Randomized, Controlled Trial of Fractional Carbon Dioxide Laser Resurfacing Followed by Ultrashort Incubation Aminolevulinic Acid Blue Light Photodynamic Therapy for Actinic Keratosis

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.

IGF1 synthesis after CO2 fractional laser resurfacing (FLR): New insights in the treatment of scalp actinic keratoses

OBJECTIVES

Actinic keratosis have a high risk of progression to a squamous cell carcinoma. Insulin-like growth factor 1 and its receptor play a relevant role in restoring repair of ultraviolet-induced cell damage. This pathway is reduced in patients older than 65 years. Ablative fractional laser resurfacing could normalize insulin-like growth factor 1 (IGF-1) secretion in elderly by recruiting new fibroblasts. The aim of the study is to evaluate restoration of IGF1 values by PCR in senescent fibroblasts after ablative fractional laser resurfacing.

METHODS

We enrolled 30 male patients with multiple actinic keratosis on the scalp, equally divided into two mirror areas of up to 50 cm2 , treating only the right one. We performed one skin biopsy for each area 30 days after treatment. Real-time PCR in fibroblasts was performed to assess the change in IGF1. At baseline and after 6 months, in vivo reflectance confocal microscopy examination was performed in all patients.

RESULTS

IGF1 values were increased in the treated side by about 60%. The right areas had fairly complete resolution of actinic keratosis at the last follow-up visit after 6 months with no appearance of new lesions. The mean number of actinic keratosis in the right area was reduced by more than 75% at four- and six-follow-up visits compared to the left area. The improvement in the right area was also evidenced by lower values of the mean AKASI (actinic keratosis area and severity index) score. Reflectance confocal microscopy showed a reduction of keratinocytic disarray and scales after treatment.

DISCUSSION

Taken together, all the clinical, laboratory, and in vivo results of our study allowed us to confirm that ablative fractional laser resurfacing is a valuable tool for the treatment of actinic keratosis and cancerization field, both for the management of clinically evident lesions and for preventing the occurrence of squamous cell carcinoma.

Gold-Polypyrrole-Loaded Eosin in Photo-Mediated Treatment of Hidradenitis Suppurativa: In Vivo Trans-Epidermal Permeation Study and Clinical Case Report

This study reports a new protocol for the management of Hidradenitis Suppurativa (HS), depending on the synergistic photodynamic and photothermal effect of eosin yellow-gold-polypyrrole hybrid nanoparticles (E-G-Ppy NPs). E-G-Ppy NPs and gold-polypyrrole NPs (G-Ppy NPs) were synthesized, characterized, and formulated in topical hydrogels. Then, in vivo trans-epidermal permeation study, under both dark and white light-irradiation conditions, was done on albino mice. The E-G-Ppy hydrogel was then applied on a twenty-four years old female with recurrent axillary HS lesions pretreated with fractional CO₂ laser. Thereafter, the treated lesions were irradiated sequentially, using an IPL system, in the visible (~550 nm) and NIR band (630-1100 nm) to activate the synthesized nanoparticles. Results showed that, upon application to mice skin, E-G-Ppy exhibited good tolerance and safety under dark conditions and induced degenerative changes into dermal layers after white-light activation, reflecting deep penetration. Photo-activation of E-G-Ppy hydrogel to a severe Hidradenitis Suppurativa case showed an improvement of 80% of the lesions according to average HS-LASI scores after 4 sessions with no recurrence during a follow-up period of six months. In summary, the dual photodynamic/photothermal activation of E-G-Ppy NPs can represent a promising modality for management of HS. Further expanded clinical studies may be needed.

Evidence-Based Clinical Practice Guidelines for Laser-Assisted Drug Delivery

Importance

Laser-assisted drug delivery (LADD) is used for various medical and cosmetic applications. However, there is insufficient evidence-based guidance to assist clinicians performing LADD.

Objective

To develop recommendations for the safe and effective use of LADD.

Evidence Review

A systematic literature review of Cochrane Central Register of Controlled Trials, Embase, and MEDLINE was conducted in December 2019 to identify publications reporting research on LADD. A multidisciplinary panel was convened to draft recommendations informed by the systematic review; they were refined through 2 rounds of Delphi survey, 2 consensus meetings, and iterative review by all panelists until unanimous consensus was achieved.

Findings

Of the 48 published studies of ablative fractional LADD that met inclusion criteria, 4 were cosmetic studies; 21, oncologic; and 23, medical (not cosmetic/oncologic), and 6 publications of nonablative fractional LADD were included at the request of the expert panel, producing a total of 54 studies. Thirty-four studies (63.0%) were deemed to have low risk of bias, 17 studies (31.5%) had moderate risk, and 3 (5.5%) had serious risk. The key findings that informed the guidelines developed by the expert panel were as follows: LADD is safe in adults and adolescents (≥12 years) with all Fitzpatrick skin types and in patients with immunosuppression; it is an effective treatment for actinic keratosis, cutaneous squamous cell carcinoma in situ, actinic cheilitis, hypertrophic scars, and keloids; it is useful for epidermal and dermal analgesia; drug delivery may be increased through the application of heat, pressure, or occlusion, or by using an aqueous drug solution; laser settings should be selected to ensure that channel diameter is greater than the delivered molecule; antibiotic prophylaxis is not recommended, except with impaired wound healing; antiviral prophylaxis is recommended when treating the face and genitalia; and antifungal prophylaxis is not recommended. The guideline's 15 recommendations address 5 areas of LADD use: (I) indications and contraindications; (II) parameters to report; (III) optimization of drug delivery; (IV) safety considerations; and (V) prophylaxis for bacterial, viral, and fungal infections.

Conclusions and Relevance

This systematic review and Delphi consensus approach culminated in an evidence-based clinical practice guideline for safe and effective use of LADD in a variety of applications. Future research will further improve our understanding of this novel treatment technique.

Laser Resurfacing Monotherapy for the Treatment of Actinic Keratosis

Treating actinic keratosis (AK) and photodamaged skin is critical to reduce the risk of progression to skin cancer. Laser resurfacing for AK treatment is available as either lesion-directed or field therapy. Laser resurfacing removes the superficial epidermis and dermis containing actinic damage, promoting re-epithelialization of healthy skin. Although laser resurfacing has been explored as a modality for AK treatment in the literature, studies summarizing its efficacy in the treatment of AK are lacking. This review summarizes existing research on laser resurfacing as a monotherapy for AK treatment, highlighting the various laser resurfacing modalities available for AK treatment as well as their complications and efficacy in comparison to other therapies. Despite longer healing time, fully ablative laser resurfacing, including carbon dioxide and erbium-doped yttrium aluminum garnet were found to be more effective for AK treatment than fractional ablative techniques. Although some studies suggest laser resurfacing monotherapy as less efficacious than photodynamic therapy, and equally effective to 5-fluorouracil and 30% trichloroacetic acid, clinical trials of larger sample size are required to establish stronger evidence-based conclusions. Moreover, laser resurfacing used as lesion-directed therapy, as opposed to the usual field-therapy, requires further investigation.

The application of physical pretreatment in photodynamic therapy for skin diseases

Photodynamic therapy (PDT) is widely used in skin diseases; the response rate of PDT treatment varies widely. The limited penetration in the tissue of photosensitizers influenced the penetration depth of PDT, which obviously impacts the therapeutic effect. The studies have improved the efficacy of PDT through various pretreatment applications; especially, the physical pretreatment had achieved significant outcomes. We will review the physical pretreatment to optimize the efficacy of PDT in skin diseases by searching the literature on this topic. The types of physical pretreatment commonly used in the clinical practice are discussed: curettage, superficial shaving, laser, surgical resection, plum-blossom needles, and microneedles. Compared with PDT alone, the physical pretreatment before PDT application was generally improved the efficacy and reduced the recurrence, especially in actinic keratoses (AK), Bowen disease (BD), basal cell carcinoma (BCC), and viral warts. The application of the physical pretreatments before PDT may improve the efficacy of PDT in various skin diseases. However, each kind of physical pretreatment has the benefit and shortcoming, and the applicable situation is different.

Ablative fractional laser-assisted treatments for keratinocyte carcinomas and its precursors-Clinical review and future perspectives

Keratinocyte carcinomas (KC) are the most common malignant human neoplasms. Although surgery and destructive approaches are first-line treatments, topical therapies are commonly used. Due to limited uptake of topical agents across the skin barrier, clearance rates are often sub-optimal. In pre-clinical investigations, ablative fractional laser (AFL)-assisted drug delivery has demonstrated improved uptake of topical drugs commonly used to treat KC. In 22 clinical trials, the effect of AFL-assisted treatments has been investigated for actinic keratosis (AK; n = 14), Bowen's disease (BD; n = 5), squamous cell carcinoma (n = 1), and basal cell carcinoma (n = 7). The most substantial evidence currently exists for AFL-assisted photodynamic therapy for the treatment of AK and BD. AFL improved 12-months follow-up clearance rates of photodynamic therapy from 45.0-51.0% to 78.5-84.8% for AK and from 50.0-55.3% to 87.0-87.5% for BD. AFL-assisted pharmacological therapy is a promising tool for optimizing topical treatments of KC and its precursor lesions. Future developments include AFL-assisted immune activation, changing drug administration route of systemic therapies, and utilizing drug chemo-combinations.

Updates on Treatment Approaches for Cutaneous Field Cancerization

Purpose of Review

Field cancerization describes the phenomenon that multiple heterogenous mutations may arise in an area exposed to chronic carcinogenic stimuli. Advances in the understanding of cutaneous field cancerization have led to novel therapeutic approaches to the management of actinic keratoses (AKs). Herein, we review the literature on the pathophysiology and emerging research of field cancerization in dermatology.

Recent Findings

The classification systems for grading AK lesions are being refined with investigations focusing on their clinical utility. There is a growing shift towards field-directed treatment for AKs as the importance of field cancerization becomes clearer. Current field-directed therapies are being optimized and novel therapeutic modalities are being studied.

Summary

Field cancerization underlies the transformation of photodamaged skin into AKs and potentially cutaneous SCC (cSCC). Clinically meaningful classification systems for AKs are needed to better inform decisions regarding treatment. As we learn more about the role of field characterization in photodamage, AKs and cSCCs, therapeutic strategies are becoming more field-directed rather than lesion-directed.

Photodynamic therapy for skin cancer: How to enhance drug penetration?

Photodynamic therapy (PDT) induced by protoporphyrin IX (PpIX) has been widely used in dermatological practices such as treatment of skin cancers. Clearance rate depends on different factors such as light irradiation, skin oxygenation and drug penetration. The poor penetration of 5-aminolevulinic acid (5-ALA) with topical application is limited and restrains the production of PpIX which could restrict PDT outcomes. This review will focus on techniques already used to enhance drug penetration in human skin, and will present their results, advantages, and drawbacks. Chemical and physical pretreatments will be discussed. Chemical pre-treatments comprise of drug formulation modification, use of agents that modify the heme cycle, enhance PpIX formation, and the combination of differentiation-promoting agent prior to PDT. On the other hand, physical pretreatments affect the skin barrier by creating holes in the skin or by removing stratum corneum. To promote drug penetration, iontophoresis and temperature modulation are interesting alternative methods. Cellular mechanisms enrolled during chemical or physical pretreatments have been investigated in order to understand how 5-ALA penetrates the skin, why it is preferentially metabolized in PpIX in tumour cells, and how it could be accumulated in deeper skin layers. The objective of this review is to compare clinical trials that use innovative technology to conventional PDT treatment. Most of these pretreatments present good or even better clinical outcomes than usual PDT.