'Mind your Moles' study: protocol of a prospective cohort study of melanocytic naevi

The SLICE-3D dataset: 400,000 skin lesion image crops extracted from 3D TBP for skin cancer detection

AI image classification algorithms have shown promising results when applied to skin cancer detection. Most public skin cancer image datasets are comprised of dermoscopic photos and are limited by selection bias, lack of standardization, and lend themselves to development of algorithms that can only be used by skilled clinicians. The SLICE-3D ("Skin Lesion Image Crops Extracted from 3D TBP") dataset described here addresses those concerns and contains images of over 400,000 distinct skin lesions from seven dermatologic centers from around the world. De-identified images were systematically extracted from sensitive 3D Total Body Photographs and are comparable in optical resolution to smartphone images. Algorithms trained on lower quality images could improve clinical workflows and detect skin cancers earlier if deployed in primary care or non-clinical settings, where photos are captured by non-expert physicians or patients. Such a tool could prompt individuals to visit a specialized dermatologist. This dataset circumvents many inherent limitations of prior datasets and may be used to build upon previous applications of skin imaging for cancer detection.

Artificial intelligence in the detection of skin cancer: State of the art

The incidence of melanoma is increasing rapidly. This cancer has a good prognosis if detected early. For this reason, various systems of skin lesion image analysis, which support imaging diagnostics of this neoplasm, are developing very dynamically. To detect and recognize neoplastic lesions, such systems use various artificial intelligence (AI) algorithms. This area of computer science applications has recently undergone dynamic development, abounding in several solutions that are effective tools supporting diagnosticians in many medical specialties. In this contribution, a number of applications of different classes of AI algorithms for the detection of this skin melanoma are presented and evaluated. Both classic systems based on the analysis of dermatoscopic images as well as total body systems, enabling the analysis of the patient's whole body to detect moles and pathologic changes, are discussed. These increasingly popular applications that allow the analysis of lesion images using smartphones are also described. The quantitative evaluation of the discussed systems with particular emphasis on the method of validation of the implemented algorithms is presented. The advantages and limitations of AI in the analysis of lesion images are also discussed, and problems requiring a solution for more effective use of AI in dermatology are identified.

Assessing the genetic risk of nodular melanoma using a candidate gene approach

BACKGROUND

Nodular melanoma (NM) is a challenge to diagnose early due to its rapid growth and more atypical clinical presentation, making it the largest contributor to melanoma mortality.

OBJECTIVES

Our study aim was to perform a rare-variant allele (RVA) analysis of whole-exome sequencing of patients with NM and non-NM (minor allele frequency ≤ 1% non-Finnish European) for a set of 500 candidate genes potentially implicated in melanoma.

METHODS

This study recruited 131 participants with NM and 194 with non-NM from South-east Queensland and patients with NM from Victoria to perform a comparative analysis of possible genetic differences or similarities between the two melanoma cohorts.

RESULTS

Phenotypic analysis revealed that a majority of patients diagnosed with NM were older males with a higher frequency of fair skin and red hair than is seen in the general population. The distribution of common melanoma polygenic risk scores was similar in patients with NM and non-NM, with over 28% in the highest quantile of scores. There was also a similar frequency of carriage of familial/high-penetrant melanoma gene and loss-of-function variants. We identified 39 genes by filtering 500 candidate genes based on the greatest frequency in NM compared with non-NM cases. The genes with RVAs of greatest frequency in NM included PTCH1, ARID2 and GHR. Rare variants in the SMO gene, which interacts with PTCH1 as ligand and receptor, were also identified, providing evidence that the Hedgehog pathway may contribute to NM risk. There was a cumulative effect in carrying multiple rare variants in the NM-associated genes. A 14.8-fold increased ratio for NM compared with non-NM was seen when two RVAs of the 39 genes were carried by a patient.

CONCLUSIONS

This study highlights the importance of considering frequency of RVA to identify those at risk of NM in addition to known high penetrance genes.

ACEMID cohort study: protocol of a prospective cohort study using 3D total body photography for melanoma imaging and diagnosis

INTRODUCTION

Three-dimensional (3D) total body photography may improve early detection of melanoma and facilitate surveillance, leading to better prognosis and lower healthcare costs. The Australian Centre of Excellence in Melanoma Imaging and Diagnosis (ACEMID) cohort study will assess long-term outcomes from delivery of a precision strategy of monitoring skin lesions using skin surface imaging technology embedded into health services across Australia.

METHODS AND ANALYSIS

A prospective cohort study will enrol 15 000 participants aged 18 years and above, across 15 Australian sites. Participants will attend study visits according to their melanoma risk category: very high risk, high risk or low/average risk, every 6, 12 and 24 months, respectively, over 3 years. Participants will undergo 3D total body photography and dermoscopy imaging at study visits. A baseline questionnaire will be administered to collect sociodemographic, phenotypic, quality of life and sun behaviour data. A follow-up questionnaire will be administered every 12 months to obtain changes in sun behaviour and quality of life. A saliva sample will be collected at the baseline visit from a subsample.

ETHICS AND DISSEMINATION

The ACEMID cohort study was approved by the Metro South Health Human Research Ethics Committee (approval number: HREC/2019/QMS/57206) and the University of Queensland Human Research Ethics Committee (approval number: 2019003077). The findings will be reported through peer-reviewed and lay publications and presentations at conferences.

TRIAL REGISTRATION NUMBER

ACTRN12619001706167.

Monitoring of Pigmented Skin Lesions Using 3D Whole Body Imaging

BACKGROUND AND OBJECTIVES

Advanced artificial intelligence and machine learning have great potential to redefine how skin lesions are detected, mapped, tracked and documented. Here, we propose a 3D whole-body imaging system known as 3DSkin-mapper to enable automated detection, evaluation and mapping of skin lesions.

METHODS

A modular camera rig arranged in a cylindrical configuration was designed to automatically capture images of the entire skin surface of a subject synchronously from multiple angles. Based on the images, we developed algorithms for 3D model reconstruction, data processing and skin lesion detection and tracking based on deep convolutional neural networks. We also introduced a customised, user-friendly, and adaptable interface that enables individuals to interactively visualise, manipulate, and annotate the images. The interface includes built-in features such as mapping 2D skin lesions onto the corresponding 3D model.

RESULTS

The proposed system is developed for skin lesion screening, the focus of this paper is to introduce the system instead of clinical study. Using synthetic and real images we demonstrate the effectiveness of the proposed system by providing multiple views of a target skin lesion, enabling further 3D geometry analysis and longitudinal tracking. Skin lesions are identified as outliers which deserve more attention from a skin cancer physician. Our detector leverages expert annotated labels to learn representations of skin lesions, while capturing the effects of anatomical variability. It takes only a few seconds to capture the entire skin surface, and about half an hour to process and analyse the images.

CONCLUSIONS

Our experiments show that the proposed system allows fast and easy whole body 3D imaging. It can be used by dermatological clinics to conduct skin screening, detect and track skin lesions over time, identify suspicious lesions, and document pigmented lesions. The system can potentially save clinicians time and effort significantly. The 3D imaging and analysis has the potential to change the paradigm of whole body photography with many applications in skin diseases, including inflammatory and pigmentary disorders. With reduced time requirements for recording and documenting high-quality skin information, doctors could spend more time providing better-quality treatment based on more detailed and accurate information.

Consumer views of melanoma early detection using 3D total-body photography: cross-sectional survey

BACKGROUND

Three-dimensional (3D) total-body photography is a recent advance in melanoma early detection that can aid in monitoring and identifying new and changing skin lesions over time.

METHODS

A cross-sectional survey of adults living in metropolitan and rural areas of Australia was conducted to assess perceptions of 3D total-body photography. Participants completed a survey detailing their previous use of skin cancer photography, personal skin checking history, perceptions of 3D total-body photography, and willingness to pay. Participants were also asked to describe the potential barriers and facilitators of 3D total-body photography in their own words.

RESULTS

A total of 1056 participants completed the survey, with 739 (70%) from metropolitan areas of Australia and 317 (30%) from rural areas. Most participants (95%, n = 1004/1056) indicated they would consider using 3D total-body photography if it became commercially available at their regular medical practice. Most participants indicated 3D total-body photography would be effective to identify suspicious skin spots (94%, n = 995/1056), monitor lesion changes (94%, n = 997/1056), and reduce skin cancer related anxiety (90%, n = 950/1055). In open-ended feedback, participants (87%, n = 918/1056) identified perceived benefits, including more comprehensive screenings, earlier detection, and less human error. Participants (84%, n = 889/1056) also identified potential barriers to 3D total-body photography, including cost, accessibility and availability, trust in the technology, and digital security concerns.

CONCLUSIONS

Participant feedback indicated a high level of acceptance and confidence in the technology. To facilitate clinical translation, addressing consumer-identified barriers to 3D total-body photography will be vital.

Protocol to evaluate a pilot program to upskill clinicians in providing genetic testing for familial melanoma

INTRODUCTION

Genetic testing for hereditary cancers can improve long-term health outcomes through identifying high-risk individuals and facilitating targeted prevention and screening/surveillance. The rising demand for genetic testing exceeds the clinical genetic workforce capacity. Therefore, non-genetic specialists need to be empowered to offer genetic testing. However, it is unknown whether patient outcomes differ depending on whether genetic testing is offered by a genetics specialist or a trained non-genetics clinician. This paper describes a protocol for upskilling non-genetics clinicians to provide genetic testing, randomise high-risk individuals to receive testing from a trained clinician or a genetic counsellor, and then determine whether patient outcomes differed depending on provider-type.

METHODS

An experiential training program to upskill dermatologically-trained clinicians to offer genetic testing for familial melanoma is being piloted on 10-15 clinicians, prior to wider implementation. Training involves a workshop, comprised of a didactic learning presentation, case studies, simulated sessions, and provision of supporting documentation. Clinicians later observe a genetic counsellor led consultation before being observed leading a consultation. Both sessions are followed by debriefing with a genetic counsellor. Thereafter, clinicians independently offer genetic testing in the clinical trial. Individuals with a strong personal and/or family history of melanoma are recruited to a parallel-group trial and allocated to receive pre- and post- genetic testing consultation from a genetic counsellor, or a dermatologically-trained clinician. A mixed method approach measures psychosocial and behavioural outcomes. Longitudinal online surveys are administered at five timepoints from baseline to one year post-test disclosure. Semi-structured interviews with both patients and clinicians are qualitatively analysed.

SIGNIFICANCE

This is the first program to upskill dermatologically-trained clinicians to provide genetic testing for familial melanoma. This protocol describes the first clinical trial to compare patient-reported outcomes of genetic testing based on provider type (genetic counsellors vs trained non-genetic clinicians).

Body Site Distribution of Acquired Melanocytic Naevi and Associated Characteristics in the General Population of Caucasian Adults: A Scoping Review

The number of melanocytic naevi is a major risk factor for melanoma. The divergent pathway hypothesis proposes that the propensity for naevus proliferation and malignant transformation may differ by body site and exposure to ultraviolet (UV) radiation. This scoping review aimed to summarise the evidence on the number and distribution of naevi (≥ 2 mm) on the body overall and by individual anatomical sites in Caucasian adults, and to assess whether studies used the International Agency for Research on Cancer (IARC) protocol to guide naevus counting processes. Systematic searches of Embase and PubMed identified 661 potentially relevant studies, and 12 remained eligible after full-text review. Studies varied widely in their counting protocols, reporting of naevus counts overall and by body sites, and used counting personnel with differing qualifications. Only one study used the IARC protocol. Studies reported that the highest number of naevi was on the trunk in males and on the arms in females. Body sites which receive intermittent exposure to UV radiation had higher density of naevi. Larger naevi (≥ 5 mm) were detected mostly on body sites intermittently exposed to UV radiation, and smaller naevi (< 5 mm) on chronically exposed sites. Studies reported that environmental and behavioural aspects related to UV radiation exposure, as well as genetic factors, all impact body site and size distribution of naevi. This review found that to overcome limitations of the current evidence, future studies should use consistent naevus counting protocols. Skin surface imaging could improve the reliability of findings. An updated IARC protocol is required that integrates these emerging standards and technologies to guide reliable and reproducible naevus counting in the future.

The Experience of 3D Total-Body Photography to Monitor Nevi: Results From an Australian General Population-Based Cohort Study

BACKGROUND

Digital 3D total-body photography of the skin surface is an emerging imaging modality that can facilitate the identification of new and changing nevi.

OBJECTIVE

We aimed to describe the experiences of study participants drawn from the general population who were provided 3D total-body photography and dermoscopy for the monitoring of nevi.

METHODS

A population-based prospective study of adults aged 20-70 years from South East Queensland, Australia was conducted. Participants underwent 3D total-body photography and dermoscopy every 6 months over a 3-year period. Participants were asked to provide closed and open-ended feedback on their 3D total-body photography and dermoscopy experience (eg, comfort, trust, intended future use, and willingness to pay) at the halfway study time point (18 months) and final study time point (36 months). We assessed changes in participants' reported experience of 3D total-body photography, and patient characteristics associated with patient experience at the end of the study (36 months) were analyzed.

RESULTS

A total of 149 participants completed the surveys at both the 18- and 36-month time points (median age 55, range 23-70 years; n=94, 63.1% were male). At the 18-month time point, most participants (n=103, 69.1%) stated they completely trusted 3D total-body imaging for the diagnosis and monitoring of their nevi, and this did not change at the 36-month (n=104, 69.8%) time point. The majority of participants reported that they were very comfortable or comfortable with the technology at both the 18- (n=138, 92.6%) and 36-month (n=140, 94%) time points, respectively; albeit, the number of participants reporting that they were very comfortable reduced significantly between the 18- and 36-month time points, from 71.1% (n=106) to 61.1% (n=91; P=.01). Almost all participants (n=140, 94%) would consider using this technology if it were to become commercially available, and this did not change during the two study time points. Half of the participants (n=74) cited barriers to participating in 3D total-body photography, including trust in the ability of this technology to detect and monitor suspicious lesions, digital privacy, cost, and travel requirements.

CONCLUSIONS

The majority of participants expressed positive attitudes toward 3D total-body photography for the monitoring of their moles. Half of the participants identified potential barriers to uptake.

Analysis of human leukocyte antigen associations in human papillomavirus-positive and -negative head and neck cancer: Comparison with cervical cancer

Background

Although the majority of human papillomavirus (HPV) infections are cleared by the immune system, a small percentage of them progress to develop HPV‐driven cancers. Cervical cancer studies highlight that HPV persistence and cancer risk are associated with genetic factors, especially at the human leukocyte antigen (HLA) genes. This study was conducted to investigate such associations in head and neck cancer (HNC).

Methods

In all, 192 patients with HNC and 384 controls were genotyped with the Infinium Global Screening Array (Illumina, Inc). HLA variants were imputed with SNP2HLA, and an association analysis was performed by logistic regression.

Results

HPV‐positive HNCs were significantly associated with single‐nucleotide polymorphisms (SNPs) at DRB1_32660090 (P = 1.728 × 10^–6) and DRB1_32660116 (P = 1.728 × 10^–6) and with the amino acid variant DRB1_11_32660115 (P = 1.728 × 10^–6). None of these associations were observed in the HPV‐negative cohort, and this suggested their specificity to convey risk for HPV‐associated HNCs. In general, associations observed for HPV‐negative HNC were relatively weak, and variants in the HLA‐DPA1 region were the strongest among them (P = 4.531 × 10^–4). Several lead signals reported by previous HNC genome‐wide association studies, including SNPs rs3135001 (P = .012), rs1049055 (P = .012), and rs34518860 (P = .029) and allele HLA‐DQB1*06 (P = .009), were replicated in the current study. However, these associations were limited to the HPV‐positive HNC group. Several cervical cancer–associated HLA variants, including SNPs rs9272143 (P = .002) and rs9271858 (P = .002) and alleles HLA‐B‐1501 (P = .009) and HLA‐B‐15 (P = .015), were also exclusively associated with HPV‐positive HNC.

Conclusions

HPV‐positive HNC risk is associated with distinct HLA variants, and some of them are shared by both cervical cancer and HPV‐positive HNC.

Human papillomavirus (HPV)–positive head and neck cancer (HNC) risk is associated with distinct human leukocyte antigen variants, and some of them are shared by both cervical cancer and HPV‐positive HNC.

Lay Summary

Cervical cancer studies highlight that human papillomavirus (HPV)–driven cancer risk is linked with human leukocyte antigen (HLA) polymorphism.

Hence, the current study was designed to investigate the HLA associations in HPV‐positive and HPV‐negative head and neck cancer (HNC) and compare these associations with cervical cancer.

Several lead signals reported by previous HNC and cervical genome‐wide association studies were replicated in the current study.

However, these associations were limited to the HPV‐positive HNC group, and this suggests that HPV‐positive HNC risk is associated with distinct HLA variants, and some of them are shared by both cervical cancer and HPV‐positive HNC.

High variability in anatomic patterns of cutaneous photodamage: a population-based study

BACKGROUND

Skin cancer is strongly associated with photodamaged skin, but body sites are often referred to as 'exposed' or 'unexposed' to sun without recognizing extent of site-specific variation.

OBJECTIVES

To assess whole-body patterns of photodamage in an Australian population.

METHODS

A random sample of adult residents of Queensland underwent imaging across 10 body sites. Photodamage was graded from images using an ordinal photonumeric scale. We used cluster analysis to identify whole-body photodamage patterns and prevalence proportion ratios (PPRs) to assess associated factors.

RESULTS

Of 190 adults (median age 52; 58% males), 58% showed severe or moderate-to-severe photodamage on most body sites. A higher proportion of woman had severe photodamage on the arms (upper: P = 0.002, lower: P = 0.034). A higher proportion of men had moderate or severe photodamage on the lower back (P = 0.004). We identified four photodamage patterns: 'severe general' (n = 24, 13%), 'moderate-severe general' (n = 86, 45%), 'moderate-severe v-neck' (n = 40, 21%) and 'mild-moderate upper body' (n = 12, 6%). All participants with 'severe-general' photodamage were >50 years and more likely to have past skin cancer (PPR: 2.54, 95% CI: 1.44-4.49) than those with 'moderate-severe v-neck' photodamage. Those with 'moderate-severe general' photodamage showed similar associations and were more likely female (PPR: 1.33, 95% CI: 1.04-1.69). Past or current smoking was associated with having higher levels of photodamage, with no smokers in those with 'mild-moderate upper body' photodamage.

CONCLUSIONS

Moderate-to-severe photodamage across much of the body is common in Queensland adults and associated with age, sex, past skin cancer and smoking. Assuming a universal pattern of site-specific sun exposure could lead to spurious correlations, while accurate and objective assessment of site-specific photodamage can add to understanding of the development of sun-associated skin cancers, in particular site-specific skin carcinogenesis. Additionally, degree of site-specific photodamage has the potential to assist skin cancer screening.

A patient-centric dataset of images and metadata for identifying melanomas using clinical context

Prior skin image datasets have not addressed patient-level information obtained from multiple skin lesions from the same patient. Though artificial intelligence classification algorithms have achieved expert-level performance in controlled studies examining single images, in practice dermatologists base their judgment holistically from multiple lesions on the same patient. The 2020 SIIM-ISIC Melanoma Classification challenge dataset described herein was constructed to address this discrepancy between prior challenges and clinical practice, providing for each image in the dataset an identifier allowing lesions from the same patient to be mapped to one another. This patient-level contextual information is frequently used by clinicians to diagnose melanoma and is especially useful in ruling out false positives in patients with many atypical nevi. The dataset represents 2,056 patients (20.8% with at least one melanoma, 79.2% with zero melanomas) from three continents with an average of 16 lesions per patient, consisting of 33,126 dermoscopic images and 584 (1.8%) histopathologically confirmed melanomas compared with benign melanoma mimickers.

A minimally invasive clinical model to test sunscreen toxicity based on oxidative stress levels using microbiopsy and confocal microscopy - a proof of concept study

OBJECTIVE

This proof-of-concept study demonstrated that using minimally invasive skin microsampling could enable significantly higher throughput of cosmetic testing in volunteers than conventional biopsy. Nanoparticle sunscreen was used as a model to test toxicity based on oxidative stress using microbiopsy and confocal imaging.

METHODS

Six volunteers were recruited for this study (3 males and 3 females). Zinc oxide nanoparticle containing topical formulation was prepared at 10% w/v. Each volunteer had 3 areas of 4 cm² each mapped on each inner forearm for a total of 6 treatment areas (intact/ tape-stripped and with/without treatment). The topical zinc-nanoparticle formulation was applied directly to volunteer skin (2mg/cm² ) for 2 hrs. Microbiopsied tissue from each treatment group was stained for reactive oxygen and nitrogen species in addition to mitochondrial superoxide. The stained samples were then imaged using confocal microscopy prior to image analysis.

RESULTS

Skin exposed to zinc oxide nanoparticles did not show any significant increases in oxidative stress. Zinc oxide nanoparticle tape-stripped skin resulted in signal significantly lower (P < 0.001) oxidative stress levels than t-butylated hydroxytoluene treated tape-stripped skin for oxidative stress markers. Topically applied zinc oxide nanoparticles had no detectable effect on the oxidative status in volunteer skin. No adverse reactions or effects were observed after all treatments including microbiopsy.

CONCLUSION

The data support the hypothesis that microbiopsy is a viable approach to study cosmeceutical- skin interactions in volunteers with capacity for molecular assays and high throughput with very low risk to the volunteer.

Evaluation of the efficacy of 3D total-body photography with sequential digital dermoscopy in a high-risk melanoma cohort: protocol for a randomised controlled trial

INTRODUCTION

Melanoma is Australia's fourth most common cancer. Early detection is fundamental in maximising health outcomes and minimising treatment costs. To date, population-based screening programmes have not been justified in health economic studies. However, a skin surveillance approach targeting high-risk individuals could improve the cost-benefit ratio.

METHODS AND ANALYSIS

This paper describes a 2-year longitudinal randomised controlled trial (RCT) to compare routine clinical care (control) with an intensive skin surveillance programme (intervention) consisting of novel three-dimensional (3D) total-body photography (TBP), sequential digital dermoscopy and melanoma-risk stratification, in a high-risk melanoma cohort. Primary outcomes will evaluate clinical, economic and consumer impact of the intervention. Clinical outcomes will evaluate differences in the rate of lesion excisions/biopsies per person, benign to malignant ratio for excisions and thickness of melanomas diagnosed. A health economic analysis using government data repositories will capture healthcare utilisation and costs relating to skin surveillance. Consumer questionnaires will examine intervention acceptability, the psychological impact, and attitudes towards melanoma risk and sun protective behaviour. Secondary outcomes include the development of a holistic risk algorithm incorporating clinical, phenotypic and genetic factors to facilitate the identification of those most likely to benefit from this surveillance approach. Furthermore, the feasibility of integrating the intervention with teledermatology to enhance specialist care in remote locations will be evaluated. This will be the first RCT to compare a targeted surveillance programme utilising new 3D TBP technology against current routine clinical care for individuals at high risk of melanoma.

ETHICS AND DISSEMINATION

This study has received Human Research Ethics Committee (HREC) approval from both Metro South Health HREC (HREC/17/QPAH/816) and The University of Queensland HREC (2018000074).

TRIAL REGISTRATION NUMBER

ANZCTR12618000267257; Pre-results.