Real-world approach to actinic keratosis management: practical treatment algorithm for office-based dermatology

If patients had a choice - Treatment satisfaction and patients' preference in therapy of actinic keratoses

BACKGROUND

Actinic keratoses (AK) are increasing in incidence and represent the most common (pre-)cancerous lesion in the fair-skinned population, with a high unmet medical need. In order to increase treatment adherence, it is very important to assess patients' therapy-related evaluations of different treatment options.

PATIENTS AND METHODS

100 patients with AK who were treated with at least two different treatment options were included. They rated their therapies using the Treatment Satisfaction Questionnaire for Medication (TSQM, maximum 100 points per category) and a Likert scale (LS, 1  =  very satisfied; 6  =  not satisfied). Patients were also asked about their needs in terms of treatment goal, cost, type, duration, and location of treatment.

RESULTS

81% of the study participants were male and on average 74 years old. 95% had field cancerization. Eight frequently used therapy procedures were evaluated by the patients (surgery, cryotherapy, various topical agents, photodynamic therapy). The TSQM satisfaction scores ranged from 78.47 ± 16.07 (surgical procedures) to 53.03 ± 22.13 (diclofenac-HA). Statistically significant differences between the procedures were only found in the area of efficacy. Side effects were classified as low. Low recurrence rate and safe removal were the most important treatment goals (LS: 1.18 ± 0.44 and 1.27 ± 0.53, respectively).

CONCLUSIONS

Understanding patient preferences is essential for adherence and is therefore of great importance for the success of AK therapy. Personalized approaches should be considered in the choice of therapy.

Dynamic optical coherence tomography unveils subclinical, vascular differences across actinic keratosis grades I-III

Actinic keratosis (AK) classification relies on clinical characteristics limited to the skin's surface. Incorporating sub-surface evaluation may improve the link between clinical classification and the underlying pathology. We aimed to apply dynamic optical coherence tomography (D-OCT) to characterize microvessels in AK I-III and photodamaged (PD) skin, thereby exploring its utility in enhancing clinical and dermatoscopic AK evaluation. This explorative study assessed AK I-III and PD on face or scalp. AK were graded according to the Olsen scheme before assessment with dermatoscopy and D-OCT. On D-OCT, vessel shapes, -pattern and -direction were qualitatively evaluated at predefined depths, while density and diameter were quantified. D-OCT's ability to differentiate between AK grades was compared with dermatoscopy. Forty-seven patients with AK I-III (n = 207) and PD (n = 87) were included. Qualitative D-OCT evaluation revealed vascular differences between AK grades and PD, particularly at a depth of 300 μm. The arrangement of vessel shapes around follicles differentiated AK II from PD (OR = 4.75, p < 0.001). Vessel patterns varied among AK grades and PD, showing structured patterns in AK I and PD, non-specific in AK II (OR = 2.16,p = 0.03) and mottled in AK III (OR = 29.94, p < 0.001). Vessel direction changed in AK II-III, with central vessel accentuation and radiating vessels appearing most frequently in AK III. Quantified vessel density was higher in AK I-II than PD (p ≤ 0.025), whereas diameter remained constant. D-OCT combined with dermatoscopy enabled precise differentiation of AK III versus AK I (AUC = 0.908) and II (AUC = 0.833). The qualitative and quantitative evaluation of vessels on D-OCT consistently showed increased vascularization and vessel disorganization in AK lesions of higher grades.

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.

Vascular feature identification in actinic keratosis grades I-III using dynamic optical coherence tomography with automated, quantitative analysis

Clinical grading of actinic keratosis (AK) is based on skin surface features, while subclinical alterations are not taken into consideration. Dynamic optical coherence tomography (D-OCT) enables quantification of the skin´s vasculature, potentially helpful to improve the link between clinical and subclinical features. We aimed to compare microvascular characteristics across AK grades using D-OCT with automated vascular analysis. This explorative study examined AK and photodamaged skin (PD) on the face or scalp. AKs were clinically graded according to the Olsen Classification scheme before D-OCT assessment. Using an open-source software tool, the OCT angiographic analyzer (OCTAVA), we quantified vascular network features, including total and mean vessel length, mean vessel diameter, vessel area density (VAD), branchpoint density (BD), and mean tortuosity from enface maximum intensity projection images. Additionally, we performed subregional analyses on selected scans to overcome challenges associated with imaging through hyperkeratosis (each lesion group; n = 18). Our study included 45 patients with a total of 205 AKs; 93 grade I lesions, 65 grade II, 47 grade III and 89 areas with PD skin. We found that all AK grades were more extensively vascularized relative to PD, as shown by greater total vessel length and VAD (p ≤ 0.009). Moreover, AKs displayed a disorganized vascular network, with higher BD in AK I-II (p < 0.001), and mean tortuosity in AK II-III (p ≤ 0.001) than in PD. Vascularization also increased with AK grade, showing significantly greater total vessel length in AK III than AK I (p = 0.029). Microvascular quantification of AK unveiled subclinical, quantitative differences among AK grades I-III and PD skin. D-OCT-based microvascular assessment may serve as a supplement to clinical AK grading, potentially raising perspectives to improve management strategies.

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.

Interdisciplinary management of skin cancer

The interdisciplinary treatment of skin cancer in the head and neck area requires close collaboration between different specialist disciplines. The most common non-melanoma skin cancer tumor entities are cutaneous squamous cell carcinoma and basal cell carcinoma as well as their precursor lesions. One of the less common tumors is Merkel cell carcinoma, which also occurs primarily in light-exposed areas and, in contrast to squamous and basal cell carcinoma, is more likely to metastasize. Due to the low tendency of basal cell carcinoma as well as cutaneous squamous cell carcinoma to metastasize, a cure can often be achieved by surgery. If the tumor growth exceeds certain levels it may require collaboration between dermatology and otorhinolaryngology. The primary goal of this interdisciplinary collaboration is to achieve a functional, cosmetically and aesthetically acceptable result in addition to adequate tumor treatment. Depending on the stage of the tumor and the clinical course, a case may be discussed in an interdisciplinary tumor board in order to determine a personalised, appropriate and adequate treatment concept for each patient, including prevention, therapy and follow-up.

Digitally Enhanced Methods for the Diagnosis and Monitoring of Treatment Responses in Actinic Keratoses: A New Avenue in Personalized Skin Care

Non-melanocytic skin cancers represent an important public health problem due to the increasing incidence and the important local destructive potential. Thus, the early diagnosis and treatment of precancerous lesions (actinic keratoses) is a priority for the dermatologist. In recent years, non-invasive skin imaging methods have seen an important development, moving from simple observational methods used in clinical research, to true diagnostic and treatment methods that make the dermatologist's life easier. Given the frequency of these precancerous lesions, their location on photo-exposed areas, as well as the long treatment periods, with variable, imprecise end-points, the need to use non-invasive imaging devices is increasingly evident to complete the clinical observations in the diagnosis and treatment of these lesions, with the aim of increasing accuracy and decreasing the adverse effects due to long treatment duration. This is the first review that brings together all skin imaging methods (dermoscopy, reflectance confocal microscopy, ultrasonography, dermoscopy-guided high frequency ultrasonography, and optical coherence tomography) used in the evaluation of actinic keratoses and their response to different treatment regimens.

A Review of the Dermatologic Clinical Applications of Topical Photodynamic Therapy

Topical photodynamic therapy is a widely approved therapy for actinic keratoses and low-risk nonmelanoma skin cancers with a rapidly growing range of emerging indications for other cutaneous diseases. This review summarizes the best-available evidence to provide a clinical update for dermatologists on the approved and emerging indications of photodynamic therapy. The body of evidence suggests that photodynamic therapy is superior or noninferior to other available treatment modalities for actinic keratoses, low-risk basal cell carcinomas, Bowen's disease, skin field cancerization, chemoprevention of keratinocyte carcinomas in organ transplant recipients, photoaging, acne vulgaris, and cutaneous infections including verrucae, onychomycosis, and cutaneous leishmaniasis. There is emerging evidence that photodynamic therapy plays a role in the management of actinic cheilitis, early-stage mycosis fungoides, extramammary Paget disease, lichen sclerosis, and folliculitis decalvans but there are no comparative studies with other active treatment modalities. Common barriers to topical photodynamic therapy include procedural pain, costs, and the time required for treatment delivery. There is significant heterogeneity in the photodynamic therapy protocols reported in the literature, including different photosensitizers, light sources, number of treatments, time between treatments, and use of procedural analgesia. Topical photodynamic therapy should be considered in the management of a spectrum of inflammatory, neoplastic, and infectious dermatoses. However, more comparative research is required to determine its role in the treatment algorithm for these dermatologic conditions and more methodological research is required to optimize photodynamic therapy protocols to improve the tolerability of the procedure for patients.

Evaluating the Efficacy and Safety of 4% 5-Fluorouracil Cream in Patients with Actinic Keratosis: An Expert Opinion

Actinic keratosis is a lesion that develops in sun-exposed areas of the skin and is considered to be a precancerous condition or an early in situ squamous cell carcinoma. Treatment of actinic keratosis is important for reducing skin cancer risk, with treatment choice based on patient-, lesion- and treatment-related considerations. Of the topical treatments used for field-directed therapy, those containing 5-fluorouracil are among the most effective and widely prescribed. The most recently developed topical 5-fluorouracil preparation (Tolak®; Pierre Fabre, France) contains 4% 5-fluorouracil in an aqueous cream. This narrative review discusses data on 4% 5-fluorouracil cream to treat actinic keratosis, and provides the authors' expert opinion on issues associated with it use. The effect of the cream has been evaluated in phase 2 and 3 trials of adult patients with actinic keratosis on the face, ears or scalp. These trials included patients with severe baseline disease, defined by high lesion counts and large-size treatment fields, which possibly affected the proportion of patients who were able to achieve complete clearance. Other efficacy parameters (e.g. percentage change in lesion count, ≥ 75% clearance of lesions or clinically significant changes in validated severity scales) should also be assessed to fully evaluate 4% 5-fluorouracil treatment efficacy in these patients. Nevertheless, 4% 5-fluorouracil is associated with high efficacy, a low level of recurrence and a satisfactory safety profile.

Topical Treatments for Basal Cell Carcinoma and Actinic Keratosis in the United States

Skin cancer is an overarching label used to classify a variety of cutaneous malignancies. Surgical excision procedures are the commonly used treatments for these lesions; however, the choice to perform operative intervention may be influenced by other factors. Established research and literature suggest that topical treatments limit the need for surgical intervention and its commonly associated adverse effects, including infection and scarring. In addition, the growing indications for the usage of topical therapies in BCC treatment, as well as their increased availability and therapeutic options, allow for their greater applicability in the dermatology clinic. Certain topical therapies have been highlighted in research, especially those targeting basal cell carcinoma (BCC) and actinic keratosis (AK). There is also a clear correlation between cost and treatment outcomes, considering BCC's ever-growing prevalence and the proportion of excised lesions being reported as malignant. This review will discuss BCC and AK lesion criteria that result in the most successful outcomes using topical treatments, then highlight the various topical treatment options, and finally address their clinical significance moving forward.

Topical GZ21T Inhibits the Growth of Actinic Keratoses in a UVB-Induced Model of Skin Carcinogenesis

Actinic keratoses (AKs) are premalignant intraepidermal neoplasms that occur as a result of cumulative sun damage. AKs commonly relapse, and up to 16% undergo malignant transformation into cutaneous squamous cell carcinoma. There is a need for novel therapies that reduce the quantity and surface area of AKs as well as prevent malignant transformation to cutaneous squamous cell carcinomas. We recently showed that GZ17-6.02, an anticancer agent composed of curcumin, haramine, and isovanillin, inhibited the growth of H297.T cells. This study evaluated the efficacy of a topical formulation of GZ17-6.02, known as GZ21T, in a murine model of AK generated by exposing SKH1 mice to UVR. Treatment of mice with topical GZ21T inhibited the growth of AKs by decreasing both lesion count (P = 0.012) and surface area occupied by tumor (P = 0.002). GZ21T also suppressed the progression of AKs to cutaneous squamous cell carcinoma by decreasing the count (P = 0.047) and surface area (P = 0.049) of lesions more likely to represent cutaneous squamous cell carcinoma. RNA sequencing and proteomic analyses revealed that GZ21T suppressed several pathways, including MAPK (P = 0.025), phosphoinositide 3-kinase-protein kinase B (P = 0.04), HIF-1α (P = 0.016), Wnt (P = 0.025), insulin (P = 0.018), and ERBB (P = 0.016) signaling. GZ21T also upregulated the autophagy-promoting protein AMPK while suppressing proteins such as PD-L1, glutaminase, pAkt1 S473, and eEF2K.

A Review of MAL-PDT for the Treatment Strategy of Actinic Keratosis: Broader Clinical Perspectives Beyond the Data and Guideline Recommendations

Methyl aminolevulinate (MAL) is a topical compound approved for use with photodynamic therapy (PDT) for the treatment of actinic keratosis (AK) and field cancerization in certain countries. There exists a high burden of disease for patients with AK: repeated treatments are required, there is a known risk of progression to keratinocyte carcinoma, and cosmetic appearance is affected. Delivery of PDT using MAL is a flexible treatment strategy available in many forms; red light, daylight, or artificial daylight can be used for illumination, all of which result in high AK clearance rates and low recurrence. MAL-PDT protocols continue to evolve to further improve adherence and treatment outcomes. Here, we used PubMed to search MEDLINE to identify guidelines, consensus recommendations, and studies describing the use of MAL for the treatment of AK. The aim of this targeted review is to consider various MAL-PDT treatment strategies on the basis of published literature, with a focus on personalizing treatment for the heterogeneous AK population.

Actinic Keratoses: A Prospective Pilot Study on a Novel Formulation of 4% 5-Fluorouracil Cream and a Review of Other Current Topical Treatment Options

BACKGROUND

Actinic keratosis (AK) is one of the most common skin diseases, with a low risk of progression into invasive squamous cell carcinoma. We aim to assess efficacy and safety of a novel formulation of 5-Fluorouracil (5-FU) 4% with once daily application for the treatment of multiple AKs.

METHODS

A pilot study was performed on 30 patients with a clinical and dermoscopic diagnosis of multiple AKs, enrolled between September 2021 and May 2022 at the Dermatology Departments of two Italian hospitals. Patients were treated with 5-FU 4% cream once daily for 30 consecutive days. The Actinic Keratosis Area and Severity Index (AKASI) was calculated before starting therapy, and at each follow-up, to assess objective clinical response.

RESULTS

The cohort analyzed included 14 (47%) males and 16 (53%) females (mean age: 71 ± 12 years). A significant decrease in AKASI score at both 6 and 12 weeks (p < 0.0001) was observed. Only three patients (10%) discontinued therapy, and 13 patients (43%) did not report any adverse reactions; no unexpected adverse events were observed.

CONCLUSIONS

In the setting of topical chemotherapy and immunotherapy, the new formulation of 5-FU 4% proved to be a highly effective treatment for AKs and field cancerization.

Tirbanibulin for Actinic Keratosis: Insights into the Mechanism of Action

Actinic keratosis (AK) is a common pre-neoplastic skin lesion constituted by uncontrolled proliferation of atypical keratinocytes that may evolve to squamous cell carcinoma. With global prevalence increasing, AK is expected to be the most common carcinoma of the skin. Tirbanibulin is a reversible tubulin polymerization inhibitor with potent anti-proliferative and anti-tumoral effects. In-vivo and in-vitro studies have shown that tirbanibulin significantly inhibits cell proliferation, tumor growth and downregulates Src signaling with no overt toxicity. Early phase and Phase III trials have shown high lesion clearance, compliance, and few side effects of once daily tirbanibulin treatment. This review discusses tirbanibulin anti-cancer activity, focusing on tubulin polymerization and Src signaling inhibitory effects, highlighting relevant literature and novel preclinical results from the ATNXUS-KX01-001 study. Furthermore, we address the relevant findings obtained in recent clinical trials to evaluate the safety, efficacy, pharmacokinetics, clearance efficacy, and side effects of the 1% tirbanibulin ointment applied once daily. In summary, we highlight preclinical and clinical evidence on the use of tirbanibulin as an effective and safe treatment option for AK.

Topical Treatment of Actinic Keratosis and Metalloproteinase Expression: A Clinico-Pathological Retrospective Study

Actinic keratosis is an intraepithelial proliferation of atypical keratinocytes that could progress into invasive squamous cell carcinoma. Most evidence suggests an important role of the dermal matrix metalloproteinases in the progression of atypical skin epithelial lesions. We evaluated the clinical efficacy of three different therapeutic modalities (a medical device containing 0.8% piroxicam cream and 50+ sunscreen, photodynamic therapy, and ingenol mebutate gel) to treat suspicious actinic keratoses, which were biopsied for histopathological examination and then analyzed for the expression of matrix metalloproteinases by immunohistochemistry. Clinical, dermoscopic, and reflectance confocal microscopy evaluations revealed a gradual decrease in all standard scores validated for actinic keratosis assessment at the end of the treatments. From a histopathological point of view, we documented the substantial restoration of normal skin architecture, while the immunohistochemical evaluation of matrix metalloproteinases showed a reduction in expression in the treated skin lesions compared to the baseline. As actinic keratoses are considered the precursors of squamous cell carcinoma, their treatment is crucial to prevent the development of a more aggressive disease. Our study monitored the evolution of actinic keratoses subjected to three different topical therapies, with the value of correlating clinical and histopathological findings. Moreover, as the matrix metalloproteinases are largely recognized factors involved in the pathogenesis and evolution of actinic keratosis to squamous cell carcinoma, the demonstration by immunohistochemistry of a reduction in their expression after the treatments adds new valuable concern to the field.

Actinic Keratoses (AK): An Exploratory Questionnaire-Based Study of Patients’ Illness Perceptions

Simple Summary

We recorded 208 patients receiving treatment for AK and conducted a cross-sectional questionnaire-based study, which aimed to investigate patients’ perceptions of their illness. Our main objective was the detection not only of the illness perception of AK patients, but also of its influence on their perception of treatment and the correlation with patients’ demographic characteristics and history, as well as the readiness to use sunscreen. The rising incidence of AK and its socioeconomic burden place the illness perception of AK patients among the most important barriers to overcome for the effective management of the disease. To the best of our knowledge, this is one of the first studies to attempt to unveil the illness perceptions of AK patients and their correlation with patients’ demographics and sunscreen use and the influence on AK treatment. We strongly support reinforcing the awareness of AK and the role of dermatologists is crucial for this direction.

Abstract

Background: Decreased illness perception among actinic keratoses (AK) patients is a major barrier to the effective management of AK. Objective: We aimed to investigate patients’ illness and treatment perceptions, their correlation to demographics and AK/skin cancer history, and secondarily the influence of these perspectives on treatment and sunscreen use. Materials and Methods: Participants completed questionnaires based on the Brief Illness Perception Questionnaire and statistical analysis was performed. Results: In total, 208 AK patients were enrolled. A large proportion were poorly aware of the disease (41.4%), with less than half (43%) being familiar with AK. Patients were aware of the chronic nature of the disease and its correlation to sunlight regardless of demographic characteristics. The level of education played a role in disease awareness (p = 0.006), and treatment plan perception (p = 0.002). The increase in sunscreen protection after AK diagnosis was higher in women (p = 0.009) and younger patients (p = 0.044). Patients’ concerns regarding treatment were mainly related to the duration (30%) and effectivity (25%). Dermatologists’ statements highlighting that AK are precancerous lesions (86.2%) influenced patients’ willingness for treatment. Conclusion: Improved awareness of AK is necessary to increase treatment seeking and compliance, regarding both treatment and sunscreen use. Dermatologists’ statements may have critical influence on patients’ decisions to receive treatment for AK.

Treatment of Actinic Keratosis: The Best Choice through an Observational Study

Actinic keratosis (AK) is a precancerous lesion that can progress to invasive squamous cell carcinoma if untreated. However, no gold standard treatment has been established. We aimed to investigate the management of AK by comparing the effectiveness and treatment duration of treatment modalities, including cryotherapy, imiquimod (IMQ), and photodynamic therapy (PDT). We reviewed the medical records of 316 patients diagnosed with AK at Seoul St. Mary’s Hospital from February 2015 to May 2020, and a total of 195 patients were included. The clearance rate was the highest in PDT, followed by cryotherapy and IMQ (82.4%, 71.2%, and 68.0%, respectively). The recurrence rate was the lowest in cryotherapy, followed by PDT and IMQ (3.5%, 6.7%, and 10.5%, respectively, p < 0.05). The average treatment duration was shortest with PDT, followed by IMQ and cryotherapy (5.5 weeks, 6.8 weeks, and 9.1 weeks, respectively, p < 0.05). The number of hospital visits was lowest for PDT, followed by cryotherapy and IMQ (1.8, 2.8, and 3.6, respectively, p < 0.05). PDT showed the highest clearance rate, a moderate recurrence rate, the shortest treatment duration, and the least number of visits, suggesting that PDT could be the first choice for treatment of AK. Considering the advantages as a topical agent, IMQ could also be a treatment option.

A Review of Existing Therapies for Actinic Keratosis: Current Status and Future Directions

Actinic keratosis (AK) is a chronic skin disease in which clinical and subclinical cutaneous lesions coexist on sun-exposed areas such as the head and neck region and the extremities. The high prevalence of AK means the disease burden is substantial, especially in middle-aged and elderly populations. Evidence indicates that AK may progress into invasive cutaneous squamous cell carcinoma, so the European guidelines recommend treatment of any AK regardless of clinical severity. Given the aging population and therefore the increasing incidence of AK and cutaneous field carcinogenesis, further updates on the long-term efficacy of current therapies and new investigational agents are critical to guide treatment choice. Patients often have difficulty adequately applying topical treatments and coping with adverse local skin reactions, leading to less than optimum treatment adherence. The development of associated local skin symptoms and cosmetic outcomes for the area of interest are also relevant to the choice of an appropriate therapeutic strategy. Treatment is always individually tailored according to the characteristics of both patients and lesions. This review focuses on the therapeutic approaches to AK and illustrates the currently available home-based and physician-managed treatments.

Colchicine in Managing Skin Conditions: A Systematic Review

(1) Background: Colchicine is a natural alkaloid with anti-inflammatory properties used to treat various disorders, including some skin diseases. This paper aims to incorporate all the available studies proposing colchicine as a treatment alternative in the management of cutaneous conditions. (2) Methods: In this systematic review, the available articles present in various databases (PubMed, Scopus-Embase, and Web of Science), proposing colchicine as a treatment for cutaneous pathological conditions, have been selected. Exclusion criteria included a non-English language and non-human studies. (3) Results: Ninety-six studies were included. Most of them were case reports and case series studies describing colchicine as single therapy, or in combination with other drugs. Hidradenitis suppurativa, pyoderma gangrenosum, erythema nodosum, erythema induratum, storage diseases, perforating dermatosis, bullous diseases, psoriasis, vasculitis, acne, urticaria, stomatitis, actinic keratosis, and pustular dermatosis were the main diseases discussed in literature. Although the therapeutic outcomes were variable, most of the studies reported, on average, good clinical results (4) Conclusions: Colchicine could be, as a single therapy or in combination with other drugs, a possible treatment to manage several skin diseases.

Intensity of Local Skin Reactions During 5-Fluorouracil Treatment Related to the Number of Actinic Keratosis Lesions: A Post Hoc, Exploratory Analysis

INTRODUCTION

Actinic keratoses (AK) are epithelial lesions caused by chronic skin exposure to ultraviolet light that can progress into squamous cell carcinoma. Although several treatments are effective, they are associated with severe skin reactions, which might be related to the extent of the disease. This study aimed to examine the relationship between the severity of local skin reactions during treatment with 5-fluorouracil 4% cream and the number of AK lesions at baseline.

METHODS

This post hoc analysis pooled data from two multicentre randomised phase III studies (HD-FUP3B-048, HD-FUP3B-049) in patients with AK treated with topical 5-fluorouracil 4% once daily (OD) or 5% twice daily (BID) for 4 weeks. First, we compared the severity, assessed using a numerical rating scale, of the local skin reactions between 5-fluorouracil 4% and 5%. Then, we investigated the relationship between the number of lesions at baseline and severe skin reactions with 5-fluorouracil 4% OD.

RESULTS

Safety data were included from 397 patients who had received 5-fluorouracil 4% (348 in study HD-FUP3B-048, 49 in study HD-FUP3B-049) OD and 342 (HD-FUP3B-048) who had received 5-fluorouracil 5% BID. For most skin reactions, severe ones were more common in patients treated with 5-fluorouracil 5% cream BID than in those treated with 5-fluorouracil 4% cream OD (P < 0.05). With 5-fluorouracil 4% OD, the incidence of severe erythema was significantly higher in patients with at least 10 lesions (46%) than in patients with 5-10 lesions (28%; P < 0.001). Similar results were observed for the other local skin reactions.

CONCLUSION

Treatment with 5-fluorouracil 4% cream OD was associated with less severe local skin reactions than 5-fluorouracil 5% BID. The number of AK lesions at baseline seems to have predictive value regarding the severity of local skin reactions that appear during treatment.

Clinical Pharmacokinetics and Safety of a 10% Aminolevulinic Acid Hydrochloride Nanoemulsion Gel (BF-200 ALA) in Photodynamic Therapy of Patients Extensively Affected With Actinic Keratosis: Results of 2 Maximal Usage Pharmacokinetic Trials

The nanoemulsion‐based 10% aminolevulinic acid (ALA) hydrochloride gel BF‐200 ALA optimizes epidermal penetration of its active ingredient and is approved for topical photodynamic therapy (PDT) for the treatment of actinic keratosis in the United States and Europe. To characterize systemic absorption from dermal application during PDT, ALA and its key active metabolite protoporphyrin IX (PpIX) were analyzed in 2 maximal usage pharmacokinetic trials (MUsT) in patients severely affected with actinic keratosis. The primary objective of both MUsTs was to assess baseline‐adjusted plasma concentration–time curves for ALA and PpIX after a single PDT treatment applying either 2 g (1 tube) of BF‐200 ALA on the face (MUsT‐1) or applying 6 g (3 tubes) of BF‐200 ALA on the face/scalp or body periphery (MUsT‐2), to 20 or 60 cm², respectively. All PDTs were performed using red light at around 635 nm wavelength. Safety and tolerability were documented along with pharmacokinetics. In both MUsTs, ALA plasma concentrations were transiently increased to a maximum concentration at about 2.5 to 3.3 times above endogenous baseline with time to maximum concentration at ≈3 hours after dosing. Plasma levels subsequently returned to baseline within 10 hours after dosing. Overall baseline‐adjusted mean area under the baseline‐adjusted plasma concentration‐time curve from time zero to the last sampling time point at which the concentration was at or above the lower limit of quantification ranged from 142.8 to 146.2, indicating that a similar, minor fraction of topical ALA is systemically absorbed under both dosing regimens. Systemic PpIX exposure after administration of either dose of BF‐200 ALA was equally minimal. Application site skin reactions were treatment area size‐related, albeit transient and consistent with the known safety profile of BF‐200 ALA.

1% Tirbanibulin Ointment for the Treatment of Actinic Keratoses

Objective

Actinic keratoses (AKs) are cutaneous lesions that arise in sun-damaged skin. AKs may transform into squamous cell carcinoma in situ. Tirbanibulin 1% ointment is a new topical treatment for AKs, recently approved by the Food and Drug Administration.

Data Sources

The PubMed database was searched for articles published from 1960 to March 31, 2021, using the keywords tirbanibulin and Klisyri.

Data Extraction

Phase 2 and phase 3 clinical trials were reviewed.

Data Synthesis

In phase 2 clinical trials, 43% of patients treated with tirbanibulin experienced complete clearance by day 57 (43% [95% CI = 32, 54]). Across two phase 3 clinical trials (pooled data), complete (100%) clearance occurred in 49% of patients in tirbanibulin groups and in only 9% of the vehicle groups (difference, 41% points; 95% CI = 35 to 47; P < 0.001). Although no comparative studies are available, tirbanibulin is applied for a shorter duration (5 days) compared with diclofenac 3% gel, fluorouracil 5% cream, and imiquimod 3.75% cream. Adverse events were mild and included pruritus, application site pain, and local skin reactions. Systemic adverse events such as necrosis and angioedema, observed with other AK treatments such as fluorouracil and imiquimod, were not observed with tirbanibulin, thus giving tirbanibulin a favorable safety profile.

Relevance to Patient Care and Clinical Practice

Tirbanibulin effectively reduces AK burden and recurrence and has a favorable safety profile with mild adverse events. In comparison, imiquimod, 5-flourouracil, and diclofenac can result in necrosis, angioedema, and arthralgias.

Conclusion

With a favorable safety profile and short regimen, tirbanibulin is an efficacious treatment for clinicians to utilize in their treatment toolbox when treating AKs on the face and scalp.

Treatment adherence with diclofenac 3% gel among patients with multiple actinic keratoses: an integrated low-intensity intervention program versus standard-of-care

BACKGROUND

Diclofenac 3% gel is a widely used topical treatment with proven efficacy in reducing the burden of Actinic Keratosis (AK), however clinical benefit might not fully translate in clinical practice as non-adherence is substantial for prolonged treatment regimens. We evaluated the efficacy of an integrated low-intensity intervention program versus standard-of-care on treatment adherence among patients with multiple AK receiving diclofenac in hyaluronic acid gel 3%.

METHODS

We designed an open label, randomized, parallel group, interventional, multicenter, longitudinal cohort study including patients with multiple, grade I/II AKs. Visits were scheduled for end of treatment (T4), follow-up 1 (T5) and follow-up 2 (T6) at 90, 180 and 365 days from baseline, respectively. Patients in the intervention group received additional visits at 30 and 60 days from baseline, a brief health education intervention, an enhanced patient-physician communication, a weekly SMS reminder to medication prescriptions.

RESULTS

Patients were equally allocated between intervention (intervention group [IG], N=86) and control group (CG, N=86); at baseline, both groups had similar socio-demographic and clinical characteristics. Change scores from baseline showed a slight increment in quality of life related to AK in both groups (CG: ΔT4 - T1=-0.079; IG: ΔT4 - T1=-0.006; p=0.39) and in quality of physicianpatient interaction reported by IG (ΔT3 - T2=0.18; p<.0001). Adherence rate was not statistically different between IG and CG (28.4% vs 40.7%; p=0.11). Patients reported similar satisfaction for effectiveness, convenience and side effects of treatment. Clinical conditions improved over time and results did not differ between groups; complete clearance rate at 1 year was 18% and 29% for CG and IG, respectively.

CONCLUSIONS

Our findings showed no difference in adherence rate between the two groups, suggesting that enhanced follow-up interventions and health care education may not be sufficient drivers to promote adherence among this clinical population. Further studies are needed to explore barriers to adherence with treatments for AKs.

Vitamin D and Vitamin D Analogs as Adjuncts to Field Therapy Treatments for Actinic Keratoses: Current Research and Future Approaches

Actinic keratoses (AK), also known as solar keratoses, are precancerous hyperkeratotic papules caused by long-term exposure to ultraviolet radiation. Management of AK prior to progression to cutaneous malignancy represents an important window of intervention. This is important on a population level, given the high incidence, morbidity, financial costs, and the low but measurable risk of mortality from cutaneous neoplasia. Treatments for AK have been refined for many years with significant progress over the past decade. Those recent advancements lead to questions about current treatment paradigms and the role of harnessing the immune system in field therapies. Recent studies suggest a key interplay between vitamin D and cancer immunity; in particular, the systemic and/or topical vitamin D analogs can augment field therapies used for severe actinic damage. In this review, we will examine the literature supporting the use of vitamin D-directed therapies to improve field therapy approaches. An enhanced understanding of these recent concepts with a focus on mechanisms is important in the optimized management of AK. These mechanisms will be critical in guiding whether selected populations, including those with immunosuppression, heritable cancer syndromes, and other risk factors for skin cancer, can benefit from these new concepts with vitamin D analogs and whether the approaches will be as effective in these populations as in immunocompetent patients.

Cold Atmospheric Plasma (CAP) for the Treatment of Actinic Keratosis and Skin Field Cancerization: Clinical and High-Frequency Ultrasound Evaluation

INTRODUCTION

Cold atmospheric plasma (CAP) has been clinically demonstrated to be an effective treatment for actinic keratosis (AK) in a number of case series. In this study, we evaluated the efficacy of CAP in the treatment of multiple AKs and assessed morphological changes induced on the skin field of cancerization both clinically and by high-frequency ultrasound (HFUS).

METHODS

Patients with multiple grade I-II AKs of the scalp and/or face who were resistant or intolerant to conventional field-directed treatments were enrolled. CAP treatments were performed using a microwave-driven argon plasma jet. At baseline and 3 months after the last CAP session, performance indexes were determined using three-dimensional digital pictures and HFUS investigations were performed on a representative Olsen grade II AK and a small spot of clinically unaffected skin within the test area.

RESULTS

Twelve patients were enrolled in the study. All clinical variables showed a statistically significant reduction after CAP. HFUS evaluation revealed that the total, epidermal and dermal thicknesses of the target AKs had not changed with treatment. CAP therapy significantly increased dermal density in both the target AK and the surrounding photodamaged skin and signficantly decreased the thickness of the subepidermal low-echogenic band in the perilesional skin, which is an ultrasound sign of photodamage.

CONCLUSIONS

Cold atmospheric plasma was found to be an effective treatment for patients with multiple AKs. CAP was not followed by skin atrophy. HFUS examiniation showed the CAP improved features of chronic photodamage of the dermis of the skin underlying and surrounding the AK spots.

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.

Mouse models for actinic keratoses

Actinic keratoses (AKs) represent a premalignant skin condition due to chronic sun damage that dramatically increases in prevalence in the aging population. Currently, animal models of AKs utilize photocarcinogenesis, chemical carcinogens, or targeted gene modulation, and each method possesses unique strengths and weaknesses. Models using photodamage most comprehensively describe methods for preferentially selecting AK lesions, while replicating the pathogenesis of AKs with greater fidelity than models utilizing other carcinogenic methods. The following review of current murine models of AKs will aid in the selection of mouse models appropriate for future in vivo studies to test the efficacy of novel therapeutic agents for the treatment of AKs.

Developments and challenges in dermatology: an update from the Interactive Derma Academy (IDeA) 2019

The 2019 Interactive Derma Academy (IDeA) meeting was held in Lisbon, Portugal, 10-12 May, bringing together leading dermatology experts from across Europe, the Middle East and Asia. Over three days, the latest developments and challenges in relation to the pathophysiology, diagnosis, evaluation and management of dermatological conditions were presented, with a particular focus on acne, atopic dermatitis (AD) and actinic keratosis (AK). Interesting clinical case studies relating to these key topics were discussed with attendees to establish current evidence-based best practices. Presentations reviewed current treatments, potential therapeutic approaches and key considerations in the management of acne, AK and AD, and discussed the importance of the microbiome in these conditions, as well as the provision of patient education/support. It was highlighted that active treatment is not always required for AK, depending on patient preferences and clinical circumstances. In addition to presentations, two interactive workshops on the diagnosis and treatment of sexually transmitted infections/diseases (STIs/STDs) presenting to the dermatology clinic, and current and future dermocosmetics were conducted. The potential for misdiagnosis of STIs/STDs was discussed, with dermoscopy and/or reflectance confocal microscopy suggested as useful diagnostic techniques. In addition, botulinum toxin was introduced as a potential dermocosmetic, and the possibility of microbiome alteration in the treatment of dermatological conditions emphasized. Furthermore, several challenges in dermatology, including the use of lasers, the complexity of atopic dermatitis, wound care, use of biosimilars and application of non-invasive techniques in skin cancer diagnosis were reviewed. In this supplement, we provide an overview of the presentations and discussions from the fourth successful IDeA meeting, summarizing the key insights shared by dermatologists from across the globe.

Actinic keratoses contiguous with squamous cell carcinomas are mostly non-hyperkeratotic and with severe dysplasia

AIMS

Actinic keratosis (AK) is a precursor of cutaneous squamous cell carcinoma (SCC). No validated parameters can predict which AKs will progress into SCCs, but especially thick AKs are under suspicion. The clinical and histopathological thickness of AKs is strongly correlated. This study aimed to investigate the thicknesses and degree of dysplasia of AKs contiguous with SCCs assuming these AKs represent the AKs that have undergone malignant transformation.

METHODS

Files of the Pathology Department, Hospital of Southern Jutland, Denmark, were reviewed. 111 cases met the inclusion criteria: a skin biopsy containing an invasive SCC. All SCCs merged with an AK at the edge. Degree of dysplasia, epidermal thickness and stratum corneum thicknesses of AKs were measured.

RESULTS

All AKs showed severe dysplasia. Most AKs had a stratum corneum thickness under 0.1 mm and an epidermal thickness under 0.5 mm, corresponding to clinically thin and non-hyperkeratotic AKs.

CONCLUSIONS

Our result suggests malignant progression potential of AKs regardless of thickness.

High-frequency ultrasound in the diagnosis of the spectrum of cutaneous squamous cell carcinoma: Noninvasively distinguishing actinic keratosis, Bowen's Disease, and invasive squamous cell carcinoma

OBJECTIVE

To evaluate high-frequency ultrasound (HFUS) features for diagnosing cutaneous squamous cell carcinoma (cSCC) as a spectrum of progressively advanced malignancies, including precursor actinic keratosis (AK), Bowen's disease (BD), and invasive squamous cell carcinoma (iSCC).

METHOD

In this retrospective study, 160 skin lesions diagnosed histopathologically (54 AK, 54 BD, and 52 iSCC) in 160 patients were included. The HFUS features of AK, BD, and iSCC were analyzed. The obtained data were evaluated using univariate and forward multivariate logistic regression analyses.

RESULTS

The most significant HFUS features in AK were regular surface (odds ratio [OR], 8.42) and irregular basal border (OR, 6.36). The most significant HFUS features in BD were crumpled surface (OR, 19.62) and layer involvement confined to the epidermis (OR, 3.96). The most significant HFUS features in iSCC were concave surface (OR, 27.06), stratum corneum (SC) detachment (OR, 14.41), irregular basal border (OR, 4.01), and convex surface (OR, 3.73). The characteristics of surface features, basal border, and layer involvement could be valuable HFUS clues in the discrimination of AK, BD, and iSCC.

CONCLUSION

High-frequency ultrasound is valuable for the differentiation of AK, BD, and iSCC, which may allow dynamic and noninvasive monitoring in the spectrum of cSCC.

Effectiveness and tolerability of treatment for isolated actinic keratoses: A retrospective comparison between cryotherapy, CO2 laser and 5-fluorouracil 0.5%/salicylic acid 10

Actinic keratoses (AK) have been described as either intraepithelial keratinocytic dysplasia that can evolve into invasive squamous cell carcinoma (SCC) or as in situ SCC that can progress into an invasive form. A retrospective study was conducted to compare outcomes of three different topical therapies for patients with single AK (<4): cryotherapy, CO₂ laser and 5-fluorouracil 0.5%/salicylic acid 10%. We included 72 patients who presented at the Dermatology Clinic of Maggiore Hospital of Trieste between 1 November 2019 and 31 January 2020 for the treatment of AKs. All treatments led to a significant reduction in the average diameter of AK. Pain felt by patients was significantly lower after 5-FU 0.5%/SA 10%. Side effects appeared similarly distributed among the three groups, with erythema and crusts being the most frequent. Aesthetic outcomes were highest in the 5-FU 5%/SA 10% group, as evaluated by both the patient and the operator. Cryotherapy, CO₂ laser and 5-FU 5%/SA 10% were all effective, with no significant efficacy differences among them. Additionally, 5-FU 5%/SA 10% was proved to have the best aesthetic result and to cause the least pain, while necessitating long-term administration. This should be taken into account for patients with low pain tolerance and low treatment adherence. Cryotherapy and CO₂ laser have the advantage of requiring a single session, which might be more suitable for uncooperative patients.

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.

Field cancerization in clinically solitary actinic keratosis: A pilot study

Clinical studies have demonstrated that subclinical actinic keratoses (AKs) may be clinically evidenced following treatment of multiple AKs with a topical immunotherapy agent known to reveal a "field cancerization". The aim of our study was to investigate if subclinical AKs may be evidenced also in case of single AKs. Ten patients with single, solitary AKs were treated with IQ 3.75% cream applied on the lesion and on a 5 × 5 cm surrounding area once daily for two 2-week treatment cycles separated by a 2-week treatment-free period. Lesions were evaluated by clinical, dermoscopic and RCM examination. At the end of treatment, subclinical lesions were evidenced in 8 of 10 patients revealing the presence of a field cancerization. If larger studies will confirm these results, field cancerization could likely be considered also in case of solitary AKs, resulting in a different approach in terms of disease evolution and treatment.

Use of complete clearance for assessing treatment efficacy for 5-fluorouracil interventions in actinic keratoses: how baseline lesion count can impact this outcome

Background: Many trials in actinic keratoses (AK) use complete clearance rate (100% reduction in number of lesions) as the primary endpoint. We explore limitations (predominantly baseline factors) associated with this outcome. Objective: This analysis assessed the effect of baseline lesion count on complete clearance rate using randomized controlled trials (RCTs) that evaluated 5-fluorouracil (5-FU) formulations, alone or with 10% salicylic acid solution, in patients with AK. Methodology: Correlation between baseline lesion count and complete clearance rate at week 8 was assessed using Pearson's coefficient. Results: Five RCTs assessing 5-FU (4%, 5%, or 0.5% in 10% salicylic acid solution) in 1,080 patients with AK were included. Mean lesion count at baseline ranged from 8.1 to 21.2 lesions per patient. Complete clearance rate was negatively associated with number of lesions at baseline. Correlation between mean number of lesions at baseline and complete clearance rate was strong (r² = 0.94) and statistically significant (p < 0.001). Conclusion: This analysis showed that, in a homogenous set of trials, complete clearance rates achieved with 5-FU interventions are inversely related to number of lesions at baseline. These findings highlight the limits of restricting treatment evaluation to complete clearance rate and the relevance of alternative measures.

[Actinic keratosis]

Actinic keratoses (AK) are common precancerous cutaneous lesions in fair-skinned individuals as a result of cumulative exposure to ultraviolet radiation. Due to their high prevalence, AK account for a large disease burden, in particular in older persons. As AK may potentially progress into invasive cutaneous squamous cell carcinoma, guidelines recommend early and consequent treatment. Numerous lesion- and field-directed interventions with different efficacy and safety profiles are currently licensed in Germany. The appropriate intervention should be chosen together with the patient based on his or her motivation and expectations towards the treatment.

Non-Melanoma Skin Cancers: Biological and Clinical Features

Non-melanoma skin cancers (NMSCs) include basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and Merkel cell carcinoma (MCC). These neoplasms are highly diverse in their clinical presentation, as well as in their biological evolution. While the deregulation of the Hedgehog pathway is commonly observed in BCC, SCC and MCC are characterized by a strikingly elevated mutational and neoantigen burden. As result of our improved understanding of the biology of non-melanoma skin cancers, innovative treatment options including inhibitors of the Hedgehog pathway and immunotherapeutic agents have been recently investigated against these malignancies, leading to their approval by regulatory authorities. Herein, we review the most relevant biological and clinical features of NMSC, focusing on innovative treatment approaches.

[Actinic keratoses : Current guideline and practical recommendations]

The S3 guideline "Actinic keratosis and squamous cell carcinoma of the skin" was published on 30 June 2019. Subsequently, publications, reviews and meta-analyses appeared with new questions regarding the comparability of study data and heterogeneity of the evaluations, which are caused, among other things, by divergent measurement parameters as well as insufficient consideration of pretreatments and combined treatments. This concise overview was written in the context of criticism and in view of necessary developments and research. Topics include epidemiology, pathogenesis, prevention, clinical presentation, therapy and BK5103. Therapy is divided into local destructive procedures and topical applications. Recommendations with quotation marks are based on the actual guideline. Corresponding evidence levels are given. For the implementation in daily routine basic data, side effects and features of therapeutic options are mentioned. The current developments and questions concerning actinic keratoses become clear.

Evaluation of diagnostic criteria of actinic keratosis through reflectance confocal microscopy

BACKGROUND

The diagnosis of actinic keratosis (AK) is based on clinical evaluation and confirmed by histopathological analysis (HA). The challenge is to establish the correct diagnosis with a minimally invasive assessment. The aim of this study is to validate the analysis of AK by reflectance confocal microscopy (RCM), a cellular resolution, noninvasive imaging method and to determine the relevant parameters for diagnosis, compared to HA, by calculating the sensitivity (S), specificity (E), positive predictive value (PPV), and negative predictive value (NPV) of each criterion.

MATERIALS AND METHODS

Through clinical examination, 25 AKs were selected for dermoscopy and RCM evaluation followed by shaving excision for HA. Statistical analysis was done by hypothesis tests (McNemar for binary and Wilcoxon for continuous variables).

RESULTS

There was no significant difference between RCM and HA for 5 of the 6 parameters analyzed. The criteria that were statistically relevant were as follows: parakeratosis (p-value 0.449690; S 90%; PPV 78.26%), hyperkeratosis (p-value 0.248213; S 87.5%; E 100%; PPV 100%; NPV 25%), dyskeratosis (p-value 0.617075; S 85.71%; E 75%; PPV 94.74%; NPV 50%), spinous layer keratinocyte atypia classified as mild, moderate or severe (P-value 0.145032) and inflammation in epidermis (P-value 1.000000; S 75%; E 20%; PPV 78.95%; NPV 16.67%). RCM could not adequately measure inflammation in dermis (P-value 0.013328), despite good sensitivity (68%) and PPV (100%).

CONCLUSION

RCM proved to be an effective method for the diagnosis of AK, contributing to the selection of the most appropriate treatment option.

Treatment monitoring of 5-fluorouracil 0.5%/salicylic acid 10% lesion-directed therapy for actinic keratosis using dermoscopy and in-vivo reflectance confocal microscopy

Recently, 5-fluorouracil 0.5%/salicylic acid 10% (5-FU/SA) topical solution has been included in the National Italian portfolio for lesion-directed treatment of grade I/II actinic keratosis (AKs) located on the face or scalp. To describe the utility of dermoscopy and RCM in treatment response monitoring of a series of AKs treated with 5-FU/SA as lesion-directed therapy. Consecutive patients were prospectively treated for a maximum of 12 weeks with 5-FU/SA for AKs located on the face or scalp. Clinical, dermoscopic, and confocal images of one index AK were acquired at each visit and pre-specified criteria were evaluated. Clinical, dermoscopic, and confocal responses were evaluated at last follow-up visit. Fourteen patients were enrolled, of which five were treated for 12 weeks, seven for 8, and two for 4 weeks. At a median follow up of 30 weeks, 64.3% (9/14) index AKs achieved complete clinical, 50% (7/14) complete dermoscopic and 42.9% (6/14) complete confocal clearance. Local skin reaction was mild and significantly decreased during therapy administration. Although the small number of cases, our study underlines the utility of both dermoscopy and in-vivo RCM in 5-FU/SA treatment response monitoring for AKs located on the face or scalp.

Effects of MAL-PDT, ingenol mebutate and diclofenac plus hyaluronate gel monitored by high-frequency ultrasound and digital dermoscopy in actinic keratosis - a randomized trial

BACKGROUND

The efficacy for actinic keratosis (AK) clearance of field-directed treatments has been investigated in randomized studies against placebo, but the comparison of results is difficult for several methodological reasons.

OBJECTIVES

The present study aims to compare efficacy of MAL-photodynamic therapy (MAL-PDT), ingenol mebutate gel (IMB) and diclofenac plus hyaluronate gel (DHA) on multiple AKs assessing a new performance index of efficacy, the cumulative AK area and evaluating dermoscopical and high-frequency ultrasound (HFUS) changes.

METHODS

Patients with ≥5 Olsen II AKs in a 25 cm² area of the scalp and face were enrolled and randomized to one of the treatment choices. Number of AKs and cumulative area were assessed before and after treatment. Dermoscopy and HFUS were performed on a single AK and surrounding photo-damaged skin in the treatment area.

RESULTS

Cumulative AKs area reduced significantly more with PDT compared to other treatment options and with IMB in comparison to DHA. PDT was also the only treatment option that increased at a significant level the dermal density in both target AK and the surrounding skin and decreased significantly the SLEB thickness in the perilesional skin at HFUS.

CONCLUSIONS

MAL-PDT is more effective than IMB and DHA for reducing the cumulative AK area which is calculated digitally from 3D pictures and should be the preferred performance index for the evaluation of the efficacy of treatments for AKs, rolling out clinical and dermoscopy evaluation. MAL-PDT improves all HFUS features of chronic photodamages of the dermis of the skin underlying and surrounding the AK spots.

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.

Educational video promotes durable knowledge about actinic keratoses in patients with field cancerization: a pseudorandomized, single-blind, controlled pilot study

Background: Diffuse actinic keratoses (AKs) have multiple treatment options. Patient understanding of treatment options may enhance patient autonomy, satisfaction, treatment adherence, and clinical outcomes. Delivering effective and consistent verbal counseling on AK treatment can be challenging.Objective: We investigated the effect on patient knowledge of implementing, prior to standard counseling, a novel video decision aid explaining diffuse AK treatment options.Methods & Materials: Participants were recruited from an academic Mohs surgery clinic and randomized to receive the video decision aid plus standard verbal counseling (video) or standard verbal counseling alone (control). Both groups completed baseline, immediate post-intervention, and 1-2 week delayed durable knowledge assessments. Secondary endpoints included participant satisfaction and verbal counseling duration.Results: Thirty-one eligible patients (16 control, 15 video) participated. No baseline differences existed between the groups. The video group had significantly higher mean durable knowledge scores than the controls (video 10.00 ± 1.48, control 8.36 ± 1.69, p = .018). Patients were highly satisfied with the video. Verbal counseling duration did not significantly differ between groups.Conclusion: A video decision aid for treatment of diffuse AKs improved durable patient knowledge.

Actinic keratosis: where do we stand and where is the future going to take us?

Introduction: Actinic keratosis (AK) is a chronic disease which is mainly located across areas of sun-exposed skin. Clinical and subclinical lesions coexist across a large area resulting in a field cancerization. As these lesions have the potential to transform into invasive squamous cell carcinoma (iSCC), treatment is crucial. With global prevalence increasing, AK is expected to be the most common in situ carcinoma of the skin.Areas covered: In this article, we cover the established algorithm of treating AK and give an insight into the drugs under development. There are six compounds under development covering different treatment angles, from Sinecatechin a Polyphenon E which targets the link between HPV infection and development of AK, over Tirbanibulin which targets the SRC proto-oncogene and fast proliferating cells, to Tuvatexib a small-molecule dual VDAC/HK2 modulator that has shown that it can compete with the established therapies.Expert opinion: These new treatment options are moving us further toward a more individually tailored treatment for each patient considering his abilities, the size and location of his lesions but also the genetic bases as well as individual risk of transforming into a iSCC and possibly other factors contributing to each patients individual AK lesions.

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.

Field cancerization therapy with ingenol mebutate contributes to restoring skin-metabolism to normal-state in patients with actinic keratosis: a metabolomic analysis

Actinic keratosis (AK) is a skin premalignant lesion, which progresses into squamous cell carcinoma (SCC) if left untreated. Ingenol mebutate gel is approved for local treatment of non-hyperkeratotic, non-hypertrophic AK; it also has the potential to act as a field cancerization therapy to prevent the progression of AK to SCC. To gain better insights into the mechanisms of ingenol mebutate beyond the mere clinical assessment, we investigated, for the first time, the metabolome of skin tissues from patients with AK, before and after ingenol mebutate treatment, with high-resolution magic angle spinning nuclear magnetic resonance spectroscopy. The metabolomic profiles were compared with those of tissues from healthy volunteers. Overall, we identified a number of metabolites, the homeostasis of which became altered during the process of tumorigenesis from healthy skin to AK, and was restored, at least partially, by ingenol mebutate therapy. These metabolites may help to attain a better understanding of keratinocyte metabolism and to unmask the metabolic pathways related to cell proliferation. These results provide helpful information to identify biomarkers with prognostic and therapeutic significance in AK, and suggest that field cancerization therapy with ingenol mebutate may contribute to restore skin metabolism to a normal state in patients with AK.

Efficacy and safety of ingenol mebutate gel in field treatment of actinic keratosis on full face, balding scalp, or approximately 250 cm2 on the chest: A phase 3 randomized controlled trial

BACKGROUND

Ingenol mebutate (IngMeb) 0.015% or 0.05% is approved for actinic keratosis (AK) areas of 25 cm² or less; some patients require treatment of larger fields.

OBJECTIVE

To determine efficacy and safety of IngMeb 0.027% in areas of AK of up to 250 cm² during an 8-week initial assessment period and extended 12-month follow-up.

METHODS

This phase 3, randomized, double-blind, vehicle-controlled trial (NCT02361216) enrolled adult patients with 5 to 20 AK lesions on the face/scalp (25-250 cm²) or chest (approximately 250 cm²). Patients received once-daily IngMeb or vehicle for 3 consecutive days on the full face, full balding scalp, or approximately 250 cm² on the chest. The primary endpoint was complete AK clearance (AKCLEAR 100; week 8). Additional endpoints included partial AK clearance (AKCLEAR 75), recurrence, patient satisfaction, cosmetic outcome, and safety.

RESULTS

IngMeb was superior to vehicle for complete AK clearance (21.4% vs 3.4%, P < .001) and AK clearance of 75% or greater (59.4% vs 8.9%, P < .001) at week 8. Probability of sustained clearance during the 12-month follow-up was 22.9% for patients treated with IngMeb. Increased treatment satisfaction and cosmetic outcomes were observed with IngMeb versus vehicle. No unexpected safety signals were identified.

LIMITATIONS

Localized skin responses hindered maintenance of double-blinding.

CONCLUSIONS

IngMeb 0.027% was superior to vehicle for treatment of AK areas of up to 250 cm². The safety profile of IngMeb was as expected.

Treatment of actinic keratosis through inhibition of cyclooxygenase-2: Potential mechanism of action of diclofenac sodium 3% in hyaluronic acid 2.5

Cyclooxygenase‐2 (COX‐2) and its metabolic product prostaglandin E₂ (PGE₂) are induced in response to growth factors, inflammatory cytokines, tumor promoters, activated oncogenes, and, in the skin, ultraviolet (UV) radiation. Accumulating evidence suggests a role for the COX‐2/PGE₂ pathway in tumorigenesis in various tissue types including cutaneous squamous cell carcinoma. There is also strong evidence for a role in the development of actinic keratoses (AKs) — common dysplastic lesions of the skin associated with UV radiation overexposure — considered as part of a continuum with skin cancer. Non‐steroidal anti‐inflammatory drugs (NSAIDs) exert their anti‐inflammatory, analgesic, and antipyretic effects by reversibly or irreversibly acetylating COX isoforms, inhibiting downstream prostaglandins, and may have a chemopreventive role in malignancies, including skin cancer. Topical treatment of AK lesions with the NSAID diclofenac sodium 3% in combination with hyaluronic acid 2.5% has been shown to be effective and well tolerated, although the mechanism of action remains to be elucidated.

Evaluation of two histological classifications for actinic keratoses - PRO classification scored highest inter-rater reliability

BACKGROUND

Actinic keratoses (AKs) can histologically be classified by the extent of atypical keratinocytes throughout the epidermis or their pattern of basal proliferation. Currently, no data on the inter-rater reliability of both scores is available.

OBJECTIVE

To evaluate the inter-rater reliability of the two classification schemes; histological grade (AK I-III) and basal proliferation (PRO I-III).

METHODS

Histological images of 54 AKs were classified by 21 independent dermatopathologists with regard to basal proliferation (PRO I-III), histological grade (AK I-III) and assumed risk of progression into invasive carcinoma.

RESULTS

Overall, of the 54 AKs 16.7% (9/54) were classified as AK I, 66.7% (36/54) as AK II, and 16.7% (9/54) as AK III. With regards to basal growth pattern, 25.9% (14/54) were classified as PRO I, 42.6% (23/54) as PRO II, and 31.5% (17/54) as PRO III. We observed a highly significant inter-rater reliability for PRO-grading (P < 0.001) which was higher than for AK-grading (Kendall's W coefficient: AK = 0.488 vs. PRO = 0.793). We found substantial agreement for assumed progression risk for AKs with worsening basal proliferation (k = 0.759) compared to moderate agreement (k = 0.563) for different AK-gradings.

CONCLUSIONS

Histological classification of basal growth pattern (PRO) showed higher inter-rater reliability compared to the established classification of atypical keratinocytes throughout epidermal layers. Moreover, experienced dermatopathologists considered basal proliferation to be more important in terms of progression risk than upwards directed growth patterns. It should be considered to classify AKs according to their basal proliferation pattern (PRO I-III).