Photodynamic therapy using aminolaevulinic acid for patients with nonhyperkeratotic actinic keratoses of the face and scalp: phase IV multicentre clinical trial with 12-month follow up

Reactive Oxygen Species Produced by 5-Aminolevulinic Acid Photodynamic Therapy in the Treatment of Cancer

Cancer is the leading cause of death worldwide and several anticancer therapies take advantage of the ability of reactive oxygen species to kill cancer cells. Added to this is the ancient hypothesis that light alone can be used to kill cancer cells. 5-aminolevulinic acid-photodynamic therapy (5-ALA-PDT) is a therapeutic option for a variety of cutaneous and internal malignancies. PDT uses a photosensitizer that, activated by light in the presence of molecule oxygen, forms ROS, which are responsible for the apoptotic activity of the malignant tissues. 5-ALA is usually used as an endogenous pro-photosensitizer because it is converted to Protoporphyrin IX (PpIX), which enters into the process of heme synthesis and contextually becomes a photosensitizer, radiating a red fluorescent light. In cancer cells, the lack of the ferrochelatase enzyme leads to an accumulation of PpIX and consequently to an increased production of ROS. PDT has the benefit of being administered before or after chemotherapy, radiation, or surgery, without impairing the efficacy of these treatment techniques. Furthermore, sensitivity to PDT is unaffected by the negative effects of chemotherapy or radiation. This review focuses on the studies done so far on 5-ALA-PDT and its efficacy in the treatment of various cancer pathologies.

Safety and efficacy of the combination of cryotherapy and photodynamic modalities with imiquimod in patients with actinic keratosis: a systematic review and meta-analysis

INTRODUCTION

Actinic keratosis (AK) is an intraepithelial tumor that, in most cases, arises in chronically sun-exposed areas. The combination of cryotherapy and photodynamic modalities with imiquimod has been proven to be a potential therapeutic option for AKs. However, there is no comprehensive systematic study that discussed this concept in literature taking into consideration both efficacy and safety.

EVIDENCE ACQUISITION

We performed a comprehensive search of the literature for studies assessing the efficacy and toxicity of the combinatorial tripartite regimen, consisting of cryotherapy and photodynamic modalities with imiquimod in AK. Metanalysis was performed using comprehensive meta-analysis version 3.0.

EVIDENCE SYNTHESIS

After the screening of 1031 studies, five studies were included. Two trials compared the effect of imiquimod/cryotherapy versus cryotherapy alone or versus cryotherapy/vehicle. Our meta-analysis indicated that imiquimod/cryotherapy effectively induces complete clinical clearance in patients with AKs (OR: 6.26; 95%CI: 1.56-24.1; P=0.01). Moreover, another two studies, which were not meta-analyzed, indicated a substantial clinical clearance in the number of AK lesions in the imiquimod plus photodynamic therapy arm as compared to 5% imiquimod or PDT alone. No serious systemic adverse events were reported in all the treatment arms.

CONCLUSIONS

Combined PDT or cryotherapy with imiquimod is more effective in the complete recovery of AK than treatment with imiquimod alone.

Uses of Polypodium leucotomos Extract in Oncodermatology

The effects of UV radiation on the skin and its damage mechanisms are well known. New modalities of exogenous photoprotection have been studied. It was demonstrated that Polypodium leucotomos extract acts as an antioxidant, photoprotectant, antimutagenic, anti-inflammatory, and immunoregulator. It is effective when taken orally and/or applied topically to support the prevention of skin cancers. It also has an important role in preventing photoaging. This review aims to report the mechanisms through which Polypodium leucotomos acts and to analyze its uses in oncodermatology with references to in vitro and in vivo studies. Additionally, alternative uses in non-neoplastic diseases, such as pigmentary disorders, photosensitivity, and atopic dermatitis, have been considered.

Identification and pharmacological modification of resistance mechanisms to protoporphyrin-mediated photodynamic therapy in human cutaneous squamous cell carcinoma cell lines

BACKGROUND

Photodynamic therapy (PDT) is clinically approved to treat neoplastic skin diseases such as precursors of cutaneous squamous cell carcinoma (cSCC). In PDT, 5-aminolevulinic acid (5-ALA) drives the selective formation of the endogenous photosensitizer protoporphyrin IX (PpIX). Although 5-ALA PDT is clinically highly effective, resistance might occur due to decreased accumulation of PpIX in certain tumors. Such resistance may be caused by any fundamental step of PpIX accumulation: 5-ALA uptake, PpIX synthesis and PpIX efflux.

METHODS

We investigated PpIX accumulation and photodynamically induced cell death in PDT refractory SCC-13, PDT susceptible A431, and normal human epidermal keratinocytes (NHEK). Expression of genes associated with cellular PpIX kinetics was investigated on mRNA and protein level. PpIX accumulation and cell death upon illumination were pharmacologically manipulated using drugs targeting 5-ALA uptake, PpIX synthesis or efflux.

RESULTS

The experiments indicate that taurine transporter (SLC6A6) is the major pathway for 5-ALA uptake in cSCC cells, while being less important in NHEK. Downregulation of PpIX synthesis enzymes in SCC-13 was counteracted by methotrexate (MTX) treatment, which restored PpIX formation and cell death. PpIX efflux inhibitors targeting ABC transporters led to significantly increased PpIX accumulation in SCC-13, thereby fully overcoming resistance.

CONCLUSIONS

The results indicate a conserved threshold for PpIX accumulation with respect to PDT-resistance. Cells showed increased viability after PDT at PpIX concentrations below 1.5 nM. Selective uptake of 5-ALA via taurine transporter SLC6A6 in cutaneous tumor cells is novel but unrelated to resistance. MTX can partially abrogate resistance by PpIX synthesis enzyme induction, while efflux mechanisms via ABC transporters seem the main driving force and promising drug targets.

A Review of Existing Therapies for Actinic Keratosis: Current Status and Future Directions

Actinic keratosis (AK) is a chronic skin disease in which clinical and subclinical cutaneous lesions coexist on sun-exposed areas such as the head and neck region and the extremities. The high prevalence of AK means the disease burden is substantial, especially in middle-aged and elderly populations. Evidence indicates that AK may progress into invasive cutaneous squamous cell carcinoma, so the European guidelines recommend treatment of any AK regardless of clinical severity. Given the aging population and therefore the increasing incidence of AK and cutaneous field carcinogenesis, further updates on the long-term efficacy of current therapies and new investigational agents are critical to guide treatment choice. Patients often have difficulty adequately applying topical treatments and coping with adverse local skin reactions, leading to less than optimum treatment adherence. The development of associated local skin symptoms and cosmetic outcomes for the area of interest are also relevant to the choice of an appropriate therapeutic strategy. Treatment is always individually tailored according to the characteristics of both patients and lesions. This review focuses on the therapeutic approaches to AK and illustrates the currently available home-based and physician-managed treatments.

Prospective study of intense pulsed light versus pulsed dye laser with or without blue light in the activation of PDT for the treatment of actinic keratosis and photodamage

BACKGROUND

Exposure to ultraviolet (UV) light from the sun is known to have a deleterious effect on the skin. Repeated insults to the dermal matrix from UV radiation result in the clinical signs of photodamage, including changes in skin elasticity, color, and texture. UV radiation also leads to the accumulation of DNA mutations and promotes tumor development, resulting in the formation of cutaneous precancerous and cancerous lesions. Continuous-wave incoherent blue light, intense pulsed light (IPL), and pulsed dye laser (PDL) are safe and efficacious light sources commonly used for aminolevulinic acid photodynamic therapy (PDT). The aim of this study was to prospectively evaluate the efficacy of PDT for the treatment of photodamage and actinic keratoses using four different combinations of light sources: PDL, PDL + blue light, IPL, and IPL + blue light.

STUDY

A total of 220 patients with either photodamage or actinic keratosis (AK) were recruited from the Miami Dermatology Laser Institute (Miami, FL) and were assigned prospectively to undergo one PDT treatment with one of the four light options: PDL, PDL + blue light, IPL or IPL + blue light. Of the 220 patients enrolled in treatment groups, 214 patients completed the study. Of the 214 patients, 88 received treatment for AK, and 126 received treatment for photodamage. All patients gave their consent to participate in the study and to allow their photographs to be utilized for the purpose of scientific presentations.

RESULTS

Treatment with IPL resulted in a 70.8% reduction of actinic keratoses at a 1-month follow-up. Treatment with IPL and blue light 84.4% reduction of actinic keratoses at 1 month follow up. Treatment with PDL 70.5% reduction of actinic keratoses at 1 month follow up. Treatment with PDL and blue light 69.3% reduction of actinic keratoses at 1 month follow up. Treatment with IPL resulted in an improvement score of 2.9. Treatment with IPL and blue light resulted in an improvement score of 3.0. Treatment PDL resulted in an improvement score of 1.5. Treatment with PDL and blue light resulted in an improvement score of 1.8.

CONCLUSION

Although all four treatment groups led to some improvement in signs of photoaging, IPL + blue light again demonstrated increased efficacy when compared to IPL, PDL, and PDL + blue light treatment groups. Results from our study were limited by an unequal distribution between treatment groups and a lack of follow-up beyond a 1-month period and warrant further research.

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 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.

Pathogenesis of Keratinocyte Carcinomas and the Therapeutic Potential of Medicinal Plants and Phytochemicals

Keratinocyte carcinoma (KC) is a form of skin cancer that develops in keratinocytes, which are the predominant cells present in the epidermis layer of the skin. Keratinocyte carcinoma comprises two sub-types, namely basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). This review provides a holistic literature assessment of the origin, diagnosis methods, contributing factors, and current topical treatments of KC. Additionally, it explores the increase in KC cases that occurred globally over the past ten years. One of the principal concepts highlighted in this article is the adverse effects linked to conventional treatment methods of KC and how novel treatment strategies that combine phytochemistry and transdermal drug delivery systems offer an alternative approach for treatment. However, more in vitro and in vivo studies are required to fully assess the efficacy, mechanism of action, and safety profile of these phytochemical based transdermal chemotherapeutics.

Real-life evaluation of the treatment of actinic keratoses by textile photodynamic therapy (FLUXMEDICARE® device)

INTRODUCTION

Actinic keratoses (AK) are a common precancerous skin condition in dermatology practice. Photodynamic therapy (PDT) with ALA or MAL is an effective but painful treatment of fields of cancerization particularly when conventional illumination sources and irradiation rates are used. Two prior studies showed that illumination with textile PDT was not inferior to conventional PDT. FLUXMEDICARE® (FLX-PDT) is the first medical device marketed with textile based lighting . We performeda real-life study to evaluate efficacy and tolerance of this device.

METHODS

We carried out a single-center retrospective study. We collected data from patients treated with FLX-PDT with MAL for AKs localized on scalp and temples between November 2018 and November 2019. The primary endpoint was complete clearance rate (CR) at 3 months-follow up.

RESULTS

Data of 39 patients were reviewed in the study, with a total of 417 AKs. The CR rate was 72.6 % (95 %CI 67.9-77.0) at 3 months-follow up and 67.5 % (95 %CI 61.2-73.3) at 6 months-follow up. The median pain felt during the session was 0 and there wasn't erythema after the session for 64.1 %.

CONCLUSION

Our real-life study confirms efficacy and safety of textile PDT by FLUXMEDICARE device in the treatment of scalp and temples AKs, with excellent tolerance and minimal pain reported.

Comparison of Grenz ray and photodynamic therapy for field treatment of actinic keratoses on the forearm: A case series

BACKGROUND

Actinic Keratosis is an intraepidermal neoplasm that represents the second most common reason for dermatologic visits in the United States. Sustained clearance with existing therapies is highly variable.

OBJECTIVE

To assess the effects of combination and monotherapy with photodynamic therapy (PDT), grenz ray therapy, and PDT with microneedling (microchannel skin system) for actinic damage of the dorsal forearms and hands.

METHODS

Full ethics approval was obtained through a Human Subjects Committee. Four patients with diffuse actinic field damage on their forearms and hands were recruited for the study. The dorsal forearm and hand from the elbow to the metacarpophalangeal joint were divided into four equal sections. Section 1 was treated with PDT. Section 2 was treated with grenz ray. Section 3 was treated with PDT plus microneedling. Section 4 was treated with grenz ray and PDT with microneedling. Lesion counts were recorded with transparent grids, photographed and evaluated by the same investigator at baseline, 1, 2, 3 and 6 months.

RESULTS

At month 6 post treatment, lesion counts, as a per cent reduction from baseline, were 91.7% in section 1 (PDT); 97.3% in section 2 (grenz ray); 92.9% in section 3 (PDT + microneedle); and 93.9% in section 4 (grenz ray + PDT + microneedle).

CONCLUSION

The greatest reduction occurred in the grenz ray monotherapy section and the second greatest reduction in the grenz ray, PDT, microneedling section. Further research on the efficacy of grenz ray therapy for field treatment of actinic keratosis of the forearms and hands is needed.

A Systematic Review and Meta-Analysis of Interventions for Actinic Keratosis from Post-Marketing Surveillance Trials

Multiple interventions are available for the treatment of actinic keratosis (AK) showing high efficacy in pivotal trials. However, data from post-marketing surveillance studies have received little attention until now. Here, we systematically investigate interventions for AK from post-marketing surveillance trials as a proxy for real-world efficacy and tolerability. A systematic literature search was conducted in Medline, Embase, and CENTRAL. Pertinent trial registers were hand-searched until 25 March 2020. Results were pooled using a random-effects model to calculate pooled proportions and relative risks (RR) or were described qualitatively. Eleven records with a total sample size of n = 4109 were included. Three of the studies had an active-controlled design, while seven were single-armed. Participant complete clearance ranged from 23.1% for diclofenac sodium 3% gel to 88.9% for ingenol mebutate 0.05% gel. The lesion-specific clearance rate for photodynamic therapy (PDT) was 74% (95% confidence interval (CI) 56–87%). The recurrence rate was significantly higher for diclofenac sodium 3% in comparison to imiquimod 5% cream (RR 1.10, 95% CI 1.02–1.1.8) and ranged from 10.6% for ingenol mebutate 0.015% gel to 23.5% for PDT. Few patients discontinued the trials due to adverse events. The results from the majority of the post-marketing surveillance studies deviated from those of pivotal trials.

European Dermatology Forum guidelines on topical photodynamic therapy 2019 Part 1: treatment delivery and established indications - actinic keratoses, Bowen's disease and basal cell carcinomas

Topical photodynamic therapy (PDT) is a widely approved therapy for actinic keratoses, Bowen's disease (squamous cell carcinoma in situ), superficial and certain thin basal cell carcinomas. Recurrence rates when standard treatment protocols are used are typically equivalent to existing therapies, although inferior to surgery for nodular basal cell carcinoma. PDT can be used both as lesional and field therapies and has the potential to delay/reduce the development of new lesions. A protocol using daylight to treat actinic keratoses is widely practised, with conventional PDT using a red light after typically a 3-h period of occlusion employed for other superficial skin cancer indications as well as for actinic keratoses when daylight therapy is not feasible. PDT is a well-tolerated therapy although discomfort associated with conventional protocol may require pain-reduction measures. PDT using daylight is associated with no or minimal pain and preferred by patient. There is an emerging literature on enhancing conventional PDT protocols or combined PDT with another treatment to increase response rates. This guideline, published over two parts, considers all current approved and emerging indications for the use of topical PDT in dermatology, prepared by the PDT subgroup of the European Dermatology Forum guidelines committee. It presents consensual expert recommendations reflecting current published evidence.

Topical treatments for skin cancer

Skin cancer is a broad term used to describe a number of different malignant indications of the skin. Skin cancers mostly comprise of the keratinocyte cancers [Basal Cell Carcinoma (BCC) and cutaneous Squamous Cell Carcinoma (SCC)], and melanoma. Surgical excision of these malignancies has been the preferred treatment of patients for decades. However, the decision to perform surgery can be affected by various considerations, including co-morbidities of the patient, the anatomical site of the lesion and potential intolerance for repeated excisions. Topical treatment of skin cancer may therefore be more appropriate in certain instances. Topical treatment potentially allows for higher drug levels at the tumor site, and may result in less overall toxicity than systemic agents. This review will specifically address the current agents used in topical treatment of skin cancers, and introduce emerging treatments from the natural product field that may also find utility in these indications.

A Randomized, Vehicle-Controlled Phase 3 Study of Aminolevulinic Acid Photodynamic Therapy for the Treatment of Actinic Keratoses on the Upper Extremities

BACKGROUND

Blue-light aminolevulinic acid photodynamic therapy (ALA-PDT) after broad-area application and 3-hour incubation is efficacious for actinic keratosis (AK) lesion clearance on upper extremities, with use of occlusive dressing significantly increasing efficacy.

OBJECTIVE

To prove the safety and efficacy of ALA-PDT versus vehicle (VEH-PDT) in the spot treatment of multiple AKs on upper extremities.

METHODS

Aminolevulinic acid or VEH was spot applied only to lesions on one upper extremity 3 hours before blue-light exposure. Treated extremity was covered with occlusive dressing during incubation. Identical treatment was repeated at Week 8 if AK lesions were present in the treated area.

RESULTS

Thirty-one percent (42/135) of subjects treated with ALA-PDT had complete clearance at Week 12, compared with 13% (17/134) of the subjects treated with VEH-PDT (p = .0001). The mean AK lesion clearance rate for ALA-treated subjects at Weeks 8 and 12 was 53% and 69%, respectively, compared with 26% and 30% for the VEH-treated group (p < .0001, linear mixed model). Safety profile observed in this study is consistent with previous studies/reports in the literature, and the therapy was well tolerated overall.

CONCLUSION

Aminolevulinic acid-PDT spot treatment using a 3-hour occluded incubation was superior to VEH-PDT for AK lesion clearance of the upper extremity.

Ablative fractional laser-assisted photodynamic therapy for lentigo maligna: a prospective pilot study

BACKGROUND

Lentigo maligna (LM) is an in situ form of melanoma carrying a risk of progression to invasive lentigo maligna melanoma (LMM). LM poses a clinical challenge, with subclinical extension and high recurrence rates after incomplete surgery. Alternative treatment methods have been investigated with varying results. Photodynamic therapy (PDT) with methylaminolaevulinate (MAL) has already proved promising in this respect.

OBJECTIVES

To investigate the efficacy of ablative fractional laser (AFL)-assisted PDT with 5-aminolaevulinic acid nanoemulsion (BF-200 ALA) for treating LM.

METHODS

In this non-sponsored prospective pilot study, ten histologically verified LMs were treated with AFL-assisted PDT three times at 2-week intervals using a light dose of 90 J/cm² per treatment session. Local anaesthesia with ropivacaine was used. Four weeks after the last PDT treatment the lesions were treated surgically with a wide excision and sent for histopathological examination. The primary outcome was complete histopathological clearance of the LM from the surgical specimen. Patient-reported pain during illumination and the severity of the skin reaction after the PDT treatments were monitored as secondary outcomes.

RESULTS

The complete histopathological clearance rate was 7 out of 10 LMs (70%). The pain during illumination was tolerable, with the mean pain scores for the PDT sessions on a visual assessment scale ranging from 2.9 to 3.8. Some severe skin reactions occurred during the treatment period, however.

CONCLUSIONS

Ablative fractional laser-assisted PDT showed moderate efficacy in terms of histological clearance. It could constitute an alternative treatment for LM but due to the side effects it should only be considered in inoperable cases.

Comparison of 10 efficient protocols for photodynamic therapy of actinic keratosis: How relevant are effective light dose and local damage in predicting the complete response rate at 3 months?

BACKGROUND

Topical photodynamic therapy is an established treatment modality for various dermatological conditions, including actinic keratosis. In Europe, the approved protocols for photodynamic therapy of actinic keratosis involve irradiation with either an Aktilite CL 128 lamp or daylight, whereas irradiation with the Blu-U illuminator is approved in the United States. Many other protocols using irradiation by a variety of light sources are also clinically efficient.

OBJECTIVES

This paper aims to compare 10 different protocols with clinically proven efficacy for photodynamic therapy of actinic keratosis and the available spectral irradiance of the light source. Effective irradiance, effective light dose, and local damage are compared. We also investigate whether there is an association between the complete response rate at 3 months and the effective light dose or local damage.

METHODS

The effective irradiance, also referred to as protoporphyrin IX-weighted irradiance, is obtained by integrating the spectral irradiance weighted by the normalized absorption spectrum of protoporphyrin IX over the wavelength. Integrating the effective irradiance over the irradiation time yields the effective light dose, which is also known as the protoporphyrin IX-weighted light dose. Local damage, defined as the total cumulative singlet oxygen molecules produced during treatment, is estimated using mathematical modeling of the photodynamic therapy process. This modeling is based on an iterative procedure taking into account the spatial and temporal variations in the protoporphyrin IX absorption spectrum during treatment.

RESULTS

The protocol for daylight photodynamic therapy on a clear sunny day, the protocol for daylight photodynamic therapy on an overcast day, the photodynamic therapy protocol for a white LED lamp for operating rooms and the photodynamic therapy protocol for the Blu-U illuminator perform better than the six other protocols-all involving red light illumination-in terms of both effective light dose and local damage. However, no association between the complete response rate at 3 months and the effective light dose or local damage was found.

CONCLUSIONS

Protocols that achieve high complete response rates at 3 months and low pain scores should be preferred regardless of the effective light dose and local damage. Lasers Surg. Med. 50:576-589, 2018. © 2018 Wiley Periodicals, Inc.

Switching From Conventional Photodynamic Therapy to Daylight Photodynamic Therapy For Actinic Keratoses: Systematic Review and Meta-analysis

Actinic keratosis is a precursor lesion to the most common nonmelanoma skin cancer. Conventional photodynamic therapy (PDT) has been shown to be effective, but the procedure is time-consuming, can be very painful, and requires infrastructure. These shortcomings led to the emergence of daylight PDT. To obtain a global estimate of efficacy, we undertook a systematic literature review and performed a meta-analysis of the available evidence on the efficacy and safety of daylight PDT as compared to conventional PDT in the treatment of actinic keratosis and/or field cancerization. The conclusion is that the difference in efficacy is clinically negligible (global estimate of the mean response rate difference, -3.69%; 95% CI, -6.54% to -0.84%). The adverse effects of daylight PDT are mild and localized (79% of patients report no discomfort), and patients report less pain (P<.001). Daylight PDT gives good to excellent cosmetic results in more than 90% of patients, and patient satisfaction is greater (P<.001).

Photodynamic Therapy and Non-Melanoma Skin Cancer

Non-melanoma skin cancer (NMSC) is the most common malignancy among the Caucasian population. Photodynamic therapy (PDT) is gaining popularity for the treatment of basal cell carcinoma (BCC), Bowen's disease (BD) and actinic keratosis (AK). A topical or systemic exogenous photosensitiser, results in selective uptake by malignant cells. Protoporphyrin IX (PpIX) is produced then activated by the introduction of a light source. Daylight-mediated MAL (methyl aminolaevulinate) PDT for AKs has the advantage of decreased pain and better patient tolerance. PDT is an effective treatment for superficial BCC, BD and both individual and field treatment of AKs. Excellent cosmesis can be achieved with high patient satisfaction. Variable results have been reported for nodular BCC, with improved outcomes following pretreatment and repeated PDT cycles. The more aggressive basisquamous, morphoeic infiltrating subtypes of BCC and invasive squamous cell carcinoma (SCC) are not suitable for PDT. Prevention of "field cancerization" in organ transplant recipients on long-term immunosuppression and patients with Gorlin syndrome (naevoid basal cell carcinoma syndrome) is a promising development. The optimisation of PDT techniques with improved photosensitiser delivery to target tissues, new generation photosensitisers and novel light sources may expand the future role of PDT in NMSC management.

Photodynamic Therapy for Non-Melanoma Skin Cancers

Non-melanoma skin cancer (NMSC) is traditionally treated with surgical excision. Nonsurgical methods such as cryotherapy and topical chemotherapeutics, amongst other treatments, are other options. Actinic keratosis (AKs) are considered precancerous lesions that eventually may progress to squamous cell carcinoma (SCC). Photodynamic therapy (PDT) offers an effective treatment for AKs, and is also effective for superficial basal cell carcinoma (BCC). Nodular BCC and Bowen's disease (SCC in situ) have shown acceptable response rates with PDT, although recurrence rates are higher for these two NMSC subtypes. Methylaminolevulinate (MAL) PDT is a more effective treatment option than 5-aminolevulinic acid (ALA) PDT for nodular BCC. Several studies have shown that PDT results in superior cosmetic outcomes compared to surgical treatment. PDT is overall well-tolerated, with pain being the most common side effect.

Resistance of Nonmelanoma Skin Cancer to Nonsurgical Treatments. Part II: Photodynamic Therapy, Vismodegib, Cetuximab, Intralesional Methotrexate, and Radiotherapy

A wide range of treatments is now available for nonmelanoma skin cancer, including 5-fluorouracil, ingenol mebutate, imiquimod, diclofenac, photodynamic therapy, methotrexate, cetuximab, vismodegib, and radiotherapy. All are associated with high clinical and histologic response rates. However, some tumors do not respond due to resistance, which may be primary or acquired. Study of the resistance processes is a broad area of research that aims to increase our understanding of the nature of each tumor and the biologic features that make it resistant, as well as to facilitate the design of new therapies directed against these tumors. In this second article, having covered the topical treatments of nonmelanoma skin cancer, we review resistance to other nonsurgical treatments, such as monoclonal antibodies against basal and squamous cell carcinomas, intralesional chemotherapy, photodynamic therapy, and radiotherapy.

Non-melanoma Skin Cancer in Canada Chapter 3: Management of Actinic Keratoses

Background

Actinic keratosis (AK) and cheilitis (AC) are lesions that develop on photodamaged skin and may progress to form invasive squamous cell carcinomas (SCCs).

Objective

To provide guidance to Canadian health care practitioners regarding management of AKs and ACs.

Methods

Literature searches and development of graded recommendations were carried out as discussed in the accompanying introduction (chapter 1 of the NMSC guidelines).

Results

Treatment of AKs allows for secondary prevention of skin cancer in sun-damaged skin. Because it is impossible to predict whether a given AK will regress, persist, or progress, AKs should ideally be treated. This chapter discusses options for the management of AKs and ACs.

Conclusions

Treatment options include surgical removal, topical treatment, and photodynamic therapy. Combined modalities may be used in case of inadequate response. AKs are particularly common following the longterm immunosuppression in organ transplant patients, who should be monitored frequently to identify emerging lesions that require surgery.

Randomized Vehicle-Controlled Study of Short Drug Incubation Aminolevulinic Acid Photodynamic Therapy for Actinic Keratoses of the Face or Scalp

BACKGROUND

Aminolevulinic acid photodynamic therapy (ALA-PDT) can be effective and well tolerated when applied over a broad area and for short drug incubation times.

OBJECTIVE

To evaluate the effect of short-incubation time and application method on the safety and efficacy of ALA-PDT versus vehicle (VEH-PDT) in the treatment of actinic keratoses (AKs) of the face or scalp.

METHODS

Aminolevulinic acid or VEH was applied to face or scalp as a broad area application for 1, 2, or 3 hours or as a spot application for 2 hours before blue light activation. An identical treatment was repeated at Week 8 if any AK lesions remained.

RESULTS

Median AK clearance rate for ALA-treated subjects ranged from 68% to 79% at Week 12, compared with 7% of the VEH-treated group (p < .0001). Complete clearance rate for ALA-treated subjects ranged from 17% (8/46) to 30% (14/47) at Week 12, compared with 2% (1/46) of the VEH-treated group (p = .0041). The safety profile seen in this study is consistent with previously reported side effects of the therapy.

CONCLUSION

Short-incubation ALA-PDT was found to be superior to VEH-PDT for AK lesion clearance. A second treatment improves efficacy.

Photodynamic therapy inhibit Fibroblast Growth Factor-10 induced keratinocyte differentiation and proliferation through ROS in Fibroblast Growth Factor Receptor-2b pathway

5-aminolevulinic acid-photodynamic therapy (ALA-PDT) is known to be effective in several skin diseases such as acne, actinic keratoses, condyloma acuminata. However, some detailed mechanisms of ALA-PDT to treat these skin diseases still remain elusive. In this study, we aimed to investigate mechanism of ALA-PDT in in-vitro and in-vivo models. For in vitro, we use human keratinocyte cell line (HaCaT) cells. CCK-8 was used to detect cell proliferation activity, immunofluorescence and western blotting method to detect the content of keratin (K)1, K6, K16, protein kinase C (PKC), fibroblast growth factor receptor-2b (FGFR2b) protein, ELISA and RT-PCR to detect expression of interleukin (IL) 1α in the cell supernatant, and detect reactive oxygen species (ROS). For in vivo, we use 20 rabbits to induce hyperkeratosis acne model in their ear. Dermatoscope was used to see follicle hyperkeratosis and skin biopsy to analyze histology and immunohistochemical of PKC, FGFR2b, K1, K6 and K16. Results from this study suggest that ROS stimulated by ALA-PDT lead to inhibition of FGFR2b pathway in PKC downstream to cause reduction of IL1α expression, and eventually, keratinocytes differentiation and proliferation. Our data thus reveal a treatment mechanism of ALA-PDT underlying hyperkeratosis related dermatoses.

Pre-treatment protoporphyrin IX concentration in actinic keratosis lesions may be a predictive biomarker of response to aminolevulinic-acid based photodynamic therapy

BACKGROUND

Although aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) photodynamic therapy (PDT) is an effective FDA-approved therapy for actinic keratosis (AK), a substantial fraction of patients (up to 25%) do not respond to treatment. This study examined the feasibility of using pre-treatment measurements of PpIX concentration in AK lesions to predict response of ALA-PpIX PDT.

METHODS

A non-invasive fiber-optic fluorescence spectroscopy system was used to measure PpIX concentration in patients undergoing standard-of-care ALA-PDT for AK. All patients provided assessments of pain at the time of treatment (n=70), and a subset reported pain and erythema 48-76 h after treatment (n=13).

RESULTS

PpIX concentration was significantly higher in lesions of patients reporting high levels of pain (VAS score ≥5) immediately after treatment vs. patients reporting pain scores below VAS=5 (p<0.022) (n=70). However, pain was not an exclusive indicator of PpIX concentration as many patients with low PpIX concentration reported high pain. In a subpopulation of patients surveyed in the days after treatment (n=13), PpIX concentration measured on the day of treatment was uncorrelated with pain-reported immediately after treatment (r=0.17, p<0.57), but positive correlations were found between PpIX concentration and patient-reported pain (r=0.55, p<0.051) and erythema (r=0.58, p<0.039) in the 48-72 h following treatment.

CONCLUSIONS

These data suggest that in vivo optical measurements of PpIX concentration acquired before light delivery may be an objective predictor of response to ALA-PpIX PDT. Identification of non-responding patients on the day of treatment could facilitate the use of interventions that may improve outcomes.

Update on topical photodynamic therapy for skin cancer

Topical photodynamic therapy has become an established therapy option for superficial non-melanoma skin cancers with a substantial evidence base. In this update the increased choice in photosensitizers and light sources are reviewed as well as novel protocols to move beyond lesional treatment and address field therapy. Daylight PDT is emerging as an alternative to conventional office/hospital-based PDT that offers the advantage of much reduced pain. Although most studies have assessed efficacy of PDT in immune-competent patients, there is accumulating evidence for topical PDT being considered an option to assist in reducing the skin cancer burden in organ transplant recipients. The fluorescence associated with photosensitizer application can help delineate lesions prior to full treatment illumination and offers a useful adjunct to treatment in patients where diagnostic uncertainty or poor lesion outline complicates clinical care. PDT may also offer significant benefit in delaying/preventing new cancer development and combined with its recognized photo-rejuvenating effects, is emerging as an effective therapy capable of clearing certain superficial skin cancers, potentially preventing new lesions as well as facilitating photo-rejuvenating effects in treated areas.

Comparative Study of Photodynamic Therapy with Topical Methyl Aminolevulinate versus 5-Aminolevulinic Acid for Facial Actinic Keratosis with Long-Term Follow-Up

Background

Few studies have compared the efficacy, cosmetic outcomes, and adverse events between 5-aminolevulinic acid photodynamic therapy (ALA-PDT) and methyl aminolevulinate-PDT (MAL-PDT) for actinic keratoses (AKs) in Asian ethnic populations with dark-skin.

Objective

We retrospectively compared the long-term efficacy, recurrence rates, cosmetic outcomes, and safety of ALA-PDT versus MAL-PDT for facial AKs in Koreans.

Methods

A total of 222 facial AKs in 58 patients were included in this study. A total of 153 lesions (29 patients) were treated with 5-ALA, and 69 lesions (29 patients) with MAL. ALA and MAL creams were applied for 6 hours and 3 hours, respectively; the lesions were then illuminated with a halogen lamp at 150 J/cm² for ALA-PDT and a diode lamp at 37 J/cm² for MAL-PDT.

Results

The complete response rates of ALA-PDT and MAL-PDT were 56.9% and 50.7%, respectively, with no significant difference at 12 months after treatment. No significant difference in recurrence rates was observed between the 2 PDT modalities at either 6 or 12 months after treatment. There was no significant difference in the cosmetic outcomes between the 2 treatment modalities at 12 months after PDT. However, ALA-PDT caused significantly more painful than MAL-PDT (p=0.005). The adverse events were mild to moderate, transient, and self-limiting for both modalities.

Conclusion

MAL-PDT was similar to ALA-PDT in terms of long-term efficacy, recurrence rates, cosmetic outcomes, and adverse events; however, it was a significantly less painful procedure than ALA-PDT in our study.

Photodynamic therapy with topical aminolevulinic acid

Photodynamic therapy (PDT) is a relatively new therapy in dermatology that uses the topical application of a porphyrin derivative to selectively destroy a cutaneous target. The action is implemented by the application of a specific light frequency. The ability of porphyrin to selectively target tumor tissue has been known since the 1960s. In the late 1970s, the underlying mechanism was defined, and Dougherty’s discovery of the first chromophore led to the production and commercialization of Photofrin^®. Many other chromophores that can act as photosensitizers have been studied since then, with aminolevulinic acid currently the most commonly used chromophore in clinical practice. PDT is simple, minimally invasive and can be administered on an outpatient basis. The efficacy of PDT has been proven for actinic keratosis, Bowen’s disease and basal cell carcinoma; another of its well-known applications is the treatment of photoaging. Indications for its use are continuously increasing, and promising results are reported for various skin diseases. In this paper we report the mechanism of action of PDT with aminolevulinic acid, the literature concerning the most common diseases treated with PDT and the subsequent level of evidence.

Melanotic and non-melanotic malignancies of the face and external ear - A review of current treatment concepts and future options

Skin has the highest incidence and variety of tumors of all organs. Its structure is of great complexity, and every component has the potential to originate a skin neoplasm (SN). Because of its exposed nature, skin is vulnerable to carcinogenic stimuli such as UV radiation. Various entities can cause SN. Nonmelanotic skin cancers (NMSC) are the most common of all cancers, with over one million cases diagnosed annually in the US. Basal cell carcinoma (BCC) accounts for approximately 80% of all NMSC, most of the remaining 20% being squamous cell carcinoma (SCC). The skin of the head and neck is the most common site for tumors, accounting for more than 80% of all NMSC. BCC, SCC, and malignant melanomas (MM) represent 85-90% of all SN. Merkel cell tumors (MCC), lymphoepithelioma-like carcinomas of the skin (LELCS), dermato-fibro-sarcomas, leiomyosarkomas, and Kaposi-sarcomas are less frequent in the facial skin region and the external ear. Based on data from the German Federal Cancer Registry (2003/2004), 140,000 people in Germany were affected by SN (100,000 BCC, 22,000 SCC, 22,000 MM). This number increases considerably if malignant precursors, such as actinic keratosis, are included. Each year, the frequency of SN diagnosis rises by 3-7%. Among all known malignant tumors, MM exhibits the highest rate of increase in incidence. In the past, SN was primarily diagnosed in people aged 50 years or older. However, recently, the risk for developing SN has shifted, and younger people are also affected. Early diagnosis is significantly correlated with prognosis. Resection of SN creates defects that must be closed with local or microvascular flaps to avoid functional disturbing scar formation and deflection of the nose, eyelids, or lips. All therapeutic strategies for SN, the current standard for adjuvant and systemic treatment, and the management of the increasing number of patients under permanent blood thinner medication are described with regard to the treatment of SN.

Spanish adaptation of the European guidelines for the evaluation and treatment of actinic keratosis

Current trends in our setting indicate that the prevalence of actinic keratosis and similar diseases will increase in coming years and impose a greater burden on health care resources. A long list of clinical features must be taken into account when approaching the treatment of actinic keratosis. Until recently, therapeutic approaches focused solely on ablative procedures and the treatment of individual lesions and did not take into account areas of field cancerization. Now that the therapeutic arsenal has grown, standardized criteria are needed to guide the optimal choice of treatment for each patient. The elaboration of evidence-based consensus recommendations for the diagnosis and treatment of actinic keratosis generates knowledge that will help clinicians to deliver the highest level of care possible, standardizing decision-making processes and enhancing awareness among all the health professionals involved in the care pathway.

Efficacy of photodynamic therapy in the short and medium term in the treatment of actinic keratosis, Basal cell carcinoma, acne vulgaris and photoaging: results from four clinical trials

OBJECTIVE

To determine the clinical efficacy of methyl-aminolevulinate (MAL)-Photodynamic Therapy (PDT) in the treatment of actinic keratosis (AK), basal cell carcinoma (BCC), acne vulgaris (AV) and photoaging (PA), in the short and medium term.

SUBJECTS AND METHODS

Four separate prospective studies were designed on patients with AK (n=25), BCC (n=20), AV (n=20) and PA (n=25). Two PDT protocols were applied, and different clinical efficacy criteria were established, including lesion count and size. Two semi-quantitative and four analogue visual scales were completed for the evaluation of results according to the therapist, the patient and two independent experts.

RESULTS

In the AK and BCC studies, full clinical remission was observed in 84.7% and 75.7% of lesions, respectively. In the AV study, the number of inflammatory and non-inflammatory lesions fell significantly (p<0.001, p<0.05). In the PA study a reduction in Dover scale scores (3.19 vs. 2.14, p<0.001) was proven. The percentages of satisfied or very satisfied patients were: AK=88%, BCC=90%, AV=89% and PA=80%. A year later, none of the AK or BCC lesions had reappeared, and the cases of AV and PA remained stable, with a tendency towards improvement.

CONCLUSION

the MAL-PDT procedures used produced efficacious, safe and satisfactory results in KA, BCC, AV and PA in the short and medium term.