shift disease diagnosis and monitoring closer to the point of care. The faster turnaround time for actionable results has improved patient care. The variations in sample quantification and analysis remain a challenge in the microsampling field. The future of microsampling looks promising. Emerging techniques are being clinically tested and monitored by regulatory bodies. This process is leading to safer and more reliable diagnostic platforms. This review discusses the advantages and disadvantages of current skin and blood microsampling techniques.

Noninvasive Monitoring of Allograft Rejection Using a Novel Epidermal Sampling Technique

Supplemental Digital Content is available in the text.

Despite promising short- and long-term results to date in vascularized composite allotransplantation (VCA), acute rejection remains the most common major complication in recipients. Currently, diagnosis of acute rejection relies on clinical inspection correlated with histopathological analysis. However, disagreement exists regarding the value of full-thickness skin and mucosal biopsies and histopathology remains semiquantitative, subject to sampling bias, and prone to intra- and inter-observer variabilities. Additionally, biopsies may cause infection, scarring, and/or potentially incite rejection through immune activation after injury. Noninvasive methods to diagnose rejection represent a critical unmet need for the emerging field of VCA. Here, we propose a novel technique utilizing skin stripping of the epidermis and subsequent molecular analysis to detect known markers of acute rejection. Using a small animal VCA model, we sought to validate our epidermal sampling technique as a noninvasive diagnostic test for acute rejection.

Targeting metabolic reprogramming in metastatic melanoma: The key role of nicotinamide phosphoribosyltransferase (NAMPT)

Cancer cells rewire their metabolism to support proliferation, growth and survival. In metastatic melanoma the BRAF oncogenic pathway is a master regulator of this process, highlighting the importance of metabolic reprogramming in the pathogenesis of this tumor and offering potential therapeutic approaches. Metabolic adaptation of melanoma cells generally requires increased amounts of NAD⁺, an essential redox cofactor in cellular metabolism and a signaling molecule. Nicotinamide phosphoribosyltransferase (NAMPT) is the most important NAD⁺ biosynthetic enzyme in mammalian cells and a direct target of the BRAF oncogenic signaling pathway. These findings suggest that NAMPT is an attractive new therapeutic target, particularly in combination strategies with BRAF or MEK inhibitors. Here we review current knowledge on how oncogenic signaling reprograms metabolism in BRAF-mutated melanoma, and discuss how NAMPT/NAD⁺ axis contributes to these processes. Lastly, we present evidence supporting a role of NAMPT as a novel therapeutic target in metastatic melanoma.

Melanoma of the eyelid and periocular skin: Histopathologic classification and molecular pathology

Cutaneous melanoma, a potentially lethal malignancy of the periocular skin, represents only a small proportion of the roughly 87,000 new cases of cutaneous melanoma diagnosed annually in the United States. Most of our understanding of melanoma of the eyelid skin is extrapolated from studies of cutaneous melanoma located elsewhere. Recent years have witnessed major breakthroughs in molecular biology and genomics of cutaneous melanoma, some of which have led to the development of targeted therapies. The molecular insights have also kindled interest in rethinking how cutaneous melanomas are classified and assessed for risk. We provide a synopsis of the epidemiology, histopathologic classification, and clinical experience of eyelid melanoma since 1990 and then review major advances in the molecular biology of cutaneous melanoma, exploring how this impacts our understanding of classification and predicting risk.

Dysplastic/Clark naevus in the era of molecular pathology

Dysplastic naevus has been a controversial entity since its first description by Clark in 1978. Despite a recent paradigm shift from the initially proposed notion that dysplastic naevus is a precursor to melanoma, its management has been increasingly more aggressive in the last decade. The latter is due to an unresolved uncertainty regarding its biological nature which necessitates further clarification. Recent molecular genetics, epigenetic and transcriptomic discoveries have revealed that a subset of dysplastic naevi exhibits a genomic profile which is intermediate between that of benign naevus and melanoma. This group of lesions often shows somatic mutations in non-V600E BRAF, NRAS and TERT and hemizygous deletion of CDKN2A gene as well as upregulation of genes involved in proliferation, cell adhesion and migration, and epidermal and follicular keratinocyte-related genes. These new genomic insights suggest that a proportion of dysplastic naevi have a greater propensity to evolve to melanoma; however, the clinical and histopathological features of this proposed intermediate category are still to be elucidated by further research.

Optical coherence tomography for diagnosing skin cancer in adults

BACKGROUND

Early accurate detection of all skin cancer types is essential to guide appropriate management and to improve morbidity and survival. Melanoma and squamous cell carcinoma (SCC) are high-risk skin cancers, which have the potential to metastasise and ultimately lead to death, whereas basal cell carcinoma (BCC) is usually localised, with potential to infiltrate and damage surrounding tissue. Anxiety around missing early cases needs to be balanced against inappropriate referral and unnecessary excision of benign lesions. Optical coherence tomography (OCT) is a microscopic imaging technique, which magnifies the surface of a skin lesion using near-infrared light. Used in conjunction with clinical or dermoscopic examination of suspected skin cancer, or both, OCT may offer additional diagnostic information compared to other technologies.

OBJECTIVES

To determine the diagnostic accuracy of OCT for the detection of cutaneous invasive melanoma and atypical intraepidermal melanocytic variants, basal cell carcinoma (BCC), or cutaneous squamous cell carcinoma (cSCC) in adults.

SEARCH METHODS

We undertook a comprehensive search of the following databases from inception up to August 2016: Cochrane Central Register of Controlled Trials; MEDLINE; Embase; CINAHL; CPCI; Zetoc; Science Citation Index; US National Institutes of Health Ongoing Trials Register; NIHR Clinical Research Network Portfolio Database; and the World Health Organization International Clinical Trials Registry Platform. We studied reference lists and published systematic review articles.

SELECTION CRITERIA

We included studies of any design evaluating OCT in adults with lesions suspicious for invasive melanoma and atypical intraepidermal melanocytic variants, BCC or cSCC, compared with a reference standard of histological confirmation or clinical follow-up.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data using a standardised data extraction and quality assessment form (based on QUADAS-2). Our unit of analysis was lesions. Where possible, we estimated summary sensitivities and specificities using the bivariate hierarchical model.

MAIN RESULTS

We included five studies with 529 cutaneous lesions (282 malignant lesions) providing nine datasets for OCT, two for visual inspection alone, and two for visual inspection plus dermoscopy. Studies were of moderate to unclear quality, using data-driven thresholds for test positivity and giving poor accounts of reference standard interpretation and blinding. Studies may not have been representative of populations eligible for OCT in practice, for example due to high disease prevalence in study populations, and may not have reflected how OCT is used in practice, for example by using previously acquired OCT images.It was not possible to make summary statements regarding accuracy of detection of melanoma or of cSCC because of the paucity of studies, small sample sizes, and for melanoma differences in the OCT technologies used (high-definition versus conventional resolution OCT), and differences in the degree of testing performed prior to OCT (i.e. visual inspection alone or visual inspection plus dermoscopy).Pooled data from two studies using conventional swept-source OCT alongside visual inspection and dermoscopy for the detection of BCC estimated the sensitivity of OCT as 95% (95% confidence interval (CI) 91% to 97%) and specificity of 77% (95% CI 69% to 83%).When applied to a hypothetical population of 1000 lesions at the mean observed BCC prevalence of 60%, OCT would miss 31 BCCs (91 fewer than would be missed by visual inspection alone and 53 fewer than would be missed by visual inspection plus dermoscopy), and OCT would lead to 93 false-positive results for BCC (a reduction in unnecessary excisions of 159 compared to using visual inspection alone and of 87 compared to visual inspection plus dermoscopy).

AUTHORS' CONCLUSIONS

Insufficient data are available on the use of OCT for the detection of melanoma or cSCC. Initial data suggest conventional OCT may have a role for the diagnosis of BCC in clinically challenging lesions, with our meta-analysis showing a higher sensitivity and higher specificity when compared to visual inspection plus dermoscopy. However, the small number of studies and varying methodological quality means implications to guide practice cannot currently be drawn.Appropriately designed prospective comparative studies are required, given the paucity of data comparing OCT with dermoscopy and other similar diagnostic aids such as reflectance confocal microscopy.

Reflectance confocal microscopy for diagnosing cutaneous melanoma in adults

BACKGROUND

Melanoma has one of the fastest rising incidence rates of any cancer. It accounts for a small percentage of skin cancer cases but is responsible for the majority of skin cancer deaths. Early detection and treatment is key to improving survival; however, anxiety around missing early cases needs to be balanced against appropriate levels of referral and excision of benign lesions. Used in conjunction with clinical or dermoscopic suspicion of malignancy, or both, reflectance confocal microscopy (RCM) may reduce unnecessary excisions without missing melanoma cases.

OBJECTIVES

To determine the diagnostic accuracy of reflectance confocal microscopy for the detection of cutaneous invasive melanoma and atypical intraepidermal melanocytic variants in adults with any lesion suspicious for melanoma and lesions that are difficult to diagnose, and to compare its accuracy with that of dermoscopy.

SEARCH METHODS

We undertook a comprehensive search of the following databases from inception up to August 2016: Cochrane Central Register of Controlled Trials; MEDLINE; Embase; and seven other databases. We studied reference lists and published systematic review articles.

SELECTION CRITERIA

Studies of any design that evaluated RCM alone, or RCM in comparison to dermoscopy, in adults with lesions suspicious for melanoma or atypical intraepidermal melanocytic variants, compared with a reference standard of either histological confirmation or clinical follow-up.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted all data using a standardised data extraction and quality assessment form (based on QUADAS-2). We contacted authors of included studies where information related to the target condition or diagnostic threshold were missing. We estimated summary sensitivities and specificities per algorithm and threshold using the bivariate hierarchical model. To compare RCM with dermoscopy, we grouped studies by population (defined by difficulty of lesion diagnosis) and combined data using hierarchical summary receiver operating characteristic (SROC) methods. Analysis of studies allowing direct comparison between tests was undertaken. To facilitate interpretation of results, we computed values of specificity at the point on the SROC curve with 90% sensitivity as this value lies within the estimates for the majority of analyses. We investigated the impact of using a purposely developed RCM algorithm and in-person test interpretation.

MAIN RESULTS

The search identified 18 publications reporting on 19 study cohorts with 2838 lesions (including 658 with melanoma), which provided 67 datasets for RCM and seven for dermoscopy. Studies were generally at high or unclear risk of bias across almost all domains and of high or unclear concern regarding applicability of the evidence. Selective participant recruitment, lack of blinding of the reference test to the RCM result, and differential verification were particularly problematic. Studies may not be representative of populations eligible for RCM, and test interpretation was often undertaken remotely from the patient and blinded to clinical information.Meta-analysis found RCM to be more accurate than dermoscopy in studies of participants with any lesion suspicious for melanoma and in participants with lesions that were more difficult to diagnose (equivocal lesion populations). Assuming a fixed sensitivity of 90% for both tests, specificities were 82% for RCM and 42% for dermoscopy for any lesion suspicious for melanoma (9 RCM datasets; 1452 lesions and 370 melanomas). For a hypothetical population of 1000 lesions at the median observed melanoma prevalence of 30%, this equated to a reduction in unnecessary excisions with RCM of 280 compared to dermoscopy, with 30 melanomas missed by both tests. For studies in equivocal lesions, specificities of 86% would be observed for RCM and 49% for dermoscopy (7 RCM datasets; 1177 lesions and 180 melanomas). At the median observed melanoma prevalence of 20%, this reduced unnecessary excisions by 296 with RCM compared with dermoscopy, with 20 melanomas missed by both tests. Across all populations, algorithms and thresholds assessed, the sensitivity and specificity of the Pellacani RCM score at a threshold of three or greater were estimated at 92% (95% confidence interval (CI) 87 to 95) for RCM and 72% (95% CI 62 to 81) for dermoscopy.

AUTHORS' CONCLUSIONS

RCM may have a potential role in clinical practice, particularly for the assessment of lesions that are difficult to diagnose using visual inspection and dermoscopy alone, where the evidence suggests that RCM may be both more sensitive and specific in comparison to dermoscopy. Given the paucity of data to allow comparison with dermoscopy, the results presented require further confirmation in prospective studies comparing RCM with dermoscopy in a real-world setting in a representative population.

Skin cancer detection using non-invasive techniques

Skin cancer is the most common form of cancer and is globally rising. Historically, the diagnosis of skin cancers has depended on various conventional techniques which are of an invasive manner. A variety of commercial diagnostic tools and auxiliary techniques are available to detect skin cancer. This article explains in detail the principles and approaches involved for non-invasive skin cancer diagnostic methods such as photography, dermoscopy, sonography, confocal microscopy, Raman spectroscopy, fluorescence spectroscopy, terahertz spectroscopy, optical coherence tomography, the multispectral imaging technique, thermography, electrical bio-impedance, tape stripping and computer-aided analysis. The characteristics of an ideal screening test are outlined, and the authors pose several points for clinicians and scientists to consider in the evaluation of current and future studies of skin cancer detection and diagnosis. This comprehensive review critically analyses the literature associated with the field and summarises the recent updates along with their merits and demerits.

Pivotal role of NAMPT in the switch of melanoma cells toward an invasive and drug-resistant phenotype

In BRAF^V600E melanoma cells, a global metabolomic analysis discloses a decrease in nicotinamide adenine dinucleotide (NAD⁺) levels upon PLX4032 treatment that is conveyed by a STAT5 inhibition and a transcriptional regulation of the nicotinamide phosphoribosyltransferase (NAMPT) gene. NAMPT inhibition decreases melanoma cell proliferation both in vitro and in vivo, while forced NAMPT expression renders melanoma cells resistant to PLX4032. NAMPT expression induces transcriptomic and epigenetic reshufflings that steer melanoma cells toward an invasive phenotype associated with resistance to targeted therapies and immunotherapies. Therefore, NAMPT, the key enzyme in the NAD⁺ salvage pathway, appears as a rational target in targeted therapy-resistant melanoma cells and a key player in phenotypic plasticity of melanoma cells.

[Strategies for the noninvasive diagnosis of melanoma]

The diagnosis of advanced cutaneous melanoma may easily be made by the unaided eye, followed by excisional biopsy and histopathological examination. However, in the setting of melanoma screening examinations in high-risk patients with many nevi, dermatologists are challenged with the differentiation of atypical but benign nevi and early invasive or in situ melanomas. In this situation, there is a real need for additional, noninvasive examination techniques that may serve as an aide to decide for or against an excisional biopsy. Conventional dermoscopy is a well-established examination procedure and an increase in sensitivity was confirmed by two independent meta-analyses. Moreover, dynamic changes or newly developed pigmented lesions may be detected by sequential digital dermoscopy or (automated) total body photography, respectively. Over the past years, a number of medicinal products gained market access after licensing by American and European agencies for the noninvasive diagnosis of cutaneous neoplasms. These devices are based on technologies including in vivo reflectance confocal microscopy, multispectral analysis, electrical impedance spectroscopy, or Raman spectroscopy. Other technologies are still on the verge of becoming less experimental but more clinically applicable for diagnosing melanoma (in vivo multiphoton tomography, stepwise two-photon laser spectroscopy, infrared thermal image analysis, epidermal genetic information retrieval). This review provides a concise overview of general principles and sheds light on indication and added value for dermatologists.

Development and validation of a noninvasive 2-gene molecular assay for cutaneous melanoma

Background

Clinical and histopathologic assessment of pigmented skin lesions remains challenging even for experts. Differentiated and accurate noninvasive diagnostic modalities are highly desirable.

Objective

We sought to provide clinicians with such a tool.

Methods

A 2-gene classification method based on LINC00518 and preferentially expressed antigen in melanoma (PRAME) gene expression was evaluated and validated in 555 pigmented lesions (157 training and 398 validation samples) obtained noninvasively via adhesive patch biopsy. Results were compared with standard histopathologic assessment in lesions with a consensus diagnosis among 3 experienced dermatopathologists.

Results

In 398 validation samples (87 melanomas and 311 nonmelanomas), LINC00518 and/or PRAME detection appropriately differentiated melanoma from nonmelanoma samples with a sensitivity of 91% and a specificity of 69%. We established LINC00518 and PRAME in both adhesive patch melanoma samples and underlying formalin fixed paraffin embedded (FFPE) samples of surgically excised primary melanomas and in melanoma lymph node metastases.

Limitations

This technology cannot be used on mucous membranes, palms of hands, and soles of feet.

Conclusions

This noninvasive 2-gene pigmented lesion assay classifies pigmented lesions into melanoma and nonmelanoma groups and may serve as a tool to help with diagnostic challenges that may be inherently linked to the visual image and pattern recognition approach.

Analytical Characteristics of a Noninvasive Gene Expression Assay for Pigmented Skin Lesions

We previously reported clinical performance of a novel noninvasive and quantitative PCR (qPCR)-based molecular diagnostic assay (the pigmented lesion assay; PLA) that differentiates primary cutaneous melanoma from benign pigmented skin lesions through two target gene signatures, LINC00518 (LINC) and preferentially expressed antigen in melanoma (PRAME). This study focuses on analytical characterization of this PLA, including qPCR specificity and sensitivity, optimization of RNA input in qPCR to achieve a desired diagnostic sensitivity and specificity, and analytical performance (repeatability and reproducibility) of this two-gene PLA. All target qPCRs demonstrated a good specificity (100%) and sensitivity (with a limit of detection of 1-2 copies), which allows reliable detection of gene expression changes of LINC and PRAME between melanomas and nonmelanomas. Through normalizing RNA input in qPCR, we converted the traditional gene expression analyses to a binomial detection of gene transcripts (i.e., detected or not detected). By combining the binomial qPCR results of the two genes, an improved diagnostic sensitivity (raised from 52%- 65% to 71% at 1 pg of total RNA input, and to 91% at 3 pg of total RNA input) was achieved. This two-gene PLA demonstrates a high repeatability and reproducibility (coefficient of variation <3%) and all required analytical performance characteristics for the commercial processing of clinical samples.

Development of a curriculum in molecular diagnostics, genomics and personalized medicine for dermatology trainees

BACKGROUND

Results of molecular studies are redefining the diagnosis and management of a wide range of skin disorders. Dermatology training programs maintain a relative gap in relevant teaching.

OBJECTIVE

To develop a curriculum in molecular diagnostics, genomics and personalized medicine for dermatology trainees at our institution. The aim is to provide trainees with a specialty-appropriate, working knowledge in clinical molecular dermatology.

METHODS

The Departments of Dermatology and Pathology and Laboratory Medicine collaborated on the design and implementation of educational objectives and teaching modalities for the new curriculum.

RESULTS

A multidisciplinary curriculum was developed. It comprises: (i) assigned reading from the medical literature and reference textbook; (ii) review of teaching sets; (iii) two 1 hour lectures; (iv) trainee presentations; (v) 1-week rotation in a clinical molecular pathology and cytogenetics laboratory; and (vi) assessments and feedback. Residents who participated in the curriculum to date have found the experience to be of value.

CONCLUSIONS

Our curriculum provides a framework for other dermatology residency programs to develop their own specific approach to molecular diagnostics education. Such training will provide a foundation for lifelong learning as molecular testing evolves and becomes integral to the practice of dermatology.

Microarray Analysis of Differentially-Expressed Genes Encoding CYP450 and Phase II Drug Metabolizing Enzymes in Psoriasis and Melanoma

Cytochrome P450 drug metabolizing enzymes are implicated in personalized medicine for two main reasons. First, inter-individual variability in CYP3A4 expression is a confounding factor during cancer treatment. Second, inhibition or induction of CYP3A4 can trigger adverse drug–drug interactions. However, inflammation can downregulate CYP3A4 and other drug metabolizing enzymes and lead to altered metabolism of drugs and essential vitamins and lipids. Little is known about effects of inflammation on expression of CYP450 genes controlling drug metabolism in the skin. Therefore, we analyzed seven published microarray datasets, and identified differentially-expressed genes in two inflammatory skin diseases (melanoma and psoriasis). We observed opposite patterns of expression of genes regulating metabolism of specific vitamins and lipids in psoriasis and melanoma samples. Thus, genes controlling the turnover of vitamin D (CYP27B1, CYP24A1), vitamin A (ALDH1A3, AKR1B10), and cholesterol (CYP7B1), were up-regulated in psoriasis, whereas melanomas showed downregulation of genes regulating turnover of vitamin A (AKR1C3), and cholesterol (CYP39A1). Genes controlling abnormal keratinocyte differentiation and epidermal barrier function (CYP4F22, SULT2B1) were up-regulated in psoriasis. The up-regulated CYP24A1, CYP4F22, SULT2B1, and CYP7B1 genes are potential drug targets in psoriatic skin. Both disease samples showed diminished drug metabolizing capacity due to downregulation of the CYP1B1 and CYP3A5 genes. However, melanomas showed greater loss of drug metabolizing capacity due to downregulation of the CYP3A4 gene.

Cross-sectional analysis of the dermoscopic patterns and structures of melanocytic naevi on the back and legs of adolescents

BACKGROUND

Junctional (flat) naevi predominate on the extremities, whereas dermal (raised) naevi are found primarily on the head, neck and trunk. Few studies have investigated the anatomical site prevalence of melanocytic naevi categorized using dermoscopy.

OBJECTIVES

To identify the prevalence of dermoscopic patterns and structures of naevi from the back and legs of adolescents.

METHODS

Dermoscopic images of acquired melanocytic naevi were obtained from the back and legs of students from a population-based cohort in Framingham, Massachusetts. Naevi were classified into reticular, globular, homogeneous or complex dermoscopic patterns. Multinomial logistic regression modelling assessed the associations between dermoscopic pattern and anatomical location.

RESULTS

In total 509 participants (mean age 14 years) contributed 2320 back naevi and 637 leg naevi. Compared with homogeneous naevi, globular and complex naevi were more commonly observed on the back than the legs [odds ratio (OR) 29·39, 95% confidence interval (CI) 9·53-90·65, P < 0·001 and OR 6·8, 95% CI 2·7-17·14, P < 0·001, respectively], whereas reticular lesions were less likely to be observed on the back than on the legs (OR 0·67, 95% CI 0·54-0·84, P = 0·001). Naevi containing any globules were more prevalent on the back than on the legs (25% vs. 3·6%, P < 0·001). Naevi containing any network were more prevalent on the legs than on the back (56% vs. 40·6%, P < 0·001).

CONCLUSIONS

These findings add to a robust body of literature suggesting that dermoscopically defined globular and reticular naevi represent biologically distinct naevus subsets that differ in histopathological growth pattern, age- and anatomical-site-related prevalence, molecular phenotype and aetiological pathways.

Practical application of new technologies for melanoma diagnosis: Part II. Molecular approaches

The criterion standard for diagnosing cutaneous melanoma continues to be histologic examination. However, classifying some melanocytic lesions by conventional microscopy can be problematic if they exhibit some architectural or morphologic characteristics of both nevus and melanoma. Moreover, histologic appearance does not always predict biologic behavior. There is therefore a need and opportunity to develop new technologies that can facilitate the histologic diagnosis of melanoma and potentially help distinguish lesions with a lesser or greater risk of metastasis. In part II of this 2-part continuing medical education article, we will review the molecular technologies currently available for facilitating melanoma diagnosis, including comparative genomic hybridization, fluorescence in situ hybridization, and epidermal genetic retrieval. Our goal is to provide the clinician with an up to date understanding of these molecular approaches so that they can be applied to their management of challenging melanocytic lesions.