Actinic keratosis: Current challenges and unanswered questions.

Actinic keratoses (AK) are common skin lesions associated with chronic exposure to sun. They are believed to be precursors of malignancy as they potentially may progress to invasive squamous cell carcinomas. The goal of current therapies is to reduce the number of AK and to prevent future cancer development. This review aims at providing an overview of the hallmarks of AK and skin field cancerization. We discuss epidemiology trends, risk factors and the state of the art and evidence of the current treatments. We review key figures of AK prevalence from different countries with regard to skin cancer risk and the associated economic burden of AK. We discuss the mutational status in AK lesions and the difficulties encountered by clinicians in evaluating AK visible and invisible lesions, referring to the concept of field cancerization. Based on a systematic literature review, we further evaluate the available treatment options. The presence of subclinical skin alterations in the periphery of visible AK lesions has gained a particular attention as those non-visible lesions are known to contain the same genetic changes as those found in the AK lesions themselves, prompting the concept of 'field cancerization'. Therefore, AK treatment guidelines now recognize the importance of treating the field in patients with AK. A recent systematic literature review and network meta-analysis showed that 5-FU interventions were associated with the best efficacy and a satisfactory acceptability profile compared with other field-directed therapies used in the treatment of AK. Although AK are considered quite common, they lack an accurate descriptive definition and conclusive epidemiologic data. Limited public awareness is a barrier to early and effective treatment, including prevention strategies. While different treatment options are available, there is still a limited understanding of long-term outcomes of treatment as measured by recurrence of cancer prevention.

Photodynamic Therapy for the Treatment of Basal Cell Carcinoma: A Comprehensive Review of Randomized Controlled Trials.

INTRODUCTION: Basal cell carcinoma (BCC) is the most common skin cancer worldwide and has been reported to have a rising incidence in the last years. Multiple therapeutic modalities are approved for the treatment of BCC, making it difficult for physicians to choose the most suitable option for every patient. Photodynamic therapy (PDT) using either 5-aminolevulinic acid (ALA) or methyl aminolevulinate (MAL) as photosensitizing agents is an established treatment option for low-risk BCC. OBJECTIVES: This review aims to summarize the available evidence from randomized clinical trials (RCTs) that utilize either ALA or MAL PDT and compare it with other treatment modalities. The main outcomes related to the effectiveness, adverse events, cosmetic outcomes and pain sensation, along with data from long-term follow-ups will be presented and discussed. METHODS: Thorough literature searches were conducted through the electronic databases ClinicalTrials. gov and Pubmed/MEDLINE from inception up to 28 March 2023. Only studies in English were included. All relevant data were extracted accordingly from the eligible studies. RESULTS: Eight RCTs included superficial BCC (sBCC) alone, 7 included nodular BCC (nBCC), 2 included both sBCC and nBCC and 1 included BCC of unspecified subtype. Follow-up duration ranged from 3 months to 5 years. Both ALA-PDT and MAL-PDT demonstrated acceptable efficacy, adverse events, cosmetic outcomes and pain sensation while no major differences were observed between them. PDT was less effective than surgery but with better reported cosmetic outcomes. CONCLUSIONS: PDT is a safe and efficacious treatment option for sBCC and to a lesser extent nBCC.

International Skin Imaging Collaboration-Designated Diagnoses (ISIC-DX): Consensus terminology for lesion diagnostic labeling.

BACKGROUND: A common terminology for diagnosis is critically important for clinical communication, education, research and artificial intelligence. Prevailing lexicons are limited in fully representing skin neoplasms. OBJECTIVES: To achieve expert consensus on diagnostic terms for skin neoplasms and their hierarchical mapping. METHODS: Diagnostic terms were extracted from textbooks, publications and extant diagnostic codes. Terms were hierarchically mapped to super-categories (e.g. 'benign') and cellular/tissue-differentiation categories (e.g. 'melanocytic'), and appended with pertinent-modifiers and synonyms. These terms were evaluated using a modified-Delphi consensus approach. Experts from the International-Skin-Imaging-Collaboration (ISIC) were surveyed on agreement with terms and their hierarchical mapping; they could suggest modifying, deleting or adding terms. Consensus threshold was >75% for the initial rounds and >50% for the final round. RESULTS: Eighteen experts completed all Delphi rounds. Of 379 terms, 356 (94%) reached consensus in round one. Eleven of 226 (5%) benign-category terms, 6/140 (4%) malignant-category terms and 6/13 (46%) indeterminate-category terms did not reach initial agreement. Following three rounds, final consensus consisted of 362 terms mapped to 3 super-categories and 41 cellular/tissue-differentiation categories. CONCLUSIONS: We have created, agreed upon, and made public a taxonomy for skin neoplasms and their hierarchical mapping. Further study will be needed to evaluate the utility and completeness of the lexicon.

Diagnosis of invasive cutaneous squamous cell carcinoma, imaging and staging.

The assessment of patients with a lesion raising the suspicion of an invasive cutaneous squamous cell carcinoma (cSCC) is a frequent clinical scenario. The management of patients with cSCC is a multistep approach, starting with the correct diagnosis. The two main diagnostic goals are to differentiate from other possible diagnoses and correctly recognize the lesion as cSCC, and then to determine the tumor spread (perform staging), that is if the patient has a common primary cSCC or a locally advanced cSCC, or a metastatic cSCC (with in-transit, regional lymph nodal, or rarely distant metastasis). The multistep diagnostic approach begins with the clinical characteristics of the primary cSCC, it is complemented with features with dermoscopy and, if available, reflectance confocal microscopy and is confirmed with histopathology. The tumor spread is assessed by physical examination and, in some cases, ultrasound and/or computed tomography or magnetic resonance imaging, mainly to investigate for regional lymph node metastasis or for local infiltration into deeper structures. In the last step, the clinical, histologic and radiologic findings are incorporated into staging systems.

European consensus-based interdisciplinary guideline for diagnosis, treatment and prevention of actinic keratoses, epithelial UV-induced dysplasia and field cancerization on behalf of European Association of Dermato-Oncology, European Dermatology Forum, European Academy of Dermatology and Venereology and Union of Medical Specialists (Union Européenne des Médecins Spécialistes).

A collaboration of multidisciplinary experts from the European Association of Dermato-Oncology, the European Dermatology Forum, the European Academy of Dermatology and Venereology, and the European Union of Medical Specialists was formed to develop European recommendations on AK diagnosis and treatment, based on current literature and expert consensus. This guideline addresses the epidemiology, diagnostics, risk stratification and treatments in immunocompetent as well as immunosuppressed patients. Actinic keratoses (AK) are potential precursors of cutaneous squamous cell carcinoma (cSCC) and display typical histopathologic and immunohistochemical features of this malignancy in an early stage. They can develop into cSSC in situ and become invasive in a low percentage of cases. AK is the most frequent neoplasia in white populations, frequently occurring within a cancerous field induced by ultraviolet radiation. Since it cannot be predicted, which lesion will progress to cSCC and when treatment is usually recommended. The diagnosis of AK and field cancerization is made by clinical examination. Dermatoscopy, confocal microscopy, optical coherence tomography or line-field confocal-OCT can help in the differential diagnosis of AK and other skin neoplasms. A biopsy is indicated in clinically and/or dermatoscopically suspicious and/or treatment-refractory lesions. The choice of treatment depends on patients' and lesion characteristics. For single non-hyperkeratotic lesions, the treatment can be started upon patient's request with destructive treatments or topical treatments. For multiple lesions, field cancerization treatment is advised with topical treatments and photodynamic therapy. Preventive measures such as sun protection, self-examination and repeated field cancerization treatments of previously affected skin areas in high-risk patients are advised.

Germline cancer susceptibility in individuals with melanoma.

BACKGROUND: Prior studies have estimated a small number of individuals with melanoma (2%-2.5%) have germline cancer predisposition, yet a recent twin study suggested melanoma has the highest hereditability among cancers. OBJECTIVE: To determine the incidence of hereditary melanoma and characterize the spectrum of cancer predisposition genes that may increase the risk of melanoma. METHODS: Four hundred individuals with melanoma and personal or family history of cancers underwent germline testing of >80 cancer predisposition genes. Comparative analysis of germline data was performed on 3 additional oncologic and dermatologic data sets. RESULTS: Germline pathogenic/likely pathogenic (P/LP) variants were identified in 15.3% (61) individuals with melanoma. Most variants (41, 67%) involved genes considered unrelated to melanoma (BLM, BRIP1, CHEK2, MLH1, MSH2, PMS2, RAD51C). A third (20, 33%) were in genes previously associated with familial melanoma (BAP1, BRCA2, CDKN2A, MITF, TP53). Nearly half (30, 46.9%) of P/LP variants were in homologous repair deficiency genes. Validation cohorts demonstrated P/LP rates of 10.6% from an unselected oncologic cohort, 15.8% from a selected commercial testing cohort, and 14.5% from a highly selected dermatologic study. LIMITATIONS: Cohorts with varying degrees of selection, some retrospective. CONCLUSION: Germline predisposition in individuals with melanoma is common, with clinically actionable findings diagnosed in 10.6% to 15.8%.

Use of Dermoscopy among Greek Dermatologists in Everyday Clinical Practice: A National Questionnaire-Based Study.

Background: Dermatoscopy has been established as an important diagnostic tool for a wide range of skin diseases. This study aims to evaluate the use of dermatoscopy in clinical practice among Greek dermatologists. Methods: A nationwide questionnaire-based survey was conducted collecting data on the frequency of dermatoscopic examinations, the types of lesions examined, training and educational resources, as well as factors influencing the choice to incorporate dermatoscopy into daily clinical routines. Results: A total of 366 Greek dermatologists participated in the survey. Most of the respondents reported the daily use of dermatoscopy in their practice. Pigmented and non-pigmented lesions, inflammatory diseases, cutaneous infectious, hair disorders, and nail lesions were the most common indications for dermatoscopy. Factors influencing the utilization of dermatoscopy included increased diagnostic accuracy, enhanced patient care, better patient communication and general compliance, and improved satisfaction among dermatologists. Conclusions: This national questionnaire-based study demonstrates that dermatoscopy has become an integral part of daily dermatological practice in Greece. The findings highlight the significance of structured training and education to promote dermoscopy's effective and routine use. Incorporating dermatoscopy into clinical practice not only improves diagnostic precision but also enhances patient care, contributing to the overall quality of dermatological services in Greece.

A Retrospective Study of Diameter and Breslow Thickness in Invasive Melanomas.

INTRODUCTION: A diameter larger than 6 mm is included in the criteria used in public health messages to detect a cutaneous melanoma. We aimed to investigate the independent association of Breslow thickness with the melanoma diameter. METHODS: A retrospective study was performed in patients with invasive melanomas of the nodular melanoma (NM) or superficial spreading melanoma (SSM) subtype. The quartiles of the diameter (lower, median, upper) were studied in non-parametric quantile regression model. RESULTS: In total, 537 cases of invasive melanomas were included and 60% had Breslow thickness ≤1.0 mm. There were 429 SSM (79.9%) and 108 NM (20.1%). Although NMs were significantly thicker (median Breslow thickness: 2.7 mm vs. 0.7 mm, respectively, p < 0.0001), they were not associated with larger diameter compared to SSMs (p = 0.71). After adjustment for age and sex, melanoma location and subtype, having Breslow thickness ≤1.0 mm was not significantly associated with the lower quartile, median and upper quartile of the diameter (p values: 0.063, 0.083, and 0.791, respectively). CONCLUSION: In our study including melanomas of the NM or SSM subtype, Breslow thickness was not associated with the diameter, adding evidence to support the limitations of using diameter larger than 6 mm for the detection of invasive melanomas and indicating the potential of smaller melanomas to be thicker tumors.

Expert Agreement on the Presence and Spatial Localization of Melanocytic Features in Dermoscopy.

Dermoscopy aids in melanoma detection; however, agreement on dermoscopic features, including those of high clinical relevance, remains poor. In this study, we attempted to evaluate agreement among experts on exemplar images not only for the presence of melanocytic-specific features but also for spatial localization. This was a cross-sectional, multicenter, observational study. Dermoscopy images exhibiting at least 1 of 31 melanocytic-specific features were submitted by 25 world experts as exemplars. Using a web-based platform that allows for image markup of specific contrast-defined regions (superpixels), 20 expert readers annotated 248 dermoscopic images in collections of 62 images. Each collection was reviewed by five independent readers. A total of 4,507 feature observations were performed. Good-to-excellent agreement was found for 14 of 31 features (45.2%), with eight achieving excellent agreement (Gwet's AC >0.75) and seven of them being melanoma-specific features. These features were peppering/granularity (0.91), shiny white streaks (0.89), typical pigment network (0.83), blotch irregular (0.82), negative network (0.81), irregular globules (0.78), dotted vessels (0.77), and blue-whitish veil (0.76). By utilizing an exemplar dataset, a good-to-excellent agreement was found for 14 features that have previously been shown useful in discriminating nevi from melanoma. All images are public (www.isic-archive.com) and can be used for education, scientific communication, and machine learning experiments.

Immunotherapy and Its Timing in Advanced Basal Cell Carcinoma Treatment.

For patients with advanced basal cell carcinoma (BCC), including locally advanced or metastatic BCC not amenable to curative surgery or radiotherapy, hedgehog pathway inhibitors (HHI) vismodegib and sonidegib are approved as first-line systemic treatment. Results from clinical trials highlight that the overall discontinuation rate of HHI treatment varies from 88% to 92% with vismodegib and is approximately 92% with sonidegib, and half of patients will discontinue HHI after approximately 8 to 12 months. The main factors weighing in on the decision to discontinue HHI include efficacy (tumor response), adverse events and patient decision. In clinical practice, some of the patients that stop HHI may be re-evaluated if the tumor becomes amenable to surgery, or restart HHI at a later time, while others will need to switch to immunotherapy, depending on the reasons for HHI discontinuation. In this review, we revisit the therapeutic decisions considering a switch from HHI to immunotherapy with anti-PD-1 agent cemiplimab and we highlight the place of cemiplimab in the therapeutic ladder for patients with advanced BCC. We discuss the evidence on the efficacy and safety of anti-PD-1 agents as second-line systemic monotherapy, or in combination with other treatments, and the emergence of checkpoint immunotherapy as a neoadjuvant treatment.

European consensus-based interdisciplinary guideline for invasive cutaneous squamous cell carcinoma: Part 2. Treatment-Update 2023.

In order to update recommendations on treatment, supportive care, education, and follow-up of patients with invasive cutaneous squamous cell carcinoma (cSCC), a multidisciplinary panel of experts from the European Association of Dermato-Oncology (EADO), the European Dermatology Forum (EDF), the European Society for Radiotherapy and Oncology (ESTRO), the European Union of Medical Specialists (UEMS), the European Academy of Dermatology and Venereology (EADV), and the European Organisation of Research and Treatment of Cancer (EORTC) was formed. Recommendations were based on an evidence-based literature review, guidelines, and expert consensus. Treatment recommendations are presented for common primary cSCC (low risk, high risk), locally advanced cSCC, regional metastatic cSCC (operable or inoperable), and distant metastatic cSCC. For common primary cSCC, the first-line treatment is surgical excision with postoperative margin assessment or micrographically controlled surgery. Achieving clear surgical margins is the most important treatment consideration for patients with cSCCs amenable to surgery. Regarding adjuvant radiotherapy for patients with high-risk localised cSCC with clear surgical margins, current evidence has not shown significant benefit for those with at least one high-risk factor. Radiotherapy should be considered as the primary treatment for non-surgical candidates/tumours. For cSCC with cytologically or histologically confirmed regional nodal metastasis, lymph node dissection is recommended. For patients with metastatic or locally advanced cSCC who are not candidates for curative surgery or radiotherapy, anti-PD-1 agents are the first-line systemic treatment, with cemiplimab being the first approved systemic agent for advanced cSCC by the Food and Drugs Administration/European Medicines Agency. Second-line systemic treatments for advanced cSCC, include epidermal growth factor receptor inhibitors (cetuximab) combined with chemotherapy or radiotherapy. Multidisciplinary board decisions are mandatory for all patients with advanced cSCC, considering the risks of toxicity, the age and frailty of patients, and co-morbidities, including immunosuppression. Patients should be engaged in informed, shared decision-making on management and be provided with the best supportive care to improve symptom management and quality of life. The frequency of follow-up visits and investigations for subsequent new cSCC depends on underlying risk characteristics.

European consensus-based interdisciplinary guideline for invasive cutaneous squamous cell carcinoma. Part 1: Diagnostics and prevention-Update 2023.

Invasive cutaneous squamous cell carcinoma (cSCC) is one of the most common cancers in white populations, accounting for 20% of all cutaneous malignancies. Overall, cSCC mostly has very good prognosis after treatment, with 5-year cure rates greater than 90%. Despite the overall favourable prognosis and the proportionally rare deaths, cSCC is associated with a high total number of deaths due to its high incidence. A collaboration of multidisciplinary experts from the European Association of Dermato-Oncology (EADO), the European Dermatology Forum (EDF), the European Society for Radiotherapy and Oncology (ESTRO), the European Union of Medical Specialists (UEMS), the European Academy of Dermatology and Venereology (EADV) and the European Organization of Research and Treatment of Cancer (EORTC), was formed to update recommendations on cSCC, based on current literature and expert consensus. Part 1 of the guidelines addresses the updates on classification, epidemiology, diagnosis, risk stratification, staging and prevention in immunocompetent as well as immunosuppressed patients.

Clinical and Dermoscopic Findings of Nevi after Photoepilation: A Review.

Atypical clinical and dermoscopic findings, or changes in pigmented melanocytic lesions located on body areas treated with lasers or intense pulsed light (IPL) for hair removal (photoepilation), have been described in the literature. There are three prospective studies in a total of 79 individuals with 287 melanocytic nevi and several case reports reporting the dermoscopic findings and changes after photoepilation. Clinical changes have been reported in 20-100% of individuals, while dermoscopic changes have been observed in 48% to 93% of nevi. More frequent dermoscopic changes included bleaching, the development of pigmented globules, and irregular hyperpigmented areas and regression structures, including gray areas, gray dots/globules, and whitish structureless areas. The diagnostic approach for pigmented lesions with atypical dermoscopic findings and changes after photo-epilation included reflectance confocal microscopy, sequential digital dermoscopy follow-up, and/or excision and histopathology. Challenges pertaining to these diagnostic steps in the context of photoepilation include the detection of findings that may warrant a biopsy to exclude melanoma (ugly duckling, irregular hyperpigmented areas, blue-gray or white areas, and loss of pigment network), the potential persistence of changes at follow-up, and that a histopathologic diagnosis may not be possible due to the distortion of melanocytes or complete regression of the lesion. Furthermore, these diagnostic approaches can be time-consuming, require familiarization of the physician with dermoscopic features, may cause anxiety to the individual, and highlight that avoiding passes of the laser or IPL devices over pigmented lesions is key.

Driver gene combinations dictate cutaneous squamous cell carcinoma disease continuum progression.

The molecular basis of disease progression from UV-induced precancerous actinic keratosis (AK) to malignant invasive cutaneous squamous cell carcinoma (cSCC) and potentially lethal metastatic disease remains unclear. DNA sequencing studies have revealed a massive mutational burden but have yet to illuminate mechanisms of disease progression. Here we perform RNAseq transcriptomic profiling of 110 patient samples representing normal sun-exposed skin, AK, primary and metastatic cSCC and reveal a disease continuum from a differentiated to a progenitor-like state. This is accompanied by the orchestrated suppression of master regulators of epidermal differentiation, dynamic modulation of the epidermal differentiation complex, remodelling of the immune landscape and an increase in the preponderance of tumour specific keratinocytes. Comparative systems analysis of human cSCC coupled with the generation of genetically engineered murine models reveal that combinatorial sequential inactivation of the tumour suppressor genes Tgfbr2, Trp53, and Notch1 coupled with activation of Ras signalling progressively drives cSCC progression along a differentiated to progenitor axis. Taken together we provide a comprehensive map of the cSCC disease continuum and reveal potentially actionable events that promote and accompany disease progression.

Adalimumab-Induced Paradoxical Psoriasis Treated with Biologics Targeting the IL-17/IL-23 Axis in Patients with Hidradenitis Suppurativa.

BACKGROUND: Paradoxical psoriasis (PP) has been mainly described in patients receiving tumor necrosis factor-α (TNFα) inhibitors for inflammatory bowel disease or psoriasis vulgaris, while such data in the context of hidradenitis suppurativa (HS) are scarce. The purpose of this study was to demonstrate the course of PP and the underlying HS upon switching from adalimumab to a biologic agent targeting the interleukin (IL)-17/IL-23 axis. METHODS: The electronic medical database of the outpatient department for HS of a tertiary hospital for skin diseases was searched to identify patients with moderate-to-severe HS under treatment with adalimumab, who developed PP and were switched to biological therapy with an IL-17 or IL-23 inhibitor between February 2016 and January 2022. Disease assessment scores were evaluated at baseline, at time of PP development, as well as six and 12 months thereafter. RESULTS: Among the 83 patients who received adalimumab for the treatment of HS between February 2016 and January 2022, 10 patients (12%) developed paradoxical psoriasiform skin reactions after a median time of seven (range, 2-48) months. There were four females (40%) and six males (60%) with a median age of 42.5 (range, 33-56) years. Five patients presented with plaque psoriasis and five with palmoplantar pustulosis, while four had intertriginous and three nail involvement. In most of the patients, HS responded well to adalimumab at onset of PP. Eight patients were changed to secukinumab, one to ustekinumab, and one to risankizumab. HS further improved in all but 2 patients, one receiving secukinumab and one receiving risankizumab. In addition, all patients achieved improvement of PP. CONCLUSION: Despite the small number of patients, this study provides support that patients with adalimumab-induced PP may benefit from biologics targeting the IL-17/IL-23 axis. Further studies are needed to establish the optimal therapeutic strategy of the anti-TNFα-induced PP in the context of HS.

European consensus-based interdisciplinary guideline for diagnosis and treatment of basal cell carcinoma-update 2023.

Basal cell carcinoma (BCC) is the most common malignant tumour in white populations. Multidisciplinary experts from European Association of Dermato-Oncology (EADO), European Dermatology Forum, European Society for Radiotherapy and Oncology (ESTRO), Union Européenne des Médecins Spécialistes, and the European Academy of Dermatology and Venereology developed updated recommendations on diagnosis and treatment of BCC. BCCs were categorised into 'easy-to-treat' (common) and 'difficult-to-treat' according to the new EADO clinical classification. Diagnosis is based on clinico-dermatoscopic features, although histopathological confirmation is mandatory in equivocal lesions. The first-line treatment of BCC is complete surgery. Micrographically controlled surgery shall be offered in high-risk and recurrent BCC, and BCC located on critical anatomical sites. Topical therapies and destructive approaches can be considered in patients with low-risk superficial BCC. Photodynamic therapy is an effective treatment for superficial and low-risk nodular BCCs. Management of 'difficult-to-treat' BCCs should be discussed by a multidisciplinary tumour board. Hedgehog inhibitors (HHIs), vismodegib or sonidegib, should be offered to patients with locally advanced and metastatic BCC. Immunotherapy with anti-PD1 antibodies (cemiplimab) is a second-line treatment in patients with a progression of disease, contraindication, or intolerance to HHI therapy. Radiotherapy represents a valid alternative in patients who are not candidates for or decline surgery, especially elderly patients. Electrochemotherapy may be offered when surgery or radiotherapy is contraindicated. In Gorlin patients, regular skin examinations are required to diagnose and treat BCCs at an early stage. Long-term follow-up is recommended in patients with high-risk BCC, multiple BCCs, and Gorlin syndrome.