This article reviews the 2022 European Society for Photodynamic Therapy (Euro-PDT) Annual Congress. PDT has been investigated for the treatment of a broad number of oncologic, infectious and inflammatory indications. New studies confirm the potential for wider use of topical PDT for acne and photoaging, as well as several uncommon conditions including tinea capitis, Mycobacterium marinum, cutaneous alternariosis, resistant acral warts, eyelid Bowen\'s disease, mycosis fungoides, pseudolymphoma, and graft-versus-host disease. Hidradenitis suppurativa patients may also benefit from intra-lesional PDT. Several methods of delivering PDT have been validated, including conventional, daylight and artificial daylight PDT. Light-emitting fabrics have emerged as an innovative solution to the delivery of uniform light over the scalp as well as anatomically-challenging sites, with opportunities now to control and monitor these devices via mobile phone applications. Pre-treatment of patients with thicker, more difficult-to-treat actinic keratoses (AK) with calcitriol appears to be a practical approach to increasing efficacy, although this is associated with increased local skin reactions. Sequential treatment of AK and photoaging with daylight-PDT and injectable NASHA gel indicates that these two therapeutic approaches offer complementary effects. Potential biomarkers may help predict responsiveness of patients with field cancerization and AK receiving daylight PDT. Over-expression of the proto-oncogene, Myc, has been observed in poor responders, whilst the tumour suppressor gene, PTEN, showed under-expression. The potential for use and methods of delivery of topical PDT for dermatological indications continue to expand the enhanced choice of treatment offered to patients.

BACKGROUND: Nicotinamide is the active form of vitamin B3 (niacin) obtained through endogenous synthesis, mainly through tryptophan metabolism and dietary supplements, fish, meats, grains, and dairy products. It participates in cellular energy metabolism and modulates multiple cellular survival and death pathways. Nicotinamide has been widely studied as a safe chemopreventive agent that reduces actinic keratosis (AKs) and non-melanoma skin cancers (NMSC).
METHODS: We used the Medline, EMBASE, PubMed, and Cochrane databases to search the concepts \"nicotinamide\", \"chemoprevention\", and \"skin cancer\" up to August 2023. Three independent authors screened titles and abstracts for intervention and study design before searching full texts for eligibility criteria. The primary outcome was the impact of oral nicotinamide on the incidence of NMSC in high-risk patients. We also conducted a systematic search to identify relevant epidemiological studies published evaluating dietary niacin intake and the risk of NMSC.
RESULTS: Two hundred and twenty-five studies were reviewed, and four met the inclusion criteria. There was no association between NAM consumption and risk for squamous cell carcinoma (SCC) (rate ratio (RR) 0.81, 95% CI 0.48-1.37; I2 = 0%), basal cell carcinoma (BCC) (RR 0.88, 95% CI 0.50-1.55; I2 = 63%), and NMSC (RR 0.82, 95% CI 0.61-1.12; I2 = 63%). Adverse events were rare and acceptable, allowing optimal compliance of patients to the treatment. We found only one article evaluating the association between niacin dietary intake and NMSC risk, supporting a potential beneficial role of niacin intake concerning SCC but not BCC or melanoma.
CONCLUSIONS: The present meta-analysis shows, by pooling immunocompetent and immunosuppressed patients, that there is insufficient evidence that oral nicotinamide therapy significantly reduces the number of keratinocyte cancers.

Photoprotection is a critical health prevention strategy to reduce the deleterious effects of ultraviolet radiation (UVR) and visible light (VL). Methods of photoprotection are reviewed in this paper, with an emphasis on sunscreen. The most appropriate sunscreen formulation for personal use depends on several factors. Active sunscreen ingredients vary in their protective effect over the UVR and VL spectrum. There are dermatologic diseases that cause photosensitivity or that are aggravated by a particular action spectrum. In these situations, sunscreen suggestions can address the specific concern. Sunscreen does not represent a single entity. Appropriate personalized sunscreen selection is critical to improve compliance and clinical outcomes. Health care providers can facilitate informed product selection with awareness of evolving sunscreen formulations and counseling patients on appropriate use. This review aims to summarize different forms of photoprotection, discuss absorption of sunscreen ingredients, possible adverse effects, and disease-specific preferences for chemical, physical or oral agents that may decrease UVR and VL harmful effects.

UNASSIGNED: Inflammation of actinic keratoses (AK) was originally described with systemic 5-fluorouracil, and led to the development of topical fluorouracil. Similar observations using different chemotherapeutics may point to other drugs with a potential for repositioning.
UNASSIGNED: This systematic review aims to evaluate chemotherapeutic agents linked to inflammation-induced cure of AK.
UNASSIGNED: This systematic review was registered in PROSPERO (CRD42022346168) and followed PRISMA guidelines. A comprehensive literature search for eligible original articles written in English and published in peer-reviewed journals until July 13, 2022 was conducted in MEDLINE and Embase.
UNASSIGNED: 28 articles met inclusion criteria accounting for 36 patients (mean age 68.4 ± 8.3 years) with inflamed AK, exposed to 21 different chemotherapeutic agents - 21/36 (58.3%) received monotherapy and 15/36 (41.7%) received multidrug combinations. Regression was complete in 13/28 (46.4%) and partial in 14/28 (50.0%) of inflamed AK. Cure rates of inflamed AK in multidrug combinations were not superior to monotherapies (p = .252), leading to the observation that the majority of the former (14/15; 93.3%) encompassed one of five chemotherapeutic agents linked to AK inflammation also as a monotherapy.
UNASSIGNED: Overall, inflammation partially/completely cured AK in 96.4% of patients (27/28). Taxanes, pemetrexed, and doxorubicin might have the potential for the management of AK.

Photodynamic therapy (PDT) is a highly effective and widely adopted treatment strategy for many skin diseases, particularly for multiple actinic keratoses (AKs). However, PDT is ineffective in some cases, especially if AKs occur in the acral part of the body. Several methods to improve the efficacy of PDT without significantly increasing the risks of side effects have been proposed. In this study, we reviewed the combination-based PDT treatments described in the literature for treating AKs; both post-treatment and pretreatment were considered including topical (i.e., diclofenac, imiquimod, adapalene, 5-fluorouracil, and calcitriol), systemic (i.e., acitretin, methotrexate, and polypodium leucotomos), and mechanical-physical (i.e., radiofrequency, thermomechanical fractional injury, microneedling, microdermabrasion, and laser) treatment strategies. Topical pretreatments with imiquimod, adapalene, 5-fluorouracil, and calcipotriol were more successful than PDT alone in treating AKs, while the effect of diclofenac gel was less clear. Both mechanical laser treatment with CO2 and Er:YAG (Erbium:Yttrium-Aluminum-Garnet) as well as systemic treatment with Polypodium leucotomos were also effective. Different approaches were relatively more effective in particular situations such as in immunosuppressed patients, AKs in the extremities, or thicker AKs. Conclusions: Several studies showed that a combination-based approach enhanced the effectiveness of PDT. However, more studies are needed to further understand the effectiveness of combination therapy in clinical practice and to investigate the role of acitretin, methotrexate, vitamin D, thermomechanical fractional injury, and microdermabrasion in humans.

This article reviews the 2020 European Society for Photodynamic Therapy (Euro-PDT) Annual Congress. Cutting edge studies included assessment of immunohistochemical variables influencing response of basal cell carcinomas and Bowen\'s disease to PDT with p53, the only biomarker associated with good response in both conditions. A further study indicated that analysis of molecular markers, such as PIK3R1, could help select patients with actinic keratoses who demonstrate the best response to daylight PDT. Novel delivery protocols include artificial daylight, and laser-assisted and textile PDT. The meeting learnt of novel indications including antimicrobial PDT, as well as methods to optimise daylight PDT, including combination therapy for actinic keratoses. Adverse events were reviewed and options for painless and efficient PDT assessed, including the effect of reduced drug-light interval. A smartphone application was also evaluated which may be used to assist clinicians and patients in effective dosing and timing of daylight PDT via computational algorithms using data from earth observation satellites, to send light and ultraviolet dose information directly to patients\' smart phones.

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

Actinic keratoses (AK) are common precancerous lesions of the skin due to cumulative sun exposure. A variety of interventions are available for the treatment; however, the majority of randomised controlled trials (RCTs) and meta-analyses focus on short-term efficacy outcomes. This network meta-analysis aims to investigate the long-term (> 12 months) efficacy of interventions for AK.
To identify relevant studies, we will perform a systematic literature research in MEDLINE, Embase, and CENTRAL and hand-search pertinent trial registers. Two authors will independently screen titles and abstracts for eligibility. We will include RCTs with an inter-individual (parallel arm) design. The study population includes patients with a clinical or histopathologic diagnosis of AK. Eligibility will be restricted to the following interventions: surgical approaches, cryosurgery, ablative laser treatment, topical drug treatment with 5-fluorouracil, imiquimod, ingenol mebutate, diclofenac, or photodynamic therapy. As outcomes, we will consider the following endpoints: (1) the participant complete clearance rate, (2) the participant partial clearance rate, (3) the lesion-specific clearance, (4) the mean lesion reduction per patient, and (5) the number of withdrawals due to adverse events after at least 12 months after the end of treatment. Monotherapy or placebo will serve as a comparison. Estimates of effects from individual studies will be pooled using a random-effects model. Heterogeneity will be evaluated based on I2 and chi-square test. The risk of bias will be estimated with the Cochrane Risk of Bias Tool by two review authors independently. The quality of evidence of the outcomes will be assessed with the GRADE approach. A network meta-analysis will be performed to combine direct and indirect evidence from the included RCTs.
The potential of interventions to achieve a sustained clearance of AK has not been assessed to date. To investigate the long-term efficacy of interventions is important as the natural disease course is highly variable and relapses occur frequently even after initial lesion clearance. This review will help to set a framework for clinical decision making in patients with AK.
CRD42018095903 (PROSPERO).

There are currently several reputable guidelines on the treatment of actinic keratosis (AK) from groups in Canada, the United Kingdom, and Europe. These recommendations, based on evidence or expert consensus, offer clinicians a variety of treatment options for the different clinical presentations of AKs. Although the guidelines are similar in some regards, variations exist in treatment options, duration, and strength of recommendation. Some guidelines also lack input on specific therapies and certain types of AK, such as hypertrophic or thin presentations. The purpose of this article is to review and compare guidelines published by Canadian, UK, and European groups for the management of AKs in patients.