Comment to: 'Evidence and consensus based (S3) Guidelines for the Treatment of Actinic Keratosis'

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.

Efficacy of new class I medical device for actinic keratoses: a randomized controlled prospective study

BACKGROUND

The presence of Actinic Keratoses (AKs) represent the most important warning sign of subclinical ultraviolet radiation. Currently, the regular use of sunscreens is considered essential for the prevention of the development of AKs.

AIM

We evaluated the effectiveness of a new class I Medical Device (MD) for the prevention and treatment of AKs vs traditional sunscreen alone (SPF 100+).

METHODS

We conducted a randomized controlled prospective study in 90 Caucasian patients: 62 immunocompetent and 28 Organ Transplant Recipients (OTRs). We randomly assigned subjects to the MD group or sunscreen alone in a 1:1 assignment ratio. The patients have been reevaluated after three and six months.

RESULTS

In immunocompetent patients treated with MD, at the end of the study the reduction of the mean number of AKs was 54.7 vs. 9.43% with photoprotector. In OTRs, the global reduction was of 36.7% after MD use compared to 14.3% with the sunscreen. The prevalence of NMSCs, in the patients treated with MD, was 11.11 and 17.18 with sunscreen; the incidence was 19.7 in patients treated with MD and 32.1 in those treated with sunscreen.

CONCLUSION

The MD has demonstrated good efficacy in the reduction of visible AKs, encouraging its use also in high-risk category, like OTRs.

Tracking actinic keratosis of face and scalp treated with 0.015% ingenol mebutate to identify clinical and dermoscopic predictors of treatment response

BACKGROUND

Ingenol mebutate (IngMeb) 0.015% gel is an approved field treatment option for non-hyperkeratotic non-hypertrophic actinic keratosis (AK) of face and scalp. Efficacy of IngMeb has been assessed only on a clinical ground, in the majority of studies. Dermoscopy is a pivotal tool for the diagnosis of AK, while its role in evaluating the response to non-surgical therapies for AK has not been fully defined.

OBJECTIVES

Our study aims to determine whether some dermoscopic features of AK of the face and scalp areas may independently predict the response to IngMeb therapy.

METHODS

Clinical and dermoscopic responses, 1 month after 0.015% IngMeb therapy, were retrospectively evaluated using a per-patient and per-lesion approach. Safety was evaluated through local skin reaction composite score calculation. Demographic, clinical and dermoscopic factors were then evaluated via univariate and multivariate logistic regression analysis to assess independent predictors of response.

RESULTS

Fifty-five patients with 245 AKs were enrolled. Clinically, per-patient response evaluation identified 25 (45.4%) poor/partial and 30 (54.5%) complete responders, corresponding on a per-lesion approach to 66 (26.9%) and 179 (73.1%) AKs, respectively. Dermoscopy reclassified 14 patients in the per-patient and 48 AKs in the per-lesion analysis from complete to poor/partial responders. Multivariate logistic regression analysis showed that AKs dermoscopically characterized by red pseudonetwork and located on the face were independently associated with a complete dermoscopic response to 0.015% IngMeb therapy, while microerosions were negative predictors.

CONCLUSION

Specific dermoscopic features of AK may predict the response to 0.015% IngMeb therapy, together with the location on the face.

From actinic keratosis to squamous cell carcinoma: pathophysiology revisited

The precursor of most cutaneous invasive squamous cell carcinomas (iSCCs) is intraepithelial UV-induced damage, known as field cancerization, which can eventually transform into actinic keratosis (AK). Although AK is the most common precursor of iSCC, many AKs will either persist in the same stage or regress, while only a few will progress into iSCC. Nevertheless, because the progression of individual AKs cannot be predicted, it has been proposed that all AKs, regardless of the grade, should be carefully monitored and appropriately treated in clinical practice. Modern imaging techniques such as dermatoscopy, reflectance confocal microscopy (RCM) and high-definition optical coherence tomography (HD-OCT) may have potential to monitor the evolution of actinic field damage. Dermatoscopy can be used to differentiate between AK, intraepidermal carcinoma (IEC) and SCC which may help clinicians to diagnose in situ or invasive lesions at an earlier stage. HD-OCT and RCM can be used to detect cellular and histological changes characteristic of subclinical lesions, allowing visualization of previously invisible lesions. As development of invasive AK directly from the cancer field cannot be ruled out, the ideal treatment should be able to eradicate AK lesions and reverse the underlying field cancerization.

Treatment considerations in actinic keratosis

The chronic skin condition actinic keratosis (AK) is characterized by the formation of keratotic lesions of variable thickness that are poorly delimited. AK occurs on areas of the skin that have had long-term exposure to the sun or UV radiation. Although AKs may regress, they usually persist and can progress to squamous cell carcinoma (SCC). Clinicians are unable to predict which AKs will progress; therefore, both clinically visible lesions and subclinical, non-visible (i.e. the entire area affected by AK/field cancerization) should be treated. AK treatment options include lesion-directed therapies that target specific AK lesions and field-directed therapies that target multiple clinical lesions and the underlying field damage. This article reviews currently available treatment options in AK, with a focus on patient-applied field therapies, and their suitability according to specific disease characteristics and patient needs. Choice of treatment in AK depends on lesion-, patient- and treatment-related factors and should be individualized. Considerations when choosing a therapy include site of application, treatment duration, surface area of application, tolerability profiles and implications on adherence. Field-directed therapies treat clinical and subclinical damage (i.e. the entire area affected by AK), achieve high rates of sustained clearance of AKs and may reduce the risk of progression to SCC. There is a clear need for field therapies with short duration of treatment and predictable, short-lived, mild local skin reactions that can be used over a large surface area. Therapies with shorter and simpler treatment courses are often associated with better adherence than treatments with longer courses. These may, therefore, represent more appropriate choices in patients for whom convenience and/or adherence are an issue.