Weekly pulse dosing: effective and comfortable topical 5-fluorouracil treatment of multiple facial actinic keratoses

Synthesis and ex vivo evaluation of PLGA chitosan surface modulated double walled transdermal Pluronic nanogel for the controlled delivery of Temozolomide

A surface modulated biodegradable transdermal strategy has been exploited for improving the biopharmaceutical properties of Temozolomide augmented in Poly Lactic-co-glycolic acid (PLGA) chitosan double walled nanogel (PCNGL). The PCNGL was synthesized by dual approach methodology showing consistent nanosize particle range of 210 nm and PDI 0.325 ± 0.43 with cationic zeta potential values +29.34 ± 0.79 mV. The PCNGL showed qualitative endothermic & exothermic temperature dependent degradation peaks by thermogravimetry analysis. Blood hemolysis and coagulation assay showed 3.37 ± 0.19 as hemolytic ratio, validating biologically safe margin for transdermal delivery. The in vitro drug release showed 85% transdermal release at slightly acidic pH mimicking skin microenvironment. The ex vivo studies displayed noteworthy penetration potential validated by concentration depth assay and confocal laser scanning microscopy, exhibiting 80% Temozolomide uptake in porcine epidermal tissue. The current research demonstrated the biodegradable controlled delivery of chemotherapeutic Temozolomide leading to biologically safe transdermal therapy.

Skin cancer prevention: a review of current topical options complementary to sunscreens

The incidence of non-melanoma skin cancer (NMSC) is dramatically increasing worldwide, despite the increased use of improved sunscreens. In 2014, the Surgeon General estimated that 2.2-5.0 million people were treated annually for NMSC. As the number of newly diagnosed skin cancers continues to rise, there is a need for additional preventative measures beyond sunscreens. Several newer topical products that focus on boosting DNA repair, modulating DNA transcription, decreasing inflammation and selectively targeting precancerous cells may play an important role in future skin cancer prevention.

pH triggered and charge attracted nanogel for simultaneous evaluation of penetration and toxicity against skin cancer: In-vitro and ex-vivo study

The current research is focused to develop and investigate the toxicity and penetration potential of biocompatible chitosan nanogel encapsulating capecitabine by ionic interaction mechanism exhibiting pH triggered transdermal targeting. The nanogel (CPNL) was synthesized by ion gelation mechanism using Pluronic F 127 and surface decoration by Transcutol as non-ionic penetration enhancer. The CPNL possesses fine morphology and nano size range when evaluated by TEM, SEM and DLS analysis with cationic charge and slightly acidic pH assayed by zeta potential and pH analysis. It showed pH responsive drug release characteristics mimicking the skin cancer micro-environment. The MTT assay and apoptotic index of CPNL on HaCaT cell line elaborated optimal cell toxicity and retention on 24h of exposure. The ex-vivo skin penetration analysis exhibited noteworthy diffusion and penetration caliber through concentration depth profile, steady state flux and fluorescent skin imaging on porcine tissue. Overall outcomes suggested CPNL as a potent alternative biocompatible, transdermal nanotherapy against skin cancer displaying significant penetration caliber with enhance toxicity on cancerous cell.

pH Responsive 5-Fluorouracil Loaded Biocompatible Nanogels For Topical Chemotherapy of Aggressive Melanoma

Combating melanoma via topical route is a highly challenging task due to low selectivity, poor efficacy and impeding biological environment of the skin. In the present study, we engineered a chitosan based pH responsive biodegradable nanogel (FCNGL), encapsulated with 5-FU that was effective even at very low drug doses (0.2% w/v) against melanoma. The FCNGL was synthesized by ion gelation technique exhibited nano-size particle distribution and sustained drug release kinetics. Hemolysis and coagulation analysis revealed high safety whereas MTT and apoptosis assays exhibited the efficacy of FCNGL. DMBA-Croton oil Swiss albino mice model was employed for in vivo assessment followed by gamma scintigraphic screening. Tumor burden and pharmacokinetic antioxidant stress levels along with whole-body gamma scintigraphy imaging using 99 mTc labelled nanogel exhibited selective accumulation in melanoma tumor nodules. The pH responsive behaviour of the nanogels resulted in triggered release of 5-FU in slightly acidic microenvironment, resulting in selective drug accumulation at the melanoma site. Immunohistochemistry (IHC) analysis of tumor showed improvement of subcutaneous layer alignment and regeneration of the epithelial skin layer when compared with standard 5% 5-FU and control mice group. Overall our preclinical data using the FCNGL portends to be a promising platform for efficient and sustained delivery of 5-FU for topical chemotherapy that can result in high efficacy, patient compliance and safety in the clinical set up.

Evaluation of the Effectiveness of Imiquimod and 5-Fluorouracil for the Treatment of Actinic Keratosis: Critical Review and Meta-Analysis of Efficacy Studies

Background:

Actinic keratosis lesions occur frequently on sun-exposed skin of Caucasians. They become more prevalent with advancing age and are important in identifying the risk factor of those people possibly predisposed to invasive squamous cell carcinoma. Topical therapies are useful alternatives to cryotherapy for treating diffuse actinic damage and a number of preparations have been developed for treating actinic keratosis.

Objectives:

A cumulative meta-analysis was performed to determine the efficacy of imiquimod 5% cream, which presents a new alternative topical therapy for actinic keratosis, and to compare it to 5-fluorouracil for the treatment of actinic keratosis lesions of the face and scalp.

Methods:

We searched MEDLINE (1966 to October 2004) for relevant studies evaluating the efficacy of actinic keratosis topical agents imiquimod and 5-fluorouracil (0.5%, 1%, and 5%). Studies included in this meta-analysis required a dosage regimen that was not significantly different from that approved by Health Canada and the U.S. FDA. Studies also required a well-defined treatment duration and followup period, with the primary efficacy variable being the complete (100%) clearance of all actinic keratosis lesions defined as the proportion of patients at followup with no clinically visible lesions in the treatment area. To determine the average efficacy rate for both drugs, the data from each study were combined for that drug.

Results:

Ten studies were included in the analysis. The average efficacy rate for each drug (with 95% confidence interval) was 5-fluorouracil, 52 ± 18% ( n = 6 studies, 145 subjects) and imiquimod, 70 ± 12% ( n = 4 studies, 393 subjects).

Conclusions:

The results of this meta-analysis show that both imiquimod and 5-fluorouracil are effective methods for the treatment of actinic keratosis and provide a useful alternative to cryotherapy. However, this analysis suggests that imiquimod may have higher efficacy than 5-fluorouracil for actinic keratosis lesions located on the face and scalp and therefore provides another option to dermatologists.

Validation of Photograph-Based Toxicity Score for Topical 5-Fluorouracil Cream Application

BACKGROUND

An objective tool quantifying the toxicity of 5-fluorouracil (5-FU) from photographs was recently reported, and its reliability was confirmed.

OBJECTIVE

The aim of this study was to validate the photograph-based toxicity score.

METHODS

Photograph-based toxicity scores of participants assigned to the 5-FU arm of a randomized placebo-controlled trial were tested for correlations with their patient-reported symptom scores and baseline characteristics.

RESULTS

Each pair of individual and overall scores of patient-reported symptoms and photograph-based toxicity was correlated at 2 and 4 weeks (correlation coefficient range, 0.34-0.95; P < .001 for all). Older age, more actinic keratoses, previous topical 5-FU use, and more keratinocyte carcinomas on the face and ears in the previous 5 years were correlated with increased 5-FU toxicity at 2 weeks (P < .05). An increase in the total number of 5-FU applications during the trial was correlated with less severe toxicity at 2 weeks (P < .001), but with increased toxicity at 4 weeks (P < .001).

CONCLUSION

This study provides evidence for construct validity of the photograph-based 5-FU toxicity score. The tool can be used to objectively measure 5-FU toxicity in clinical or research setting, and it can be a prototype for toxicity measurements of other topical medications.

Pharmacotherapy of actinic keratosis: an update

INTRODUCTION

Actinic keratosis (AK) represents the initial intraepidermal manifestation of abnormal keratinocyte proliferation, with the potential of progression to squamous cell carcinoma (SCC). Few visible AKs lead to the use of lesion-directed treatments, including ablative and/or surgical procedures. Multiple and/or the suspicion of subclinical (non-visible) AKs lead to the use of field-directed therapies, including topical and ablative treatments. Predicting which AK will progress to SCC is difficult, and so all are treated. The goals of treatment are to eliminate visible AKs and to treat subclinical (non-visible) AKs, minimizing their risk of progression to invasive SCC, while pursuing good cosmesis.

AREAS COVERED

This review discusses the prevention of AKs (such as ultraviolet light avoidance, sunscreen use, protective clothing, and frequent self-examinations, in addition to chemoprevention with retinoids, eflornithine, silymarin, and others). It also covers lesion-directed treatments (e.g., cryotherapy, electrodessication and curettage, and surgery). Field-directed treatments are also mentioned (including laser resurfacing, dermabrasion, chemical peels, topical immunomodulators (imiquimod and diclofenac), topical chemotherapeutic agents (5-fluorouracil and retinoids), and photodynamic therapy). Finally, newer and investigational treatments are discussed (including ingenol mebutate).

EXPERT OPINION

There is no panacea in the treatment of AKs. The current best approach is the sequential treatment with a lesion-directed and a field-directed therapy. Several combinations seem to work well; they just need to be selected based on the evidence and adjusted to patient needs, preferences and dermatologist expertise.

Current and emerging treatment strategies for the treatment of actinic keratosis

Actinic keratoses are encountered by physicians worldwide on a daily basis. As these precancerous lesions can transform to skin carcinomas, it is important to understand the many available options to use as treatment. In recent years, new therapeutic options have emerged to treat this common condition. These treatments as well as a review of the literature of conventional therapies will be discussed.

Impact of interval and combination therapies on the management of actinic keratosis: review and clinical considerations

Abstract An increasing body of evidence, including epidemiological data, clinical and histopathologic observations, and molecular biological findings, has highlighted the underlying malignant nature of actinic keratosis (AK). Scientific evidence accumulated over the past decade supports the concept that AK should no longer be considered premalignant but instead is now thought to be the earliest stage of a biologic continuum ending in squamous cell carcinoma. This paradigm shift, coupled with a worldwide increase in the incidence of AK, has changed how dermatologists treat AK. These changes include the development of novel topical and procedural therapies; modification of established topical monotherapy regimens to include interval, sequential, short-course, and short-contact therapies; combining various topical therapies; and combining topical and procedural therapies. This review will examine the mechanisms of action and the safety and efficacy data for emerging interval and combination therapies used to treat AK.

Psoriasis of the nail: anatomy, pathology, clinical presentation, and a review of the literature on therapy

Psoriasis is a chronic skin disease that affects millions of people throughout the world. Even though cutaneous signs and symptoms are the most common clinical manifestations, the nails can be involved in up to 50% of cases, and their involvement remains an important yet often overlooked aspect of the disease. There is a broad spectrum of nail dystrophies associated with psoriasis, ranging from the common pitting and loosening of the nail plate to the less frequent discoloration and splinter hemorrhages seen in the nail bed. This article discusses the normal anatomy and embryology of the nail unit as well as the current understanding of the pathogenesis of the disease. It also provides an extensive review of the existing literature with respect to psoriatic nail therapy. Although there have been many recent advances in the treatment of the cutaneous form of the disease-most notably in the field of immunotherapies-the options for nail psoriasis are far more limited. While a number of treatment alternatives currently exist for nail disease, the general paucity of clear evidence regarding these choices often makes it difficult to select the most efficient, safe, and optimal treatment for the patient. Even though the current literature has shown some support for the use of topical, intralesional, radiation, systemic, and combination therapies for nail psoriasis, the available studies lack sufficient power to extrapolate a standardized therapeutic regimen. Therefore, until better-documented evidence validating the treatment options emerges within the literature, clinicians and patients are left with a vague and relatively unproven approach to psoriatic nail disease.

Treatment of post-transplant premalignant skin disease: a randomized intrapatient comparative study of 5-fluorouracil cream and topical photodynamic therapy

BACKGROUND

Organ transplant recipients (OTR) are at high risk of developing nonmelanoma skin cancer and premalignant epidermal dysplasia (carcinoma in situ/ Bowen's disease and actinic keratoses). Epidermal dysplasia is often widespread and there are few comparative studies of available treatments.

OBJECTIVES

To compare topical methylaminolaevulinate (MAL) photodynamic therapy (PDT) with topical 5% fluorouracil (5-FU) cream in the treatment of post-transplant epidermal dysplasia.

METHODS

Eight OTRs with epidermal dysplasia were recruited to an open-label, single-centre, randomized, intrapatient comparative study. Treatment with two cycles of topical MAL PDT 1 week apart was randomly assigned to one area of epidermal dysplasia, and 5-FU cream was applied twice daily for 3 weeks to a clinically and histologically comparable area. Patients were reviewed at 1, 3 and 6 months after treatment. The main outcome measures were complete resolution rate (CRR), overall reduction in lesional area, treatment-associated pain and erythema, cosmetic outcome and global patient preference.

RESULTS

At all time points evaluated after completion of treatment, PDT was more effective than 5-FU in achieving complete resolution: eight of nine lesional areas cleared with PDT (CRR 89%, 95% CI: 0.52-0.99), compared with one of nine lesional areas treated with 5-FU (CRR 11%, 95% CI: 0.003-0.48) (P = 0.02). The mean lesional area reduction was also proportionately greater with PDT than with 5-FU (100% vs. 79% respectively). Cosmetic outcome and patient preference were also superior in the PDT-treated group.

CONCLUSIONS

Compared with topical 5-FU, MAL PDT was a more effective and cosmetically acceptable treatment for epidermal dysplasia in OTRs and was preferred by patients. Further studies are now required to confirm these results and to examine the effect of treating epidermal dysplasia with PDT on subsequent development of squamous cell carcinoma in this high risk population.

Guidelines for the management of actinic keratoses

These guidelines stemmed from a consensus meeting held by the British Photobiology Group (BPG) in 1999. Following this meeting one of the authors (J.M.M.) was invited to draw up guidelines for the management of actinic keratoses by the British Association of Dermatologists Therapy Guidelines and Audit Subcommittee. Relevant evidence was sought using the search terms 'solar keratosis' and 'actinic keratosis' in Medline from 1966 onwards. Additional and earlier literature was reviewed on the basis of references within post-1966 publications. All articles of apparent relevance were reviewed independently of the nature of the publication. The quality of the evidence elicited has been indicated. The National Ambulatory Medical Care Survey (U.S.A.) was used for further data on topical chemotherapy. Papers were reviewed and discussed by the contributors to the BPG Workshop (see Acknowledgments). Recommendations are evidence based where possible. Strength of recommendation is coupled with quality of evidence. Strength of recommendation includes consideration of apparent cost-benefit and practical considerations. Quality of evidence reflects the nature of the trial structure that provides data of efficacy.

Evaluation of the effectiveness of imiquimod and 5-fluorouracil for the treatment of actinic keratosis: Critical review and meta-analysis of efficacy studies

BACKGROUND

Actinic keratosis lesions occur frequently on sun-exposed skin of Caucasians. They become more prevalent with advancing age and are important in identifying the risk factor of those people possibly predisposed to invasive squamous cell carcinoma. Topical therapies are useful alternatives to cryotherapy for treating diffuse actinic damage and a number of preparations have been developed for treating actinic keratosis.

OBJECTIVES

A cumulative meta-analysis was performed to determine the efficacy of imiquimod 5% cream, which presents a new alternative topical therapy for actinic keratosis, and to compare it to 5-fluorouracil for the treatment of actinic keratosis lesions of the face and scalp.

METHODS

We searched MEDLINE (1966 to October 2004) for relevant studies evaluating the efficacy of actinic keratosis topical agents imiquimod and 5-fluorouracil (0.5%, 1%, and 5%). Studies included in this meta-analysis required a dosage regimen that was not significantly different from that approved by Health Canada and the U.S. FDA. Studies also required a well-defined treatment duration and followup period, with the primary efficacy variable being the complete (100%) clearance of all actinic keratosis lesions defined as the proportion of patients at followup with no clinically visible lesions in the treatment area. To determine the average efficacy rate for both drugs, the data from each study were combined for that drug.

RESULTS

Ten studies were included in the analysis. The average efficacy rate for each drug (with 95% confidence interval) was 5-fluorouracil, 52 +/- 18% (n = 6 studies, 145 subjects) and imiquimod, 70 +/- 12% (n = 4 studies, 393 subjects).

CONCLUSIONS

The results of this meta-analysis show that both imiquimod and 5-fluorouracil are effective methods for the treatment of actinic keratosis and provide a useful alternative to cryotherapy. However, this analysis suggests that imiquimod may have higher efficacy than 5-fluorouracil for actinic keratosis lesions located on the face and scalp and therefore provides another option to dermatologists.

A randomized trial of topical 5% 5-fluorouracil (Efudix cream) in the treatment of actinic keratoses comparing daily with weekly treatment

BACKGROUND

Topical 5-fluorouracil (5-FU) cream is widely used in the treatment of actinic keratoses (AKs) but the optimum treatment regimen that provides efficacy while minimizing side-effects remains unclear.

OBJECTIVES

A randomized trial to compare the efficacy and side-effects of daily vs. weekly application of 5% 5-FU in the treatment of AKs of the scalp and face.

PATIENTS/METHODS

Twenty patients were recruited and randomized to two groups. Group 1 (13 patients) applied 5% 5-FU twice daily for 3 weeks, group 2 (seven patients) applied 5% 5-FU twice daily for 1 day per week for 12 weeks. Patients were reviewed at weeks 3, 12, 24 and 52. At each review a lesion count and lesion map were completed and patients were asked to score efficacy and inflammation.

RESULTS

At week 0 the median lesion count was the same in both groups, 17.5 lesions. At 12 weeks the median lesion count in group 1 had fallen to 0 where it remained for the duration of follow-up. In group 2 the median lesion count fell to 6 at 12 weeks, 5.5 at 24 weeks and was 3 at 52 weeks. The difference in the lesion count was significant at all time points after week 0: P < 0.05 at weeks 12 and 52, and P < 0.01 at week 24. The mean inflammation score was higher in patients clear of AKs at 12 weeks compared with those who had not cleared, 3.8 compared with 1.9. This difference was statistically significant (P < 0.05) suggesting that inflammation is necessary for efficacy.

CONCLUSIONS

We conclude that daily application of 5% 5-FU cream is more effective than weekly application at clearing AKs from the scalp and face. Our results also suggest that inflammation is likely to be required to achieve a therapeutic effect.

Topical treatment strategies for non-melanoma skin cancer and precursor lesions

The ability to manage non-melanoma skin cancers and pre-malignant lesions with topical pharmacologic agents is highly compelling. This article examines currently available products and discusses their emerging roles and limitations. These include fluorouracil, diclofenac sodium, imiquimod, and photodynamic therapy.

Intermittent topical 5-fluorouracil is effective without significant irritation in the treatment of actinic keratoses but prolongs treatment duration

BACKGROUND

Controversy exists as to whether treatment of actinic keratoses with intermittent doses of topical 5-fluorouracil is effective in the absence of significant irritation.

OBJECTIVE

To evaluate the efficacy and degree of irritation of 5-fluorouracil as a function of its application frequency.

METHODS

A total of 85 actinic keratoses in 53 patients were treated, initially with four applications per week for the first week. After this first week, if intolerable irritation arose, patients were instructed to reduce application frequency to two times per week for the rest of the treatment period.

RESULTS

Treatment was completed for 95.4% of the lesions included, with healing of 88.6% of them. The mean time to healing was 7.4 weeks (with four applications weekly) and 10.2 weeks (with two applications). The healing rate was similar in the two groups. Significant correlations (p<0.001) were observed between application frequency and time to healing.

CONCLUSION

Intermittent 5-fluorouracil treatment is effective without causing significant irritation, but time to healing increases with declining application frequency.

Optimum treatment strategies for actinic keratosis (intraepidermal squamous cell carcinoma)

Actinic keratoses are superficial squamous cell carcinomas. Treatment of these lesions is indicated to prevent the cells from invading the dermis and possibly metastasizing. If a lesion exhibits evidence of possible dermal invasion, such as marked erythema, ulceration, tenderness, bleeding, and especially induration, the physician should always consider performing a biopsy. Cryosurgical destruction, the most common treatment employed, has been shown to be 98.8% effective in eliminating the lesions. Adverse reactions such as scarring, textural changes, infection, and pigmentation alteration rarely occur. Physical destruction using electrodesiccation and curettage is particularly effective when the patient has hyperkeratotic lesions. When a patient has a multitude of actinic keratoses, the use of other treatments including fluorouracil, nonsteroidal anti-inflammatory preparations, immune response modifiers, and photodynamic therapy should be considered. However, none of these treatments has proven to be as effective overall as cryosurgical destruction. If a lesion does not respond to treatment, obtaining a biopsy of the lesion should be considered to be certain that the lesion is not an invasive squamous cell carcinoma.

Topical and light-based treatments for actinic keratoses

Actinic keratosis is currently believed to be an early stage in the evolution of squamous cell carcinoma. Active and intensive treatment of actinic keratosis may prevent the formation of invasive squamous cell carcinoma and potential metastases. While destructive methods of treatment of actinic keratosis remain the gold standard for the eradication of visible and palpable actinic keratoses, new medical therapies may accomplish this goal more comfortably and reliably for the patient. Newer topical medications, light therapy and photodynamic therapy are generating promising results that presage more widespread use in the future. These novel therapies for the early treatment of actinic keratosis may be administered in combination or serially, with the locus of treatment at any given time possibly restricted to a region of affected skin. Treatment of incipient or subclinical lesions may mitigate the risk of future squamous cell carcinomas lesions. Widespread actinic keratosis constitutes a persistent medical problem that requires long-term management. The role of traditional and novel treatments in the routine treatment of actinic keratosis will be determined by the efficacy, limitations and the practicality of each of these methods in individual patients. As the first stage of squamous cell carcinoma, actinic keratosis is worthy of prompt evaluation and active treatment.

Photodynamic therapy: is it a valuable treatment option for actinic keratoses?

Photodynamic therapy (PDT) is proposed as an effective therapy with a good safety profile for patients with actinic keratoses. PDT involves the application of a photosensitizer to dysplastic or neoplastic tissue such that when exposed to light of an appropriate wavelength, the target tissue undergoes a cytotoxic reaction. Studies to date have demonstrated that PDT for the treatment of patients with actinic keratoses achieves clearance of lesions with minimal morbidity, maintenance of functional integrity of underlying tissues, and excellent cosmetic results. We present a review of the treatment of patients with actinic keratoses and the role of PDT in this context.

Cycle therapy of actinic keratoses of the face and scalp with 5% topical imiquimod cream: An open-label trial

BACKGROUND

Preliminary studies indicate that topically applied immune response modifiers may be an effective and safe method of treating actinic keratoses (AKs).

OBJECTIVE

Our aim was to study the potential efficacy of topical 5% imiquimod cream in the treatment of facial or scalp AKs and improve the safety profile by using a novel "cycle" dosing regimen.

METHODS

This pilot study is an open-label trial that included 25 patients who had between 5 and 20 discrete AKs within a cosmetic unit of the forehead, scalp, or cheek. Treatment consisted of once-daily application of 5% imiquimod cream, 3 times a week for 4 weeks. to the entire cosmetic unit, followed by a rest period of 4 weeks. The cycle was repeated if any AKs remained after a complete 8-week cycle. A maximum of 3 cycles was permitted (24 weeks). Thirty-three sites in 25 patients were evaluated.

RESULTS

Compliance was excellent with a very tolerable safety profile. Complete clearing of all AKs was noted in 82% (27/33) of anatomic sites in 25 study subjects. Almost half the sites (15/33) were clear at the end of the first cycle. A "therapeutic interval" was noted during the rest period wherein clinical inflammation subsided but AKs continued to clear. An added effect was the uncovering and clinical appearance and subsequent eradication of incipient (subclinical) AKs in the treatment area.

CONCLUSION

There was excellent compliance with the cycle therapy regimen. The observations and hypotheses made in this pilot study will be tested in controlled, randomized trials with larger study populations. The identification of a therapeutic interval may prove to be beneficial in formulating individualized dosing regimens.

Skin cancer in the elderly

This article describes the clinical features, treatment options, and prognosis of the most common skin cancers: basal cell carcinoma, squamous cell carcinoma, and melanoma. Emphasis is placed on specific issues that need to be considered when dealing with cancers of the skin in the elderly population. In addition, issues surrounding the early detection and prevention of skin cancer are addressed.

Photodynamic therapy of actinic keratoses with topical aminolevulinic acid hydrochloride and fluorescent blue light

BACKGROUND

Aminolevulinic acid hydrochloride (ALA, Levulan) applied topically to actinic keratoses (AKs) leads to accumulation of the photosensitizer protoporphyrin IX, which, when activated by exposure to light, eradicates AKs.

OBJECTIVE

We examined the safety and efficacy of photodynamic therapy using topical 20% ALA in a solution formulation and varying blue light doses to treat multiple AKs on the face and scalp.

METHOD

This is a multicenter, investigator-blinded, randomized, vehicle-controlled study.

RESULTS

Thirty-six patients with clinically typical AKs were treated with 20% ALA; 14 to 18 hours later, they were irradiated with a nonlaser fluorescent blue light source. With the optimal light dose of 10 J/cm(2), 88% of the AKs completely cleared 8 weeks after a single photodynamic treatment, compared with 6% after treatment with vehicle and light.

CONCLUSION

Topical ALA PDT using a nonlaser, blue light source is an effective treatment for multiple AKs.

Cryopeeling (extensive cryosurgery) for treatment of actinic keratoses: an update and comparison

BACKGROUND

The treatment of actinic keratoses is the most common procedure in dermatology and liquid nitrogen freezing is the most used method of destruction. Yet it is criticized for its limitations of treating only small areas and its tendency to leave hypopigmented skin. 5-fluorouracil (5-FU) treatment is also widely utilized. It has the advantage of treating large areas, but the disadvantages of length of treatment, morbidity, and only partial effectiveness in removing deep or hyperkeratotic actinic keratoses.

OBJECTIVE

Long-term follow-up results are reported on the use of extensive cryosurgery to treat areas of widespread solar damage. The literature is reviewed comparing the advantages and disadvantages versus 5-FU treatment.

METHODS

Three hundred and seventy-three patients were initially treated for extensive actinic keratoses in a private dermatology office in an retirement community in Florida. Individual lesions were counted under good lighting conditions with the aid of a 2.5x stereoscopic lens. The treated areas were predominately on the face and scalp areas, although some arms and hands were treated. A total of 34,604 were initially treated by spraying each individual keratosis with liquid nitrogen as well as the entire surrounding skin area.

RESULTS

The data show that cryopeeling was approximately twice as effective as 5-FU when measured at 1-3 years postoperatively. In addition, the ease of application, its availability, the low cost of materials, its versatility in treating all forms of actinic keratoses, the reduced healing times, and its predictably good cosmetic results make this procedure a logical choice for treating widespread actinic keratoses. The number of squamous cell carcinoma recorded over the entire 6. 5-year study was 33 with no metastases, much lower than predicted for patients with actinic keratoses left untreated.

CONCLUSION

Extensive cryosurgery (cryopeeling) is a highly effective method for removing actinic keratoses and preventing recurrences. The subsequent incidence of squamous cell carcinoma is also greatly reduced.

Actinic keratosis. Current treatment options

Actinic keratoses are hyperkeratotic skin lesions that represent focal abnormal proliferation of epidermal keratinocytes. Some actinic keratoses evolve into squamous cell carcinoma of the skin, while others resolve spontaneously. The conversion rate of actinic keratosis to squamous cell carcinoma is not accurately known, but appears to be in the range of 0.25 to 1% per year. Although there is a low rate of conversion of actinic keratoses to squamous cell carcinoma, 60% of squamous cell carcinomas of the skin probably arise from actinic keratoses. The main cause of actinic keratoses in otherwise healthy Caucasians appears to be the sun. Therapy for actinic keratoses begins with prevention which starts with sun avoidance and physical protection. Sunprotection with sunscreens actually slows the return of actinic keratoses in patients already getting actinic keratoses. Interestingly, a few studies are available that demonstrate that a high fat diet is associated with the production of more actinic keratoses than is a low fat diet. One of the mainstays of therapy has been local destruction of the actinic keratoses with cryotherapy, and curettage and electrodesiccation. A new addition to this group of therapies to treat individual actinic keratoses is photodynamic therapy with topical aminolevulinic acid and light. In patients who have numerous actinic keratoses in an area of severely sun damaged skin, therapies which are applied to the whole actinic keratosis area are used. The goal of treating such an area of skin is to treat all of the early as well as the numerous clinically evident actinic keratoses at the same time. The classical approaches for treating areas of photodamaged skin without treating actinic keratoses individually include: the use of topically applied fluorouracil cream, dermabrasion, and cutaneous peels with various agents like trichloroacetic acid. Both topically as well as orally administered retinoids have been used to treat actinic keratoses but retinoids alone are probably not an optimal monotherapy. Photodynamic therapy with topical aminolevulinic acid and light is a new therapy for actinic keratoses. Aminolevulinic acid is a precursor of protoporphyrin IX (PpIX) which is synthesized in the actinic keratosis when it is treated with aminolevulinic acid, and the PpIX photosensitizes the actinic keratosis so that light exposure can lead to its destruction. Photodynamic therapy with topical aminolevulinic acid is approved in the US to treat multiple individual actinic keratoses on the face and scalp and has similar cure rates to those reported for cryotherapy and fluorouracil therapy.

The treatment of actinic keratoses

BACKGROUND

Actinic keratoses are epidermal tumors that can develop into invasive squamous cell carcinoma. Recently, some Medicare carriers have limited reimbursement for destruction of actinic keratoses.

OBJECTIVE

We review treatments for actinic keratoses and the rationale for their use.

METHODS

Computerized literature searches were performed in MEDLINE. The search terms were "actinic keratoses" and "solar keratosis." Information from these searches was combined with considerable personal experience for the body of this work.

RESULTS

Many effective treatments for actinic keratoses exist. Cryosurgery and curettage are the most commonly used treatments. Cryosurgery is considered the standard of care for treatment of actinic keratoses. Topical 5-fluorouracil is used in 3. 6% of cases and is rarely used alone on the first patient visit. Many other effective, less commonly used treatments are available.

CONCLUSION

A physician should select the best treatment by considering features of the lesion(s) and the patient being treated. All actinic keratoses cannot be treated in the same manner. The failure to treat actinic keratoses may have serious consequences for the patient.

New and emerging treatments for photoaging

It is easy to become too busy treating the sequelae of photoaging, actinic keratoses, and skin cancers to discuss prevention adequately with patients. With children, sun-protective measures and sunscreen information should be the main therapeutic intervention. In any young adult with an actinic keratosis or skin cancer, topical and resurfacing treatments should be considered. In older patients with fragile skin and solar purpura, reversal of photodamage can have a positive effect on daily functioning.

A randomized paired comparison of photodynamic therapy and topical 5-fluorouracil in the treatment of actinic keratoses

BACKGROUND

Photodynamic therapy (PDT) has not been compared with topical 5-fluorouracil (5-FU) in the treatment of epidermal dysplasia.

OBJECTIVE

The purpose of this study was to assess the efficacy and tolerability of these two treatment modalities in 17 patients with actinic keratoses on the backs of the hands.

METHODS

Each patient's right and left hands were randomized to receive either a 3-week course of topical 5-FU applied twice per day or PDT using topical 5-aminolevulinic acid (5-ALA) and then, after 4 hours, irradiation with an incoherent light source consisting of a 1200 W metal halogen lamp emitting red light (580 to 740 nm). Each hand randomized for PDT received 150 J/cm(2). The observed median fluence rate was 86 mW/cm(2) (interquartile range, 53 to 100 mW/cm(2)). All patients were reviewed at 1, 4, and 24 weeks after starting treatment.

RESULTS

Fourteen of 17 patients (82%) completed the study. The mean lesional area treated with topical 5-FU decreased from 1390 mm(2) (standard deviation [SD], 1130) to 297 mm(2) (SD, 209). This represents a mean reduction in lesional area of 70% (confidence interval [CI], 61%-80%). The mean lesional area treated with topical PDT decreased from 1322 mm(2) (SD, 1280) to 291 mm(2) (SD, 274), representing a mean reduction in lesional area of 73% (CI, 61%-84%). The reduction in lesional area elicited by the two treatment methods was similar (CI, -25% to 17%). There was no statistically significant difference between the treatment methods in overall symptom scores for pain and redness.

CONCLUSION

One treatment with PDT using topical 5-ALA appears to be as effective and well tolerated as 3 weeks of twice-daily topical 5-FU, a cheap and widely available alternative.

Does intermittent "pulse" topical 5-fluorouracil therapy allow destruction of actinic keratoses without significant inflammation?

BACKGROUND

Topical 5-fluorouracil (5-FU) is effective in removing actinic keratoses but causes unsightly and painful erosions. Intermittent "pulse" 5-FU therapy has been described as being an effective and comfortable technique for destroying actinic keratoses.

OBJECTIVE

The purpose of this study was to determine the efficacy and cutaneous side effects of intermittent 5-FU therapy.

METHODS

Efficacy of treatment was evaluated by three experienced dermatologists separately comparing randomly arranged before and after photographs. Degree of skin reaction was graded from photographs taken during treatment.

RESULTS

Of 13 patients treated with intermittent 5-FU, two had an excellent result, three a good result, but eight failed to show discernible improvement. Efficacy was linked to the degree of skin irritation.

CONCLUSION

Pulse 5-FU failed to clear actinic keratoses in most patients. Intermittent 5-FU treatment does not dissociate its therapeutic efficacy from its undesirable erosive effects. Pulse therapy is a less intensive way of employing 5-FU and may be of value in patients unwilling to accept the erosions and discomfort that accompany the traditional course of daily 5-FU applications.

Primary clinical response and long-term follow-up of solar keratoses treated with topically applied 5-aminolevulinic acid and irradiation by different wave bands of light

Photodynamic therapy with 5-aminolevulinic acid (ALA-PDT) is based on photosensitization by endogenous synthesis of protoporphyrin IX and its transient accumulation especially in malignant epithelially derived tissues. Recent studies have indicated that ALA-PDT is effective for the treatment of solar keratoses (SK), but there has been a lack of long-term clinical follow-up. The goal of the present study was to investigate the immediate and long-term effect of ALA-PDT on SK. Twenty-eight patients with a total of 251 SK were enrolled in the study. Standard treatment involved the topical application of 20% ALA, under occlusive and light-shielding dressing for 4 hours before exposure to UVA and/or different wave bands or wave band combinations of polychromatic visible light (full-spectrum visible light, and/or different wave bands of filtered visible light > 515, > 530, > 570, or > 610 nm) in one or two treatment sessions. The primary complete response rate of SK to ALA-PDT was 64% after one treatment, but 85% when the responses to a second treatment were included. Taken all treatments together, the complete response rate for lesions on face, scalp and neck was 93% for full-spectrum visible light, 96% for the combination of full-spectrum visible light and filtered light, 91% for different wave bands of filtered visible light, and 100% for the combination of long wave UVA and full-spectrum visible light, respectively. The complete response rate for lesions on forearms and hands was 51% for full-spectrum visible light and 33% for the combination of full-spectrum visible light and filtered light. The greater response rate for SK on the face, scalp, and neck was associated with a higher surface fluorescence and immediate response rate after ALA photosensitization at these sites (chi 2; p = 0.0001). However, due to the treatment protocol the mean light dose applied to lesions on the face, scalp and neck (50 J cm-2) was substantially higher than that for lesions on forearms and hands (35 J cm-2). In the long term follow-up of SK on face scalp and neck, the projected disease-free rate at 36 months after therapy was 71% for lesions treated with full-spectrum visible light versus 23% for lesions treated with different wave bands of filtered light (Log rank-Mantel Cox; p = 0.0001). These results indicate that treatment with full-spectrum visible light at higher light doses may be the most effective and promising form of light exposure in ALA-PDT of SK.

The actinic keratosis. A perspective and update

BACKGROUND

Actinic keratosis (AK) is a common sun-induced precancerous neoplasm confined to the epidermis. It is the initial manifestation of a continuum of clinical and histologic abnormalities that progresses to invasive squamous cell carcinoma (SCC), a disorder that accounts for thousands of preventable deaths in America each year.

OBJECTIVE

The purpose of this work is to describe the actinic keratosis.

METHODS

This effort was performed by a literature review and analysis.

RESULTS

Like SCCs, the vast majority of AKs are asymptomatic. Although some actinic keratoses may become clinically inapparent, possibly either due to immune rejection or simply having their external surface unknowingly scraped off, an untreated AK represents a potentially curable fatal cancer.

CONCLUSIONS

Each AK should be treated before it progresses to invasive squamous cell carcinoma. Destructive modalities such as cryosurgery using liquid nitrogen and electrodesiccation and curettage are the mainstays of therapy. Each case must be individualized.

LEARNING OBJECTIVES

After studying this article, participant should be able to: 1. Understand the concept of an actinic keratosis. 2. Learn how to recognize its clinical manifestations. 3. Be aware of the danger it poses as an easily curable papulonodule that may become a fatal cancer.

Long-term efficacy and safety of Jessner's solution and 35% trichloroacetic acid vs 5% fluorouracil in the treatment of widespread facial actinic keratoses

BACKGROUND

Few studies have examined the long-term efficacy of fluorouracil (FU) or chemical peels for the treatment of actinic keratoses (AK). Our earlier work examined the efficacy and safety of a medium-depth chemical peel compared with the standard regimen of topical FU in the treatment of widespread facial AK through 12 months.

OBJECTIVES

To determine long-term efficacy of both treatments by extending our observations through 32 months.

METHODS

Fifteen patients with severe facial actinic damage were treated on the left side with a single application of Jessner's solution and 35% trichloroacetic acid and on the right side with twice daily applications of 5% FU cream for 3 weeks. Parameters evaluated at 1, 6, 12, and 32 months included counts of visible AK, random skin biopsies from both treatment areas, development of intercurrent neoplasms, and surveys assessing sun exposure.

RESULTS

Eight patients were available for reevaluation at 32 months. Both treatment sides showed a reduction in mean number of AK at 12 months followed by an increase in mean AK number between 12 and 32 months. Improvements in biopsies of clinically actinically damaged skin were seen in keratinocytic atypia, hyperkeratosis, parakeratosis, and inflammation at all treatment times during the study with both treatments. Three squamous cell carcinomas developed in the patients after initial treatment; one developed on the side treated with the peel, and two developed on the side treated with fluorouracil. Surveys failed to demonstrate an association between sun exposure and clinical response.

CONCLUSION

Based on these findings, patient with widespread actinic keratoses treated with medium-depth chemical peel or with 5% FU should be reevaluated yearly or every 1.5 years for reappearance of AK and retreatment.

Dermabrasion for prophylaxis and treatment of actinic keratoses

BACKGROUND

After dermabrasion, patients with actinic keratoses remain free of new lesions for many years. This clinical effect has been alluded to for 40 years in the dermatologic literature. However, there has been no consensus on how long this clinical benefit actually lasts.

OBJECTIVE

To ascertain the longevity of the beneficial effect of dermabrasion, clinical records of patients who underwent this procedure for treatment of actinic keratosis were reviewed.

METHOD

Retrospective review.

RESULTS

A total of 23 such patients with at least 2 years good clinical follow-up were identified. Their ages ranged from 33 to 76 years. One year after dermabrasion, 96% remained free of new actinic keratoses. The benefits of dermabrasion gradually diminished with 83% clear at 2 years, 79% at 3 years, 64% at 4 years, and 54% at 5 years. The average time after dermabrasion before the appearance of one actinic keratoses was 4 years (median, 4.5 years). Dermabrasion, however did not prevent the appearance of basal cell carcinomas in the perinasal area.

CONCLUSION

Dermabrasion provides long-term effective prophylaxis against actinic keratoses and presumably squamous cell carcinomas. The benefits last for an average of 4 years before even one new actinic keratosis reappears. Cryosurgery, 5-Fluorouracil, and chemical peels result in much shorter prophylaxis. Dermabrasion is the most effective modality for prevention of new actinic keratoses.

Short-term intensive 5-fluorouracil treatment of actinic keratoses

BACKGROUND

5-Fluorouracil therapy is an efficacious treatment for actinic keratoses. However, the prolonged courses of therapy traditionally prescribed are unpleasant, uncomfortable, and can lead to noncompliance.

OBJECTIVE

To treat patients with shorter courses of 5-fluorouracil therapy.

METHODS

5-Fluorouracil cream or solution is applied four times daily for periods varying between 7 and 21 days, depending upon the body location.

RESULTS

The same brisk inflammatory reaction and clearing of the majority of actinic keratoses associated with longer courses of application twice daily is realized.

CONCLUSION

5-Fluorouracil can be applied four times daily for shorter periods of time, resulting in clearing of actinic keratoses and patient acceptability.

Current dermatologic therapy

This article reviews therapeutic advances reported in the English-language literature during 1991. Readers should review the original article in full before attempting any experimental or controversial therapy.