Current and emerging treatment strategies for the treatment of actinic keratosis

Twist1 as a target for prevention of cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) represents an important clinical problem requiring novel approaches for both prevention and treatment. The transcription factor, Twist-related protein 1 (Twist1), has been identified as having a key mechanistic role in the development and progression of cSCC. Studies in relevant mouse models of cSCC have shown that Twist1 regulates epithelial-mesenchymal transition (EMT) and stemness driving progression and metastasis of cSCC. In addition, further research has shown that Twist1 regulates the balance between keratinocyte proliferation and differentiation and therefore impacts earlier stages of cSCC development. Through use of keratinocyte specific Twist1 knockout models, a role for this gene in keratinocyte stem cell homeostasis has been revealed. As a transcription factor, Twist1 regulates a large number of genes both in a positive, as well as a negative manner across several interdependent pathways. Studies in keratinocyte specific knockout models have shown that Twist1 upregulates the expression of genes involved in proliferation, stemness, and EMT while downregulating the expression of genes associated with differentiation. Furthermore, a number of compounds, including naturally occurring compounds, have been identified that target Twist1 and can block its effects in cancer cells and in keratinocytes in vivo. Collectively, the current understanding of Twist1 function in cSCC development and progression suggests that it represents a potential target for prevention and treatment of cSCC.

Actinic keratosis - review for clinical practice

Actinic keratosis (AK) is a lesion that arises as a result of excessive exposure to solar radiation and appearing predominantly on Fitzpatrick phototype I and II skin. Given that some AKs evolve into squamous cell carcinoma, these lesions are considered premalignant in nature, occurring mostly in elderly men and immunosuppressed individuals chronically exposed to ultraviolet (UV) radiation. There are several mechanisms for the formation of AKs; among them are oxidative stress, immunosuppression, inflammation, altered proliferation and dysregulation of cell growth, impaired apoptosis, mutagenesis, and human papillomavirus (HPV). Through the understanding of these mechanisms, several treatments have emerged. Among the options for AK treatment, the most commonly used include 5-fluorouracil (5-FU), cryotherapy, diclofenac, photodynamic therapy (PDT), imiquimod (IQ), retinoids, and ingenol mebutate (IM). There have been recent advances in the treatment options that have seen the emergent use of newer agents such as resiquimod, betulinic acid, piroxicam, and dobesilate. The combination between therapies has presented relevant results with intention to reduce duration of therapy and side effects. All AK cases must be treated because of their propensity to transform into malignancy and further complicate treatment. In addition to medical or surgical care, education about sun exposure prevention remains the best and most cost-effective method for AK prevention. The objective of this article is to conduct a literature review of the clinical presentation of AK including advances in treatment options available.

Patient-reported outcomes in topical field treatment of actinic keratosis in Swedish and Danish patients

Topical treatments in dermatology can be long, complex and lead to nonadherence and nonpersistence to prescribed treatment. Clinical efficacy observed in randomized clinical trials (RCT) may therefore be reduced in real-world clinical practice. The objective of this study was to analyze patient-reported treatment adherence, treatment satisfaction and health-related quality of life (HRQoL) with topical treatments of actinic keratosis (AK) in routine clinical practice in Denmark and Sweden. Adult patients prescribed field-directed topical AK treatments with diclofenac gel, imiquimod or ingenol mebutate per routine clinical practice were eligible for the observational RAPID-ACT study. Data were collected through physician and patient questionnaires that included validated instruments to measure treatment satisfaction (TSQM-9), treatment adherence (MMAS) and HRQoL (EQ-5D-5L, EQ-VAS, AKQoL). In total, 446 patients from Denmark and Sweden were included. Ingenol mebutate patients reported a higher satisfaction with treatment effectiveness compared to patients treated with diclofenac (p = .006) while no other differences in treatment satisfaction could be determined. Treatment adherence was generally high, but higher for ingenol mebutate compared to both diclofenac (p < .001) and imiquimod (p = .007), possibly due to shorter treatment duration. No differences in improved HRQoL were found. More research is needed about the link between treatment adherence and real-world effectiveness.

Histopathological analysis of the therapeutic response to cryotherapy with liquid nitrogen in patients with multiple actinic keratosis

Actinic keratoses are premalignant lesions of the skin caused by excessive sun exposure. Lesions may become mainly squamous cell carcinoma. Cryotherapy with liquid nitrogen is one of the main treatments. In order to evaluate the response of actinic keratosis to cryotherapy by histopathology, two lesions were selected in each of 14 patients with multiple actinic keratoses. In one lesion a biopsy was performed and in the other lesion a biopsy was performed after cryotherapy. Subsequently, both biopsies were compared histologically. Of the thirteen patients who completed the study, the best results were obtained in lesions undergoing cryotherapy concerning the atypia of keratinocytes, epithelial thickness and corneal layer and lymphocytic infiltrate. Despite the small number of patients, it was concluded that, if performed correctly, cryotherapy has high efficacy in the treatment of actinic keratoses.