Topical immunomodulation under systemic immunosuppression: results of a multicentre, randomized, placebo-controlled safety and efficacy study of imiquimod 5% cream for the treatment of actinic keratoses in kidney, heart, and liver transplant patients

Anal cancer: current standards in care and recent changes in practice

Answer questions and earn CME/CNE The management of squamous cell carcinomas of the anal canal has evolved from surgery as first-line treatment to curative chemoradiation, with surgery reserved for salvage. Significant progress has been made in understanding how to most effectively deliver chemotherapy and reduce toxicity through advancements in radiation delivery. The purpose of this article is to review the multimodality approach to the diagnosis and management of anal cancer based on a review of the published data and in light of available guidelines.

HPV Carcinomas in Immunocompromised Patients

Human papillomavirus (HPV) infection is the most common sexually transmitted disease worldwide and can result in pre-malignancies or overt malignancies of the skin and mucosal surfaces. HPV-related illnesses are an important personal and public health problem causing physical, mental, sexual and financial detriments. Moreover, this set of malignancies severely affects the immunosuppressed population, particularly HIV-positive patients and organ-transplant recipients. There is growing incidence of HPV-associated anogenital malignancies as well as a decrease in the average age of affected patients, likely related to the rising number of high-risk individuals. Squamous cell carcinoma is the most common type of HPV-related malignancy. Current treatment options for HPV infection and subsequent disease manifestations include imiquimod, retinoids, intralesional bleomycin, and cidofovir; however, primary prevention with HPV vaccination remains the most effective strategy. This review will discuss anogenital lesions in immunocompromised patients, cutaneous warts at nongenital sites, the association of HPV with skin cancer in immunocompromised patients, warts and carcinomas in organ-transplant patients, HIV-positive patients with HPV infections, and the management of cutaneous disease in the immunocompromised patient.

Toll receptor agonist therapy of skin cancer and cutaneous T-cell lymphoma

PURPOSE OF REVIEW

The use of agents which exhibit the ability to potently activate the innate immune response has gained significant interest as therapeutics to treat cancer. We will review the history and the current applications of these agents to treat skin cancer and cutaneous T-cell lymphoma.

RECENT FINDINGS

Particular attention has been focused upon Toll-like receptor (TLR) agonists, including imidazoquinolines, which can trigger TLR 7 and TLR 8, and cytosine-phosphate-guanine (CpG) oligodeoxynucleotides, which activate TLR 9-expressing cells. Imiquimod, a TLR 7 agonist, has been found to be efficacious for basal cell and squamous cell cancers, as well as cutaneous T-cell lymphoma and lentigo maligna melanoma. CpGs have demonstrated efficacy for cutaneous T-cell lymphoma. Additional more potent compounds, including resiquimod, are presently in clinical trials for several types of skin cancers.

SUMMARY

TLR agonists that can activate the innate immune response have been used to treat a variety of skin cancers including basal cell cancer, squamous cell cancer, lentigo maligna melanoma and cutaneous T-cell lymphoma. Significant clinical efficacy has been observed for all of these conditions. It is anticipated that additional members of the TLR agonist family will be available in the clinic for the future treatment of skin cancers as well as other malignancies.

Optimal management of skin cancer in immunosuppressed patients

Skin cancer is the most common malignancy in humans with basal cell carcinoma representing the majority of cases in the general population. The prevalence of skin cancer is increased amongst immunosuppressed patients such as those with lymphoproliferative disorders including non-Hodgkin lymphoma and chronic lymphocytic leukemia or those with iatrogenic immunosuppression following organ transplantation. In addition, these patients experience greater morbidity and mortality associated with skin cancers. The most common skin cancer in immunosuppressed patients is squamous cell carcinoma, which often presents with more aggressive features and has a greater rate of metastasis. This article reviews the risk factors, etiology, clinical presentation, and prevalence of skin cancer amongst immunosuppressed patients, including organ transplant, lymphoproliferative disorders, autoimmune disorders, and human immunodeficiency virus. We also provide a comprehensive review of treatment guidelines for immunosuppressed patients with cutaneous malignancy. Surgical therapy is the cornerstone of treatment; however, we also discuss pharmacologic treatment options, lifestyle modifications, and revision of immunosuppressive regimens.

The natural history of actinic keratosis: a systematic review

Knowledge about the development of untreated actinic keratosis (AK) and risk of progression into squamous cell carcinoma (SCC) is important. Therefore, we set out to synthesize primary data on the natural history of AK. We carried out a systematic literature search (Medline, Medline in Process, Embase, Cochrane) of studies on the natural course of AK, regarding (i) progression and regression rates per lesion-year, (ii) changes in total lesion counts over time, and (iii) spontaneous field regression and recurrence rates, taking into account studies on participants without immunosuppression and history of skin cancer, immunosuppressed patients and participants with a history of skin cancer and sunscreen use. Twenty-four eligible studies were identified providing data on at least one of the outcomes. Progression rates of AK to SCC ranged from 0% to 0·075% per lesion-year, with a risk of up to 0·53% per lesion in patients with prior history of nonmelanoma skin cancer. Rates of regression of single lesions ranged between 15% and 63% after 1 year. The data available on recurrence rates of single lesions 1 year after regression indicate a recurrence rate of 15-53%. Data on the relative change of total AK count over time are heterogeneous, and range from -53% to +99·1%. Spontaneous complete field regression rates range from 0% to 21%, with recurrences in 57%. In general, the available data are limited. Important methodological limitations apply. Currently, no reliable estimates concerning the frequency of AK developing into invasive carcinoma can be given, and further studies are needed.

Cutaneous field cancerization: clinical, histopathological and therapeutic aspects

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

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

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

Understanding efficacy end-points in studies of field-directed therapy for actinic keratosis

BACKGROUND

The rates of short-term clearance of actinic keratoses appear to be comparable in clinical trials of topical treatments used in field therapy, but direct comparisons of efficacy results can be problematic. Trials use different efficacy end points, have different study designs, involve different anatomic sites, and enroll different patient populations. In addition, because adherence in real-world clinical practice differs from that observed in clinical trials, conclusions drawn from efficacy outcomes can be misleading. The objective of this review was to examine the efficacy end points used in studies of topical therapy for actinic keratosis, address other factors influencing efficacy outcomes in these studies, and discuss the possible influence of nonadherence on effectiveness.

METHODS

Review of the available literature on topical therapy for actinic keratosis.

RESULTS

The end points used to determine efficacy of therapies for actinic keratosis include a disparate group of outcomes, which can often make comparison between studies impossible.

CONCLUSIONS

Efficacy end points of clinical studies designed to assess the treatment of actinic keratosis should be standardized to facilitate between-trial comparisons, and studies should focus on the end points that are most clinically relevant.

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.

The efficacy and safety of topical 5% 5-fluorouracil in renal transplant recipients for the treatment of actinic keratoses

Actinic keratoses (AK) occur more commonly and behave more aggressively in renal transplant recipients (RTR). Topical 5% 5-fluorouracil (5-FU) cream is a commonly used agent whose efficacy and safety have never been exclusively studied in the RTR population before. Eight RTR were enrolled and 5% 5-FU cream applied to AK lesions on their face twice daily for 3 weeks. They were reviewed at 2 and 8 weeks, and 12 months post-commencement of treatment. Their AK were counted and their cumulative surface areas measured. Patients completed surveys monitoring adverse effects and tolerability. Complete (100%) and partial clearance (≥ 75%) rates were measured, as well as mean percentages of the reduction in AK surface area. Patients had complete clearance rates of 63 and 0% at 8 weeks and 12 months, respectively. All (100%) patients had partial clearance at week 8 and 71% had partial clearance at 12 months. Patients had on average 15 AK at week 0 and 1 and 3 at 8 weeks and 12 months, respectively. The mean AK clearance rate was 98% at week 8 and 79% at 12 months. Common side-effects were erythema, itch and flaking or scaling, mostly mild in severity. 5-FU appears to be an efficacious and safe treatment for AK in RTR.

[New developments in photodynamic therapy]

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

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.

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

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

Management of non-melanoma skin cancer in immunocompromised solid organ transplant recipients

The management of non-melanoma skin cancers (NMSCs) in solid organ transplant recipients (OTRs) presents a variety of clinical challenges for physicians. OTRs are at a 65-fold increased risk for developing cutaneous squamous cell carcinomas (SCC), the most common NMSC that develops after transplantation. Risk factors contributing to the development of NMSCs in OTRs include a past medical history of any previous skin cancer, a personal history of significant sun exposure and a fair skin complexion or phototype. Further, greater immunosuppressive medication levels lead to an increased risk of NMSCs. Among immunosuppressants, specific older agents such as azathioprine and cyclosporine may increase the risk of developing NMSCs in contrast to newer agents such as sirolimus. Early skin biopsy and treatment of premalignant and malignant lesions are essential for treating these patients successfully. In this regard, the concept of field cancerization has been instructive in broadening treatments to include entire affected areas rather than individual lesions given that the areas with significant ultraviolet irradiation will continue to develop numerous individual precancerous and cancerous lesions. Field therapy with photodynamic therapy or topical 5-fluorouracil, imiquimod or diclofenac is often used in OTRs according to individual patient tolerability. Prompt excision or Mohs micrographic surgery is the standard of care of primary, uncomplicated squamous cell and basal cell carcinomas. For patients with in-transit or metastatic squamous cell carcinomas, adjuvant radiation, chemotherapy, and staging by sentinel lymph node dissection may be employed. For patients who develop numerous SCC per year, chemoprophylaxis can be effective in limiting the burden of disease. In consultation with the multidisciplinary transplant team, the immunosuppressive regimen can be revised to lower overall immunosuppression or altered to include newer drugs that have decreased oncogenic potential in OTRs. The greatest impact may be made by the prevention of NMSCs through simple, but rigorous, patient education on the benefits of UV protection, periodic self-skin examinations, and regular follow-ups. Accordingly, vitamin D and calcium supplementation should also be incorporated in transplant recipients. Management of OTRs requires patient education, frequent motivation for vigilance, regular follow-up, and interdisciplinary collaboration between transplant surgeons, nephrologists, hepatologists, cardiologists, transplant nurses, dermatologists, oncologists, pharmacists, and other relevant physicians ideally orchestrated by the essential transplant coordinators.

Interventions for actinic keratoses

BACKGROUND

Actinic keratoses are a skin disease caused by long-term sun exposure, and their lesions have the potential to develop into squamous cell carcinoma. Treatments for actinic keratoses are sought for cosmetic reasons, for the relief of associated symptoms, or for the prevention of skin cancer development. Detectable lesions are often associated with alteration of the surrounding skin (field) where subclinical lesions might be present. The interventions available for the treatment of actinic keratoses include individual lesion-based (e.g. cryotherapy) or field-directed (e.g. topical) treatments. These might vary in terms of efficacy, safety, and cosmetic outcomes.

OBJECTIVES

To assess the effects of topical, oral, mechanical, and chemical interventions for actinic keratosis.

SEARCH METHODS

We searched the following databases up to March 2011: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library, MEDLINE (from 2005), EMBASE (from 2010), and LILACS (from 1982). We also searched trials registers, conference proceedings, and grey literature sources.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing the treatment of actinic keratoses with either placebo, vehicle, or another active therapy.

DATA COLLECTION AND ANALYSIS

At least two authors independently abstracted data, which included adverse events, and assessed the quality of evidence. We performed meta-analysis to calculate a weighted treatment effect across trials, and we expressed the results as risk ratios (RR) and 95% confidence intervals (CI) for dichotomous outcomes (e.g. participant complete clearance rates), and mean difference (MD) and 95% CI for continuous outcomes (e.g. mean reduction in lesion counts).

MAIN RESULTS

We included 83 RCTs in this review, with a total of 10,036 participants. The RCTs covered 18 topical treatments, 1 oral treatment, 2 mechanical interventions, and 3 chemical interventions, including photodynamic therapy (PDT). Most of the studies lacked descriptions of some methodological details, such as the generation of the randomisation sequence or allocation concealment, and half of the studies had a high risk of reporting bias. Study comparison was difficult because of the multiple parameters used to report efficacy and safety outcomes, as well as statistical limitations. We found no data on the possible reduction of squamous cell carcinoma.The primary outcome 'participant complete clearance' significantly favoured four field-directed treatments compared to vehicle or placebo: 3% diclofenac in 2.5% hyaluronic acid (RR 2.46, 95% CI 1.66 to 3.66; 3 studies with 420 participants), 0.5% 5-fluorouracil (RR 8.86, 95% CI: 3.67 to 21.44; 3 studies with 522 participants), 5% imiquimod (RR 7.70, 95% CI 4.63 to 12.79; 9 studies with1871 participants), and 0.025% to 0.05% ingenol mebutate (RR 4.50, 95% CI 2.61 to 7.74; 2 studies with 456 participants).It also significantly favoured the treatment of individual lesions with photodynamic therapy (PDT) compared to placebo-PDT with the following photosensitisers: aminolevulinic acid (ALA) (blue light: RR 6.22, 95% CI 2.88 to 13.43; 1 study with 243 participants, aminolevulinic acid (ALA) (red light: RR 5.94, 95% CI 3.35 to 10.54; 3 studies with 422 participants), and methyl aminolevulinate (MAL) (red light: RR 4.46, 95% CI 3.17 to 6.28; 5 studies with 482 participants). ALA-PDT was also significantly favoured compared to cryotherapy (RR 1.31, 95% CI 1.05 to 1.64).The corresponding comparative risks in terms of number of participants completely cleared per 1000 were as follows: 313 with 3% diclofenac compared to 127 with 2.5% hyaluronic acid; 136 with 0.5% 5-fluorouracil compared to 15 with placebo; 371 with 5% imiquimod compared to 48 with placebo; 331 with ingenol mebutate compared to 73 with vehicle; 527 to 656 with ALA/MAL-PDT treatment compared to 89 to 147 for placebo-PDT; and 580 with ALA-PDT compared to 443 with cryotherapy.5% 5-fluorouracil efficacy was not compared to placebo, but it was comparable to 5% imiquimod (RR 1.85, 95% Cl 0.41 to 8.33).A significant number of participants withdrew because of adverse events with 144 participants affected out of 1000 taking 3% diclofenac in 2.5% hyaluronic acid, compared to 40 participants affected out of 1000 taking 2.5% hyaluronic acid alone, and 56 participants affected out of 1000 taking 5% imiquimod compared to 21 participants affected out of 1000 taking placebo.Based on investigator and participant evaluation, imiquimod treatment and photodynamic therapy resulted in better cosmetic outcomes than cryotherapy and 5-fluorouracil.

AUTHORS' CONCLUSIONS

For individual lesions, photodynamic therapy appears more effective and has a better cosmetic outcome than cryotherapy. For field-directed treatments, diclofenac, 5-fluorouracil, imiquimod, and ingenol mebutate had similar efficacy, but their associated adverse events and cosmetic outcomes are different. More direct comparisons between these treatments are needed to determine the best therapeutic approach.

Human papillomavirus-related genital disease in the immunocompromised host: Part II

Human papillomavirus is responsible for common condyloma acuminata and a number of premalignant and malignant anogenital lesions. The immunocompromised population is at particular risk because of a higher incidence of malignant transformation. Lesions in this population may prove refractory to standard treatment. This is part II of a two-part review that will discuss the treatment of condyloma acuminata and vaginal, vulvar, penile, and anal intraepithelial neoplasias. This article will provide an updated review of available treatments, with a focus on recent advances and the challenges faced in successfully treating human papillomavirus lesions in the immunocompromised host.

Nitric oxide-producing myeloid-derived suppressor cells inhibit vascular E-selectin expression in human squamous cell carcinomas

Squamous cell carcinomas (SCC) are sun-induced skin cancers that are particularly numerous and aggressive in immunosuppressed individuals. SCC evade immune detection at least in part by down-regulating E-selectin on tumor vessels, thereby restricting entry of skin homing T cells into tumors. We find that nitric oxide potently suppresses E-selectin expression on human endothelial cells and that SCC are infiltrated by nitric oxide-producing iNOS⁺ CD11b⁺ CD33⁺ CD11c⁻ HLA-DR⁻ myeloid-derived suppressor cells (MDSC). MDSC from SCC produced NO, TGFβ and arginase and inhibited endothelial E-selectin expression in vitro. MDSC from SCC expressed the chemokine receptor CCR2 and tumors expressed the CCR2 ligand HBD3, suggesting CCR2-HBD3 interactions may contribute to MDSC recruitment to SCC. Treatment of SCC in vitro with the iNOS inhibitor L-NNA induced E-selectin expression at levels comparable to imiquimod-treated SCC undergoing immunologic destruction. Our results suggest that local production of NO in SCC may impair vascular E-selectin expression. We show that MDSC are critical producers of NO in SCC and that NO inhibition restores vascular E-selectin expression, potentially enhancing T cell recruitment. iNOS inhibitors and other therapies that reduce NO production may therefore be effective in the treatment of SCC and their premalignant precursor lesions actinic keratoses.

Therapeutic options to decrease actinic keratosis and squamous cell carcinoma incidence and progression in solid organ transplant recipients: a practical approach

BACKGROUND

Solid organ transplant recipients (SOTRs) have a 50 to 250 times greater risk of squamous cell carcinoma (SCC) than the general population and experience higher rates of invasive and metastatic disease. These greater risks are a product of the tumorigenic effects of their immunosuppressive medications. As the number of transplantations and the life expectancy of SOTRs increase, SCCs are becoming a major source of morbidity and mortality.

OBJECTIVE

To present a practical approach for busy practicing clinicians to the care of SOTRs who are developing SCCs. Topics include assessment and treatment of new and neglected SOTRs; the dermatologist's role with the transplantation team; and practical considerations in the choice of topical agents, systemic agents, and immunosuppressive therapy manipulation.

METHODS AND MATERIALS

An extensive literature search of the understanding of SCC pathophysiology and treatment in SOTRs was conducted.

RESULTS

Presented here is a logical, concise guide to the care of SOTRs who are developing actinic keratoses and SCCs.

CONCLUSION

Proper assessment of patients, understanding therapeutic alternatives and their application, and early institution of preventative and adjuvant therapies can help to decrease skin cancer-related morbidity and mortality in SOTRs.

Results of an investigator-initiated single-blind split-face comparison of photodynamic therapy and 5% imiquimod cream for the treatment of actinic keratoses

BACKGROUND

Topical photodynamic therapy (PDT) with aminolevulinic acid (ALA) and 5% imiquimod cream are effective therapies for the treatment of actinic keratoses (AKs), but no split-face studies directly comparing these treatment options are available in the literature.

OBJECTIVE

To compare the efficacy and tolerability of ALA-PDT and imiquimod 5% cream for the treatment of AKs.

RESULTS

Sixty-one patients were enrolled from the Salt Lake City Veterans Affairs Hospital; 51 completed the study and were included in the analysis. All patients were randomized to receive half of a sachet of imiquimod 5% cream twice weekly on half of their face and two sessions of PDT with 20% solution of ALA applied for 1 hour to the other side of the face. The 75% AK clearance rate was 34.6% for ALA-PDT and 25% for imiquimod 5% cream (p = .30). The mean reduction in AK count was 59.2% for ALA-PDT and 41.4% for imiquimod 5% cream (p = .002). Dermatology Life Quality Index (DLQI) scores were assessed for each treatment modality at week 4 and were 1.95 and 1.38, respectively (p = .20).

LIMITATIONS

The sample size was small, and patients applied a small amount of imiquimod 5% cream (half a sachet) to a large surface area.

CONCLUSION

There was no statistically significant difference in treatment response when the 100% or 75% clearance rate cutoff was used, but our secondary outcome suggests that two sessions of ALA-PDT is superior to imiquimod 5% cream for the treatment of AKs. There was no statistically significant difference in effect on quality of life as assessed using the DLQI.

Topical treatment of cutaneous Kaposi sarcoma with imiquimod 5% in renal-transplant recipients: a clinicopathological observation

Kaposi sarcoma (KS) is a vascular neoplasm pathogenetically linked to human herpesvirus 8. Transplant recipients, in particular renal-transplant recipients (RTRs) are at higher risk for post-transplant (P)-KS which affects 0.2-11% of RTRs. The course of P-KS is influenced by the post-transplantation immunosuppressive treatment. Reduction of immunosuppressive drugs can result in tumour regression, and is the treatment of choice for P-KS, but is associated with the risk for transplant rejection. Imiquimod is a topically applied immunomodulator without relevant systemic absorption, and may thus represent a promising treatment for cutaneous KS in RTRs. The aim of this study was to investigate the clinical and histological effects of imiquimod in two RTRs with cutaneous KS. Imiquimod resulted in complete clinical and histologically proven remission in one patient, but in the second patient, although there was clinical remission, histological persistence of KS was found. Imiquimod may represent an effective treatment for RTRs with cutaneous P-KS. However, clinical remission does not necessarily indicate complete tumour regression, as shown in one of our patients, who had a persisting tumour, as shown by biopsy examination. Thus, histological confirmation is crucial to confirm complete response.

Non-melanoma skin cancers in elderly patients

Non-melanoma skin cancers are a common reality worldwide. The principal cause that determines the occurrence of these diseases is the exposition of the sun, which principally causes an alteration in the immune system. Therefore, it is possible that other forms of innate or acquired alterations of the immune system could favor the occurrence of non-melanoma skin cancers. For example, several studies have demonstrated that immunosenescence creates an immunosuppressive state that encourages the development of malignances, and new discoveries have noted the importance of T cells and in particular of T regulatory cells (Treg) and T receptor CD28 in this mechanism. Similar results are obtained analyzing the effect of immunosuppressive drugs. The importance of the immune system and its alteration in the genesis of non-melanoma skin cancers is fundamental for the creation of a new therapeutic and less invasive approach.

Imiquimod 3.75% cream (Zyclara) for the treatment of actinic keratoses

INTRODUCTION

actinic keratosis is a premalignant disease with a high incidence and is a strong predictor for the development of squamous cell carcinoma. Various treatment options have been established over recent years, including topical treatment with imiquimod, 5-fluorouracil, diclofenac or photodynamic therapy, cryotherapy and surgical procedures.

AREAS COVERED

this review covers basic and clinical experiences with imiquimod 3.75% for topical treatment of actinic keratosis of the face and balding scalp and its comparators with special focus on imiquimod 5%. It also covers pharmacology of imiquimod 3.5% and its contribution to the current treatment options of actinic keratoses.

EXPERT OPINION

imiquimod 3.75% is an interesting, safe and well-tolerated treatment option for actinic keratoses of the face or balding scalp especially in respect of compliance, as it is indicated for daily use for a shorter time period (2 times, 2-week cycles) and approved for use on larger areas compared with imiquimod 5%. Data from current trials indicate lower efficacy compared with imiquimod 5% cream when applied three times a week for 16 weeks or for two 4-week cycles with a 4-week no-treatment interval, but indicate similar efficacy when compared with a twice-weekly schedule for 16 weeks. An additive effect was observed when combining cryosurgery followed by imiquimod 3.75%.

Safety, efficacy, and patient acceptability of imiquimod for topical treatment of actinic keratoses

Imiquimod, an immune-modulating imidazoquinoline compound, has been approved in topical formulation for the treatment of actinic keratoses, superficial basal cell carcinomas, and external genital warts. Its use in the treatment of field cancerization, in particular, has been rapidly evolving. With the recent approval of a new drug application for a new concentration, as well as generic formulations, this drug has emerged at the forefront of treatment for actinic keratoses, with improved dosage scheduling and more patients having access to generic options. In the nearly 15 years since its original approval by the Food and Drug Administration for the treatment of actinic keratoses in 1997, topical imiquimod has been reviewed and studied extensively, not only for its safety and efficacy, but also for its tolerability in patients. This paper provides an indepth review of the literature, and provides clinical evidence for its inclusion in the arsenal of treatment options for patients with actinic keratoses.

Malignancies following lung transplantation

Malignancy is an important complication of thoracic organ transplantation and is associated with significant morbidity and mortality. Lung transplant recipients are at greater risk for cancer than immunocompetent persons, with cancer-specific incidence rates up to 60-fold higher than the general population. The increased risk for cancer is attributed to neoplastic properties of immunosuppressive medications, oncogenic viruses, and cancer-specific risk factors. This article addresses the epidemiology, presentation, and treatment of the most common malignancies after lung transplantation, including skin cancer, posttransplant lymphoproliferative disorder, and bronchogenic carcinoma.

Efforts to counteract locally the effects of systemic immunosupression: a review on the use of imiquimod, a topical immunostimulator in organ transplant recipients

The potent systemic immunosuppression therapy necessary to sustain a life-saving solid organ transplant is associated with an increased incidence of various infections including human papillomavirus infection and skin cancers in organ transplant recipients. Imiquimod, a topical agent that functions through local induction of a specific anti-viral or anti-tumor immune response, appears to be a promising therapeutic option that could potentially counteract in situ the effects of systemic immunosupression in this vulnerable group. Up-to-date studies using this local immune-response modifier in transplanted patients have yielded reassuring and encouraging results regarding its safety and efficacy in this population. However, in order to establish the use of imiquimod as a standard treatment option for organ transplant recipients, additional research and clinical trials are required.

[Skin cancer in organ transplant patients. Epidemiology and management]

Transplant recipients are at significantly increased risk of cancer development as a long term complication. Skin cancer is the most common cancer, representing 40-50% of post transplant malignancies. In the first 10 years post transplantation, some 15%-40% of patients develop skin cancer, primarily squamous cell carcinoma and basal cell carcinoma, but also melanoma, Merkel cell carcinoma and virally-induced Kaposi sarcoma. The management of skin cancer includes secondary prophylaxis and address attention to areas of widespread actinic damage, usually with topical agents. In high risk skin cancer or metastatic disease a substantial reduction in immunosuppression to switching to mTOR inhibitors appears to substantially improve the prognosis. The management of the individual tumor types is discussed; in general it follows the current guidelines.

[Primary and secondary prevention of skin cancer in organ transplant recipients]

Skin cancer constitutes the most frequently reported post-transplant malignancy in solid organ transplant recipients (OTR) worldwide. Whereas the risk for malignant melanoma is only moderately increased, non-melanoma skin cancers (NMSC) seem to thrive on chronic immunosuppression and account for up to 95% of post-transplant cutaneous malignancies. Compared to the general population cutaneous squamous cell carcinoma (SCC) and actinic keratoses (AK) characteristically show even higher incidences than basal cell carcinoma (BCC) and act as an indicator for the development of multiple primary cutaneous neoplasias and locally recurrent cancers (field cancerization). Early diagnosis and therapy of pre-malignant cutaneous lesions is crucial for the secondary prophylaxis of further invasive and highly aggressive skin cancers. High quality interdisciplinary care and prophylactic modalities, including consistent and sufficient UV protection, topical immunmodulatory therapies of UV-damaged skin areas, retinoid chemoprevention as well as tapering immunosuppressive treatment or the selection of immunosuppressants with proposed antiangiogenic properties like mTor-inhibitors may help to reduce the multiplicity of subsequent primary skin cancers in high-risk patients. Apart from the continuous need for educational intervention of OTR in the primary prophylaxis of post-transplant skin cancers, dermatologic care occupies a central position within the field of transplantation medicine in terms of pre- and post-transplantation dermatologic evaluation and therapy as well as the implication of timely and effective secondary preventive approaches in the management of this high-risk patient population.

Nonsurgical innovations in the treatment of nonmelanoma skin cancer

Basal cell carcinoma and squamous cell carcinoma are the most frequent types of cancer in the United States and represent 75 percent and 20 percent, respectively, of all nonmelanoma skin cancers. Since ultraviolet radiation is implicated in their development, photoprotection is fundamental in their prevention. Additional preventive measures include identifying high-risk individuals for early detection along with using agents, such as retinoids, that are effective in decreasing the risk of premalignant cells further developing into carcinomas. Newer agents achieving this goal include perillyl alcohol, T4 endonuclease 5, DL-alpha-tocopherol, and alpha-difluoromethylornithine. Procedural modalities are currently the standard of treatment, but recent evidence has consistently shown that newer (nonsurgical) therapies, such as interferon, imiquimod, retinoids, and 5-fluorouracil, can be used effectively either as monotherapies or as adjuvants to those surgical modalities for the treatment of superficial nonmelanoma skin cancers and premalignant lesions. These newer therapies have achieved significant reductions in morbidity and mortality. Procedural modalities that have been evolving into important tools for the treatment of actinic keratosis and nonmelanoma skin cancers include photodynamic therapy and lasers. Nonsurgical therapies currently proving to be effective in clinical trials include ingenol mebutate and cyclooxygenase-2 inhibitors. Agents that are showing promising results in early phases of clinical trials include betulinic acid; hedgehog signaling pathway inhibitors, such as cyclopamine and GDC-0449; alpha-melanocyte-stimulating hormone analogs, such as afamelanotide; epidermal growth factor receptor inhibitors, such as gefitinib and erlotinib; anti-epidermal growth factor receptor monoclonal antibodies, such as cetuximab and panitumumab; and the 5-fluorouracil prodrug capecitabine.

Organ transplantation and skin cancer: basic problems and new perspectives

Solid organ transplant and subsequent graft survival have increased worldwide, while immunosuppression has prevented rejection with increasing success. Side effects of cutaneous infection and neoplasm, however, affect the majority of solid organ transplant recipients (OTRs). Squamous cell carcinoma of the skin (SCC) is the most common neoplasm overall following organ transplant with a risk that is 60-100 times greater than for the immunocompetent population. This review focuses on questions of ongoing debate about SCC formation in OTRs such as viral carcinogenesis, systemic photoprotection, photosensitization by drugs, the impact of immunosuppressive drugs and inflammation as a driver of carcinogenesis.

Reduction in the incidence of squamous cell carcinoma in solid organ transplant recipients treated with cyclic photodynamic therapy

BACKGROUND AND OBJECTIVES

Squamous cell carcinomas (SCCs) produce significant morbidity in solid organ transplant recipients (SOTRs), particularly in patients who develop multiple tumors. Topical photodynamic therapy (PDT) has been shown to decrease the number of keratotic lesions in SOTRs, but the duration of the beneficial effect is limited. The aim of this study was to evaluate the potential benefit of cyclic PDT in the prevention of new SCCs in SOTRs.

METHODS

Twelve high-risk SOTRs received cyclic PDT treatments at 4- to 8-week intervals for 2 years. The development of new SCCs (invasive and in situ) performed 12 and 24 months after the start of cyclic PDT were compared with the number of SCCs developed during the year before initiation of cyclic PDT.

RESULTS

The median reduction in the 12- and 24-month post-treatment counts from the 1-month pretreatment counts was 79.0% (73.3-81.8%) and 95.0% (87.5-100.0%), respectively. Treatments were well tolerated.

CONCLUSION

Cyclic PDT with 5-aminolevulinic acid may reduce the incidence of SCC in SOTRs. Additional studies with larger numbers of patients and optimized protocols are necessary to further explore the potential benefits of cyclic PDT in the prevention of skin cancer in this high-risk patient population.

Imiquimod enhances IFN-gamma production and effector function of T cells infiltrating human squamous cell carcinomas of the skin

Squamous cell carcinomas (SCCs) are sun-induced skin cancers that are particularly numerous and aggressive in patients taking T-cell immunosuppressant medications. Imiquimod is a topical immune response modifier and Toll-like receptor 7 (TLR7) agonist that induces the immunological destruction of SCC and other skin cancers. TLR7 activation by imiquimod has pleiotropic effects on innate immune cells, but its effects on T cells remain largely uncharacterized. Because tumor destruction and formation of immunological memory are ultimately T-cell-mediated effects, we studied the effects of imiquimod therapy on effector T cells infiltrating human SCC. SCC treated with imiquimod before excision contained dense T-cell infiltrates associated with tumor cell apoptosis and histological evidence of tumor regression. Effector T cells from treated SCC produced more IFN-gamma, granzyme, and perforin and less IL-10 and transforming growth factor-beta (TGF-beta) than T cells from untreated tumors. Treatment of normal human skin with imiquimod induced activation of resident T cells and reduced IL-10 production but had no effect on IFN-gamma, perforin, or granzyme, suggesting that these latter effects arise from the recruitment of distinct populations of T cells into tumors. Thus, imiquimod stimulates tumor destruction by recruiting cutaneous effector T cells from blood and by inhibiting tonic anti-inflammatory signals within the tumor.

Skin cancer in organ transplant recipients--where do we stand today?

Skin cancers are the most frequent malignancies in organ transplant recipients (OTR), with 95% being nonmelanoma skin cancers (NMSC), especially squamous (SCC) and basal cell carcinomas. Most OTR with a first SCC subsequently develop multiple NMSC within 5 years, highlighting the concept of 'field cancerization', and are also at high risk for noncutaneous cancers. In order to reduce the tumor burden in these patients, their management requires an interdisciplinary approach including revision of immunosuppression, new dermatological treatments and adequate education about photoprotection in specialized dermatology clinics for OTR. Whereas surgery remains the gold-standard therapy for NMSC, noninvasive methods have shown promising results to treat superficial keratoses and subclinical lesions on large body areas. Although the threshold of skin cancer necessitating revision of immunosuppression is debated, this measure should be envisaged at the occurrence of the first SCC, or in case of multiple non-SCC NMSC. While the role of immunosuppressants in the occurrence of NMSC is widely recognized, the best immunosuppressive strategies remain to be defined. Presently, randomized prospective studies assess the burden of new skin tumors, as well as graft and patient survival, in patients with one or several NMSC after the introduction of mTOR (mammalian target of rapamycin) inhibitors.

[Skin cancers after organ transplants]

Squamous cell carcinoma and basal cell carcinoma are the most common cancers after transplants, affecting more than half of all patients in the long term. In the 5 years after a first squamous cell carcinoma, 90 to 100% of transplant patients subsequently develop multiple skin carcinomas of various types and at least 20% develop noncutaneous cancers. Management of these patients requires, beyond the usual dermatologic treatments, a revision of their immunosuppression regimen to reduce the tumor risk. New immunosuppressants that inhibit the m-TOR protein (sirolimus and everolimus) appear to offer promising perspectives, and patients treated with these drugs from the time of their transplantation have fewer skin cancers than patients with the standard protocols. On the other hand, the benefit of prescribing them later after the transplant remains to be shown, because of the frequency of intolerance phenomena. Several prospective French multicenter studies are currently assessing the effect of replacing anticalcineurins by sirolimus or everolimus for secondary prevention of skin cancers in renal or cardiac transplant patients who have already developed skin cancer. Primary prevention requires that patients be educated about strict sun protection from the transplant onwards and have a routine annual dermatologic examination enabling early treatment of lesions.

Clinical investigations of Toll-like receptor agonists

BACKGROUND

Toll-like receptors (TLR) represent a family of surface molecules that function as primary sensors of the innate immune system to recognize microbial pathogens. Ligand binding to TLR results in activation of cellular signaling pathways that regulate expression of genes involved in inflammation and immunity.

OBJECTIVE

Use of synthetic TLR ligands (agonists) for treatment and prevention of infectious and neoplastic diseases.

METHODS

Review of literature about clinical investigations of agonists of TLR 4, 7, 8, and 9.

RESULTS/CONCLUSIONS

Imiquimod was the first TLR agonist approved for treatment of anogenital warts, actinic keratosis and superficial basal cell carcinoma in humans. Several other agonists of TLRs 4, 7, 8 and 9 were also shown to be effective for treatment of infections and cancers and, furthermore, were used as adjuvants for vaccination. Based on safety and efficacy of the TLR agonists used to date, applications are likely to increase in the future.

Current awareness: pharmacoepidemiology and drug safety

In order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of pharmacoepidemiology and drug safety. Each bibliography is divided into 20 sections: 1 Reviews; 2 General; 3 Anti‐infective Agents; 4 Cardiovascular System Agents; 5 CNS Depressive Agents; 6 Non‐steroidal Anti‐inflammatory Agents; 7 CNS Agents; 8 Anti‐neoplastic Agents; 9 Haematological Agents; 10 Neuroregulator‐Blocking Agents; 11 Dermatological Agents; 12 Immunosuppressive Agents; 13 Autonomic Agents; 14 Respiratory System Agents; 15 Neuromuscular Agents; 16 Reproductive System Agents; 17 Gastrointestinal System Agents; 18 Anti‐inflammatory Agents ‐ Steroidal; 19 Teratogens/fetal exposure; 20 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.

Current awareness: Pharmacoepidemiology and drug safety

In order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of pharmacoepidemiology and drug safety. Each bibliography is divided into 20 sections: 1 Reviews; 2 General; 3 Anti‐infective Agents; 4 Cardiovascular System Agents; 5 CNS Depressive Agents; 6 Non‐steroidal Anti‐inflammatory Agents; 7 CNS Agents; 8 Anti‐neoplastic Agents; 9 Haematological Agents; 10 Neuroregulator‐Blocking Agents; 11 Dermatological Agents; 12 Immunosuppressive Agents; 13 Autonomic Agents; 14 Respiratory System Agents; 15 Neuromuscular Agents; 16 Reproductive System Agents; 17 Gastrointestinal System Agents; 18 Anti‐inflammatory Agents ‐ Steroidal; 19 Teratogens/fetal exposure; 20 Others. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.