Histopathology of incipient intraepidermal squamous cell carcinoma ("actinic keratosis")

MicroRNA-23b Plays a Tumor-Suppressive Role in Cutaneous Squamous Cell Carcinoma and Targets Ras-Related Protein RRAS2

Cutaneous squamous cell carcinoma (cSCC) is one of the most common types of cancer with metastatic potential. MicroRNAs regulate gene expression at the post-transcriptional level. In this study, we report that miR-23b is downregulated in cSCCs and in actinic keratosis and that its expression is regulated by the MAPK signaling pathway. We show that miR-23b suppresses the expression of a gene network associated with key oncogenic pathways and that the miR-23b-gene signature is enriched in human cSCCs. miR-23b decreased the expression of FGF2 both at mRNA and protein levels and impaired the angiogenesis-inducing ability of cSCC cells. miR23b overexpression suppressed the capacity of cSCC cells to form colonies and spheroids, whereas the CRISPR/Cas9-mediated deletion of MIR23B resulted in increased colony and tumor sphere formation in vitro. In accordance with this, miR-23b-overexpressing cSCC cells formed significantly smaller tumors upon injection into immunocompromised mice with decreased cell proliferation and angiogenesis. Mechanistically, we verify RRAS2 as a direct target of miR-23b in cSCC. We show that RRAS2 is overexpressed in cSCC and that interference with its expression impairs angiogenesis and colony and tumorsphere formation. Taken together, our results suggest that miR-23b acts in a tumor-suppressive manner in cSCC, and its expression is decreased during squamous carcinogenesis.

KI-basierte Bestimmung des PRO-Scores in aktinischen Keratosen anhand von LC-OCT-Bilddatensätzen: Artificial intelligence-based PRO score assessment in actinic keratoses from LC-OCT imaging using Convolutional Neural Networks

Hintergrund

Mit Hilfe des histologischen PRO‐Scores (I–III) kann das Risiko einer malignen Transformation aktinischer Keratosen (AK) abgeschätzt werden, indem er das Ausmaß der Undulation und basalen Proliferation der dermoepidermalen Junktionszone (DEJ) bewertet. Die konfokale Line‐Field optische Kohärenztomographie (LC‐OCT) ermöglicht eine nichtinvasive Bestimmung des PRO‐Scores in Echtzeit. Anhand von LC‐OCT‐Bilddatensätzen kann eine künstliche Intelligenz (KI) mit Hilfe von Convolutional Neural Networks (CNN) zur automatischen Quantifizierung des PRO‐Scores von AK in vivo trainiert werden.

Patienten und Methodik

Convolutional Neural Networks wurden trainiert, um LC‐OCT‐Bilder von gesunder Haut und von AK zu segmentieren. PRO‐Score‐Modelle wurden in Übereinstimmung mit dem histopathologischen Goldstandard entwickelt und an einer Teilmenge von 237 LC‐OCT‐AK‐Bildern trainiert und an 76 Bildern getestet, wobei der von der KI‐berechnete PRO‐Score mit dem visuellen Konsens der Bildgebungsexperten verglichen wurde.

Ergebnisse

Eine signifikante Übereinstimmung wurde in 57/76 (75%) Fällen festgestellt. Die KI‐basierte Bewertung des PRO‐Scores korrelierte am besten mit dem visuellen Score für PRO II (84,8%) vs. PRO III (69,2%) vs. PRO I (66,6%). In 25% der Fälle kam es zu Fehlinterpretationen, die meist auf eine Verschattung der DEJ sowie störende Merkmale wie Haarfollikel zurückzuführen waren.

Schlussfolgerungen

Die Ergebnisse deuten darauf hin, dass CNN für die automatische Quantifizierung des PRO‐Scores in LC‐OCT‐Bilddatensätzen hilfreich sind. Dies könnte zur nichtinvasiven Bewertung des Proliferationsrisikos in der Diagnostik und Nachsorge von AK herangezogen werden.

Artificial intelligence-based PRO score assessment in actinic keratoses from LC-OCT imaging using Convolutional Neural Networks

BACKGROUND AND OBJECTIVES

The histological PRO score (I-III) helps to assess the malignant potential of actinic keratoses (AK) by grading the dermal-epidermal junction (DEJ) undulation. Line-field confocal optical coherence tomography (LC-OCT) provides non-invasive real-time PRO score quantification. From LC-OCT imaging data, training of an artificial intelligence (AI), using Convolutional Neural Networks (CNNs) for automated PRO score quantification of AK in vivo may be achieved.

PATIENTS AND METHODS

CNNs were trained to segment LC-OCT images of healthy skin and AK. PRO score models were developed in accordance with the histopathological gold standard and trained on a subset of 237 LC-OCT AK images and tested on 76 images, comparing AI-computed PRO score to the imaging experts' visual consensus.

RESULTS

Significant agreement was found in 57/76 (75%) cases. AI-automated grading correlated best with the visual score for PRO II (84.8%) vs. PRO III (69.2%) vs. PRO I (66.6%). Misinterpretation occurred in 25% of the cases mostly due to shadowing of the DEJ and disruptive features such as hair follicles.

CONCLUSIONS

The findings suggest that CNNs are helpful for automated PRO score quantification in LC-OCT images. This may provide the clinician with a feasible tool for PRO score assessment in the follow-up of AK.

Innovation in Actinic Keratosis Assessment: Artificial Intelligence-Based Approach to LC-OCT PRO Score Evaluation

Actinic keratosis (AK) is a common skin cancer in situ that can progress to invasive SCC. Line-field confocal optical coherence tomography (LC-OCT) has emerged as a non-invasive imaging technique that can aid in diagnosis. Recently, machine-learning algorithms have been developed that can automatically assess the PRO score of AKs based on the dermo-epidermal junction's (DEJ's) protrusion on LC-OCT images. A dataset of 19.898 LC-OCT images from 80 histologically confirmed AK lesions was used to test the performance of a previous validated artificial intelligence (AI)-based LC-OCT assessment algorithm. AI-based PRO score assessment was compared to the imaging experts' visual score. Additionally, undulation of the DEJ, the number of protrusions detected within the image, and the maximum depth of the protrusions were computed. Our results show that AI-automated PRO grading is highly comparable to the visual score, with an agreement of 71.3% for the lesions evaluated. Furthermore, this AI-based assessment was significantly faster than the regular visual PRO score assessment. The results confirm our previous findings of the pilot study in a larger cohort that the AI-based grading of LC-OCT images is a reliable and fast tool to optimize the efficiency of visual PRO score grading. This technology has the potential to improve the accuracy and speed of AK diagnosis and may lead to better clinical outcomes for patients.

A novel combination of isovanillin, curcumin, and harmine (GZ17-6.02) enhances cell death and alters signaling in actinic keratoses cells when compared to individual components and two-component combinations

Actinic keratosis is a pre-malignant skin disease caused by excessive exposure to ultraviolet light. The present studies further defined the biology of a novel combination of isovanillin, curcumin, and harmine in actinic keratosis cells in vitro . An oral formulation (GZ17-6.02) and topical preparation (GZ21T) comprised of the same fixed, stoichiometric ratio have been developed. Together, the three active ingredients killed actinic keratosis cells more effectively than any of its component parts as either individual agents or when combined in pairs. The three active ingredients caused greater levels of DNA damage than any of its component parts as either individual agents or when combined in pairs. As a single agent, compared to isolated components, GZ17-6.02/GZ21T caused significantly greater activation of PKR-like endoplasmic reticulum kinase, the AMP-dependent protein kinase, and ULK1 and significantly reduced the activities of mTORC1, AKT, and YAP. Knockdown of the autophagy-regulatory proteins ULK1, Beclin1, or ATG5 significantly reduced the lethality of GZ17-6.02/GZ21T alone. Expression of an activated mammalian target of rapamycin mutant suppressed autophagosome formation and autophagic flux and reduced tumor cell killing. Blockade of both autophagy and death receptor signaling abolished drug-induced actinic keratosis cell death. Our data demonstrate that the unique combination of isovanillin, curcumin, and harmine represents a novel therapeutic with the potential to treat actinic keratosis in a manner different from the individual components or pairs of the components.

FGFR2c Upregulation Contributes to Cancer-Associated Fibroblast Program Activation and to Enhanced Autophagy in Actinic Keratosis-Derived Dermal Fibroblasts: A Possible Role in Precancerous Cell/Stromal Cell Crosstalk

Actinic keratosis (AK) is a preneoplastic skin disorder which can rapidly progress to cutaneous squamous cell carcinomas (SCCs). In light of our previous findings, indicating a possible oncogenic role of the mesenchymal isoform of FGFR2 (FGFR2c) aberrantly expressed in AK keratinocytes, we analyzed the possible tumor-promoting role of this receptor in the stromal AK counterpart in this work. Molecular analysis showed that, particularly in early AK lesions, FGFR2c dermal upregulation is accompanied by the downregulation of the cancer-associated fibroblasts (CAF) transcription repressor CSL, the upregulation of the CAF activator ULK3, and the consequent CAF gene induction. Immunofluorescence and molecular analysis, coupled with silencing approaches by siRNA, applied on primary cultures of KIN I-derived fibroblasts, indicated that FGFR2c upregulation contribute to CAF signature and the increased autophagy in response to FGF2. Magnetic bead-based multiplex assay, combined with FGFR2 signaling shut-off approaches, indicated that, especially in response to FGF2, IL-6 secretion could depend on FGFR2c high expression and signaling, suggesting the possible establishment of FGFR2c-dependent secretory autophagy, contributing to tumor-promoting factor release. Overall, our results identified FGFR2c as a signaling molecule involved in controlling precancerous/stromal cell oncogenic crosstalk, pointing to this receptor as a possible early molecular marker predictive for AK’s rapid malignant progression.

Factors for risk stratification of patients with actinic keratosis using integrated analysis of clinicopathological features and gene expression patterns

BACKGROUND

Actinic keratosis (AK) is considered as precursor lesion of invasive squamous cell carcinoma. Molecular studies on AK are limited because of too small size of the biopsy specimen to obtain enough DNA or RNA.

METHODS

Twenty biopsy cases of AK, followed by second same-sited biopsies, were included. Ten cases were diagnosed with total regression (regression group), while the other 10 were diagnosed with invasive carcinoma (progression group) in the follow-up biopsies. Using digital spatial profiling (DSP) technology, whole-gene expression analysis defined by specific regions of interest was performed for all 20 cases. After the clinicopathological features were assessed, separate and integrated analyses of these features and gene expression patterns were performed using machine-learning technology. All analyses were performed on both lesion keratinocytes (KT) and infiltrated stromal lymphocytes (LC).

RESULTS

Among the 18,667 genes assessed, 33 and 72 differentially expressed genes (DEGs) between the regression and progression groups were found in KT and LC respectively. The primary genes distinguishing the two groups were KRT10 for KT and CARD18 for LC. Clinicopathological features were weaker in risk stratification of AK progression than the gene expression patterns. Pathways associated with various cancers were upregulated in the progression group of KT, whereas the nucleotide-binding oligomerization domain (NOD)-like receptor signalling pathway was upregulated in the progression of LC.

CONCLUSION

Gene expression patterns were effective for risk stratification of AK progression, and their distinguishing power was higher than that of clinicopathological features.

Skin Photodamage Lesions in a Bilateral Feline Auricular Primary Fibrosarcoma

As with human species, recent studies also suggest a photoinduced etiopathology for non-epithelial cutaneous tumors in feline species. We report a recent case of a ten-year-old male cat with a white-hair coat and mesenchymal neoplasms of both auricles. Cytology, complete blood count (CBC), serum biochemistry and imaging examinations were performed. After surgery, the samples underwent routinary histopathology and were additionally stained with orcein. A routine analysis yielded values within a normal range and the imaging examination showed no abnormalities, suggesting that the bilateral presentation of neoplasms was primary rather than metastatic. The cytology was inconclusive, but, through histopathology, two well-differentiated fibrosarcomas were diagnosed and histopathological changes related to chronic UV exposure (such as epidermal hyperplasia, stratification disorders, keratinocyte dysplasia and an accumulation of elastotic material) were documented in the skin adjacent to the lesions. An orcein stain succeeded in highlighting elastosis. The elastic fibers lost their regular structure and orientation and appeared to be fragmented, wavy to branched and knotted. A morphometric analysis showed that the amount of elastotic material in the dermis close to the tumors was more than double compared with the more distant areas. Elastosis is considered to be a hallmark of photodamage; thus, an involvement of UV rays in the carcinogenic process of the tumors may be suspected.

Exposome and Skin. Part 2. The Influential Role of the Exposome, Beyond UVR, in Actinic Keratosis, Bowen's Disease and Squamous Cell Carcinoma: A Proposal

Actinic keratosis (AK) is the main risk factor for the development of cutaneous invasive squamous cell carcinoma (SCC). It represents the first sign of severe chronic ultraviolet radiation exposure, which has a clear significant effect. Nevertheless, the skin is exposed to many other exposome factors which should be thoroughly considered. Our aim was to assess the impact of exposome factors other than ultraviolet radiation (UVR) on the etiopathology of AK and Bowen's disease (BD) and progression of AK to SCC and to design tailored prevention strategies. We performed an exhaustive literature search in September 2021 through PubMed on the impact of exposome factors other than UVR on AK, BD and SCC. We conducted several parallel searches combining terms of the following topics: AK, BD, SCC and microbiome, hormones, nutrition, alcohol, tobacco, viral infections, chemical contaminants and air pollution. Notably, skin microbiome studies have shown how Staphylococcus aureus infections are associated with AK and AK-to-SCC progression by the production of chronic inflammation. Nutritional studies have demonstrated how a caloric restriction in fat intake, oral nicotinamide and moderate consumption of wine significantly reduce the number of premalignant keratoses and SCC. Regarding lifestyle factors, both alcohol and smoking are associated with the development of SCC in a dose-dependent manner. Relevant environmental factors are viral infections and chemical contaminants. Human papillomavirus infections induce deregulation of cellular proliferation and are associated with AK, BD and SCC. In addition to outdoor jobs, occupations such as industrial processing and farming also increase the risk of developing keratoses and SCC. The exposome of AK will undoubtedly help the understanding of its etiopathology and possible progression to SCC and will serve as a basis to design tailored prevention strategies.

Non-invasive scoring of cellular atypia in keratinocyte cancers in 3D LC-OCT images using Deep Learning

Diagnosis based on histopathology for skin cancer detection is today's gold standard and relies on the presence or absence of biomarkers and cellular atypia. However it suffers drawbacks: it requires a strong expertise and is time-consuming. Moreover the notion of atypia or dysplasia of the visible cells used for diagnosis is very subjective, with poor inter-rater agreement reported in the literature. Lastly, histology requires a biopsy which is an invasive procedure and only captures a small sample of the lesion, which is insufficient in the context of large fields of cancerization. Here we demonstrate that the notion of cellular atypia can be objectively defined and quantified with a non-invasive in-vivo approach in three dimensions (3D). A Deep Learning (DL) algorithm is trained to segment keratinocyte (KC) nuclei from Line-field Confocal Optical Coherence Tomography (LC-OCT) 3D images. Based on these segmentations, a series of quantitative, reproducible and biologically relevant metrics is derived to describe KC nuclei individually. We show that, using those metrics, simple and more complex definitions of atypia can be derived to discriminate between healthy and pathological skins, achieving Area Under the ROC Curve (AUC) scores superior than 0.965, largely outperforming medical experts on the same task with an AUC of 0.766. All together, our approach and findings open the door to a precise quantitative monitoring of skin lesions and treatments, offering a promising non-invasive tool for clinical studies to demonstrate the effects of a treatment and for clinicians to assess the severity of a lesion and follow the evolution of pre-cancerous lesions over time.

Metabolomic Analysis of Actinic Keratosis and SCC Suggests a Grade-Independent Model of Squamous Cancerization

Simple Summary

Actinic keratoses (AKs) are the most common sun-induced precancerous lesions that can progress to squamocellular carcinoma (SCC). AK I have been considered low-risk lesions, often evolving into AK II, the AK grade II and III have the potential to evolve to SCC. This research has assessed the metabolomic fingerprints of AK I, AK II, AK III and SCC by HR-MAS NMR spectroscopy, with the aim of evaluating the hypothesis of grade-association AK to SCC. The association between AKs and SCCs has also been evaluated by histopathology. Our findings support the notion that AK I are different from healthy skin and share different features with SCCs, indeed, they are metabolically active lesions with metabolic profiles similar to high-grade AKs and to SCC. The negative association of AKs with parakeratosis and the positive association with hypertrophy also suggested a similar behavior between AKs and SCCs. Therefore, all AKs should be treated independently from their clinical appearance or histological grade, since it is not possible to predict their potential evolution to SCC.

Abstract

Background—Actinic keratoses (AKs) are the most common sun-induced precancerous lesions that can progress to squamocellular carcinoma (SCC). Recently, the grade-independent association between AKs and SCC has been suggested; however, the molecular bases of this potential association have not been investigated. This study has assessed the metabolomic fingerprint of AK I, AK II, AK III and SCC using high resolution magic angle spinning (HR-MAS) nuclear magnetic resonance (NMR) spectroscopy in order to evaluate the hypothesis of grade-independent association between AK and SCC. Association between AKs and SCCs has also been evaluated by histopathology. Methods—Metabolomic data were obtained through HR-MAS NMR spectroscopy. The whole spectral profiles were analyzed through multivariate statistical analysis using MetaboAnalyst 5.0. Histologic examination was performed on sections stained with hematoxylin and eosin; statistical analysis was performed using STATA software version 14. Results—A group of 35 patients affected by AKs and/or SCCs and 10 healthy controls were enrolled for metabolomics analysis. Histopathological analysis was conducted on 170 specimens of SCCs and AKs (including the ones that underwent metabolomic analysis). SCCs and AK I were found to be significantly associated in terms of the content of some metabolites. Moreover, in the logistic regression model, the presence of parakeratosis in AKs appeared to be less frequently associated with SCCs, while AKs with hypertrophy had a two-fold higher risk of being associated with SCC. Conclusions—Our findings, derived from metabolomics and histopathological data, support the notion that AK I are different from healthy skin and share some different features with SCCs. This may further support the expanding notion that all AKs should be treated independently from their clinical appearance or histological grade because they may be associated with SCC.

A multicenter retrospective analysis of the clinical and pathological characteristics of 1188 cases of actinic keratosis in different ultraviolet radiation intensity areas of China

BACKGROUND

Actinic keratosis (AK) is a precancerous disease, caused by ultraviolet radiation (UV).

OBJECTIVE

To analyze the clinical and pathological characteristics of AK in four areas with different ultraviolet radiation intensities.

METHODS

1188 diagnosed AK patients, from January 2000 to July 2015, in dermatology department of four hospitals were collected. The UV intensity of hospital located cities from high to low is Kunming, Yinchuan, Shenyang and Nanjing. The information comes from medical records, and the pathological types and Keratinocyte Intraepithelial Neoplasia (KIN) grades were checked by two experienced pathologists. All information was conducted a retrospective multicenter research.

RESULTS

The patients were mainly middle-aged and elderly female, which was in direct contrast to the majority of men in European. The age of onset in Kunming group was lower than that in Yinchuan Group (p = 0.013) and Nanjing Group (p < 0.01). The course of disease in Kunming group was significantly shorter than that in Nanjing Group (p < 0.001). The lesions were almost located in the exposed area. The proportion of unexposed areas in Shenyang group was significantly higher than that in other groups (p < 0.001). There were statistical differences in pathological morphological classification among the four groups. These differences were not affected by age and gender. The number of KIN III grade patients in Shenyang group was significantly higher than that in other three groups (p < 0.05).

CONCLUSION

The Asian patients were mainly female. The clinical characteristics of AK are closely related to UV intensity, and environmental pollution, lifestyle, religious beliefs and other factors are also related.

In Vivo Reflectance Confocal Microscopy as a Response Monitoring Tool for Actinic Keratoses Undergoing Cryotherapy and Photodynamic Therapy

Simple Summary

The assessment of actinic keratoses (AKs) in prevention and therapeutic trials, as well as clinical practice, could significantly benefit from the incorporation of non-invasive imaging technology. Such technology has the potential to enhance the objective evaluation of clinical and subclinical AKs with the added advantage of sequential monitoring. In vivo reflectance confocal microscopy (RCM) allows for the non-invasive imaging of AKs at a cellular level. We aimed to establish an in in vivo RCM protocol for AK response monitoring, ultimately leading to more reliable characterization of longitudinal responses and therapy optimization.

Abstract

Reflectance confocal microscopy (RCM) presents a non-invasive method to image actinic keratosis (AK) at a cellular level. However, RCM criteria for AK response monitoring vary across studies and a universal, standardized approach is lacking. We aimed to identify reliable AK response criteria and to compare the clinical and RCM evaluation of responses across AK severity grades. Twenty patients were included and randomized to receive either cryotherapy (n = 10) or PDT (n = 10). Clinical assessment and RCM evaluation of 12 criteria were performed in AK lesions and photodamaged skin at baseline, 3 and 6 months. We identified the RCM criteria that reliably characterize AK at baseline and display significant reduction following treatment. Those with the highest baseline odds ratio (OR), good interobserver agreement, and most significant change over time were atypical honeycomb pattern (OR: 12.7, CI: 5.7–28.1), hyperkeratosis (OR: 13.6, CI: 5.3–34.9), stratum corneum disruption (OR: 7.8, CI: 3.5–17.3), and disarranged epidermal pattern (OR: 6.5, CI: 2.9–14.8). Clinical evaluation demonstrated a significant treatment response without relapse. However, in grade 2 AK, 10/12 RCM parameters increased from 3 to 6 months, which suggested early subclinical recurrence detection by RCM. Incorporating standardized RCM protocols for the assessment of AK may enable a more meaningful comparison across clinical trials, while allowing for the early detection of relapses and evaluation of biological responses to therapy over time.

Guidelines of care for the management of actinic keratosis

BACKGROUND

Actinic keratoses (AK) are rough scaly patches that arise on chronically ultraviolet-exposed skin and can progress to keratinocyte carcinoma.

OBJECTIVE

This analysis examined the literature related to the management of AK to provide evidence-based recommendations for treatment. Grading, histologic classification, natural history, risk of progression, and dermatologic surveillance of AKs are also discussed.

METHODS

A multidisciplinary Work Group conducted a systematic review to address 5 clinical questions on the management of AKs and applied the Grading of Recommendations, Assessment, Development, and Evaluation approach for assessing the certainty of the evidence and formulating and grading clinical recommendations. Graded recommendations were voted on to achieve consensus.

RESULTS

Analysis of the evidence resulted in 18 recommendations.

LIMITATIONS

This analysis is based on the best available evidence at the time it was conducted. The pragmatic decision to limit the literature review to English language randomized trials may have excluded data published in other languages or limited identification of relevant long-term follow-up data.

CONCLUSIONS

Strong recommendations are made for using ultraviolet protection, topical imiquimod, topical 5-fluorouracil, and cryosurgery. Conditional recommendations are made for the use of photodynamic therapy and diclofenac for the treatment of AK, both individually and as part of combination therapy regimens.

In-Vivo LC-OCT Evaluation of the Downward Proliferation Pattern of Keratinocytes in Actinic Keratosis in Comparison with Histology: First Impressions from a Pilot Study

It is known that actinic keratoses (AKs) can progress to invasive squamous cell carcinoma (SCC). The histological PRO grading of AKs is based on the growth pattern of basal keratinocytes and relates to their progression risk. AKs can be non-invasively characterized by line-field confocal optical coherence tomography (LC-OCT). The aim of the study was to define criteria for an LC-OCT grading of AKs based on the PRO classification and to correlate it with its histological counterpart. To evaluate the interobserver agreement for the LC-OCT PRO classification, fifty AKs were imaged by LC-OCT and biopsied for histopathology. PRO histological grading was assessed by an expert consensus, while two evaluator groups separately performed LC-OCT grading on vertical sections. The agreement between LC-OCT and histological PRO grading was 75% for all lesions (weighted kappa 0.66, 95% CI 0.48-0.83, p ≤ 0.001) and 85.4% when comparing the subgroups PRO I vs. PRO II/III (weighted kappa 0.64, 95% CI 0.40-0.88, p ≤ 0.001). The interobserver agreement for LC-OCT was 90% (Cohen's kappa 0.84, 95% CI 0.71-0.91, p ≤ 0.001). In this pilot study, we demonstrated that LC-OCT is potentially able to classify AKs based on the basal growth pattern of keratinocytes, in-vivo reproducing the PRO classification, with strong interobserver agreement and a good correlation with histopathology.

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.

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.

Expression Profile of Fibroblast Growth Factor Receptors, Keratinocyte Differentiation Markers, and Epithelial Mesenchymal Transition-Related Genes in Actinic Keratosis: A Possible Predictive Factor for Malignant Progression?

Simple Summary

In this work, we checked the modulation of Fibroblast Growth Factor Receptors (FGFRs) along with differentiation-related and epithelial-to-mesenchymal transition (EMT)-related markers to identify expression profiles that could be predictive for actinic keratosis (AK) progression through the “differentiated” pathway. We found that the downregulation of the analyzed differentiation markers, but not the modulation of the EMT-related markers, correlated with the canonical progression of AK. In addition, the observed modulation of FGFR2 mesenchymal/epithelial isoforms compatible with FGFR2 isoform switch, as well as the upregulation of FGFR4 suggested their correlation with early steps of AK pathogenesis. In contrast, the increase of mesenchymal FGFR3c isoform expression appeared to suggest that this event correlated with late steps of AK progression. In addition, the strong modulation of filaggrin (FIL), Snail1, as well as of FGFR2c, FGFR4, and their ligand Fibroblast Growth Factor 2 (FGF2), observed in some of the keratinocytic intraepithelial neoplasia grade I (KIN I) samples, may indicate that they could be molecular markers predictive for those KIN I lesions destined to a direct progression to squamous cell carcinoma (SCC) through the “differentiated” pathway.

Abstract

Actinic keratosis (AK) is the ultra violet (UV)-induced preneoplastic skin lesion clinically classified in low (KIN I), intermediate (KIN II), and high (KIN III) grade lesions. In this work we analyzed the expression of Fibroblast Growth Factor Receptors (FGFRs), as well as of keratinocyte differentiation and epithelial-to-mesenchymal transition (EMT)-related markers in differentially graded AK lesions, in order to identify specific expression profiles that could be predictive for direct progression of some KIN I lesions towards squamous cell carcinoma (SCC). Our molecular analysis showed that the keratinocyte differentiation markers keratin 1 (K1), desmoglein-1 (DSG1), and filaggrin (FIL) were progressively downregulated in KIN I, II, and III lesions, while the modulation of epithelial/mesenchymal markers and the induction of the transcription factors Snail1 and Zinc finger E-box-binding homeobox 1 (ZEB1) compatible with pathological EMT, even if observable, did not appear to correlate with AK progression. Concerning FGFRs, a modulation of epithelial isoform of FGFR2 (FGFR2b) and the mesenchymal FGFR2c isoform compatible with an FGFR2 isoform switch, as well as FGFR4 upregulation were observed starting from KIN I lesions, suggesting that they could be events involved in early steps of AK pathogenesis. In contrast, the increase of FGFR3c expression, mainly appreciable in KIN II and KIN III lesions, suggested a correlation with AK late progression. Interestingly, the strong modulation of FIL, Snail1, as well as of FGFR2c, FGFR4, and of their ligand FGF2, observed in some of the KIN I samples, may indicate that they could be molecular markers predictive for those low graded lesions destined to a direct progression to SCC. In conclusion, our data point on the identification of molecular markers predictive for AK rapid progression through the “differentiated” pathway. Our results also represent an important step that, in future, will help to clarify the molecular mechanisms underlying FGFR signaling deregulation in epithelial tissues during the switch from the pre-neoplastic to the oncogenic malignant phenotype.

In vivo reflectance confocal microscopy for monitoring actinic keratosis treated with 5-aminolevulinic acid photodynamic therapy

BACKGROUND

Actinic keratosis (AK) occurs frequently in sun-exposed skin while its diagnosis and treatment were still in exploration.

MATERIALS AND METHODS

Thirty two patients with facial AK lesions were selected and examined with reflective confocal microscopy (RCM) firstly, followed by biopsy at the same site. RCM was used to observe AK lesions before 5-aminolevulinic acid photodynamic therapy (ALA-PDT) treatment, after the first treatment, after 4 treatments, and at 1 and 6 months follow-up. Retrospective analysis of RCM images was performed.

RESULTS

Thirty two AK cases showed initial RCM microscopic features including disorderly arranged epidermal cells (100%), atypical keratinocytes (100%), and blurry border between the epidermis and dermis (100%). 4 patients quitted trail. After treatments, 24 cases showed basically regular arrangement of epidermal cells, absent atypical keratinocytes, and clear border between epidermis and dermis, while 4 cases improved little. At 1 and 6 months follow-up, 23 cases remained relapse-free while 1 case developed recurrent symptoms. Effective rate of 4 ALA-PDT treatments for AK was 100%; recurrence and cure rates were 4.2% and 82.1%, respectively.

CONCLUSION

ALA-PDT is effective to treat AK, while RCM can be recommended for in vivo evaluating and monitoring the effect of ALA-PDT on AK.

Red light photodynamic therapy with BF-200 ALA showed superior efficacy in the treatment of actinic keratosis on the extremities, trunk, and neck in a vehicle-controlled phase III study

BACKGROUND

Actinic keratoses (AK) may occur in all sun-exposed skin areas. Those occurring outside the head area are generally more resistant to treatment than those on the face.

OBJECTIVE

To determine efficacy and safety of BF-200 ALA versus vehicle in the treatment of mild-to-severe AK located on extremities, trunk, and neck with red light photodynamic therapy (PDT).

METHODS

This phase III study had an intra-individual design with 50 patients in 6 centers in Germany. Each patient received a maximum of 2 field-directed PDTs. Clinical end points and 1-year follow-up results were recorded.

RESULTS

BF-200 ALA was superior to the vehicle with respect to total lesion clearance rates (86.0% vs 32.9%; P < .0001) and patient complete clearance per patient's side (67.3% vs 12.2%, P < .0001). One-year overall lesion recurrence rate was 14.1% versus 27.4% (BF-200 ALA vs vehicle; P = .0068). Patients were more satisfied by the cosmetic outcome of BF-200 ALA/PDT than the vehicle/PDT. Adverse events were consistent with the known safety profile of BF-200 ALA/PDT.

LIMITATIONS

Small number of severe lesions; limited sample size; unbalanced but representative distribution of AK.

CONCLUSION

BF-200 ALA showed significantly higher AK clearance rates on extremities, trunk, and neck than the vehicle and was well tolerated.

Dermatoscopic findings and dermatopathological correlates in clinical variants of actinic keratosis, Bowen's disease, keratoacanthoma, and squamous cell carcinoma

Non-melanoma skin cancer (NMSC), predominantly squamous cell carcinoma (SCC) and basal cell carcinoma, is increasing worldwide. Dermatoscopy, which is one of the non-invasive diagnostic techniques, is important for early diagnosis of NMSC. In this study we aimed to determine dermatoscopic features of keratinocyte derived tumors including actinic keratosis (AK), Bowen's disease (BD), keratoacanthoma (KA), and SCC and correlate the dermatoscopic findings with pathology. A total of 242 lesions from 169 patients were included in the study and dermatoscopic and dermatopathological findings of the lesions were retrospectively studied. Revised pattern analysis was used for the dermatoscopic evaluation. Among 242 lesions, 145 were clinically flat (86 AK, 30 BD, and 29 SCC). Presence of vessels, ulceration, fiber sign, keratin mass, and blood spots decreased the probability of a lesion being AK. When the differential diagnosis was considered between KA and SCC vs AK and BD; vessel presence, ulceration, fiber sign, blood spots, white structureless, keratin, and centred vessels favored the diagnosis of KA and SCC. Our results may contribute to the determination of the lesions to be biopsied in patients with multiple AK on chronically sun damaged skin. In non-pigmented lesions when a final diagnosis cannot be established, knowledge of dermatopathologic and dermatoscopic correlation may significantly assist interpretation of dermatoscopic patterns and clues.

Effects of Solanum undatum extract (SR-T100) on photocarcinogenesis and photoaging of actinic keratosis

SR-T100 gel, containing solamargine extracted from Solanum undatum (synonym: Solanum incanum), had good therapeutic effects on actinic keratosis (AK) in human and ultraviolet B-induced papilloma in mice. This study aimed to investigate the immunohistochemical changes in the human skin after SR-T100 treatment. An immunohistochemical study was performed and the changes in photocarcinogenesis and photoaging markers after 16-week SR-T100 gel treatment were documented. SR-T100 gel treatment for 16 weeks resulted in complete remission in nine AK lesions and partial remission in four AK lesions. SR-T100 gel abolished the expression of mutant p53 and SOX2 and restored the expression of NOTCH1. Additionally, SR-T100 gel improved wrinkling in human skin, while restoring the expression of lamin B1 and increasing synthesis of new elastic fibers. SR-T100 gel had therapeutic effects on photocarcinogenesis and photoaging of photodamaged skin with AK.

Long non-coding RNAs in cutaneous biology and keratinocyte carcinomas

Long non-coding RNAs (lncRNAs) are a largely uncharacterized group of non-coding RNAs with diverse regulatory roles in various biological processes. Recent observations have elucidated the functional roles of lncRNAs in cutaneous biology, e.g. in proliferation and differentiation of epidermal keratinocytes and in cutaneous wound repair. Furthermore, the role of lncRNAs in keratinocyte-derived skin cancers is emerging, especially in cutaneous squamous cell carcinoma (cSCC), which presents a significant burden to health care services worldwide and causes high mortality as metastatic disease. Elucidation of the functions of keratinocyte-specific lncRNAs will improve understanding of the molecular pathogenesis of epidermal disorders and skin cancers and can be exploited in development of new diagnostic and therapeutic applications for keratinocyte carcinomas. In this review, we summarize the current evidence of functionally important lncRNAs in cutaneous biology and in keratinocyte carcinomas.

P53 staining index and zonal staining patterns in actinic keratoses

Actinic keratoses (AKs) are common dysplastic lesions resulting from chronic excessive ultraviolet exposure. Neither the clinical grade of thickness nor the histological grade of dysplasia seems valid predictors of aggressive potential of AKs. Instead, the mutational status in AKs appears to predict well the clinical course. TP53 gene mutations result in a non-functional protein resistant to degradation, thus immunohistochemical staining for p53 can suggest mutation status. Increased p53 was associated with progression from AK to squamous cell carcinoma. To investigate how the intensity of p53 staining (p53 staining index) varies according to body site, histological subtype and grade dysplasia of AKs. Secondly, we sought to investigate the distribution in the epidermal layers of non-functional p53 (zonal staining patterns). p53 staining index was greater than 50% in 90.7% of AKs. p53 staining index was significantly higher in older age (p < 0.0093) and in facial AKs compared to other body areas (p = 0.03). A significant correlation between p53 staining index and grade of dysplasia was observed (p = 0.006) and between p53 staining index and zonal p53 staining pattern (p = 0.003). No significant differences in p53 staining index among the various histological AK types were observed. No correlation between clinical and histological grade. All AKs, independently from their clinical appearance, should be treated but special attention is required for AKs on severely photodamaged skin on the face and in older patients.

Histological classification of cutaneous squamous cell carcinomas with different severity

Cutaneous squamous cell carcinoma (cSCC) is the second most common non-melanoma skin cancer. Histology represents the gold standard to confirm the diagnosis of cSCC and is mandatory to determine important findings for tumour grading, such as tumour thickness, depth of invasion, degree of differentiation and histological subtype, perineural and vascular invasion, and assessing tumour margins. In daily clinical practice, the combination of clinical and histological features should be considered when grading the tumours and treating the patients, accordingly. This article aims to provide a structured overview of the most common histological findings of in situ and invasive cSCCs, namely those relevant to their severity, and should facilitate the understanding and evaluation of these results.

Assessment of 5-Aminolaevulinic Acid Photodynamic Therapy (ALA-PDT) in Chinese patients with actinic keratosis: Correlation of dermoscopic features with histopathology

OBJECTIVES

The study examines the changes in dermoscopic features of actinic keratosis (AK) after photodynamic therapy, and delineates the association between AK dermoscopic and histopathological findings.

METHODS

A total of 21 patients (23 lesions) with pathologically confirmed actinic keratosis who received 5-aminolaevulinic acid (ALA) photodynamic therapy (ALA-PDT) were enrolled. The numbers of PDT treatments were: 1, n = 1; 2, n = 2; 3, n = 10; 4, n = 6; 5, n = 2; 6, n = 2). The dermoscopic features before and after the PDT were compared.

RESULTS

There were statistically significant decreases in the positive rates of dermoscopic features including scales (P < 0.001), follicular plugs with whitish halo (P = 0.013), and red pseudonetwork (P = 0.022) among patients treated with ALA-PDT. Dermoscopic feature was significantly associated with pathological grade (P < 0.001). Histopathological hyperkeratosis was significantly associated with dermoscopic red pseudonetwork (P = 0.034) and wavy vessel (P = 0.005). Parakeratosis was associated with wavy vessels (P = 0.001). For vascular hyperplasia in dermal papillae, the significant correlates included scales (P = 0.011), follicular plugs with whitish halo (P = 0.011), red pseudonetwork (P < 0.001); coiled vessels (P = 0.003) and rosette sign (P = 0.004). Wavy vessels was the only feature correlating keratosis pilaris (P = 0.003).

CONCLUSIONS

The findings of the present study support dermoscopy as having potential to be useful for diagnosing and monitoring of actinic keratosis.

Molecular Biology of Basal and Squamous Cell Carcinomas

The prevalent keratinocyte-derived neoplasms of the skin are basal cell carcinoma and squamous cell carcinoma. Both so-called non-melanoma skin cancers comprise the most common cancers in humans by far. Common risk factors for both tumor entities include sun exposure, DNA repair deficiencies leading to chromosomal instability, or immunosuppression. Yet, fundamental differences in the development of the two different entities have been and are currently unveiled. The constitutive activation of the sonic hedgehog signaling pathway by acquired mutations in the PTCH and SMO genes appears to represent the early basal cell carcinoma developmental determinant. Although other signaling pathways are also affected, small hedgehog inhibitory molecules evolve as the most promising basal cell carcinoma treatment options systemically as well as topically in current clinical trials. For squamous cell carcinoma development, mutations in the p53 gene, especially UV-induced mutations, have been identified as early events. Yet, other signaling pathways including epidermal growth factor receptor, RAS, Fyn, or p16INK4a signaling may play significant roles in squamous cell carcinoma development. The improved understanding of the molecular events leading to different tumor entities by de-differentiation of the same cell type has begun to pave the way for modulating new molecular targets therapeutically with small molecules.

Actinic keratoses: review of clinical, dermoscopic, and therapeutic aspects

Actinic keratoses are dysplastic proliferations of keratinocytes with potential for malignant transformation. Clinically, actinic keratoses present as macules, papules, or hyperkeratotic plaques with an erythematous background that occur on photoexposed areas. At initial stages, they may be better identified by palpation rather than by visual inspection. They may also be pigmented and show variable degrees of infiltration; when multiple they then constitute the so-called field cancerization. Their prevalence ranges from 11% to 60% in Caucasian individuals above 40 years. Ultraviolet radiation is the main factor involved in pathogenesis, but individual factors also play a role in the predisposing to lesions appearance. Diagnosis of lesions is based on clinical and dermoscopic examination, but in some situations histopathological analysis may be necessary. The risk of transformation into squamous cell carcinoma is the major concern regarding actinic keratoses. Therapeutic modalities for actinic keratoses include topical medications, and ablative and surgical methods; the best treatment option should always be individualized according to the patient.

Effects of topical piroxicam and sun filters in actinic keratosis evolution and field cancerization: a two-center, assessor-blinded, clinical, confocal microscopy and dermoscopy evaluation trial

Background: Actinic keratosis (AK) is considered an "in situ" non-melanoma skin cancer induced by ultraviolet chronic exposure. Sunscreen and topical anti-inflammatory agents like diclofenac could improve the evolution of this kind of lesions. A topical product containing piroxicam 0.8% and sun filters (50 SPF) (ACTX) has been shown to be very effective in reducing AK lesions. So far, no data are available regarding the effects of this product on skin modifications evaluated by reflectance confocal microscopy (RCM) and dermoscopy at the lesion sites and on the skin around the lesions (field cancerization). Study aim: To evaluate in a two-center, assessor-blinded, prospective trial the effect of ACTX on AK number, RCM and dermoscopy parameter evolution of a target lesion in subjects with multiple AK lesions. Subjects and methods: A total of 54 subjects (42 men and 12 women; mean age 65 years) with AK lesions grade I-III located on the scalp (n = 36) or face (n = 18) were enrolled after their written informed consent. ACTX was applied twice daily on the face and scalp for six consecutive months. AK lesion count was performed at baseline and after 3 and 6 months. Lesion count was assessed in a blind fashion evaluating digital color high definition images performed at each visit and coded in a blinded fashion. RCM evaluations were performed at the same time-points. A dermoscopy evaluation was performed at baseline and after 6 months. RCM and dermoscopy were assessed on a pre-specified target lesion. The RCM severity score was used evaluating 11 items, examining stratum corneum, stratum granulosum, stratum spinous and dermal layers (maximum score 11 points). The dermoscopy score evaluated erythema, scaling and follicular plugs (from 0 to 4 for each item) and pigmentation (from 0 to 5). Results: Forty-nine subjects (90%) concluded the trial. At baseline, the mean (SD) number of AK lesions was 9.6 (5.2). AK lesions significantly decreased to 5.9 and to 5.6 after 3 and 6 months of ACTX treatment (p = .001; intention to treat analysis), representing a -42% reduction. A reduction of AK lesion numbers >50% in comparison with baseline was observed in 51% of subjects at month 6. New AK lesions appeared in five subjects (9%). The RCM mean (SD) severity score at baseline was 6.4 (2.0). ACTX treatment was associated with a progressive and significant (p = .002) reduction to 4.9 after 3 months and to 4.8 (2.3) at month 6 (a -25% reduction). The dermoscopy score at baseline was 5.5 (2) and it was reduced significantly (p = .007) to 4.5 (2) at the end of the study. The product was in general very well tolerated. Conclusion: A 6 month application of ACTX in subjects with AK lesions was associated with an improvement in AK lesion count and with a reduction in the RCM/dermoscopy severity scores of the target lesion. Trial registration number: ISRCTN22070974.

Nonmelanoma skin cancer - from actinic keratosis to cutaneous squamous cell carcinoma

Actinic keratoses (AKs) are defined as intraepithelial proliferation of atypical keratinocytes. Given their potential for progression to invasive squamous cell carcinoma, they may eventually evolve into a life-threatening disease. In recent decades, there has been a significant increase in the incidence of AKs, primarily due to changes in recreational activities and demographic trends in industrialized countries. As it is currently impossible to predict if and when a given AK might progress to invasive carcinoma, rigorous treatment of field cancerization is a key component in preventing potential progression. In addition to a broad armamentarium of procedures as well as pharmaceutical treatment options, primary prevention through diligent UV protection likewise plays a crucial role. New clinical, histomorphological, or molecular classifications are needed to be able to reliably stratify patients based on their individual risk. Especially in light of socio-economic aspects, such a step might prevent over- and undertreatment of an ever-growing patient population and help develop treatment concepts based on individual patient needs.

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).

High-resolution quantitative acoustic microscopy of cutaneous carcinoma and melanoma: Comparison with histology

BACKGROUND

The increased incidence rate of skin cancers during the last decades is alarming. One of the significant difficulties in the histopathology of skin cancers is appearance variability due to the heterogeneity of diseases or tissue preparation and staining process. This study aims to investigate whether the high-resolution acoustic microscopy has the potential for identifying and quantitatively classifying skin cancers.

MATERIAL/METHODS

Unstained standard formalin-fixed skin tissue samples were used for ultrasonic examination. The high-frequency acoustic microscope equipped with the 320 MHz transducer was utilized to visualize skin structure. Fourier transform was performed to calculate the sound speed and attenuation in the tissue.

RESULTS

The acoustic images demonstrate good concordance with the traditional histology images. All histological features in the tumour were easily identifiable on acoustic images. Each skin cancer type has its combination of ultrasonic properties significantly different from the healthy skin.

CONCLUSIONS

High-resolution acoustic imaging strengthened with quantitative analysis shows a potential to work as an auxiliary imaging modality assisting pathologists to lean to the particular decision in doubtful cases. The method can also assist surgeon to ensure the complete resection of a tumour.

Cyclooxygenase-2 expression in actinic keratosis

Introduction

Actinic keratosis (AK) is a common age-associated dermatosis typical for skin with photo-ageing features. Actinic keratosis lesions transform into invasive squamous cell carcinoma, if left untreated, but inductive factors remain unknown. A role of prostaglandins in the neoplastic process has been postulated.

Aim

To evaluate the possible correlation between cyclooxygenase-2 (COX-2) antigen expression in the immunohistochemical reaction and the stage of AK using the keratinocytic intraepidermal neoplasia (KIN) classification, age, sex and skin phenotype.

Material and methods

Skin samples of AK were examined histopathologically using the KIN classification. Immunohistochemical analysis of COX-2 expression was conducted using a commercially available kit and Image Processing and Analysis in Java. The intensity was presented as the percentage of cells with a positive reaction.

Results

Out of the 94 subjects with AK (aged 51–93 years; mean: 76.51 ±9.64), 58 were female and 36 male. Phenotype 2 was found in 50 and phenotype 3 in 44 patients. Mean values of positive immunohistochemical reaction for COX-2 were 2.16 ±6.56% for women and 1.96 ±6.59% for men (2.47 ±6.61%), with no statistically significant difference. Mean values of anti-COX-2 antibody reaction were 2.30 ±6.82% in the KIN1 group and 2.48 ±7.01% in the KIN2 group, while no expression was found in all cases with KIN3. No statistically significant differences were found between the percentage of COX-2 positive cells in KIN1/KIN2.

Conclusions

No statistically significant correlations between the intensity of COX-2 reaction and AK stage were found. Cyclooxygenase-2 expression in AK is not affected by age, sex, or skin phenotype.

Histological intralesional heterogeneity of actinic keratoses relates to field cancerization

BACKGROUND/OBJECTIVES

Histological heterogeneity within distinct actinic keratosis (AK) lesions has been described and might serve as an additional feature of AKs. We aimed to investigate and quantify the histological heterogeneity of AKs regarding different grading systems.

METHODS AND MATERIAL

We assessed the histology of 3 mm biopsies of AK lesions located on the scalp or face. We documented basal proliferation (PRO I-III), histological grade (AK I-III) and determined the overall classification of each lesion.

RESULTS

Of the 305 lesions included, 48 (15.7 %) lesions were classified as AK I, 152 (49.8 %) as AK II and 105 (34.4 %) as AK III. 33 AKs (10.8 %) showed no basal proliferation, 94 (30.8 %) were graded as PRO I, 99 (32.5 %) as PRO II and 79 (25.9 %) as PRO III. One histological grade and basal growth pattern per lesion was observed in 94 (30.8 %) and 104 (34.1 %) cases respectively, two grades in 170 (55.7 %) and 168 (55.1 %) cases, and three grades in 41 (13.4 %) and 33 (10.8 %) cases (Chi-squared test, p < 0.0001).

CONCLUSIONS

By analogy with the clinical heterogeneity of field cancerization, AKs show a high histological grade heterogeneity even within small lesions. Variations in AK grading reflect the heterogeneity of the cancerization field and might serve as additional feature.

Effect of ingenol mebutate on actinic keratosis in a Korean population: A prospective clinical, dermoscopic and histopathological study from a single center

Actinic keratosis (AK) is an in situ squamous cell carcinoma which is mostly found on sun-damaged skin, and it is prevalent among Caucasians. However, there is a lack of research on evaluating the treatment efficacy of ingenol mebutate (IM) on AK in Asians. This study was intended to analyze the treatment outcomes of IM on AK in Korean patients with regards to clinical, dermoscopic and histopathological aspects. A prospective study on 46 Korean patients who were diagnosed with AK and treated with IM was conducted. Clinically, 80% (24/30) of the patients showed an improvement at 8 weeks. Twenty out of the 30 (66.7%) patients were found to have achieved histopathological clearance. All local skin responses had disappeared at T4 in all patients. Patients with Fitzpatrick skin type III were proven to exhibit better treatment outcomes, both clinically (P = 0.001) and histopathologically (P = 0.001), than those with Fitzpatrick skin type IV. The clinical and histopathological clearance rate of AK with IM in Korean patients was 80% and 66.7%, respectively. The patients with Fitzpatrick skin type IV showed a tendency to have residual AK, histopathologically after treatment with IM. In conclusion, IM could be an effective and safe treatment option on AK in Korean patients. In addition, it would be helpful to carry out a cautious check-up when treating AK with IM in patients with a darker skin color.

Efficacy of Ingenol Mebutate in the Treatment of Actinic Keratoses: A Pre- and Posttreatment Dermoscopic Comparative Analysis

Actinic keratosis (AK) is a common skin lesion in adults which usually occurs on chronically photoexposed areas and considered as a precancerous lesion or a superficial squamous-cell carcinoma. Many classifications have been proposed and its diagnosis is generally clinical but, sometimes, its wide variety of presentations can make diagnosis difficult, even among expert observers. The malignant potential of AKs imposes an early diagnosis and treatment in order to reduce morbidity and mortality, and, for the characterization of photodamaged skin, noninvasive diagnostic techniques, such as dermoscopy, have proved to be useful, while multiple therapeutic strategies, lesion-directed versus field-directed therapies, are available for the treatment of AKs. In this study, we evaluated the efficacy of ingenol mebutate for the treatment of AKs, with a particular focus on patients' compliance, correlating it to clinical and dermoscopic grading, pre- and posttreatment, of these lesions. Fifty-two enrolled patients with AKs received treatment with ingenol mebutate gel (0.015% for face and scalp; 0.05% for trunk and extremities) and multiple dermatological evaluations. End points of the study were complete and partial clearance of clinically visible AKs on day 90. All acquired data were recorded and statistical analyses were performed. Univariate and multivariate analyses were used to identify possible predictive factors. We retrospectively analyzed patient-related and lesion-related factors to identify which variables, among age, gender, lesion site, pain, LSR score, and pretreatment clinical and dermoscopic grading, could independently predict the response to ingenol mebutate treatment. Our findings showed that pretreatment dermoscopic grade II represents an independent predictive factor of the efficacy of ingenol mebutate therapy (OR=14.78, 95% CI: 1.83–119.59, P=0.012) and that response rates differ on the basis of the treated anatomical sites (OR=0.16, 95% CI: 0.03–0.85, P=0.031). Data from this study provide evidence that ingenol mebutate gel is an effective treatment for AK, with relative ease of use, short exposure, and rapid resolution of local reactions, benefits contributing to high adherence of this therapy. Moreover, dermoscopic analysis of skin lesions offers more information than clinical evaluation alone and can be helpful in identifying different groups of AKs, thus selecting the adequate therapeutic choice.

A randomized, intraindividual, non-inferiority, Phase III study comparing daylight photodynamic therapy with BF-200 ALA gel and MAL cream for the treatment of actinic keratosis

Background

The most effective treatment modality for actinic keratosis (AK) is photodynamic therapy (PDT). Major obstacles of PDT are the need of a special illumination device and pain accompanying the illumination. These issues may be overcome by replacing an artificial high‐power light source with natural daylight for more extended illumination at lower light doses.

Objective

To determine whether BF‐200 ALA (a nanoemulsion gel containing 7.8% 5‐aminolaevulinic acid) is non‐inferior to MAL (a cream containing 16% methyl‐aminolaevulinate) in the treatment of mild‐to‐moderate AK with daylight PDT (dPDT). Non‐inferiority of the primary efficacy variable (total lesion clearance rate per patient's side 12 weeks after PDT) is established if the mean response for BF‐200 ALA is no worse than for MAL, within a statistical margin of Δ = −12.5%.

Methods

The study was performed as an intraindividual comparison with 52 patients in seven centres in Germany and Spain. Each patient received one dPDT. Results include clinical endpoints as well as 1‐year follow‐up results.

Results

Twelve weeks after a single dPDT, 79.8% of the AK lesions treated with BF‐200 ALA gel and 76.5% of the lesions treated with MAL cream were completely cleared. The median of differences was 0.0 with a one‐sided 97.5% CI of 0.0, establishing non‐inferiority (P < 0.0001). Results for secondary efficacy parameters were in line with the primary outcome. Recurrence rates 1 year after the treatment were 19.9% for lesions treated with BF‐200 ALA and 31.6% for lesions treated with MAL. Adverse reactions including pain were mostly mild and transient and identical to those previously described for dPDT.

Conclusion

Daylight PDT of AK with BF‐200 ALA is well‐tolerated and non‐inferior to MAL/dPDT. The study demonstrates a trend towards higher efficacies after 3 months and significantly lower recurrence rates after 1 year follow‐up.