Clinical Diagnosis Of Skin Cancer Research Articles

SkiNet: A deep learning framework for skin lesion diagnosis with uncertainty estimation and explainability

Skin cancer is considered to be the most common human malignancy. Around 5 million new cases of skin cancer are recorded in the United States annually. Early identification and evaluation of skin lesions are of great clinical significance, but the disproportionate dermatologist-patient ratio poses a significant problem in most developing nations. Therefore a novel deep architecture, named as SkiNet, is proposed to provide faster screening solution and assistance to newly trained physicians in the process of clinical diagnosis of skin cancer. The main motive behind SkiNet's design and development is to provide a white box solution, addressing a critical problem of trust and interpretability which is crucial for the wider adoption of Computer-aided diagnosis systems by medical practitioners. The proposed SkiNet is a two-stage pipeline wherein the lesion segmentation is followed by the lesion classification. Monte Carlo dropout and test time augmentation techniques have been employed in the proposed method to estimate epistemic and aleatoric uncertainty. A novel segmentation model named Bayesian MultiResUNet is used to estimate the uncertainty on the predicted segmentation map. Saliency-based methods like XRAI, Grad-CAM and Guided Backprop are explored to provide post-hoc explanations of the deep learning models. The ISIC-2018 dataset is used to perform the experimentation and ablation studies. The results establish the robustness of the proposed model on the traditional benchmarks while addressing the black-box nature of such models to alleviate the skepticism of medical practitioners by incorporating transparency and confidence to the model's prediction.

Electrical Characterization of Basal Cell Carcinoma Using a Handheld Electrical Impedance Dermography Device

Sensitive, objective, and easily applied methods for evaluating skin lesions are needed to improve diagnostic accuracy. In this study, we evaluated whether a developed noninvasive electrical impedance dermography device URSKIN could serve this purpose. In this pilot study, 17 subjects with subsequently confirmed basal cell carcinoma underwent four-electrode electrical impedance dermography measurements to assess the electrical properties of basal cell carcinoma and adjacent normal skin. A linear mixed-effects model with random intercept and slope terms was used for the analysis of multifrequency values in longitudinal and transverse directions. A significant difference in the intercept of frequency trajectories was observed for the longitudinal conductivity of 0.13 siemens/m (P < 0.001, 95% confidence interval = 0.10–0.16), transverse conductivity of 0.06 siemens/m (P < 0.001, 95% confidence interval = 0.05–0.07), longitudinal relative permittivity (dimensionless) of 203,742 (P < 0.001, 95% confidence interval = 180,292–227,191), and transverse relative permittivity (dimensionless) of 86,894 (P < 0.001, 95% confidence interval = 81,549 – 92,238). Thus, our device detected significant electrical differences between basal cell carcinoma and adjacent normal skin. Given these preliminary performance metrics and the ease of use, this technology merits further study to establish its value in facilitating the clinical diagnosis of skin cancers.

Assessment of Skin Deep Layer Biochemical Profile Using Spatially Offset Raman Spectroscopy

Skin cancer is currently the most common type of cancer with millions of cases diagnosed worldwide yearly. The current gold standard for clinical diagnosis of skin cancer is an invasive and relatively time-consuming procedure, consisting of visual examination followed by biopsy collection and histopathological analysis. Raman spectroscopy has been shown to efficiently aid the non-invasive diagnosis of skin cancer when probing the surface of the skin. In this study, we employ a recent development of Raman spectroscopy (Spatially Offset Raman Spectroscopy, SORS) which is able to look deeper in tissue and create a deep layer biochemical profile of the skin in areas where cancer lesions subtly evolve. After optimizing the measurement parameters on skin tissue phantoms, we then adopted SORS on human skin tissue from different anatomical areas to investigate the contribution of the different skin layers to the recorded Raman signal. Our results show that using a diffuse beam with zero offset to probe a sampling volume where the lesion is typically included (surface to epidermis-dermis junction), provides the optimum signal-to-noise ratio (SNR) and may be employed in future skin cancer screening applications.

Characteristic Clinical and Dermoscopic Features of Nonvolar Poroma.

A poroma typically presents as a solitary, pink-to-red papule or nodule in acral volar areas. However, in nonvolar areas, this typical clinical feature (TCF) can be difficult to identify. We aimed to compare clinical and dermoscopic characteristics between nonvolar poroma (NVP) and volar (ie, typical) poroma (VP). We assessed the clinical and dermoscopic characteristics of 40 patients with poromas who were divided into the NVP and VP groups. Of the 40 patients, 20 (50.0%) were allocated to the NVP group and 20 (50.0%) to the VP group. Pigmented variants were more common in the NVP group than in the VP group (60.0% vs 5.0%). The TCF of poroma was observed less frequently in the NVP than the VP group (45.0% vs 85.0%). Approximately one-third (30.0%) of patients with NVP received an initial clinical diagnosis of skin cancer. Dermoscopic patterns associated with melanoma or basal cell carcinoma were more common in the NVP group than in the VP group (65% vs 30%). Skin cancer-associated clinicodermoscopic features were more frequently observed in patients with NVP, who simultaneously lost dermoscopic patterns associated to poromas and acquired those associated with skin cancer, than those with VP.

The first 30 years of the American Academy of Dermatology skin cancer screening program: 1985-2014

The incidence of melanoma is rising faster than that of any other preventable cancer in the United States. The American Academy of Dermatology has sponsored free skin cancer education and screenings conducted by volunteer dermatologists in the United States since 1985. We aimed to assess the American Academy of Dermatology's national skin cancer screening program from 1986 to 2014 by analyzing the risk factor profile, access to dermatologic services, and examination results. We conducted several detailed statistical analyses of the screening population. From 1986 to 2014, records were available for 2,046,531 screenings, 1,963,141 (96%) of which were subjected to detailed analysis. Men comprised 38% of all participants. The number of annual screenings reached approximately 100,000 in 1990 and remained relatively stable thereafter. From 1991 to 2014 (data for 1995, 1996 and 2000 were unavailable), clinical diagnoses were rendered for 20,628 melanomas, 156,087 dysplastic nevi, 32,893 squamous cell carcinomas, and 129,848 basal cell carcinomas. Only 21% of screenees had a regular dermatologist. Those with a clinical diagnosis of skin cancer were more likely than the general screening population to be uninsured. Inability to verify clinical diagnoses histopathologically. Our findings suggest that the SPOTme program has detected thousands of skin cancers that may have gone undetected or experienced a delay in detection.

Clinical Diagnosis of Skin Cancer: Enhancing Inspection and Early Recognition.

The annual incidence rate for melanoma and nonmelanoma skin cancer continues to rise and morbidity and deaths from skin cancer are increasing. Despite advances in therapeutics, the factors that most impact prognosis remain early recognition and removal of neoplasms before deep invasion or metastatic disease can occur. There are numerous public health and screening initiatives that have been introduced to help recognize disease earlier and to increase patients' awareness of signs or changes of lesions that may represent skin cancers. Early recognition and removal of suspicious lesions remains critical in significantly reducing morbidity and mortality associated with skin cancers.

Cost-Effectiveness Analysis of a Skin Awareness Intervention for Early Detection of Skin Cancer Targeting Men Older Than 50 Years.

To assess the cost-effectiveness of an educational intervention encouraging self-skin examinations for early detection of skin cancers among men older than 50 years. A lifetime Markov model was constructed to combine data from the Skin Awareness Trial and other published sources. The model incorporated a health system perspective and the cost and health outcomes for melanoma, squamous and basal cell carcinomas, and benign skin lesions. Key model outcomes included Australian costs (2015), quality-adjusted life-years (QALYs), life-years, and counts of skin cancers. Univariate and probabilistic sensitivity analyses were undertaken to address parameter uncertainty. The mean cost of the intervention was A$5,298 compared with A$4,684 for usual care, whereas mean QALYs were 7.58 for the intervention group and 7.77 for the usual care group. The intervention was thus inferior to usual care. When only survival gain is considered, the model predicted the intervention would cost A$1,059 per life-year saved. The likelihood that the intervention was cost-effective up to A$50,000 per QALY gained was 43.9%. The model was stable to most data estimates; nevertheless, it relies on the specificity of clinical diagnosis of skin cancers and is subject to limited health utility data for people with skin lesions. Although the intervention improved skin checking behaviors and encouraged men to seek medical advice about suspicious lesions, the overall costs and effects from also detecting more squamous and basal cell carcinomas and benign lesions outweighed the positive health gains from detecting more thin melanomas.

Novel approaches to imaging basal cell carcinoma.

The gold standard of diagnosis for nonmelanoma and melanoma skin cancer has been skin biopsy with routine paraffin embedded hematoxylin and eosin histopathology. This practice is frequently carried out on suspicious lesions to rule out a malignant process. Therefore, as a result, many biopsies are done on benign lesions. Unlike other fields of medicine that rely on noninvasive imaging modalities, the use of imaging devices in dermatology has not been as robust. This has been mainly due to the limited resolution offered by imaging devices that is needed to detect malignant changes in the cutaneous layers. However, the demand for more efficient in vivo and ex vivo imaging tools to reduce the amount of biopsies have led to new areas of investigation using noninvasive modalities to augment the clinical diagnosis of skin cancer. The use of noninvasive imaging both in vivo and ex vivo has the potential to increase efficiency of diagnosis and management, decrease healthcare cost, improve clinical care and enhance patient satisfaction.

Actinic keratosis among seafarers

The aim of this study was to assess the prevalence of UV-induced actinic keratosis and further skin lesions. A newly developed questionnaire about lifetime UV radiation exposure was completed by 514 seafarers. An experienced dermatologist inspected the whole-body skin status of all participants. The questionnaire revealed a pre-employment UV radiation exposure in 104 seafarers, sunbed use in 26 subjects and a median work-related UV radiation exposure at sea of 20years. The diagnosis of actinic keratoses was made in 94 seafarers and the clinical diagnosis of skin cancers in 48 seafarers (28 basal cell carcinoma, 11 squamous cell carcinoma, 9 malignant melanoma). After age standardisation according to a European reference population, the male European seafarers in this study had a 1.80-fold increased risk of actinic keratosis. Actinic keratoses [OR 1.03 (1.01-1.05)] and squamous cell carcinoma [OR 1.07 (1.01-1.13)] were related to the duration of seafaring time in years. A significant association was also found between actinic keratosis/squamous cell carcinoma and sunlight exposure during home leave [OR 1.67 (1.03-2.81) and OR 6.19 (1.18-32.40)]. Furthermore, the engine room personnel-especially the technical officers-were at higher risk of developing actinic keratosis. Due to the high prevalence of actinic keratosis especially among older seafarers with fair skin, with longer duration of seafaring employment at sea and with higher UV exposure during home leave, more intensive advice should be given on sun protection both at sea and ashore.

Emergence of microstructural patterns in skin cancer: a phase separation analysis in a binary mixture

Clinical diagnosis of skin cancers is based on several morphological criteria, among which is the presence of microstructures (e.g. dots and nests) sparsely distributed within the tumour lesion. In this study, we demonstrate that these patterns might originate from a phase separation process. In the absence of cellular proliferation, in fact, a binary mixture model, which is used to represent the mechanical behaviour of skin cancers, contains a cell–cell adhesion parameter that leads to a governing equation of the Cahn–Hilliard type. Taking into account a reaction–diffusion coupling between nutrient consumption and cellular proliferation, we show, with both analytical and numerical investigations, that two-phase models may undergo a spinodal decomposition even when considering mass exchanges between the phases. The cell–nutrient interaction defines a typical diffusive length in the problem, which is found to control the saturation of a growing separated domain, thus stabilizing the microstructural pattern. The distribution and evolution of such emerging cluster morphologies, as predicted by our model, are successfully compared to the clinical observation of microstructural patterns in tumour lesions.

An automatic based nonlinear diffusion equations scheme for skin lesion segmentation

The clinical diagnosis of skin lesions is not an easy task for dermatologists. A segmentation method that makes the extraction of important characteristics of the skin lesion image can aid dermatologists in the clinical diagnosis of skin cancer. In this paper a segmentation method that combines the use of nonlinear diffusion equations and the Canny edge detector for the automatic detection of the skin edge lesions is presented. Experimental results show the efficacy of the proposed method even when the lesion is noisy or when the lesion is covered by hairs.

Asertividad en el diagnóstico clínico de los tumores cutáneos

There is an increase in the incidence rates of skin cancer in Chile. To study the clinical diagnostic accuracy (CDA) for skin cancer. CDA was defined as the percentage of agreement between clinical and pathological diagnosis. Approximately 600,000 pathological reports from five hospitals in Santiago were reviewed. A total of 2,593 skin tumours; 230 Malignant Melanoma (MM); 412 Squamous Cell Carcinoma (SCC) and 1,951 Basal Cell Carcinoma (BCC) were studied. These tumours were clinically diagnosed and surgically treated by dermatologists. The CDA was studied for each tumour, by the anatomical localization of the tumour, Breslow Index in MM, by age and sex of the patient. The highest CDA was observed for BCC (76.2%); followed by MM (64.3%) and SCC (34.7%). By anatomical localization, for MM the highest CDA was observed in the soles (p < 0.05); for BCC, the highest CDA was in the face (p < 0.05). No significant differences were observed in SCC. By age, for MM, the CDA was higher in patients aged less than 50 years. No differences in CDA by age were observed in the other two tumours. By sex, no differences were found. A higher CDA was found in MM with Breslow indexes III and IV than for MM with Breslow indexes I and II. CDA is affected by the clinical variables analyzed in this study. A more accurate clinical diagnosis of skin cancer could be obtained taking into account these variables.

Utility of step sections: demonstration of additional pathological findings in biopsy samples initially diagnosed as actinic keratosis.

To discover additional diagnostic findings on step sections of biopsy samples showing features of actinic keratosis on the initial section and to correlate such findings with clinical and histological variables. Prospective study comparing initial histological findings with those noted on deeper tissue levels. University-based dermatopathology practice. Fifty-seven patients (36 men and 21 women) with biopsy samples from 69 skin lesions. Identification of additional pathological diagnoses in step sections and correlation with clinical diagnosis, size and location of lesion, history of skin cancer or immunosuppression, size and handling of specimen, and presence of ulceration on the initial level. Additional diagnostic findings were present on step sections in 23 specimens (33%), including 9 (13%) with squamous cell carcinoma in situ, 3 (4%) with basal cell carcinoma, and 2 (3%) with invasive squamous cell carcinoma. Three variables were significantly correlated with the discovery of cancer on step sections: (1) ulceration on the first level, (2) clinical diagnosis of skin cancer, and (3) history of skin cancer diagnosed by biopsy examination. The latter 2 variables were also correlated with the discovery of any additional finding, whether benign or malignant, on step sections. In biopsy samples initially diagnostic of actinic keratosis, examination of step sections contributes clinically important information. Step sections are particularly useful when a clinical diagnosis of skin cancer is present. The results of this study confirm the pathogenetic importance of actinic keratosis as a precursor to fully evolved malignant neoplasia and suggest that such lesions merit thorough histological study.

The prevalence and accuracy of diagnosis of non-melanotic skin cancer in Victoria.

SummarySurveys of Victorian dermatologists and pathologists were undertaken to determine the number of patients attending medical practitioners with non‐melanotic skin cancers and solar keratoses. Results suggest that at least 1,000 patients per week are attending for diagnosis and treatment.Accuracy of clinical diagnosis studies suggest that the correct diagnosis of these tumours isbeing made clinically in approximately 70% of cases by experienced clinicians. It is suggested that histology be obtained in all lesions in which a clinical diagnosis of skin cancer is considered. The incidence of squamous cell carcinoma compared to that of basal cell carcinoma is seen to rise where histological examination is performed.