S3 guideline "actinic keratosis and cutaneous squamous cell carcinoma" - update 2023, part 2: epidemiology and etiology, diagnostics, surgical and systemic treatment of cutaneous squamous cell carcinoma (cSCC), surveillance and prevention.

Actinic keratosis (AK) are common lesions in light-skinned individuals that can potentially progress to cutaneous squamous cell carcinoma (cSCC). Both conditions may be associated with significant morbidity and constitute a major disease burden, especially among the elderly. To establish an evidence-based framework for clinical decision making, the guideline "actinic keratosis and cutaneous squamous cell carcinoma" was updated and expanded by the topics cutaneous squamous cell carcinoma in situ (Bowen's disease) and actinic cheilitis. The guideline is aimed at dermatologists, general practitioners, ear nose and throat specialists, surgeons, oncologists, radiologists and radiation oncologists in hospitals and office-based settings, as well as other medical specialties, policy makers and insurance funds involved in the diagnosis and treatment of patients with AK and cSCC. A separate guideline exists for patients and their relatives. In this part, we will address aspects relating to epidemiology and etiology, diagnostics, surgical and systemic treatment of cutaneous squamous cell carcinoma (cSCC), surveillance and prevention.

Basal Proliferation and Acantholysis May Represent Histological High-Risk Factors for Progression into Invasive Squamous Cell Carcinoma: A Comparison Study in Solid Organ Transplant Recipients and Matched Immunocompetent Patients.

Histological risk factors of AKs cannot be directly determined. Recent studies indicate that AKs restricted to the lower third of the epidermis (AK I), with marked basal proliferation (PRO III) and acantholysis, are associated with an increased risk of progression to invasive squamous cell carcinoma (iSCC). To confirm the aforementioned histological risk factors, this study compared AKs from solid organ transplant recipients (sOTRs), known to carry an up to 250-fold higher risk for progression into iSCC, to a matched immunocompetent control group (ICG). In total, 111 AKs from 43 sOTRs showed more AKs (n = 54, 48.7%) graded as AK I compared to 35 AKs (31.5%) in the ICG (p = 0.009). In line with these findings, 89 AKs (80.2%) from sOTRs showed pronounced basal proliferation (PRO III) compared to 37 AKs (33.3%) in the ICG (p < 0.0001). Acantholysis was more frequent in sOTRs than the ICG (59.5% vs. 32.4%, p < 0.0001) and more frequently associated with advanced basal proliferation (p < 0.0001). In conclusion, this study showed that acantholytic AKs graded as AK I and PRO III are predominantly found in a population at high risk of iSCC. Thus, AKs with marked basal proliferation and acantholysis should be assumed to be histological high-risk factors for the progression into iSCC.

Deep Learning Assisted Diagnosis of Onychomycosis on Whole-Slide Images.

BACKGROUND: Onychomycosis numbers among the most common fungal infections in humans affecting finger- or toenails. Histology remains a frequently applied screening technique to diagnose onychomycosis. Screening slides for fungal elements can be time-consuming for pathologists, and sensitivity in cases with low amounts of fungi remains a concern. Convolutional neural networks (CNNs) have revolutionized image classification in recent years. The goal of our project was to evaluate if a U-NET-based segmentation approach as a subcategory of CNNs can be applied to detect fungal elements on digitized histologic sections of human nail specimens and to compare it with the performance of 11 board-certified dermatopathologists. METHODS: In total, 664 corresponding H&E- and PAS-stained histologic whole-slide images (WSIs) of human nail plates from four different laboratories were digitized. Histologic structures were manually annotated. A U-NET image segmentation model was trained for binary segmentation on the dataset generated by annotated slides. RESULTS: The U-NET algorithm detected 90.5% of WSIs with fungi, demonstrating a comparable sensitivity with that of the 11 board-certified dermatopathologists (sensitivity of 89.2%). CONCLUSIONS: Our results demonstrate that machine-learning-based algorithms applied to real-world clinical cases can produce comparable sensitivities to human pathologists. Our established U-NET may be used as a supportive diagnostic tool to preselect possible slides with fungal elements. Slides where fungal elements are indicated by our U-NET should be reevaluated by the pathologist to confirm or refute the diagnosis of onychomycosis.

Classifying Actinic Keratosis: What the Reality of Everyday Clinical Practice Shows Us.

Difficulties faced by clinicians in routine clinical practice when selecting the appropriate treatment for patients with actinic keratosis (AK) include: the independent evaluation of AK lesions, the absence of a standardized definition of field cancerization (FC), and the lack of a reproducible classification to grade the entire AK-affected area. Moreover, to assess the severity of AK, most guidelines rely on lesion count, which is often not reproducible among specialists. The present work has 2 main objectives: first, to review and highlight some of the issues clinicians tackle when classifying and monitoring AK lesions and the status of FC, looking in more detail at some of the most commonly used clinical scales for classifying AK lesions. Second, we pose questions that we encounter in daily clinical practice, and whose answers or comments help to deal with cases of AK, facilitating the work of clinicians: How should we approach AK diagnosis? How do the challenges of clinical studies on the evaluation of treatment efficacy translate into clinical practice? We review the literature on the clinical classifications and management of AK, and propose how to guide the diagnosis, management, and monitoring of patients with AK. J Drugs Dermatol. 2022;21(8):845-849. doi:10.36849/JDD.6704.

Impact of Extracorporeal Photopheresis on Blood Parameters of Atopic Dermatitis Patients.

BACKGROUND: Extracorporeal photopheresis (ECP) is a safe treatment modality with immunomodulatory effects. The latter may also explain efficacy of ECP in patients with atopic dermatitis (AD). OBJECTIVE: We aimed to assess various blood parameters of AD patients who underwent ECP over a maximum 1-year treatment period. METHODS: We performed a retrospective single-center chart review (clinical data, laboratory data) of adult patients with AD who had received for at least 3 ECP cycles, in part combined with other treatment modalities. RESULTS: We studied 60 patients with AD (85% extrinsic type, 15% intrinsic type) who had median number of 14 (4-23) ECP cycles within a maximum 1-year treatment. When compared with baseline, leukocytes and lymphocytes remained significantly decreased after 3-, 6-, 9-, and 12-month ECP ( P = 0.014 and P = 0.0012, respectively). A significant decline of eosinophils, as well as eosinophilic cationic protein levels, was observed after 3-, 6-, 9-, and 12-month ECPs ( P = 0.011 and P = 0.0017, respectively). Total serum immunoglobulin E (IgE), as well as lactate dehydrogenase, were significantly decreased at 3-, 6-, 9-, and 12-month evaluation compared with baseline ( P < 0.00001 and P = 0.00007, respectively). Patients with slight or marked improvement of AD after their ECP treatment period had significantly higher median baseline serum IgE levels than patients who did not respond to ECP ( P = 0.0023). CONCLUSIONS: Several laboratory parameters, including eosinophils, eosinophilic cationic protein, total serum IgE, and lactate dehydrogenase, which declined under ECP, are well-known disease biomarkers for AD patients. With normalization of the abovementioned laboratory parameters, a clinical response to ECP treatment was observed in almost two thirds of patients, confirming that ECP may be an effective combination treatment modality for AD.

How to Assess the Efficacy of Interventions for Actinic Keratosis? A Review with a Focus on Long-Term Results.

Actinic keratoses (AK) are common lesions of the skin caused by cumulative sun exposure. Since AK may progress to invasive cutaneous squamous cell carcinoma (cSCC), guidelines uniformly recommend early and consequent treatment. A variety of interventions are available; however, most randomized controlled trials, meta-analyses, and guidelines focus on outcomes that are usually evaluated 8-12 weeks after the end of treatment. Importantly, these assessments can capture the short-term, transient outcomes, but do not allow any conclusions about long-term results to be drawn and do not reflect the probability of transition towards cSCC. Until now, few studies have assessed the long-term results of interventions for AK. Indeed, finding the most appropriate end-point and adjunct time point for determining the long-term results of interventions for AK remains a challenge. Here, we provide an overview of the different ways of measuring the efficacy of AK treatments, such as using recurrence rates or sustained clearance rates, and discuss methodological aspects. Furthermore, we highlight the importance of evidence from post-marketing surveillance trials for the detection of efficacy values and safety signals. Additionally, we emphasize that a follow-up period of 12 months might not be sufficient to reflect the long-term results and stress the urgent need for a longer follow-up period and regular risk-stratified surveillance.

Evaluation of Long-term Clearance Rates of Interventions for Actinic Keratosis: A Systematic Review and Network Meta-analysis.

IMPORTANCE: Multiple interventions are available for the treatment of actinic keratosis (AK). However, most randomized clinical trials and meta-analyses focus on short-term efficacy outcomes. OBJECTIVE: To investigate and synthesize the long-term efficacy (≥12 months) of interventions for AK from parallel-arm randomized clinical trials. DATA SOURCES: Searches in MEDLINE, Embase, and Central were conducted from inception until April 6, 2020. The reference lists of the included studies and pertinent trial registers were hand searched. The study was completed February 27, 2021. STUDY SELECTION: Two reviewers screened the titles and abstracts of 2741 records. Finally, 17 published reports (original studies and follow-up reports) referring to 15 independent randomized clinical trials with an overall sample size of 4252 patients were included. DATA EXTRACTION AND SYNTHESIS: Two reviewers independently extracted data on study, patient, and intervention characteristics. Network meta-analysis (NMA) of each outcome was conducted with a frequentist approach. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) guidance for NMA was used to assess the certainty of evidence. The revised Cochrane risk-of-bias tool for randomized clinical trials was used to evaluate the methodologic quality. MAIN OUTCOMES AND MEASURES: Participant complete clearance, participant partial clearance, and lesion-specific clearance were the outcomes, with each assessed at least 12 months after the end of treatment. RESULTS: Data from 15 independent randomized clinical trials including 4252 patients were extracted and synthesized. Ten studies were included in an NMA for the outcome of participant complete clearance, with photodynamic therapy with aminolevulinate (ALA-PDT) showing the most favorable risk ratio (RR) compared with placebo (RR, 8.06; 95% CI, 2.07-31.37; GRADE, moderate), followed by imiquimod, 5% (RR, 5.98; 95% CI, 2.26-15.84; GRADE, very low), photodynamic therapy with methyl aminolevulinate (MAL-PDT) (RR, 5.95; 95% CI, 1.21-29.41; GRADE, low), and cryosurgery (RR, 4.67; 95% CI, 1.36-16.66; GRADE, very low). Similarly, ALA-PDT had the highest RR in the NMA for lesion-specific clearance (RR, 5.08; 95% CI, 2.49-10.33; GRADE, moderate). No NMA was possible for participant partial clearance owing to poor reporting of this outcome. CONCLUSIONS AND RELEVANCE: This systematic review and network meta-analysis found that therapy including ALA-PDT, imiquimod, 5%, MAL-PDT, and cryosurgery was associated with significant long-term efficacy in the NMA. This study provides data for a possible use in an evidence-based framework for selecting interventions with sustained lesion clearance.

The Role of Circular RNAs in Keratinocyte Carcinomas.

Keratinocyte carcinomas (KC) include basal cell carcinomas (BCC) and cutaneous squamous cell carcinomas (cSCC) and represents the most common cancer in Europe and North America. Both entities are characterized by a very high mutational burden, mainly UV signature mutations. Predominately mutated genes in BCC belong to the sonic hedgehog pathway, whereas, in cSCC, TP53, CDKN2A, NOTCH1/2 and others are most frequently mutated. In addition, the dysregulation of factors associated with epithelial to mesenchymal transition (EMT) was shown in invasive cSCC. The expression of factors associated with tumorigenesis can be controlled in several ways and include non-coding RNA molecules, such as micro RNAs (miRNA) long noncoding RNAs (lncRNA) and circular RNAs (circRNA). To update findings on circRNA in KC, we reviewed 13 papers published since 2016, identified in a PubMed search. In both BCC and cSCC, numerous circRNAs were identified that were differently expressed compared to healthy skin. Some of them were shown to target miRNAs that are also dysregulated in KC. Moreover, some studies confirmed the biological functions of individual circRNAs involved in cancer development. Thus, circRNAs may be used as biomarkers of disease and disease progression and represent potential targets of new therapeutic approaches for KC.

Treatment-resistant actinic keratoses are characterized by distinct clinical and histological features.

BACKGROUND: Actinic keratoses (AK) are generally treated to reduce the risk of progression into invasive cutaneous squamous cell carcinoma (cSCC). However, this risk of transformation is low, and rather than focusing on these lesions, current treatment studies report on complete clearance of AKs in an entire field. This study aimed to investigate treatment-resistant AKs (trAK) after field therapy compared to randomly chosen AKs prior to treatment. METHODS: AKs were clinically assessed according to the grade of hyperkeratosis and pain on palpation, prior to treatment. TrAKs were biopsied and compared to AKs which were biopsied prior to any treatment. AKs were evaluated regarding histological severity (AKI-III), their basal growth grading (PROI-III), acantholysis, elastosis, follicular extension of atypical keratinocytes and accompanying infiltrate. RESULTS: Two hundred eleven AKs in 171 patients were identified. TrAKs (N.=79) were significantly more painful (64.6% vs. 22.0%; P<0.0001), showing acantholysis (57.0% vs. 33.3%; P=0.0007); and with distinct basal proliferation (PROIII) (64.4% vs. 46.2%; P=0.0099) compared to the control group (N.=132). In a multivariate analysis using logistic regression, pain and PRO III graded lesions were significant independent (P<0.0001 and P=0.0179) predictors for trAKs. Focusing on individual histological features in the trAK group, AKs with grade AKIII, PROIII or follicular extension reaching the sebaceous gland were the most common findings with 51.9%, 64.6%, and 59.5% AKs demonstrating this, respectively. CONCLUSIONS: TrAKs are often painful, showing a distinct basal proliferation (PROIII) and acantholysis. As these features are also seen in invasive cSCCs, trAKs may represent a subgroup of AKs and, for this reason, it requires further evaluations.

Treatment responder analysis in actinic keratosis: can it lead the way to individualized choice of treatment?

BACKGROUND: It is unclear if there are any distinct AK patient populations that might respond best to a given treatment. OBJECTIVE: To identify if a distinct subgroup of patients with AK might respond better to treatment with ingenol mebutate (IngMeb) versus diclofenac sodium (DS). METHODS: Complete clearance of AK and mean lesion reduction at end of first treatment course and week 17 were evaluated within subgroups. RESULTS: 502 patients (255 IngMeb; 247 DS) were included in the analysis. At week 17, complete clearance was achieved by more patients treated with IngMeb versus DS within the majority of patient subgroups, including patients with <6 lesions and ≥6 lesions at baseline, aged ≥65 years, males, females, Fitzpatrick skin types II and III, and facial lesions. Mean lesion reduction at week 17 was greater with IngMeb than DS within the same subgroups, and in patients with scalp lesions. CONCLUSIONS: This responder analysis did not identify any distinct population that responded more optimally than others with IngMeb or DS. More patients achieved complete clearance and higher lesion reduction of AK with IngMeb compared with DS in most subgroups.

Interventions for Actinic Keratosis in Nonscalp and Nonface Localizations: Results from a Systematic Review with Network Meta-Analysis.

Myriad interventions are available for the treatment of actinic keratosis located on the face or scalp. However, lesions located outside the head and neck have received little attention until now. We aimed to synthesize the current knowledge of interventions for actinic keratosis in nonscalp and nonface localizations. Randomized controlled trials reporting data for these localizations were searched in MEDLINE, Embase, and The Cochrane Library CENTRAL, as well as in pertinent trial registers until 25 March 2020. A total of 13 randomized controlled trials with 1,380 patients were included in a systematic review. Five treatment modalities were evaluated and compared with placebo in a frequentist network meta-analysis, including cryosurgery, ingenol mebutate, photodynamic therapy, colchicine, and 5-fluorouracil. In the network meta-analysis, cryosurgery showed the highest participant complete clearance rates (risk ratio, 7.73; 95% confidence interval = 3.21-18.61; 10 studies; I2 = 20.3%; Grading of Recommendations Assessment, Development, and Evaluation, ++--) and lesion clearance rates (risk ratio, 2.97; 95% confidence interval = 2.45-3.59; 4 studies; I2 = 0%; Grading of Recommendations Assessment, Development, and Evaluation, ++--) compared with placebo. Ingenol mebutate demonstrated the highest participant partial clearance rates compared with placebo (risk ratio, 7.12; 95% confidence interval = 4.36-11.64; 5 studies; I2 = 0%; Grading of Recommendations Assessment, Development, and Evaluation, +++-). The mean reduction of lesions and occurrence of adverse events was poorly reported. The certainty of the evidence varied from very low to high and was limited by imprecision and study limitations.

Treatment Motivations and Expectations in Patients with Actinic Keratosis: A German-Wide Multicenter, Cross-Sectional Trial.

Patient-centered motives and expectations of the treatment of actinic keratoses (AK) have received little attention until now. Hence, we aimed to profile and cluster treatment motivations and expectations among patients with AK in a nationwide multicenter, cross-sectional study including patients from 14 German skin cancer centers. Patients were asked to complete a self-administered questionnaire. Treatment motives and expectations towards AK management were measured on a visual analogue scale from 1-10. Specific patient profiles were investigated with subgroup and correlation analysis. Overall, 403 patients were included. The highest motivation values were obtained for the items "avoid transition to invasive squamous cell carcinoma" (mean ± standard deviation; 8.98 ± 1.46), "AK are considered precancerous lesions" (8.72 ± 1.34) and "treating physician recommends treatment" (8.10 ± 2.37; p < 0.0001). The highest expectation values were observed for the items "effective lesion clearance" (8.36 ± 1.99), "safety" (8.20 ± 2.03) and "treatment-related costs are covered by health insurance" (8.00 ± 2.41; p < 0.0001). Patients aged ≥77 years and those with ≥7 lesions were identified at high risk of not undergoing any treatment due to intrinsic and extrinsic motivation deficits. Heat mapping of correlation analysis revealed four clusters with distinct motivation and expectation profiles. This study provides a patient-based heuristic tool for a personalized treatment decision in patients with AK.

S3 guideline for actinic keratosis and cutaneous squamous cell carcinoma (cSCC) - short version, part 2: epidemiology, surgical and systemic treatment of cSCC, follow-up, prevention and occupational disease.

Actinic keratoses (AKs) are common lesions in light-skinned individuals that can potentially progress to cutaneous squamous cell carcinoma (cSCC). Both conditions may be associated with significant morbidity and constitute a major disease burden, especially among the elderly. To establish an evidence-based framework for clinical decision making, the guidelines for actinic keratosis and cutaneous squamous cell carcinoma were developed using the highest level of methodology (S3) according to regulations issued by the Association of Scientific Medical Societies in Germany (AWMF). The guidelines are aimed at dermatologists, general practitioners, ENT specialists, surgeons, oncologists, radiologists and radiation oncologists in hospitals and office-based settings as well as other medical specialties involved in the diagnosis and treatment of patients with AKs and cSCC. The guidelines are also aimed at affected patients, their relatives, policy makers and insurance funds. In the second part, we will address aspects relating to epidemiology, etiology, surgical and systemic treatment of cSCC, follow-up and disease prevention, and discuss AKs and cSCC in the context of occupational disease regulations.

S3 guideline for actinic keratosis and cutaneous squamous cell carcinoma - short version, part 1: diagnosis, interventions for actinic keratoses, care structures and quality-of-care indicators.

Actinic keratoses (AK) are common lesions in light-skinned individuals that can potentially progress to cutaneous squamous cell carcinoma (cSCC). Both conditions may be associated with significant morbidity and constitute a major disease burden, especially among the elderly. To establish an evidence-based framework for clinical decision making, the guideline "actinic keratosis and cutaneous squamous cell carcinoma" was developed using the highest level of methodology (S3) according to regulations issued by the Association of Scientific Medical Societies in Germany (AWMF). The guideline is aimed at dermatologists, general practitioners, ENT specialists, surgeons, oncologists, radiologists and radiation oncologists in hospitals and office-based settings as well as other medical specialties involved in the diagnosis and treatment of patients with AK and cSCC. The guideline is also aimed at affected patients, their relatives, policy makers and insurance funds. In the first part, we will address aspects relating to diagnosis, interventions for AK, care structures and quality-of-care indicators.