Topical treatment of actinic keratoses with piroxicam 1% gel: a preliminary open-label study utilizing a new clinical score

Recent Advances in Clinical Research for Skin Cancer Chemoprevention

Neoplasm arising from the keratinocytes or melanocytes in the skin is the most prevalent type of cancer in the United States and worldwide. Since ultraviolet (UV) radiation may be a causing factor for several types of skin cancer, effective strategies to manage skin cancer include preventive measures such as minimizing exposure to UV and applying sunscreens. However, the effect of sunscreen in reducing skin cancer incidence remains uncertain. An alternative approach to prevent skin cancer is chemoprevention, which is defined as using either natural products or synthetic compounds to inhibit, delay, or reverse the development of cancer. Preclinical studies have demonstrated the effectiveness of multiple pharmacological agents and dietary supplements. However, whether preclinical findings can be translated into clinical application is unknown. This review evaluates the state of recent clinical trials investigating chemopreventive agents focusing on skin cancer to compare the target populations, interventions, endpoints, and outcomes of these trials. The ClinicalTrials and PubMed databases were searched for their available literature using the key words "skin cancer" and "chemoprevention". The objective of this review is to provide updated information on the effectiveness and side effects of promising chemopreventive agents in human subjects and to identify research gaps.

Topical Treatment of Actinic Keratosis and Metalloproteinase Expression: A Clinico-Pathological Retrospective Study

Actinic keratosis is an intraepithelial proliferation of atypical keratinocytes that could progress into invasive squamous cell carcinoma. Most evidence suggests an important role of the dermal matrix metalloproteinases in the progression of atypical skin epithelial lesions. We evaluated the clinical efficacy of three different therapeutic modalities (a medical device containing 0.8% piroxicam cream and 50+ sunscreen, photodynamic therapy, and ingenol mebutate gel) to treat suspicious actinic keratoses, which were biopsied for histopathological examination and then analyzed for the expression of matrix metalloproteinases by immunohistochemistry. Clinical, dermoscopic, and reflectance confocal microscopy evaluations revealed a gradual decrease in all standard scores validated for actinic keratosis assessment at the end of the treatments. From a histopathological point of view, we documented the substantial restoration of normal skin architecture, while the immunohistochemical evaluation of matrix metalloproteinases showed a reduction in expression in the treated skin lesions compared to the baseline. As actinic keratoses are considered the precursors of squamous cell carcinoma, their treatment is crucial to prevent the development of a more aggressive disease. Our study monitored the evolution of actinic keratoses subjected to three different topical therapies, with the value of correlating clinical and histopathological findings. Moreover, as the matrix metalloproteinases are largely recognized factors involved in the pathogenesis and evolution of actinic keratosis to squamous cell carcinoma, the demonstration by immunohistochemistry of a reduction in their expression after the treatments adds new valuable concern to the field.

Keratinocyte Carcinoma and Photoprevention: The Protective Actions of Repurposed Pharmaceuticals, Phytochemicals and Vitamins

Simple Summary

Keratinocyte carcinoma is the most common type of cancer. Sun exposure and ultraviolet radiation are significant contributors to the development of carcinogenesis, mediated by DNA damage, increased oxidative stress, inflammation, immunosuppression and dysregulated signal transduction. Photoprevention involves using different compounds to delay or prevent ultraviolet radiation-induced skin cancer. In this review, we look at new avenues for systemic photoprevention that are based on pharmaceuticals, plant-derived phytochemicals and vitamins. We also investigate the mechanisms underlying these strategies for preventing the onset of carcinogenesis.

Abstract

Ultraviolet radiation (UVR) arising from sun exposure represents a major risk factor in the development of keratinocyte carcinomas (KCs). UVR exposure induces dysregulated signal transduction, oxidative stress, inflammation, immunosuppression and DNA damage, all of which promote the induction and development of photocarcinogenesis. Because the incidence of KCs is increasing, better prevention strategies are necessary. In the concept of photoprevention, protective compounds are administered either topically or systemically to prevent the effects of UVR and the development of skin cancer. In this review, we provide descriptions of the pathways underlying photocarcinogenesis and an overview of selected photoprotective compounds, such as repurposed pharmaceuticals, plant-derived phytochemicals and vitamins. We discuss the protective potential of these compounds and their effects in pre-clinical and human trials, summarising the mechanisms of action involved in preventing photocarcinogenesis.

Photosensitizing Medications and Skin Cancer: A Comprehensive Review

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

Repurposing of Drug Candidates for Treatment of Skin Cancer

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

NSAIDs as a Drug Repurposing Strategy for Biofilm Control

Persistent infections, usually associated with biofilm-producing bacteria, are challenging for both medical and scientific communities. The potential interest in drug repurposing for biofilm control is growing due to both disinvestment in antibiotic R&D and reduced efficacy of the available panel of antibiotics. In the present study, the antibacterial and antibiofilm activities of four non-steroidal anti-inflammatory drugs (NSAIDs), piroxicam (PXC), diclofenac sodium (DCF), acetylsalicylic acid (ASA) and naproxen sodium (NPX) were evaluated against Escherichia coli and Staphylococcus aureus. The minimum inhibitory/bactericidal concentrations (MICs and MBCs) and the dose–response curves from exposure to the selected NSAIDs were determined. MICs were found for PXC (800 μg/mL) and ASA (1750 μg/mL) against E. coli, and for DCF (2000 μg/mL) and ASA (2000 μg/mL) against S. aureus. No MBCs were found (>2000 μg/mL). The potential of NSAIDs to eradicate preformed biofilms was characterized in terms of biofilm mass, metabolic activity and cell culturability. Additionally, the NSAIDs were tested in combination with kanamycin (KAN) and tetracycline (TET). ASA, DCF and PXC promoted significant reductions in metabolic activity and culturability. However, only PXC promoted biofilm mass removal. Additive interactions were obtained for most of the combinations between NSAIDs and KAN or TET. In general, NSAIDs appear to be a promising strategy to control biofilms as they demonstrated to be more effective than conventional antibiotics.

Expression of Cyclooxygenase-2 in Human Epithelial Skin Lesions: A Systematic Review of Immunohistochemical Studies

Permanent, elevated expression of cyclooxygenase-2 (COX-2) in keratinocytes of epidermis can stimulate its hyperplasia and constitute a factor promoting cancer development, as demonstrated in animal models. Intratumoral level and localization of COX-2 in epithelial lesions of human skin was examined immunohistochemically in 26 studies. In squamous cell carcinomas (SCCs), strong staining was observed with great compatibility. High COX-2 detectability throughout the entire tumor mass could be helpful in the finding of SCC cells. However, in basal cell carcinomas, and precancerous lesions, frequency and detection level of this protein, as well as the type and/or localization of stained cells within the tumor, varied among different research groups. The discrepancies may be due to the heterogeneity of each of these 2 groups of lesions. However, differences in COX-2 staining in normal skin indicate also possible methodological reasons. In general, COX-2 levels were significantly decreased in basal cell carcinomas compared with SCCs, which could be used in the differential diagnosis of these cancers. Reduced, although heterogenous, COX-2 expression in precancerous lesions may suggest its association with SCC development. These observations are consistent with data on the efficacy of preventive and therapeutic effects of nonsteroidal anti-inflammatory drugs that are COX-2 inhibitors.

New drugs are not enough‑drug repositioning in oncology: An update

Drug repositioning refers to the concept of discovering novel clinical benefits of drugs that are already known for use treating other diseases. The advantages of this are that several important drug characteristics are already established (including efficacy, pharmacokinetics, pharmacodynamics and toxicity), making the process of research for a putative drug quicker and less costly. Drug repositioning in oncology has received extensive focus. The present review summarizes the most prominent examples of drug repositioning for the treatment of cancer, taking into consideration their primary use, proposed anticancer mechanisms and current development status.

New local treatment for photoaging using a formulation containing piroxicam 0.8% and sunscreen

Objective

Skin aging is a complex process influenced by several factors that cause DNA damage and alter the extracellular matrix. The anti-inflammatory drug piroxicam can counteract photocarcinogenesis and photoaging by blocking cyclooxygenases-1 and 2, matrix metalloproteinases, and ornithine decarboxylase, and inducing apoptosis.

Methods

We conducted an open observational study in 50 adults with moderate to severe signs of photoaging treated with a new local formulation of piroxicam 0.8% plus sunscreen for 16 weeks. Photoaging was assessed using a validated dermoscopic photoaging scale. Each patient’s own perception of their skin quality was assessed using a graphic scale.

Results

The new formulation demonstrated a reliable effect on photoaging after 16 weeks, based on improved median dermoscopic photoaging and skin-quality scores. No patients experienced any adverse effects.

Conclusions

To the best of our knowledge, this study provides the first evidence for the safe and effective use of a local piroxicam formulation for the treatment of moderate to severe photoaging.

Effects of topical 0.8% piroxicam and 50+ sunscreen filters on actinic keratosis in hypertensive patients treated with or without photosensitizing diuretic drugs: an observational cohort study

Background

Photosensitizing diuretics use (especially thiazide compounds) is associated with a significantly higher risk of squamous cell carcinoma (SCC). Actinic keratosis (AK) is a precursor of SCC.

Study aim

To evaluate in a prospective cohort study the efficacy of topical piroxicam 0.8% and sunscreen 50+ (ACTX) in the treatment of AK in hypertensive subjects with or without TD treatment.

Subjects and methods

A total of 119 hypertensive subjects with multiple AK (39 under chronic TD treatment; and 80 treated with other non-TD, non-photosensitizing antihypertensive drugs) were enrolled after their informed consent in a 6-month observational cohort study. All the subjects were treated with ACTX twice daily. The primary endpoint was the evolution of AK lesions at baseline, after 3 and 6 months. The secondary endpoint was the clearance of AK target lesions and field of cancerization by dermoscopic evaluation using a score evaluating erythema, scaling, pigmentation, and follicular plugs (ESPFP score; ranging from 0 to 20). An investigator, unaware of the type of antihypertensive treatments (TD or non-TD), performed all the clinical and dermoscopy evaluations.

Results

At baseline, AK mean (SD) lesion number in TD group was 14.1(4) and 14.6(4) in the non-TD group. ESPFP mean (SD) score at baseline was 5.8(1.2) in both groups. A significant reduction of AK lesions in comparison with baseline was observed in both groups. A statistically significant greater reduction was observed in TD in comparison with the non-TD group (−54% vs −32%). ESPFP score was reduced in a higher proportion in the TD group in comparison with the non-TD group (−60% vs −37%, respectively). ACTX treatment was very well tolerated.

Conclusion

In hypertensive subjects with multiple AK, the topical use of ACTX is associated with a significant reduction of lesions count with an improvement in the field cancerization. The clinical efficacy is more pronounced in subjects under thiazide diuretics treatment.

Current developments in pharmacotherapy for actinic keratosis

INTRODUCTION

Actinic keratosis (AK) is a superficial squamous cell carcinoma (SCC) where chronic sun exposure playing central role in its pathogenesis. UVB causes direct damage to DNA, producing pyrimidine dimers, and suppressing the protective role of p53. The stepwise progression of AK, with increased expression of anti-apoptotic Bcl-2, favors progression to SCC. Moreover, the dermal response characterized by inflammation and mediated by prostaglandins is a critical component of tumorigenesis that promotes tumor growth, tissue invasion, angiogenesis and metastasis. Other risk factors are represented by age, gender, phototype and drugs.

AREAS COVERED

In this review, the authors document the recent developments of different therapies used to treat AK and provide their perspectives on current and future treatment strategies.

EXPERT OPINION

The usefulness of long-term treatment with piroxicam and sun filters or diclofenac targeting the inflammation phases of skin tumorigenesis favors AK's healing and provides greater control of the cancerization field. Nonsteroidal anti-inflammatory drugs can be safely used in patients who use photosensitizing drugs and, therefore, are more at risk of developing skin tumors. Immunomodulatory therapies, which require shorter treatment, are characterized by more common local side effects, and need more attention by the dermatologist in the concern of patient education, resulting essential to improve adherence and outcomes.

Field Cancerization Therapies for Management of Actinic Keratosis: A Narrative Review

Actinic keratoses (AKs) are atypical, precancerous proliferations of keratinocytes that develop because of chronic exposure to ultraviolet (UV) radiation. Treatment of AK can be lesion-directed or field-directed. Field cancerization theory postulates that the skin surrounding AK is also at increased risk for possible malignant transformation since it has been exposed to the same chronic UV light. Field-directed therapies thus have the potential to address subclinical damage, reduce AK recurrence rates, and potentially reduce the risk of squamous cell carcinoma (SCC) development. Published clinical studies have found lesion clearance rates ranging from 81 to 91% for photodynamic therapy (PDT) with either aminolevulinic acid (ALA) or methylaminolevulinate (MAL). Clinical studies have also been published on various topical treatments. Complete clinical clearance (CCC) was significantly higher in patients treated with a combination of 5-fluorouracil and salicylic acid (5-FU-SA) than in the vehicle group across multiple studies, and CCC ranged between 46 and 48% following treatment with imiquimod. Additionally, treatment with diclofenac sodium (DFS) found reduction in lesion sizes to range from 67 to 75%. Reported results have been similar for another non-steroidal anti-inflammatory drug (NSAID), piroxicam, which has more cyclooxygenase (COX)-1 activity than DFS. Active treatments with ingenol mebutate were also significantly more effective than vehicle at clearing AK lesions. All treatments resulted in mild, localized skin reactions. PDT using conventional light sources was associated with increased severity of pain and/or discomfort, while PDT using daylight as the light source was associated with less pain and occasionally no pain at all. Though no widely accepted algorithm for the treatment of AKs exists, field-directed therapy can be particularly useful for treating photo-exposed areas containing multiple AKs. Additional research with more direct comparisons between these field-directed therapies will help clinicians determine the best therapeutic approach. Here, we provide a balanced and comprehensive narrative review of the literature, considering both light-based and topical therapies with a focus on their field-therapy aspects, and propose a therapeutic algorithm for selecting an appropriate treatment in the clinical setting.

Treatment of facial actinic keratoses with a cream containing octatrienoic acid: a multicenter clinical experience

BACKGROUND

Actinic keratosis (AKs) are premalignant skin lesions characterized by high rate of transformation in squamous cell carcinoma if not treated. Preclinical published data on parrodiene-derivative 2,4,6-octatrienoic acid, encourages us to study and to evaluate the effect of a topical product containing it in patients affected by mild to moderate actinic keratosis.

METHODS

Seventy subjects with at least 1-3 clinically diagnosed actinic keratosis lesions, non-hyperkeratotic, non-hypertrophic, localized on the face (I-II degree actinic keratosis) were enrolled in the study. The product was applied twice/day for 60 consecutive days.

RESULTS

After 60 days of treatment, a significant improvement in lesions occurred as shown by the decrease in the AKESA Score (P<0.05). Moreover, octatrienoic acid containing cream induced a 90% response rate (63/70 patients P<0.5; 95% confidence interval) with 20% complete remission (14/70 patients, P<0.05). Compared to baseline, a significant number of patients reported improvement of each AKESA sub-score after 60 days of treatment: skin thickness improved in 46 patients (P<0.0001), erythema in 21 patients (P<0.0001) and atrophy in 57 patients (P<0.0348). The average pigmentation score significantly decreased from 1.50 to 0.79 (P<0.05).

CONCLUSIONS

The results of the study, confirmed also by self-assessment, allow us not only to state that the use of topical octatrienoic acid was effective and well tolerated for topical treatment of AKs leading to overall clinical improvement in approximately 90% of subjects treated for 60 days.

Treatment of Grade II and III Actinic Keratosis Lesions with a Film-Forming Medical Device Containing Sunscreen/Piroxicam 0.8% and a Retinoic Acid/Glycolic Gel: A Pilot Trial

Introduction

Lesion and field-targeted treatments of actinic keratosis (AK) are commonly indicated for grade I and II type lesions. Grade III lesions are in general more difficult to treat. A film-forming medical device containing piroxicam 0.8% and sunscreen (SPF 50+) (PS) has been shown to be effective in the treatment of grade I and II AK lesions. Topical and oral retinoids have been utilized in AK and non-melanoma skin cancers. Topical glycolic acid promotes keratolysis and stimulates collagen synthesis for repair and skin rejuvenation and could be useful in AK treatment strategies. A gel containing retinoid acid (0.02%) and glycolic acid (4%) (RC) is commercially available. The objective of the study was to evaluate the efficacy and local tolerability of a combined treatment approach with PS and RC in subjects with multiple grade II and III AK lesions.

Methods

Twenty-two subjects (16 males and 6 females; mean age 68 years) with more than five AK lesions were enrolled after obtaining their informed consent in a 3-month trial. PS cream was applied twice daily every day and RC gel was applied twice daily for 2 consecutive days every week. The primary endpoint was the evolution of the AK mean number from baseline to the end of the trial. Secondary endpoints were the thickness of the target lesion (expressed in mm³) and the erythema score (hemoglobin content), evaluated using a standardized computer-based image acquisition analysis system (Anthera 3D).

Results

At baseline, the mean (SD) lesion number was 7.7 (3) for grade II and 1.4 (1) for grade III AK. At the end of the study, a significant (P = 0.001) reduction was observed for both grade II (− 81%; from 7.7 to 1.5) and grade III (− 22%) lesions. Six grade III lesions out of 31 (20%), presented at baseline, completely disappeared at month 3. For grade III lesions, a significant mean thickness reduction of 51% was observed at month 3. The erythema score (all lesions) was reduced by 70%. Four patients out of 22 (18%) were completely free of AK lesions at month 3. No severe side effects were reported.

Conclusion

In this exploratory trial, a combined treatment with a cream containing piroxicam and sunscreen and a retinoic/glycolic gel was associated with a substantial reduction of both grade II and III AK lesions with good local tolerability.

Funding

Cantabria Labs Difa Cooper.

Neoplastic Multifocal Skin Lesions: Biology, Etiology, and Targeted Therapies for Nonmelanoma Skin Cancers

Neoplastic skin lesions are multifocal, diffuse skin infiltrations of particular relevance in the differential diagnosis of ulcerative, nodular, or crusting skin lesions. Nonmelanoma skin cancers (NMSCs), namely, basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and also actinic keratosis (AK), are the most common malignant tumors in humans. BCCs do not proliferate rapidly and most of the times do not metastasize, while SCCs are more infiltrative, metastatic, and destructive. AKs are precursor lesions of cutaneous SCCs. The classical therapy of NMSCs makes use of photodynamic therapy associated with chemotherapeutics. With improved understanding of the pathological mechanisms of tumor initiation, progression, and differentiation, a case is made towards the use of targeted chemotherapy with the intent to reduce the cytotoxicity of classical treatments. The present review aims to describe the current state of the art on the knowledge of NMSC, including its risks factors, oncogenes, and skin carcinogenesis, discussing the classical therapy against new therapeutic options.

Efficacy of a film-forming medical device containing sunscreen (50+) and piroxicam 0.8% in actinic keratosis and field cancerization: a multicenter, assessor-blinded, 3 month trial

INTRODUCTION

Sunscreen protection in subjects with actinic keratosis (AK) is highly recommended to prevent clinical evolution of this in situ skin cancer condition. Use of topical anti-cyclooxygenase drugs such as diclofenac and piroxicam reduces the number of lesions and improves the cancerization field. A film-forming medical device in a cream formulation containing organic and inorganic sun-filters (50+ SPF) and piroxicam 0.8% (ACTX) has shown in a pilot, single-center, open trial to reduce AK lesions improving the cancerization field.

AIM

We evaluated in a multicenter, assessor-blinded, 3 month trial the efficacy of ACTX in AK.

METHODS

A total of 70 subjects with at least three AK lesions on the scalp or face were enrolled after written informed consent. Primary outcomes of the study were the clinical evolution of number of AK lesions on a target zone area and the evolution of dermoscopy features of the target lesion, assessing erythema, scaling, pigmentation, and follicular plug, using a 5 point score (from 0 to 4; maximum score: 16). Lesion count and dermoscopy score were evaluated in a blind fashion assessing digital color high definition coded images. A secondary outcome was the Investigator Global Score (IGS) of clinical evolution of the target area using a 7 point scale from -2 (significantly worse) to +4 (completely cured). IGS was evaluated in an open fashion. Subjects were instructed to apply the cream twice daily on the target area, using one finger-tip unit for the treatment of a 35 cm² area.

RESULTS

All but one subject (40 men and 30 women, mean age 73 years) concluded the study period. At baseline the mean (±SD) number of AK lesions in the target area were 7.0 (5.9) with a median value of 5 and the dermoscopy score of the target lesion was 7.0 (2.3) with a median value of 7.0. ACTX treatment reduced AK lesions to 3.2 (2.9), (p = .0001; Wilcoxon Test), representing a 55% relative reduction. Dermoscopy score was reduced to 3.3 (2.6) (p = .0001) (a reduction of 53%). The IGS after ACTX treatment was +1.9 (1.1), with a median of 2.0. A total of 86% of subjects showed a clinical improvement of IGS (≥1) with a very significant/complete clearance (score +3 or +4) in 42% subjects. No change or a worsening of AK lesions was observed in 14% of the subjects. The product was well tolerated. No serious adverse events were reported during the duration of the trial.

CONCLUSION

In this multicenter, assessor-blinded trial, the use of a film-forming medical device with sun protection and anti-inflammatory actions was effective in reducing AK lesions and improving the dermoscopy aspect of the target lesion in 86% of treated subjects. A head-to-head trial evaluating the efficacy of this medical device in comparison with diclofenac is warranted to establish whether this therapeutic approach could offer additional advantages in term of AK lesion reduction compared to an established topical treatment. (Trial ID: ISRCTN72020277).

Efficacy of a Film-Forming Medical Device Containing Piroxicam and Sun Filters in the Treatment of Multiple Actinic Keratosis Lesions in a Subject with a History of Kaposi Sarcoma

Actinic keratosis (AK) is considered a premalignant form of skin cancer due to chronic sun exposure. In addition, human papilloma virus (HPV) has been advocated a role in the pathogenesis of this clinical condition. HPV proteins (mainly E6 and E7) seem to act synergistically with ultraviolet (UV) radiation in reducing the defensive mechanisms of keratinocyte apoptosis after UV damage. Data regarding the involvement of other viruses, i.e. human herpes viruses (HHV), in the pathogenesis of AK are so far controversial. HHV8 is considered the infective agent involved in the development of Kaposi sarcoma. Some experimental data have shown that AK lesions carry HHV8 in more than 30% of the bioptic samples. Topical piroxicam was shown to be effective in the treatment of AK. In addition, the molecule shows antiviral action against HPV and HHV8. Here, we report the efficacy of a medical device containing a film-forming substance (polyvinyl alcohol), chemical and physical sun filters (SPF 50+), and 0.8% piroxicam (Actixicam™, Difa Cooper; ACTX) in the treatment of multiple scalp AK lesions, unresponsive to other treatments, in a subject with Kaposi sarcoma and a history of severe contact dermatitis. The subject presented with severe involvement of the scalp, with multiple hypertrophic AK lesions. Previous lesion-directed and field-targeted treatments have not been effective. The subject was treated with ACTX applied twice daily on the affected scalp. Relevant clinical improvement was observed as soon as 1 month of therapy. Complete clinical resolution of all scalp lesions was observed after 3 months of treatment. The product was well tolerated.

Long-term use of a new topical formulation containing piroxicam 0.8% and sunscreen: efficacy and tolerability on actinic keratosis. A proof of concept study

INTRODUCTION

Cyclooxygenase (COX) 1 and 2 enzyme up-regulation is involved in the pathogenetic process of actinic keratosis (A.K.) and non-melanoma skin cancers. Diclofenac, a non-steroidal anti-inflammatory (N.S.A.I.D.) drug, is used as topical treatment of A.K. Piroxicam is a N.S.A.I.D. characterized by a high COX-1 inhibition activity.

STUDY AIM

We conducted an 18 month exploratory open-label study on A.K., to assess the efficacy and tolerability of a new topical formulation of piroxicam and sunscreen in A.K.

PATIENTS

Enrolled subjects applied a galenic formulation of piroxicam 0.8%, vehiculated in a topical product containing sun filters with high (50+) and broad spectrum (UVA) actions, twice a day for 6 months. Subjects were then followed up for additional 12 months. Thirty-eight subjects with a total of 69 A.K. lesions participated in the trial. The primary outcome was the evolution of the Actinic Keratosis Erythema Scale Atrophy (A.K.E.S.A) score assessing erythema, scale, and atrophy of a target A.K. lesion. Secondary outcomes were the percentage of treated lesions with complete (100%) or partial (≥75%) clearance and the evaluation skin tolerability.

RESULTS

A.K.E.S.A. mean (S.D.) score at baseline was 7.5 (1.2). After 6 months of treatment, A.K.E.S.A. score decreased to 0.9 (1.1), a -88% reduction versus baseline. At the end of follow-up, A.K.E.S.A. score was 0.8 (1.2). A complete response was achieved in 38 of the 69 lesions (55%, 95% C.I.: 43% to 66%) and clearance was maintained 1 year post-treatment. A partial clearance was observed in 57 of 69 treated lesions (83%, 95% C.I.: 73% to 91%). Adverse events were limited to mild local irritation.

CONCLUSION

Our experience suggests that 6 month topical piroxicam 0.8% is efficacious and well tolerated in A.K. Clinical efficacy is maintained 1 year post-treatment. The main limitation of our study is that it was an open label non-controlled trial. Future controlled trials are warranted in order to compare the efficacy and tolerability of this topical piroxicam preparation with standard treatments in the management of A.K.

The relevance of piroxicam for the prevention and treatment of nonmelanoma skin cancer and its precursors

Piroxicam (PXM), a nonsteroidal anti-inflammatory drug, is an enolic benzothiazine and a potent member of the oxicam series. The drug suppresses the synthesis of proinflammatory enzymes, such as cyclo-oxygenases-1 and -2 (COX-1 and 2), downregulates the production of prostaglandins (PGs) and tromboxanes, and inhibits polyamines production by blocking ornithine decarboxylase induction involved in nonmelanoma skin carcinogenesis. In addition, PXM is able to induce tumor cell apoptosis and suppresses metalloproteinase 2 activities. Skin carcinogenesis is a multistep process in which the accumulation of genetic events leads to a gradually dysplastic cellular expression, deregulation of cell growth, and carcinomatous progression. COX-1 upregulation plays a significant role in PG and vascular epidermal growth factor production supporting tumor growth. Increased level of PGs in premalignant and/or malignant cutaneous tumors is also favored by upregulation of COX-2 and downregulation of the tumor suppressor gene 15-hydroxy-prostaglandin dehydrogenase. Chemoprevention can be a hopeful approach to inhibit carcinoma occurrence before an invasive tumor develops. The chemopreventive effect of nonsteroidal anti-inflammatory drugs on nonmelanoma skin cancers has been established. In this study, we highlighted the different modalities of action of PXM on the pathogenesis of nonmelanoma skin cancer, analyzing and evaluating binding modes and energies between COX-1 or COX-2 and PXM by protein–ligand molecular docking. Our clinical experience about the local use of PXM on actinic keratoses and field cancerization is also reported, confirming its efficacy as target therapy.

Topical pharmacotherapy for skin cancer: part I. Pharmacology

Topical pharmacotherapy represents an effective alternative treatment for superficial skin cancer, primarily actinic keratoses and basal cell carcinomas. We provide an in-depth analysis of the pharmacologic aspects of available topical drugs for the treatment of primary skin tumors. In particular, we evaluate the mechanisms of action, formulations and indications, side effects, and contraindications of 5-fluorouracil, imiquimod, diclofenac, ingenol mebutate, and retinoids. Moreover, the characteristics of some investigational molecules (ie, resiquimod, piroxicam, dobesilate, and betulinic acid) are presented.

Topical pharmacotherapy for skin cancer: part II. Clinical applications

The purpose of the paper is to provide an in-depth, evidence-based analysis of the clinical use of topical treatments for skin cancer. A comprehensive review of topical drugs has been performed, including 5-fluorouracil, imiquimod, diclofenac, ingenol mebutate, retinoids, resiquimod, piroxicam, dobesilate, and betulinic acid. The evaluated studies were rated according to their level of evidence level (I-V), as indicated by recent guidelines for evidence-based medicine, The Oxford 2011 Levels of Evidence. Therapeutic response is generally related to tumor type, extent, and localization, and also to patient compliance. Careful patient selection is required in order to achieve the desired goal of complete tumor clearance.

Retinoids for prevention and treatment of actinic keratosis

Actinic keratosis is a common cause of dermatological consultations and it presents a strong association with squamous cell carcinoma. Many substances are used for treatment and prevention, such as retinoids. Nevertheless, many studies on retinoids emphasize their application in treating and preventing non melanoma skin cancers. In this article, we reviewed studies about systemic and topical retinoids used with immunocompetent patients and organ transplant recipients with actinic keratosis, as primary or secondary outcomes. The majority of these papers pointed to a reduction in actinic keratosis count after treatment with retinoids. However, studies need to be better-defined in order to address the lack of a standardized dose, the absence of control groups, the low number of patients and short follow-up periods. Blind, randomized and controlled clinical trials with adequate sample sizes, specifically focused on actinic keratosis, are needed to clarify the real benefit of topical and/or oral retinoids. Comparison of efficacy and safety between oral and topical retinoids in the prevention and treatment of non-melanoma skin cancers and actinic keratosis is an essential pre requisite to establish new strategies to control these conditions.

Actinic keratosis: rationale and management

Actinic keratoses (AKs) are common skin lesions heralding an increased risk of developing squamous cell carcinoma (SCC) and other skin malignancies, arising principally due to excessive ultraviolet (UV) exposure. They are predominantly found in fair-skinned individuals, and increasingly, are a problem of the immunosuppressed. AKs may regress spontaneously, remain stable or transform to invasive SCC. The risk of SCC increases for those with more than 5 AKs, and the majority of SCCs arise from AKs. The main mechanisms of AK formation are inflammation, oxidative stress, immunosuppression, impaired apoptosis, mutagenesis, dysregulation of cell growth and proliferation, and tissue remodeling. Human papilloma virus has also been implicated in the formation of some AKs. Understanding these mechanisms guides the rationale behind the current available treatments for AKs. One of the main principles underpinning the management of AKs is that of field cancerization. Wide areas of skin are exposed to increasing amounts of UV light and other environmental insults as we age. This is especially true for the head, neck and forearms. These insults do not target only the skin where individual lesions develop, but also large areas where crops of AKs may appear. The skin between lesions is exposed to the same insults and is likely to contain as-yet undetectable preclinical lesions or areas of dysplastic cells. The whole affected area is known as the ‘field’. Management is therefore divided into lesion-directed and field-directed therapies. Current therapies include lesion-directed cryotherapy and/or excision, and topical field-directed creams: 5-fluorouracil, imiquimod, diclofenac, photodynamic therapy and ingenol mebutate. Combining lesion- and field-directed therapies has yielded good results and several novel therapies are under investigation. Treatment is variable and tailored to the individual making a gold standard management algorithm difficult to design. This literature review article aims to describe the rationale behind the best available therapies for AKs in light of current understanding of pathophysiology and epidemiology. A PubMed and MEDLINE search of literature was performed between January 1, 2000 and September 18, 2013. Where appropriate, articles published prior to this have been referenced. This is not a systematic review or meta-analysis, but aims to highlight the most up to date understanding of AK disease and its management.

Pharmacotherapeutic management of actinic keratosis: focus on newer topical agents

Actinic (solar) keratoses (AK) have the potential for malignant transformation and are the second most common diagnosis in dermatologic practices. No well-established clinical criteria are available to determine which AK are more likely to undergo malignant transformation; therefore, many dermatologists utilize field-directed approaches to treat all visible and subclinical AK on an affected skin surface. Current topical therapeutic agents require lengthy treatment regimens and are less well tolerated than many newer and investigational agents. We review and compare the efficacy and tolerability of well-established topical agents for the management of AK in the United States including 5-fluorouracil, imiquimod 5% cream as well as the newer 2.5 and 3.75% formulations, diclofenac 3% gel, photodynamic therapy, and the recently approved ingenol mebutate gel and discuss the therapeutic potential of investigational agents. Cryotherapy and 5-fluorouracil are efficacious at treating AK but less tolerable than imiquimod cream, particularly at its lower concentrations. The newer agents, diclofenac gel and ingenol mebutate, appear to be more tolerable than cryotherapy and 5- fluorouracil; however, comparative studies regarding efficacy are not available.

Binding of Cu(II) complexes of oxicam NSAIDs to alternating AT and homopolymeric AT sequences: differential response to variation in backbone structure

Besides their principal functions as painkillers and anti-inflammatory agents, drugs belonging to the nonsteroidal anti-inflammatory drug (NSAID) group also have anticancer properties. Cu(II) complexes of these drugs enhance the anticancer effect. How they exert this effect is not clear. As a possible molecular mechanism, our group has already shown that the Cu(II) complexes of two oxicam NSAIDs with anticancer properties, viz. piroxicam and meloxicam, can directly bind to the DNA backbone. AT stretches are abundant in the eukaryotic genome. These stretches are more accessible to binding of different ligands, resulting in expression of different functions. AT stretches containing both alternating base pairs and homopolymeric bases in individual strands show subtle differences in backbone structures. It is therefore of interest to see how the Cu(II)-NSAID complexes respond to such differences in backbone structure. Binding studies of these complexes with alternating polydA-dT and homopolymeric polydA-polydT have been conducted using UV-vis absorption titration studies, UV melting studies and circular dichroism spectroscopy. Competitive binding with the standard intercalator ethidium bromide and the minor groove binder 4',6-diamidino-2-phenylindole was monitored using fluorescence to identify the possible binding mode. Our results show that Cu(II)-NSAID complexes are highly sensitive to the subtle differences in backbone structures of polydA-dT and polydA-polydT and respond to them by exhibiting different binding properties, such as binding constants, effect on duplex stability and binding modes. Both complexes have a similar binding mode with polydA-dT, which is intercalative, but for polydA-polydT, the results point to a mixed mode of binding.

Topical treatment of actinic keratoses with potassium dobesilate 5% cream. a preliminary open-label study

BACKGROUND

Fibroblast growth factor (FGF) is involved in skin tumorigenesis: it promotes cell viability, induces angiogenesis and stimulates invasiveness. Dobesilate is a drug that blocks the activity of FGF. The primary objective was to evaluate the efficacy and tolerability of potassium dobesilate 5% cream in the treatment of actinic keratoses.

METHODS

Potassium dobesilate 5% cream was applied twice daily for 16 weeks to actinic keratosis lesions in 30 patients. The lesions were evaluated clinically at an initial baseline visit, at intermediate visits, and at 16 weeks of treatment. -

RESULTS

The use of potassium dobesilate 5% cream for 16 weeks induced complete regression in 70% of evaluated actinic keratoses, corresponding to grade I, II and III clinical variants, and a partial response (at least 75% reduction of lesions) in 20% of the cases.

CONCLUSION

Our preliminary trial shows that potassium dobesilate exerts anti-tumorigenic effects and may play a useful role in the chemoprevention of skin cancers.