Photodynamic therapy reduces the histological features of actinic damage and the expression of early oncogenic markers

Chlorin E6-Curcumin-Mediated Photodynamic Therapy Promotes an Anti-Photoaging Effect in UVB-Irradiated Fibroblasts

Skin photoaging due to ultraviolet B (UVB) exposure generates reactive oxygen species (ROS) that increase matrix metalloproteinase (MMP). Chlorin e6-photodynamic therapy (Ce6-PDT), in addition to being the first-line treatment for malignancies, has been shown to lessen skin photoaging, while curcumin is well known for reducing the deleterious effects of ROS. In the current study, PDT with three novel Ce6-curcumin derivatives, a combination of Ce6 and curcumin with various linkers, including propane-1,3-diamine for Ce6-propane-curcumin; hexane-1,6-diamine for Ce6-hexane-curcumin; and 3,3'-((oxybis(ethane-2,1-diyl))bis(oxy))bis(propan-1-amine) for Ce6-dipolyethylene glycol (diPEG)-curcumin, were studied for regulation of UVB-induced photoaging on human skin fibroblast (Hs68) and mouse embryonic fibroblast (BALB/c 3T3) cells. We assessed the antiphotoaging effects of Ce6-curcumin derivatives on cell viability, antioxidant activity, the mechanism of matrix metalloproteinase-1 and 2 (MMP-2) expression, and collagen synthesis in UVB-irradiated in vitro models. All three Ce6-curcumin derivatives were found to be non-phototoxic in the neutral red uptake phototoxicity test. We found that Ce6-hexane-curcumin-PDT and Ce6-propane-curcumin-associated PDT exhibited less cytotoxicity in Hs68 and BALB/c 3T3 fibroblast cell lines compared to Ce6-diPEG-curcumin-PDT. Ce6-diPEG-curcumin and Ce6-propane-curcumin-associated PDT showed superior antioxidant activity in Hs68 cell lines. Further, in UVB-irradiated in vitro models, the Ce6-diPEG-curcumin-PDT greatly attenuated the expression levels of MMP-1 and MMP-2 by blocking mitogen-activated protein kinases (MAPKs), activator protein 1 (AP-1), and tumor necrosis factor-α (NF-κB) signaling. Moreover, Ce6-diPEG-curcumin effectively inhibited inflammatory molecules, such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression, while accelerating collagen synthesis. These results demonstrate that Ce6-diPEG-curcumin may be a potential therapy for treating skin photoaging.

Influence of serum vitamin D level in the response of actinic keratosis to ingenol mebutate

Vitamin D (VD) serum levels, and keratinocytic basal expression of vitamin D receptor (VDR) before treatment of actinic keratoses (AK) have been previously reported as possible biomarkers of the response of AK to treatments. We intended to evaluate the association between these and other serum and immunohistochemical parameters with the response of AK to treatment with topical ingenol mebutate (IM). Twenty-five patients with AK on the head were treated with topical IM 0.015% gel once daily for 3 days. Biopsies were taken at baseline and 6 weeks after treatment. Immunohistochemical staining was performed for VDR, P53, Ki67, Aurora B, Survivin and β-catenin. Basal serum 25(OH)D levels were determined. IM was more effective for KIN I and II AKs than in KIN III, and histological responders showed significantly higher serum VD levels (30.278 [SD 8.839] ng/mL) than nonresponders (21.14 [SD 7.079] ng/mL, p = 0.023). In addition, mean basal expression of VDR (45.63 [SD 16.105] %) increased significantly (57.92 [SD 14.738] %, p = 0.003) after treatment with IM. A significant decrease after treatment in the expression of several markers of aggressiveness and progression to squamous cell carcinoma, namely P53, Ki-67, aurora B kinase and survivin, was also observed. Our results support a relationship between VD status and the response of AK to treatment with topical IM, suggesting that its previous correction to proper serum levels in VD-deficient patients could improve the response of AK to the treatment.

Comparison of clinical and histologic findings in daylight photodynamic therapy for skin field cancerization: A randomized controlled four-arm study on physical methods-assisted delivery of methyl aminolevulinate

BACKGROUND

Daylight photodynamic therapy (DL-PDT) has similar efficacy to conventional photodynamic therapy in treating actinic keratosis (AKs). Good clinical outcomes have been reported when associated with physical methods such as microneedles, but a comparison of different methods and histologic studies is lacking.

OBJECTIVES

To evaluate clinical and histologic modifications induced by standard DL-PDT and compare with DL-PDT associated with physical methods in treating skin field cancerization of the face.

METHODS

Forty patients with photodamaged skin and at least one AK lesion on the face were randomly distributed into four groups, ten patients in each (I: Standard DL-PDT; II: DL-PDT + microneedles; III: DL-PDT + CO2 laser; IV: DL-PDT + microdermabrasion) and underwent two DL-PDT sessions with methyl aminolevulinate cream and 2-hour daylight exposure. Skin biopsies were performed on all patients before and 3 months after. All fragments were stained using the hematoxylin-eosin, orcein, and picrosirius.

RESULTS

All 40 patients completed the study. Group III had a higher AK-clearance after 1 (p = 0,002) and 3 (p = 0,034) months, but it was similar in every group at 6 months (p = 0,441). Group III and IV had better clinical global improvement on texture, pigmentation and fine lines. In the groups associated with physical methods, the improvement of the keratinocytes' atypia and solar elastosis were remarkable. Only group III showed a significant reduction in solar elastosis (p = 0.034) and increased collagen type I (p = 0.028) after treatment.

CONCLUSION

DL-PDT-associated with physical methods had better clinical and histologic results. AK-clearance were significantly higher after 1 and 3 months with pretreatment-CO2 laser. Photorejuvenation were more evident with pretreatment-CO2 laser and microdermabrasion. Pretreatment-CO2 laser showed a significant reduction in solar elastosis and increase of collagen type 1. These results pointed to the pretreatment with laser as a potentially better option for skin field cancerization of the face.

Effects of Solanum undatum extract (SR-T100) on photocarcinogenesis and photoaging of actinic keratosis

SR-T100 gel, containing solamargine extracted from Solanum undatum (synonym: Solanum incanum), had good therapeutic effects on actinic keratosis (AK) in human and ultraviolet B-induced papilloma in mice. This study aimed to investigate the immunohistochemical changes in the human skin after SR-T100 treatment. An immunohistochemical study was performed and the changes in photocarcinogenesis and photoaging markers after 16-week SR-T100 gel treatment were documented. SR-T100 gel treatment for 16 weeks resulted in complete remission in nine AK lesions and partial remission in four AK lesions. SR-T100 gel abolished the expression of mutant p53 and SOX2 and restored the expression of NOTCH1. Additionally, SR-T100 gel improved wrinkling in human skin, while restoring the expression of lamin B1 and increasing synthesis of new elastic fibers. SR-T100 gel had therapeutic effects on photocarcinogenesis and photoaging of photodamaged skin with AK.

Long-term improvement on photoaging after ALA photodynamic therapy for actinic keratosis: A retrospective study

BACKGROUND

5-aminolevulinic acid photodynamic therapy (ALA-PDT) is not only the first-line treatment for actinic keratosis (AK), but also demonstrated to improve photoaging during AK field treatment. However, its long-term effect on photoaging remains elusive.

OBJECTIVE

To evaluate the long-term improvement effect of ALA-PDT on photoaging.

METHODS

The data of 10 patients with AK who received field-directed ALA-PDT on one side of the face and lesion-directed ALA-PDT on the other side were retrospectively reviewed. Their clinical photographs were evaluated with Global scores of photoaging (GSP) assessment independently by two dermatologists at baseline and 1 month, 6 months and 24 months after ALA-PDT.

RESULTS

GSP evaluation was performed after 24 months of follow-up. Improvements in the fine line and mottled pigmentation were observed (p < 0.05). All the 10 patients achieved complete response of AK lesions and had no relapse during the 24-month follow-up period.

LIMITATION

A small sample size.

CONCLUSION

Photoaging can be effectively alleviated in the long-term follow-up after ALA-PDT treatment for AK. The present study may inspire new treatment strategies for photoaging.

Cytoplasmic Increase in Hsp70 Protein: A Potential New Biomarker of Early Infiltration of Cutaneous Squamous Cell Carcinoma Arising from Actinic Keratosis

BACKGROUND

Cutaneous squamous skin cell carcinoma (SCC) is the second most frequent type of non-melanoma skin cancer and is the second leading cause of death by skin cancer in Caucasian populations. However, at present it is difficult to predict patients with poor SCC prognosis.

OBJECTIVE

To identify proteins with expression levels that could predict SCC infiltration in SCC arising from actinic keratosis (SCC-AK).

METHODS

A total of 20 biopsies from 20 different patients were studied; 10 were SCC-AK samples and 10 were taken from normal skin. Early infiltrated SCC-AK samples were selected based on histological examination, and to determine the expression of proteins, fresh skin samples were processed by two-dimensional electrophoresis.

RESULTS

The expression levels of three proteins, namely alpha hemoglobin and heat shock proteins 27 and 70 (Hsp27 and Hsp70, respectively) were significantly increased in SCC-AK samples with respect to normal control skin. However, only the expression level of Hsp70 protein positively correlated with the level of SCC-AK dermis infiltration. Immunohistological examination suggested that increased expression of Hsp70 proteins seemed to mainly occur in the cytoplasm of keratinocytes. The increased cytoplasmic Hsp70 expression in SCC-AK was confirmed by Western blot experiments.

CONCLUSION

Cytoplasmic expression of Hsp70 could be a potential biomarker of early infiltration of SCC arising from AK.

Influence of Serum Vitamin D Level in the Response of Actinic Keratosis to Photodynamic Therapy with Methylaminolevulinate

In mouse models of squamous cell carcinoma, pre-treatment with calcitriol prior to photodynamic therapy with aminolevulinic acid (ALA) enhances tumor cell death. We have evaluated the association between vitamin D status and the response of actinic keratoses to photodynamic therapy with methylaminolevulinate. Twenty-five patients with actinic keratoses on the head received one session of photodynamic therapy with methylaminolevulinate. Biopsies were taken at baseline and six weeks after treatment. Immuno-histochemical staining was performed for VDR, P53, Ki67 and β-catenin. Basal serum 25(OH)D levels were determined. Cases with a positive histological response to treatment had significantly higher serum 25(OH)D levels (26.96 (SD 7.49) ngr/mL) than those without response (18.60 (SE 7.49) ngr/mL) (p = 0.05). Patients with a complete clinical response displayed lower basal VDR expression (35.71% (SD 19.88)) than partial responders (62.78% (SD 16.735)), (p = 0.002). Our results support a relationship between vitamin D status and the response of actinic keratoses to photodynamic therapy with methylaminolevulinate.

European Dermatology Forum guidelines on topical photodynamic therapy 2019 Part 2: emerging indications - field cancerization, photorejuvenation and inflammatory/infective dermatoses

In addition to approved indications in non-melanoma skin cancer in immunocompetent patients, topical photodynamic therapy (PDT) has also been studied for its place in the treatment of, as well as its potential to prevent, superficial skin cancers in immune-suppressed patients, although sustained clearance rates are lower than for immune-competent individuals. PDT using a nanoemulsion of ALA in a daylight or conventional PDT protocol has been approved for use in field cancerization, although evidence of the potential of the treatment to prevent new SCC remained limited. High-quality evidence supports a strong recommendation for the use of topical PDT in photorejuvenation as well as for acne, refractory warts, cutaneous leishmaniasis and in onychomycosis, although these indications currently lack approvals for use and protocols remain to be optimized, with more comparative evidence with established therapies required to establish its place in practice. Adverse events across all indications for PDT can be minimized through the use of modified and low-irradiance regimens, with a low risk of contact allergy to photosensitizer prodrugs, and no other significant documented longer-term risks with no current evidence of cumulative toxicity or photocarcinogenic risk. The literature on the pharmacoeconomics for using PDT is also reviewed, although accurate comparisons are difficult to establish in different healthcare settings, comparing hospital/office-based therapies of PDT and surgery with topical ointments, requiring inclusion of number of visits, real-world efficacy as well as considering the value to be placed on cosmetic outcome and patient preference. This guideline, published over two parts, considers all current approved and emerging indications for the use of topical photodynamic therapy in Dermatology prepared by the PDT subgroup of the European Dermatology Forum guidelines committee. It presents consensual expert recommendations reflecting current published evidence.

Sequential daylight photodynamic therapy and ingenol mebutate versus 2 sessions of daylight photodynamic therapy for the treatment of actinic keratosis: An observational, prospective, comparative study

BACKGROUND

Field-directed therapy, such as daylight-photodynamic therapy (DL-PDT) or ingenol mebutate (IM), is indicated for multiple actinic keratosis (AK) lesions located on contiguous areas of skin with significant sun damage.

OBJECTIVE

To compare the efficacy of sequential DL-PDT and IM treatment with that of 2 sessions of DL-PDT in AK patients.

MATERIAL AND METHODS

For this observational, multicenter, prospective study we recruited patients for whom DL-PDT was indicated for the treatment of AK lesions (grades I and II) located on the head. After 1 month of follow-up those who did not achieve a satisfactory clinical response received either a second session of DL-PDT or were treated with IM. Epidemiological and clinical data were collected and analyzed.

RESULTS

Forty-three patients were enrolled (39 male, 4 female). The mean (standard deviation, SD) age was 78 (7.84) years, and the mean (SD) number of AK lesions per patient was 9.58 (1.16). After the first session of DL-PDT, 27 patients (62.8%) required further treatment: 13 (48.1%) received a second session of DL-PDT and 14 (51.9%) were treated with IM. After 1 year of follow-up, lesion clearance rates were higher in patients who received 2 sessions of DL-PDT than those treated with sequential DL-PDT plus IM (75.2%vs 54.6%, p = 0.0013). Local skin reactions were more frequent in the DL-PDT plus IM group than the group treated with 2 sessions of DL-PDT (p = 0.0245).

CONCLUSIONS

The combination of DL-PDT plus IM appears to have no synergistic effect in the treatment of field cancerization, and offers no benefits over 2 sessions of DL-PDT monotherapy, although both combinations produced high lesion clearance rates, a good safety profile, excellent cosmetic outcome, and good patient satisfaction.

Low-level light-assisted photodynamic therapy using a wearable cap-like device for the treatment of actinic keratosis of the scalp

BACKGROUND

Daylight photodynamic therapy (dlPDT) is a painless and increasingly cost-effective treatment for actinic keratosis (AK). New protocols avoid incubation, minimizing pain and adverse events. However, it is time-consuming and dependent on specific weather conditions. In patients with AK of the scalp, we evaluated the efficacy of indoor photodynamic therapy (PDT) using a wearable low-level light therapy (LLLT) device, without pre-incubation with a photosensitizing agent.

METHODS

In this pilot study, 27 patients with thin and moderately thick AK (Olsen Grades I-II) underwent a single 15-minute session of LLLT using a wearable cap-like device immediately after application of methyl-aminolevulinate (MAL) cream, with no prior preparation of the affected area. Treatment efficacy was quantified by measuring the reduction in AK lesion number and the AK quality of life (AKQoL) score. All AK lesions were mapped at baseline for follow-up 2 months later. Paired pre/post scalp biopsies from 5 patients were analysed using histological and immunohistochemical techniques (p53, p27, cyclin D1, p63, and Ki67 expression). Data were analysed using the Wilcoxon signed-rank test.

RESULTS

In all patients we observed a global reduction in the number of AK lesions (71%; p < 0.0001) and AKQoL score (from 5.6 to 4.4; p = 0.034) 2 months after treatment. Histology and immunohistochemistry of skin biopsies from 5 patients also revealed marked improvements after LLLT. No patients reported any pain during treatment.

CONCLUSION

PDT using LLLT is a rapid, painless, and efficacious modality for the treatment of AK.

Daylight Photodynamic Therapy for Actinic Keratoses

Topical photodynamic therapy (PDT) using daylight is effective in the treatment of actinic keratoses (AKs), offering the potential for treatment of large fields such as full face and balding scalp, but with minimal therapy-associated pain. Comparison with conventional PDT indicates similar efficacy for thin and moderate-thickness AKs, but with significantly less discomfort/pain, driving a patient preference for daylight-mediated PDT (DL-PDT) compared with conventional PDT using high-intensity office/hospital-based light sources. Treatment protocol involves the application of a photosensitizing agent without occlusion and subsequent exposure to ambient daylight within 30 min, with patients exposed to daylight for 1.5-2.0 h. Pivotal randomized controlled trials in Europe and Australia have confirmed the efficacy of methyl aminolevulinic acid (MAL) DL-PDT in comparison with conventional MAL-PDT for mild and moderate-thickness lesions on the face and scalp. Initial clearance rates of 70-89% are reported. DL-PDT using a nanoemulsion aminolevulinic acid (ALA) has recently been shown to be at least as effective as MAL DL-PDT in treating mild and moderate-thickness AKs. DL-PDT may offer a better-tolerated method for treating patients with extensive AK disease. There is emerging literature on the potential for field PDT to reduce the number of new AKs developing, potentially preventing/slowing skin cancer development. Conventional PDT remains established as a therapy for Bowen's disease (squamous cell carcinoma in situ), superficial and certain thin basal cell carcinomas (BCCs), and AKs. The evidence for the use of DL-PDT beyond AK is limited, although has been reported in actinic cheilitis, superficial BCC, and acne and cutaneous leishmaniasis. There is emerging interest in combination therapy for AK, using one or more field therapies such as DL-PDT as an option to complement with localized treatment for residual lesions. We review current recommendations and consider the appropriate place for DL-PDT in our treatment armamentarium.

Recent advances in field cancerization and management of multiple cutaneous squamous cell carcinomas

Cutaneous squamous cell carcinoma (SCC) is among the most common cancers in humans, and many patients with SCC will develop multiple tumors within their lifetime. The field cancerization concept, originally proposed over 60 years ago, hypothesized that multiple primary cancers may arise simultaneously and coexist with subclinical precursor lesions within a defined field. Genetic sequencing of SCC and precursor lesions has identified what may be the earliest clonal proliferations in SCC development and confirmed that field cancerization in the skin is mediated by ultraviolet radiation. For patients with multiple SCCs and severe actinic damage, treatment of precursor lesions within a cancerized field can decrease the risk of subsequent cancer development. Sunblock is an effective intervention for field cancerization, even in patients with established disease. There is now direct evidence that field therapy with topical 5-fluorouracil is effective in reducing the incidence of subsequent SCC, and there is indirect evidence suggesting that topical imiquimod, topical ingenol mebutate, and photodynamic therapy are similarly effective. There is limited direct evidence to show that systemic acitretin or nicotinamide can decrease incident SCC in patients with field cancerization. In this review, an approach to the management of patients with multiple SCCs and field cancerization is presented along with the rationale to support field-directed therapy.

Photodynamic therapy corrects abnormal cancer-associated gene expression observed in actinic keratosis lesions and induces a remodeling effect in photodamaged skin

BACKGROUND

Actinic keratoses (AK) are proliferations of neoplastic keratinocytes in the epidermis resulting from cumulative exposure to ultraviolet radiation (UVR), which are liable to transform into squamous cell carcinoma (SCC). Organ Transplant Recipients (OTR) have an increased risk of developing SCC as a consequence of long-term immunosuppressive therapy. The aim of this study was to determine the molecular signature of AKs from OTR prior to treatment with methyl aminolevulinate-photodynamic therapy (MAL-PDT), and to assess what impact the treatment has on promoting remodeling of the photo-damaged skin.

METHODS

Seven patients were enrolled on a clinical trial to assess the effect of MAL-PDT with biopsies taken at screening prior to the first treatment session (week 1), and six weeks after completion of final treatment (week 18). Whole-genome gene expression analysis was carried out on skin biopsies isolated from an AK lesion, an area surrounding the lesion, and a non-sun exposed region of the body. Quantitative PCR was utilized to confirm the differential expression of key genes.

RESULTS

MAL-PDT treatment corrected abnormal proliferation-related gene profiles, corrected aberrantly expressed cancer-associated genes and induced expression of dermal extracellular matrix genes in photo-exposed skin.

CONCLUSION

The efficacy of the MAL-PDT on AK lesions was confirmed at whole-genome gene expression level. A transcriptional signature of remodeling, identified through assessing the effect of MAL-PDT on photodamaged skin, supports the use of MAL-PDT for treating photodamaged skin and field cancerized areas.

Photodynamic therapy for aesthetic-cosmetic indications

Photodynamic therapy (PDT) is a well-established, non-invasive treatment for a variety of dermatologic disorders, including actinic keratosis. Furthermore, PDT results in marked improvements in the signs of skin aging, although currently there are no standardized guidelines for PDT in skin rejuvenation. Two types of PDT are available: conventional-PDT (c-PDT) and the newly introduced daylight-PDT (DL-PDT). Both require a topical photosensitizer, a light source and oxygen, and both are comparable regarding safety and efficacy for treatment of photo-induced skin aging. Treatment is particularly effective for improvement of fine wrinkles, skin roughness, actinic elastosis and mottled hyperpigmentation. The most widely studied topical sensitizers used in PDT are 5-aminolevulinic acid (ALA) and methyl aminolevulinate (MAL). A range of pre-treatment procedures help improve skin absorption of the photosensitizer and lead to significantly improved efficacy. A variety of activating light sources can be used for c-PDT, while DL-PDT uses natural daylight, making it easier to treat larger areas of photodamaged skin. A major limitation of c-PDT is significant treatment-related pain, but DL-PDT has proved to be an almost pain-free procedure. Treatment duration is based on individual patient need but most patients receive 2 to 3 treatment cycles, with results fully evident 3-6 months post-treatment. PDT for aesthetic-cosmetic treatments has established its value in modern procedural dermatology as mono- or combination therapy. A major, unique advantage of PDT is that it is a non-invasive treatment that effectively rejuvenates photodamaged skin, while successfully treating a range of dermatologic conditions, including prevention and therapy of pre-cancerous actinic keratosis.

Daylight photodynamic therapy versus cryosurgery for the treatment and prophylaxis of actinic keratoses of the face - protocol of a multicenter, prospective, randomized, controlled, two-armed study

BACKGROUND

Photodynamic therapy with daylight (DL-PDT) is efficacious in treating actinic keratosis (AK), but the efficacy of field-directed, repetitive DL-PDT for the treatment and prophylaxis of AK in photodamaged facial skin has not yet been investigated.

METHODS/DESIGN

In this multicenter, prospective, randomized, controlled, two-armed, observer-blinded trial, patients with a minimum of 5 mild-to-moderate AK lesions on photodamaged facial skin are randomly allocated to two treatment groups: DL-PDT with methyl aminolevulinate (MAL) and cryosurgery. In the DL-PDT group (experimental group), 5 treatments of the entire face are conducted over the course of 18 months. After preparation of the lesion and within 30 min after MAL application, patients expose themselves to daylight for 2 h. In the control group, lesion-directed cryosurgery is conducted at the first visit and, in the case of uncleared or new AK lesions, also at visits 2 to 5. The efficacy of the treatment is evaluated at visits 2 to 6 by documenting all existing and new AK lesions in the face. Cosmetic results and improvement of photoaging parameters are evaluated by means of a modified Dover scale. Primary outcome parameter is the cumulative number of AK lesions observed between visits 2 and 6. Secondary outcome parameters are complete clearance of AK, new AK lesions since the previous visit, cosmetic results independently evaluated by both patient and physician, patient-reported pain (visual analogue scale), patient and physician satisfaction scores with cosmetic results, and patient-reported quality of life (Dermatology Life Quality Index). Safety parameters are also documented (adverse events and serious adverse events).

DISCUSSION

This clinical trial will assess the efficacy of repetitive DL-PDT in preventing AK and investigate possible rejuvenating effects of this treatment. (Trial registration: ClinicalTrials.gov Identifier: NCT02736760).

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02736760 . Study Code Daylight_01. EudraCT 2014-005121-13.

Evaluation of the efficacy of photodynamic therapy for the treatment of actinic cheilitis

INTRODUCTION

Actinic cheilitis (AC) is a lip intraepithelial neoplasia, whose cells present alterations similar to those presented by invasive squamous cell carcinomas (SCCs).

OBJECTIVE

To conduct clinical and laboratory evaluation by histopathology and immunohistochemistry of the efficacy of actinic cheilitis treatment using photodynamic therapy (PDT) with methyl aminolevulinate (MAL) and noncoherent red light.

MATERIALS AND METHODS

Patients with actinic cheilitis detected by histopathological examination were submitted to two sessions of photodynamic therapy with a two-week interval between them. They were examined immediately after the sessions, four, six, and twelve weeks after beginning treatment when a new biopsy was carried out. Clinical histopathological and immunohistochemical parameters were evaluated before and after treatment.

RESULTS

Of the 23 patients who underwent biopsy, 16 completed two photodynamic therapy sessions and the material of one patient was insufficient for immunohistochemistry. Complete clinical response was achieved in 62.5% (10 of 16 patients) and 37.5% still remained with clinical evidence of AC. In spite of this, no case of cure by histopathological analysis was found. There was no significant statistical change among the values of Ki-67, survivin, and p53 observed before and after treatment.

CONCLUSION

Photodynamic therapy, as carried out in this trial, was not an efficacious therapeutic option for treating patients with actinic cheilitis included in this sample.

Comparison of "Lesion-by-Lesion" and Field Photodynamic Therapy in the Prevention of Actinic Keratoses: A Randomized, Split-Face, Single-Blind Pilot Study

BACKGROUND

Actinic keratoses (AKs) are often treated separately, lesion by lesion. However, in the past years, AKs have been described as a field disease and not limited to single clinically apparent lesions. Treatment should therefore target an area of field change which may reduce the risk of development of further AKs, second tumours, and local recurrence.

OBJECTIVE

The primary objective was to determine the number of new lesions at 9 months after methyl aminolevulinate photodynamic therapy (MAL-PDT). Secondary objectives were to determine the number of new lesions at 3 and 6 months after treatment and the percentage reduction of AKs from baseline at 3, 6, and 9 months after MAL-PDT.

METHODS

This was a single-centre, prospective, randomized, split-face, investigator-blinded pilot study with a study duration of 1 year. The study population comprised patients with AKs on the face or scalp, with a maximum of 10 AKs on each side. One side was treated with 1 session of "lesion-by-lesion" MAL-PDT (LT side) and the other side with 1 session of field MAL-PDT (FT side).

RESULTS

At 9 months the FT demonstrated significantly fewer new lesions. At every time point during the follow-up, we found a significant reduction in the number of AKs in the LT as well as in the FT sides. After 3 and 6 months we did not observe significant differences between the sides. However, after 9 months, the LT area showed significantly fewer remaining AKs, whereas the FT area demonstrated significantly fewer new lesions.

CONCLUSIONS

Field treatment results in significantly fewer new AK lesions compared with lesion-by-lesion treatment.

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.

In situ production of ROS in the skin by photodynamic therapy as a powerful tool in clinical dermatology

Photodynamic therapy (PDT) is a clinical modality of photochemotherapy based on the accumulation of a photosensitizer in target cells and subsequent irradiation of the tissue with light of adequate wavelength promoting reactive oxygen species (ROS) formation and cell death. PDT is used in several medical specialties as an organ-specific therapy for different entities. In this review we focus on the current dermatological procedure of PDT. In the most widely used PDT protocol in dermatology, ROS production occurs by accumulation of the endogenous photosensitizer protoporphyrin IX after treatment with the metabolic precursors 5-methylaminolevulinic acid (MAL) or 5-aminolevulinic acid (ALA). To date, current approved dermatological indications of PDT include actinic keratoses (AK), basal cell carcinoma (BCC) and in situ squamous cell carcinoma (SCC) also known as Bowen disease (BD). With regards to AKs, PDT can also treat the cancerization field carrying an oncogenic risk. In addition, an increasing number of pathologies, such as other skin cancers, infectious, inflammatory or pilosebaceous diseases are being considered as potentially treatable entities with PDT. Besides the known therapeutic properties of PDT, there is a modality used for skin rejuvenation and aesthetic purposes defined as photodynamic photorejuvenation. This technique enables the remodelling of collagen, which in turn prevents and treats photoaging stygmata. Finally we explore a new potential treatment field for PDT determined by the activation of follicular bulge stem cells caused by in situ ROS formation.

Photodynamic Photorejuvenation: A Review

INTRODUCTION

Topical photodynamic therapy (PDT) is acknowledged to be a safe and efficient therapeutic option for the selective destruction of actinic keratosis and superficial carcinomas. Over the past 15 years, topical PDT has also been shown to be a possible method for "photorejuvenation."

MATERIALS AND METHODS

An extensive review was performed of in vitro and in vivo (animals, organ transplant recipients, or immunocompetent patients) studies.

RESULTS

The studies point to a high level of efficacy. Tone, lentigos, skin roughness, and moreover texture and fine wrinkles because of the effects of dermal remodeling are improved. Adverse effects are generally described as mild to moderate, without scarring, along with a fast recovery time. Patients with fair phototypes and a history of sun exposure and actinic damage of varying severity are the best candidates for this technique. Photodynamic photorejuvenation sessions can both rejuvenate their skins and also treat their visible or incipient UV-induced lesions. New protocols either with daylight use and/or previous intensification by laser or microneedling seem promising.

CONCLUSION

The photodynamic rejuvenation technique seems to show excellent short-term efficacy and tolerability.

Primary prevention of skin dysplasia in renal transplant recipients with photodynamic therapy: a randomized controlled trial

Organ transplant recipients (OTRs) are at high risk of developing cutaneous squamous cell carcinoma (SCC); prevention includes early treatment of premalignant actinic keratosis (AK). Photodynamic therapy (PDT) is a noninvasive field therapy that reduces new AKs in patients with existing AK and delays SCC development in mice. We investigated the effect of repeated PDT over 5 years for primary prophylaxis of skin dysplasia. These data represent an interim analysis of an on-going randomized controlled trial. During 2008-2011, 25 renal transplant recipients with clinically normal skin were randomized to split-side PDT of the face, forearm and hand, the contralateral side serving as untreated control. Patients received PDT on inclusion and at 6-monthly intervals for 5 years. Blinded evaluation was performed at each visit. We found that prophylactic PDT significantly delayed onset of AK compared with untreated skin, p = 0.020. At 3-year follow-up, we observed AK in 63% of patients in untreated skin areas compared with 28% of patients in PDT-treated skin, with a total number of cumulated AKs in untreated skin (n = 43) compared with PDT-treated skin (n = 8), p = 0.005. These preliminary data indicate a novel approach to early prevention of skin dysplasia that may reduce morbidity from multiple AKs and SCCs in OTR.

Combined Treatments with Photodynamic Therapy for Non-Melanoma Skin Cancer

Non-melanoma skin cancer (NMSC) is the most common form of cancer in the Caucasian population. Among NMSC types, basal cell carcinoma (BCC) has the highest incidence and squamous cell carcinoma (SCC) is less common although it can metastasize, accounting for the majority of NMSC-related deaths. Treatment options for NMSC include both surgical and non-surgical modalities. Even though surgical approaches are most commonly used to treat these lesions, Photodynamic Therapy (PDT) has the advantage of being a non-invasive option, and capable of field treatment, providing optimum cosmetic outcomes. Numerous clinical research studies have shown the efficacy of PDT for treating pre-malignant and malignant NMSC. However, resistant or recurrent tumors appear and sometimes become more aggressive. In this sense, the enhancement of PDT effectiveness by combining it with other therapeutic modalities has become an interesting field in NMSC research. Depending on the characteristics and the type of tumor, PDT can be applied in combination with immunomodulatory (Imiquimod) and chemotherapeutic (5-fluorouracil, methotrexate, diclofenac, or ingenol mebutate) agents, inhibitors of some molecules implicated in the carcinogenic process (COX2 or MAPK), surgical techniques, or even radiotherapy. These new strategies open the way to a wider improvement of the prevention and eradication of skin cancer.

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.

Daylight photodynamic therapy for actinic keratoses: a randomized double-blinded nonsponsored prospective study comparing 5-aminolaevulinic acid nanoemulsion (BF-200) with methyl-5-aminolaevulinate

BACKGROUND

Daylight-mediated photodynamic therapy (DL-PDT) using methyl-5-aminolaevulinate (MAL) is effective for thin, grade I, actinic keratoses (AK). There are no published studies of other photosensitizers used in DL-PDT.

OBJECTIVES

To compare the efficacy and adverse effects of 5-aminolaevulinic acid nanoemulsion (BF-200 ALA) with MAL in DL-PDT of grade I-III AKs.

METHODS

In 13 patients, 177 AKs were randomized symmetrically for a split-face prospective observer-blinded study and received either BF-200 ALA or MAL DL-PDT. Grade I AKs were treated once and grade II-III AKs twice with a 0·25-mm layer of photosensitizer precursors. Pain was assessed during and after the daylight exposure. Efficacy at 3 months was assessed clinically and histologically.

RESULTS

BF-200 ALA cleared 71/84 (84·5%) and MAL 69/93 (74·2%) of the AKs (P = 0·099), all grades responding equally, but with new AKs appearing during follow-up (n = 4, BF-200 ALA; n = 8, MAL). In per patient half-face analysis BF-200 ALA showed significantly higher clearance rates for grade I AKs than did MAL (P = 0·027), but for thicker grades, clearance was equal (P = 0·564). BF-200 ALA and MAL treatments resulted in 61·5% and 38·5% complete histological clearance (P = 0·375), respectively. p53 expression decreased by 54·4% and 33·7%, respectively (P = 0·552). Both treatments were nearly painless with similar adverse reactions and no difference in patient preference.

CONCLUSIONS

BF-200 ALA showed a trend towards improved efficacy results compared with MAL. Thicker lesions in both groups responded when treated repeatedly. Importantly, a thin 0·25-mm layer of the photosensitizer precursors was sufficient, which may lead to lower expense.

Histological comparison of two cryopeeling methods for photodamaged skin

Background. Cryopeeling is a technique that uses cryotherapy not only on actinic keratoses lesions, but also all over the photodamaged skin. Objectives. To investigate the histological changes induced by two cryopeeling methods (liquid nitrogen (LN) and portable system (PS)). Methods. Sixteen patients (n = 16) with multiple actinic keratoses on the forearms were treated with cryopeeling technique using LN for one forearm and PS for the other, randomly. Skin biopsies were taken before and after the procedures. Results. There was no statistical difference between the epidermal and Grenz zone thicknesses or density of elastic fibers after treatments. The amount of melanin pigment was lower after PS treatment (P < 0.05). In a blind analysis of paired pre- and postprocedure slides, it was not possible to identify cases which underwent treatment, both in global analysis of quality of the skin and in specific analysis (considering only the aspect of stratum corneum). Discussion. The results indicate the inconsistency of histological improvement after treatments, and, likely, since the method causes superficial exfoliation, a reliable marker was not found in the analysis. Conclusions. Despite cosmetic benefits on photodamaged skin and efficient treatment of actinic keratoses lesions, cryopeeling was not able to induce measurable histological changes in solar elastosis, epidermal organization, or epidermal and Grenz zone thicknesses. One should keep in mind the possibility of hypopigmentation risk of the method.

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.

Cutaneous field cancerization: clinical, histopathological and therapeutic aspects

The concept of "field cancerization" was first introduced by Slaughter in 1953 when studying the presence of histologically abnormal tissue surrounding oral squamous cell carcinoma. It was proposed to explain the development of multiple primary tumors and locally recurrent cancer. Organ systems in which field cancerization has been described since then are: head and neck (oral cavity, oropharynx, and larynx), lung, vulva, esophagus, cervix, breast, skin, colon, and bladder. Recent molecular studies support the carcinogenesis model in which the development of a field with genetically altered cells plays a central role. An important clinical implication is that fields often remain after the surgery for the primary tumor and may lead to new cancers, designated presently as "a second primary tumor" or "local recurrence," depending on the exact site and time interval. In conclusion, the development of an expanding pre-neoplastic field appears to be a critical step in epithelial carcinogenesis with important clinical consequences. Diagnosis and treatment of epithelial cancers should not only be focused on the tumor but also on the field from which it developed. The most important etiopathogenetic, clinical, histopathological and therapeutic aspects of field cancerization are reviewed in this article.

Cellular intrinsic factors involved in the resistance of squamous cell carcinoma to photodynamic therapy

Photodynamic therapy (PDT) is widely used to treat non-melanoma skin cancer. However, some patients affected with squamous cell carcinoma (SCC) do not respond adequately to PDT with methyl-δ-aminolevulinic acid (MAL-PDT) and the tumors acquire an infiltrative phenotype and became histologically more aggressive, less differentiated, and more fibroblastic. To search for potential factors implicated in SCC resistance to PDT, we have used the SCC-13 cell line (parental) and resistant SCC-13 cells obtained by repeated MAL-PDT treatments (5th and 10th PDT-resistant generations). Xenografts assays in immunodeficient mice showed that the tumors generated by resistant cells were bigger than those induced by parental cells. Comparative genomic hybridization array (aCGH) showed that the three cell types presented amplicons in 3p12.1 CADM2, 7p11.2 EFGR, and 11q13.3 CCND1 genes. The 5th and 10th PDT-resistant cells showed an amplicon in 5q11.2 MAP3K1, which was not present in parental cells. The changes detected by aCGH on CCND1, EFGR, and MAP3K1 were confirmed in extracts of SCC-13 cells by reverse-transcriptase PCR and by western blot, and by immunohistochemistry in human biopsies from persistent tumors after MAL-PDT. Our data suggest that genomic imbalances related to CCND1, EFGR, and particularly MAP3K1 seem to be involved in the development of the resistance of SCC to PDT.

[New developments in photodynamic therapy]

We review new developments in recent years in photodynamic therapy. Since 2009 two new photosensitizers, a self-adhesive 5-aminolevulinic acid (ALA) patch and a nanoemulsion formulation of 5-aminolevulinic acid have been approved for the treatment of actinic keratoses. Pretreatment with ablative fractional lasers enhances penetration of the photosensitizer and enables intensified PDT in acral lesions and in field-cancerized skin. Several clinical trials have demonstrated the skin-rejuvenating effects of photodynamic therapy, while the underlying mechanisms of action have been clarified. The efficacy of photodynamic therapy has been shown in the treatment and prophylaxis of actinic keratoses in organ transplant recipients at high risk for developing skin cancer. We also summarize the results of available studies on daylight-mediated photodynamic therapy.

Use of photodynamic therapy for treatment of actinic keratoses in organ transplant recipients

Solid organ transplant recipients are predisposed to actinic keratoses (AK) and nonmelanoma skin cancers, owing to the lifelong immunosuppression required. Today, increasing numbers of organ transplants are being performed and organ transplant recipients (OTRs) are surviving much longer. Photodynamic therapy (PDT) is proving a highly effective treatment modality for AK amongst this susceptible group of patients. Following an overview of the pathogenesis of AK amongst OTRs, the authors review current safety and efficacy data and how this relates to the role of PDT for the treatment of AK in OTRs.

Photodynamic therapy for skin rejuvenation: review and summary of the literature--results of a consensus conference of an expert group for aesthetic photodynamic therapy

Skin rejuvenating effects of photodynamic therapy (PDT) for photoaged skin has been well-documented in several clinical trials. Different photosensitizers (5-aminolevulinic acid, methyl aminolevulinate) and diverse light sources (light-emitting diodes, lasers, intense pulsed light) have been used with promising results. An improvement of lentigines, skin roughness, fine lines and sallow complexion has been achieved with PDT. These clinically evident effects are at least in part due to histologically proven increase of collagen and decrease of elastotic material in the dermis. Effective improvement of photoaged skin, simultaneous treatment and possibly also prevention of actinic keratoses, the possibility of repeated treatments and, in contrast to other procedures, limited and calculable side effects make PDT a promising procedure for skin rejuvenation.

Clinical, histopathological and immunohistochemical assessment of human skin field cancerization before and after photodynamic therapy

BACKGROUND

The field cancerization concept in photodamaged patients suggests that the entire sun-exposed surface of the skin has an increased risk for the development of (pre)-malignant lesions, mainly epithelial tumours. Topical photodynamic therapy (PDT) is a noninvasive therapeutic method for multiple actinic keratosis (AK) with excellent outcome.

OBJECTIVES

To evaluate the clinical, histological and immunohistochemical changes in human skin with field cancerization after multiple sessions of PDT with methyl-aminolaevulinate (MAL).

METHODS

Twenty-six patients with photodamaged skin and multiple AK on the face received three consecutive sessions of MAL-PDT with red light (37 J cm(-2)), 1 month apart. Biopsies before and 3 months after the last treatment session were taken from normal-appearing skin on the field-cancerized area. Immunohistochemical stainings were performed for TP-53, procollagen-I, metalloproteinase-1 (MMP-1) and tenascin-C (Tn-C).

RESULTS

All 26 patients completed the study. The global score for photodamage improved considerably in all patients (P < 0·001). The AK clearance rate was 89·5% at the end of the study. Two treatment sessions were as effective as three MAL-PDT sessions. A significant decrease in atypia grade and extent of keratinocyte atypia was observed histologically (P < 0·001). Also, a significant increase in collagen deposition (P = 0·001) and improvement of solar elastosis (P = 0·002) were noticed after PDT. However, immunohistochemistry showed only a trend for decreased TP-53 expression (not significant), increased procollagen-I and MMP-1 expressions (not significant) and an increased expression of Tn-C (P = 0·024).

CONCLUSIONS

Clinical and histological improvement in field cancerization after multiple sessions of MAL-PDT is proven. The decrease in severity and extent of keratinocyte atypia associated with a decreased expression of TP-53 suggest a reduced carcinogenic potential of the sun-damaged area. The significant increase of new collagen deposition and the reduction of solar elastosis explain the clinical improvement of photodamaged skin.