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

The clinical value of reflectance confocal microscopy in monitoring treatment of actinic keratosis: A systematic review

BACKGROUND

Actinic keratosis (AK) is a precancerous skin lesion that can progress to squamous cell carcinoma (SCC). Early diagnosis and effective treatment are crucial, but current treatment evaluation methods lack consistency. Reflectance confocal microscopy (RCM) has emerged as a promising non-invasive tool for monitoring treatment outcomes in AK, but the absence of standardized evaluation protocols limits its clinical applicability.

OBJECTIVE

This study aims to establish standardized RCM imaging features for evaluating treatment responses in AK, thereby enhancing the consistency and clinical utility of RCM in treatment monitoring.

METHODS

A systematic review was conducted following the PRISMA 2020 guidelines. Studies that evaluated the treatment of AK using RCM were included. A comprehensive literature search was performed across MEDLINE, Embase, and the Cochrane Library up to October 2024. Data on study design, treatment modalities, RCM imaging features, and scoring systems were extracted. A meta-analysis was not performed due to heterogeneity in study designs and outcome measures.

CONCLUSION

This review identifies key RCM imaging features of AK, including keratinocyte atypia and architectural disarray, and highlights the lack of a standardized scoring system for evaluating treatment outcomes. The findings underscore the need for a universally accepted protocol to improve the consistency and reliability of RCM in clinical practice. Standardization of RCM evaluation will enhance its utility in both clinical monitoring and future research on AK treatment.

Field Cancerization Therapies for the Management of Actinic Keratosis: An Updated Review

Field cancerization theory highlights that the skin surrounding actinic keratoses (AK) is also at increased risk for possible malignant transformation; thus, field-directed treatments may both reduce the risk of AK recurrence and potentially reduce the risk of development of cutaneous squamous cell carcinoma (cSCC). Photodynamic therapy (PDT) with either aminolevulinic acid (ALA) or methylaminolevulinate (MAL), as well as topical treatments such as 5-fluorouracil (5-FU), diclofenac gel, piroxicam, imiquimod, and ingenol mebutate, have all shown higher efficacy than vehicle treatments. PDT is widely recognized for its high efficacy; however, concerns for associated pain have driven new studies to begin using alternative illumination and pretreatment techniques, including lasers. Among topical treatments, a combination of 5-FU and salicylic acid (5-FU-SA) has shown to be the most effective but also causes the most adverse reactions. Tirbanibulin, a new topical agent approved for use in 2020, boasts a favorable safety profile in comparison with imiquimod, 5-FU, and diclofenac. Meanwhile, ingenol mebutate is no longer recommended for the treatment of AKs due to concerns for increased risk of cSCC development. Moving forward, an increasing number of studies push for standardization of outcome measures to better predict risk of future cSCC and use of more effective measures of cost to better guide patients. Here, we present an updated and comprehensive narrative review both confirming the efficacy of previously mentioned therapies as well as highlighting new approaches to PDT and discussing the use of lasers and novel topical treatments for treatment of AK.

The phenomenon of phototoxicity and long-term risks of commonly prescribed and structurally diverse drugs

Photosensitivity to structurally diverse drugs is a common but under-reported adverse cutaneous reaction and can be classified as phototoxic or photoallergic. Phototoxic reactions occur when the skin is exposed to sunlight after administering topical or systemic medications that exhibit photosensitizing activity. These reactions depend on the dose of medication, degree of exposure to ultraviolet light, type of ultraviolet light, and sufficient skin distribution volume. Accurate prediction of the incidence and phototoxic response severity is challenging due to a paucity of literature, suggesting that phototoxicity may be more frequent than reported. This paper reports an extensive literature review on phototoxic drugs; the review employed pre-determined search criteria that included meta-analyses, systematic reviews, literature reviews, and case reports freely available in full text. Additional reports were identified from reference sections that contributed to the understanding of phototoxicity. The following drugs and/or drug classes are discussed: amiodarone, voriconazole, chlorpromazine, doxycycline, fluoroquinolones, hydrochlorothiazide, nonsteroidal anti-inflammatory drugs, and vemurafenib. In reviewing phototoxic skin reactions, this review highlights drug molecular structures, their reactive pathways, and, as there is a growing association between photosensitizing drugs and the increasing incidence of skin cancer, the consequential long-term implications of photocarcinogenesis.

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.

Efficacy and safety of microneedling, fractional CO2 laser, and cryotherapy combined with 5-aminolevulinic acid photodynamic therapy in the treatment of actinic keratosis: A multicenter prospective randomized controlled study

BACKGROUND

Photodynamic therapy (PDT) for actinic keratosis (AK) is limited by the depth of treatment. Microneedling or fractional CO2 laser can facilitate the penetration of photosensitizer, while cryotherapy can treat deeper tissues but is not suitable for field cancerization.

OBJECTIVE

To investigate the efficacy of microneedling, fractional CO2 laser, and cryotherapy in combination with PDT for AK.

METHODS

Patients with AK were randomized into 4 groups, including group A with microneedling + PDT, group B with fractional CO2 laser + PDT, group C with cryotherapy + PDT, and group D with PDT. After 12 weeks, the clinical, dermoscopic, and reflectance confocal microscopy (RCM) outcomes were assessed.

RESULTS

A total of 129 patients were included in this study, with 31, 30, 35, and 31 patients in each group, yielding clinical response rates of 90.3%, 93.3%, 97.1%, and 74.2%, respectively (P=0.026). The RCM response rates were 71.0%, 80.0%, 85.7%, and 54.8%, respectively (P=0.030). The dermoscopic response rates were 77.4%, 83.3%, 88.6%, and 60.0%, respectively (P=0.039). Group C showed the best efficacy in terms of clinical, dermoscopic, and RCM outcomes.

CONCLUSIONS

All three treatments improved the efficacy of PDT and were well tolerated, with cryotherapy + PDT showing the best efficacy.

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.

Early clinical response to 5-fluorouracil 0.5% and salicylic acid 10% topical solution in the treatment of actinic keratoses of the head: an observational study

BACKGROUND

Actinic keratosis is one of the most common dermatological disorders. A new topical solution, constituted by 0.5% 5-fluorouracil and 10% salicylic acid (Actikerall, Almirall) has been introduced in the treatment pipeline of non-hyperkeratotic actinic keratoses of the head and neck.

PATIENTS AND METHODS

We analyzed in an observational prospective clinical study the short-term treatment effectiveness of 5-fluorouracil and salicylic acid on face and scalp actinic keratoses of grade 1 and 2 of forty patients. Efficacy assessment was performed by clinical dermatological examination, collecting color photographs, calculating AKASI score, and by means of dermoscopy for each target lesion at every visit.

RESULTS

AKASI score decreased from an initial score of 3.3 to a final score of 0.9. At week 4, we were able to record a complete clearance of 50% of the treated lesions and a partial clearance of 28%. At the end of 12 weeks, 84% of the total lesions showed complete clearance, while 8% had partial clearance.

CONCLUSIONS

5-fluorouracil and salicylic acid topical solution is effective in the treatment of mild to moderate actinic keratoses. In the future, further studies are needed to evaluate the chance of adjusting drug dosage according to patients' and actinic keratoses features.

Photosensitizing Medications and Skin Cancer: A Comprehensive Review

(1) The incidence of skin cancer is increasing in the United States (US) despite scientific advances in our understanding of skin cancer risk factors and treatments. In vitro and in vivo studies have provided evidence that suggests that certain photosensitizing medications (PSMs) increase skin cancer risk. This review summarizes current epidemiological evidence on the association between common PSMs and skin cancer. (2) A comprehensive literature search was conducted to identify meta-analyses, observational studies and clinical trials that report on skin cancer events in PSM users. The associated risks of keratinocyte carcinoma (squamous cell carcinoma and basal cell carcinoma) and melanoma are summarized, for each PSM. (3) There are extensive reports on antihypertensives and statins relative to other PSMs, with positive and null findings, respectively. Fewer studies have explored amiodarone, metformin, antimicrobials and vemurafenib. No studies report on the individual skin cancer risks in glyburide, naproxen, piroxicam, chlorpromazine, thioridazine and nalidixic acid users. (4) The research gaps in understanding the relationship between PSMs and skin cancer outlined in this review should be prioritized because the US population is aging. Thus the number of patients prescribed PSMs is likely to continue to rise.

Repurposing of Drug Candidates for Treatment of Skin Cancer

Skin cancers are highly prevalent malignancies that affect millions of people worldwide. These include melanomas and nonmelanoma skin cancers. Melanomas are among the most dangerous cancers, while nonmelanoma skin cancers generally exhibit a more benign clinical pattern; however, they may sometimes be aggressive and metastatic. Melanomas typically appear in body regions exposed to the sun, although they may also appear in areas that do not usually get sun exposure. Thus, their development is multifactorial, comprising endogenous and exogenous risk factors. The management of skin cancer depends on the type; it is usually based on surgery, chemotherapy, immunotherapy, and targeted therapy. In this respect, oncological treatments have demonstrated some progress in the last years; however, current therapies still present various disadvantages such as little cell specificity, recurrent relapses, high toxicity, and increased costs. Furthermore, the pursuit of novel medications is expensive, and the authorization for their clinical utilization may take 10-15 years. Thus, repositioning of drugs previously approved and utilized for other diseases has emerged as an excellent alternative. In this mini-review, we aimed to provide an updated overview of drugs' repurposing to treat skin cancer and discuss future perspectives.

In Vivo Reflectance Confocal Microscopy in General Dermatology: How to Choose the Right Indication

Reflectance confocal microscopy (RCM) is a high-resolution, noninvasive imaging technique being increasingly used as an aid to diagnosis in the dermatology setting. RCM is applied in the diagnosis of both melanoma and nonmelanoma skin tumors, but also in the interpretation and management of inflammatory skin diseases. Two different devices with different designs for specific indications are available in the market: a static and a handheld probe. Several clinical presentations of the lesion could affect the examination, such as the presence of ulceration or hyperkeratosis; moreover, the anatomical site can drive the probe selection as well as the effective indication to RCM examination. In this review article, indications for the use of RCM are described in detail with a schematic approach for practical purposes.