Defining the actinic keratosis field: a literature review and discussion

Despite the chronic and increasingly prevalent nature of actinic keratosis (AK) and existing evidence supporting assessment of the entire cancerization field during clinical management, a standardized definition of the AK field to aid in the understanding and characterization of the disease is lacking. The objective of this review was to present and appraise the available evidence describing the AK cancerization field, with the aim of determining a precise definition of the AK field in terms of its molecular (including genetic and immunological), histological and clinical characteristics. Eight European dermatologists collaborated to conduct a review and expert appraisal of articles detailing the characteristics of the AK field. Articles published in English before August 2016 were identified using PubMed and independently selected for further assessment according to predefined preliminary inclusion and exclusion criteria. In addition, a retrospective audit of patients with AK was performed to define the AK field in clinical terms. A total of 32 review articles and 47 original research articles provided evidence of sun-induced molecular (including genetic and immunological) and histological skin changes in the sun-exposed area affected by AK. However, the available literature was deemed insufficient to inform a clinical definition of the AK field. During the retrospective audit, visible signs of sun damage in 40 patients with AK were assessed. Telangiectasia, atrophy and pigmentation disorders emerged as 'reliable or very reliable' indicators of AK field based on expert opinion, whereas 'sand paper' was deemed a 'moderately reliable' indicator. This literature review has revealed a significant gap of evidence to inform a clinical definition of the AK field. Therefore, the authors instead propose a clinical definition of field cancerization based on the identification of visible signs of sun damage that are reliable indicators of field cancerization based on expert opinion.

The importance of patient-centred care to overcome barriers in the management of actinic keratosis

Visible actinic keratosis (AK) lesions and subclinical (non-visible) sun damage in the field of cancerization are associated with risk of both non-melanoma skin cancer, including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), and, more rarely, melanoma. As the incidences of AK and skin cancer are increasing, effective prevention and treatment of AK is essential to minimize disease burden and improve patient quality of life. Currently, AK lesions are often left untreated and field therapies are underused. Patient-centred care, with a focus on the patient-physician relationship, has proven cost-effective, and improved clinical outcomes and patient satisfaction in a number of therapy areas. Strategies for applying patient-centred care to AK are warranted. Existing barriers to the effective treatment of AK were identified and patient-centric strategies to overcome each barrier were discussed. Barriers to effective AK treatment include poor disease awareness (for both patient and physician), concerns associated with the cosmetic effects of treatment, treatment-related side effects, cost perceptions for lesion-directed vs field-directed therapies, and inadequate adherence, particularly with long treatment duration. Overcoming these barriers will involve patient and physician education that promotes: disease prevention and awareness; the importance of self-examination; an understanding of treatment options; and the importance of adherence to treatment. To maximize its effectiveness, education should be delivered within a patient-centric framework, where the relationship between patient and physician is built on effective communication, empathy and a feeling of partnership. Patient-centric care, including patient education, is key to overcoming the barriers associated with effective AK treatment.

A Novel Actinic Keratosis Field Assessment Scale for Grading Actinic Keratosis Disease Severity

Actinic keratosis (AK) lesions are surrounded by field cancerization (areas of subclinical, non-visible sun damage). Existing AK grading tools rely on AK counts, which are not reproducible. An Actinic Keratosis Field Assessment Scale (AK-FAS) for grading the severity of AK/field was developed. Standardized photographs of patients representing the full range of AK severity were collected. Six investigators independently rated each photograph according to 3 criteria: AK area (total skin area affected by AK lesions), hyperkeratosis and sun damage. Inter-rater reproducibility was good for all 3 criteria. Validation of the AK-FAS showed good reproducibility for AK area and hyperkeratosis, even for dermatologists untrained on use of the scale. In conclusion, the AK-FAS is objective, easy to use and implement, and reproducible. It incorporates assessment of the entire field affected by AK instead of relying on lesion counts. Use of the AK-FAS may standardize AK diagnosis, making it relevant to routine clinical practice.

Acantholytic dermatosis of the vagina: the diagnostic challenge of acantholytic disease in the genital region

We report the case of a 24-year-old woman with an 8-month history of deep pelvic pain and postcoital bleeding. Examination revealed desquamation of the vaginal epithelium with tender fissured plaques in the vagina, initially thought to be vaginal intraepithelial neoplasia. Histology showed squamous mucosa with suprabasal acantholysis and hyperkeratosis, and no evidence of viral infection, dysplasia or malignancy. These findings were consistent with acantholytic dermatosis (AD), a rare lesion that resembles Hailey-Hailey and Darier disease histopathologically, but can be distinguished on a clinical basis. Vulval cases of AD are well recognized, but to our knowledge, this is the first reported case involving the vaginal epithelium alone.

Suppression of TGFβ and Angiogenesis by Type VII Collagen in Cutaneous SCC

BACKGROUND

Individuals with severe generalized recessive dystrophic epidermolysis bullosa (RDEB), an inherited blistering disorder caused by mutations in the COL7A1 gene, develop unexplained aggressive squamous cell carcinomas (SCC). Here we report that loss of type VII collagen (Col7) in SCC results in increased TGFβ signaling and angiogenesis in vitro and in vivo.

METHODS

Stable knockdown (KD) of Col7 was established using shRNA, and cells were used in a mouse xenograft model. Angiogenesis was assessed by immunohistochemistry, endothelial tube-forming assays, and proteome arrays. Mouse and zebrafish models were used to examine the effect of recombinant Col7 on angiogenesis. Findings were confirmed in anonymized, archival human tissue: RDEB SCC tumors, non-EB SCC tumors, RDEB skin, normal skin; and two human RDEB SCC cell lines. The TGFβ pathway was examined using immunoblotting, immunohistochemistry, biochemical inhibition, and siRNA. All statistical tests were two-sided.

RESULTS

Increased numbers of cross-cut blood vessels were observed in Col7 KD compared with control xenografts (n = 4 to 7 per group) and in RDEB tumors (n = 21) compared with sporadic SCC (n = 24, P < .001). Recombinant human Col7 reversed the increased SCC angiogenesis in Col7 KD xenografts in vivo (n = 7 per group, P = .04). Blocking the interaction between α2β1 integrin and Col7 increased TGFB1 mRNA expression 1.8-fold and p-Smad2 levels two-fold. Increased TGFβ signaling and VEGF expression were observed in Col7 KD xenografts (n = 4) compared with control (n = 4) and RDEB tumors (TGFβ markers, n = 6; VEGF, n = 17) compared with sporadic SCC (TGFβ markers, n = 6; VEGF, n = 21). Inhibition of TGFβ receptor signaling using siRNA resulted in decreased endothelial cell tube formation (n = 9 per group, mean tubes per well siC = 63.6, SD = 17.1; mean tubes per well siTβRII = 29.7, SD = 6.1, P = .02).

CONCLUSIONS

Type VII collagen suppresses TGFβ signaling and angiogenesis in cutaneous SCC. Patients with RDEB SCC may benefit from anti-angiogenic therapy.

Successful treatment of a patient with severe atopic dermatitis and severe asthma by centrifugal therapeutic plasma exchange

This is a case of a 42-year-old atopic man with severe atopic dermatitis and asthma who despite long-term immunosuppression was not well controlled. He had a very high IgE at 7897 Iu/mL prior to treatment. He underwent two therapeutic plasma exchanges (TPEs) through two peripheral lines in our outpatient department, which led to an absolute decrease of 44.1% and 37% in his plasma IgE for each exchange, and immediate sustained improvement in shortness of breath, and atopic dermatitis, and hence led to a vast improvement in his quality of life. TPE offers a new exciting adjunctive treatment option for severe atopic individuals, where it may provide a novel role to reduce health burden and improve clinical symptoms. Further studies need to be performed to establish an optimal protocol and potential maintenance with recently available targeted anti-IgE biologics.

A consensus approach to improving patient adherence and persistence with topical treatment for actinic keratosis

BACKGROUND

Topical therapy is important in the treatment of actinic keratosis, but guidance for improving adherence/persistence during topical therapy is still lacking.

OBJECTIVES

To utilize expert consensus to generate a list of recommendations to improve real-world efficacy when prescribing topical therapy for actinic keratosis.

METHODS

An expert panel of eight dermatologists was convened to generate recommendations based on facilitated discussion and consensus generation using a modified Delphi session. The recommendations were ratified with the expert panel.

RESULTS

Facilitated discussion generated 31 issues within five themes, which were prioritized using expert voting. Consensus was achieved on the importance of short and simple treatment regimens for maximizing patient compliance, physician awareness of the progression of actinic keratosis to squamous cell carcinoma, provision of appropriate patient information, and the use of effective communication strategies to educate physicians about actinic keratosis. Based on these key findings, eight recommendations were generated.

CONCLUSIONS

The recommendations will assist physicians when prescribing topical actinic keratosis therapy. Further research should focus on the types of patient outcomes that are influenced by the characteristics of topical field therapy.

A consensus approach to improving patient adherence and persistence with topical treatment for actinic keratosis

BACKGROUND

Topical therapy is important in the treatment of actinic keratosis, but guidance for improving adherence/persistence during topical therapy is still lacking.

OBJECTIVES

To utilize expert consensus to generate a list of recommendations to improve real-world efficacy when prescribing topical therapy for actinic keratosis.

METHODS

An expert panel of eight dermatologists was convened to generate recommendations based on facilitated discussion and consensus generation using a modified Delphi session. The recommendations were ratified with the expert panel.

RESULTS

Facilitated discussion generated 31 issues within five themes, which were prioritized using expert voting. Consensus was achieved on the importance of short and simple treatment regimens for maximizing patient compliance, physician awareness of the progression of actinic keratosis to squamous cell carcinoma, provision of appropriate patient information, and the use of effective communication strategies to educate physicians about actinic keratosis. Based on these key findings, eight recommendations were generated.

CONCLUSIONS

The recommendations will assist physicians when prescribing topical actinic keratosis therapy. Further research should focus on the types of patient outcomes that are influenced by the characteristics of topical field therapy.

Key differences identified between actinic keratosis and cutaneous squamous cell carcinoma by transcriptome profiling

Background:

Cutaneous squamous cell carcinoma (cSCC) is one of the most common malignancies in fair-skinned populations worldwide and its incidence is increasing. Despite previous observations of multiple genetic abnormalities in cSCC, the oncogenic process remains elusive. The purpose of this study was to elucidate key molecular events associated with progression from premalignant actinic keratoses (AKs) to invasive cSCC by transcriptome profiling.

Methods:

We combined laser capture microdissection with the Affymetrix HGU133 Plus 2.0 microarrays to profile 30 cSCC and 10 AKs.

Results:

We identified a core set of 196 genes that are differentially expressed between AK and cSCC, and are enriched for processes including epidermal differentiation, cell migration, cell-cycle regulation and metabolism. Gene set enrichment analysis highlighted a key role for the mitogen activated protein kinase (MAPK) pathway in cSCC compared with AK. Furthermore, the histological subtype of the tumour was shown to influence the expression profile.

Conclusion:

These data indicate that the MAPK pathway may be pivotal to the transition from AK to cSCC, thus representing a potential target for cSCC prevention. In addition, transcriptome differences identified between cSCC subtypes have important implications for future development of targeted therapies for this malignancy.

Prospective study of sentinel lymph node biopsy for conjunctival melanoma

BACKGROUND

To report our experience with sentinel lymph node biopsy for staging patients with conjunctival melanoma.

METHODS

A prospective review of patients with conjunctival melanoma who underwent sentinel lymph node biopsy at St Bartholomew's Hospital from May 2008 to May 2012. The selection criterion for sentinel node biopsy depended on the tumour thickness (≥2 mm) and location of the conjunctival melanoma. The main outcome measures were the incidence of sentinel lymph node positivity and the procedure-related complications.

RESULTS

In 4 years, 26 out of 70 patients met the selection criteria for sentinel lymph node biopsy. 4 patients declined and 22 patients consented for the procedure. Technetium-99m failed to identify a sentinel lymph node in four of the 22 patients (18%). Of the remaining 18 patients, two were found to have subclinical micrometastasis in regional lymph nodes. Median follow-up was 20 months (range 6-36 months). No false-negative events were observed. Complications of the procedure included transient blue staining of the epibulbar surface in five patients and transient facial nerve palsy in one patient.

CONCLUSIONS

Sentinel lymph node biopsy is a safe procedure with minimal complications. It should be considered for the staging of conjunctival melanomas, especially melanomas in non-limbal location or conjunctival melanomas ≥2 mm thick.

p63 is an alternative p53 repressor in melanoma that confers chemoresistance and a poor prognosis

p63 is up-regulated in melanoma and prevents nuclear accumulation of p53.

The role of apoptosis in melanoma pathogenesis and chemoresistance is poorly characterized. Mutations in TP53 occur infrequently, yet the TP53 apoptotic pathway is often abrogated. This may result from alterations in TP53 family members, including the TP53 homologue TP63. Here we demonstrate that TP63 has an antiapoptotic role in melanoma and is responsible for mediating chemoresistance. Although p63 was not expressed in primary melanocytes, up-regulation of p63 mRNA and protein was observed in melanoma cell lines and clinical samples, providing the first evidence of significant p63 expression in this lineage. Upon genotoxic stress, endogenous p63 isoforms were stabilized in both nuclear and mitochondrial subcellular compartments. Our data provide evidence of a physiological interaction between p63 with p53 whereby translocation of p63 to the mitochondria occurred through a codependent process with p53, whereas accumulation of p53 in the nucleus was prevented by p63. Using RNA interference technology, both isoforms of p63 (TA and ΔNp63) were demonstrated to confer chemoresistance, revealing a novel oncogenic role for p63 in melanoma cells. Furthermore, expression of p63 in both primary and metastatic melanoma clinical samples significantly correlated with melanoma-specific deaths in these patients. Ultimately, these observations provide a possible explanation for abrogation of the p53-mediated apoptotic pathway in melanoma, implicating novel approaches aimed at sensitizing melanoma to therapeutic agents.

A surveillance model for skin cancer in organ transplant recipients: a 22-year prospective study in an ethnically diverse population

Skin cancer is a frequent complication of organ transplantation. Current guidelines advise specialist skin surveillance but there are limited data on how these should be implemented. This study determines overall burden of cancer and relevant intervals for strategic surveillance in an ethnically diverse transplant population. Prospective data on time to first and subsequent cancers and cumulative burden with respect to defined risk factors were analyzed in a cohort of 1010 patients in a UK center over 22 years. Among 931 individuals transplanted >6 months (mean 10.3 years), 1820 skin cancers occurred in 267 (29%) individuals and were multiple in 66%. Cumulative incidence at 5, 10, 20 and 30 years was 11%, 25%, 54% and 74%, with median time to second, third and fourth cancers of 24, 14.7 and 8.4 months, respectively. Tumors were overwhelmingly squamous and basal cell carcinomas (73% and 24%, respectively). Skin phototype, ultraviolet radiation exposure, age at transplant and duration of transplant were significant risk predictors and were used to construct clinically relevant surveillance intervals. This study provides a comprehensive, prospective analysis of skin cancer morbidity and risk in an ethnically diverse transplant population from which we derive an evidence-based skin cancer surveillance program.

Synchronous melanoma and renal carcinoma: a clinicopathological study of five cases

An increased frequency of renal carcinoma in men with melanoma has been reported in population based-studies. We report the clinicopathological findings of five cases of synchronous renal cell carcinoma (RCC), identified after routine radiological staging for cutaneous malignant melanoma (MM) between October 2006 and October 2008. The five patients (three men and two women, with a mean age of 62.4 years), presented with six melanomas of varying subtypes. The mean Breslow thickness was 1.87 mm. There was no family history of cancer in any of the cases. Routine radiological staging identified a mass arising from the left kidney in three cases and the right kidney in two cases. All patients underwent radical nephrectomy, and histology in each case confirmed RCC of the clear-cell subtype. Mean follow-up was 3 years. Although the simultaneous occurrence of RCC and MM may be coincidental, there are several plausible aetiological links. Further analysis of the synchronous occurrence of MM and renal cancer may provide therapeutic insights into these two important tumours.

Current application of National Institute for Health and Clinical Excellence (NICE) guidance in the management of patients with severe psoriasis: a clinical audit against NICE guidance in seven National Health Service specialist dermatology units in England

BACKGROUND

Psoriasis affects 1-2% of the U.K. population, with 20-30% of those affected having severe psoriasis managed with systemic therapies. Biological agents are a useful option when other systemic therapies have failed. The National Institute for Health and Clinical Excellence (NICE) in the U.K. has published three sets of guidance relating to the use of biological agents.

AIM

To establish whether biological agents were being used in line with NICE guidance.

METHODS

The study was conducted in seven specialist dermatology units, and involved the retrospective collection of data from patients treated with biological agents since the introduction of the NICE guidance.

RESULTS

In total, 176 patients with 212 episodes of treatment were included in the study. Biologics were started for appropriately severe disease in 85% of cases (n = 180) and only after failure, intolerance or contraindication to standard systemic therapies in 97% of cases (n = 206). Etanercept was discontinued appropriately in responders before week 24 in only 12% (five of 60 responders). Across all agents, 40% (72 of 178 with continuity status) were continued on treatment despite not achieving an adequate response according to NICE criteria.

CONCLUSIONS

In the seven sites audited, compliance with national guidance was entirely appropriate in terms of therapy initiation; however, the requirement to discontinue etanercept in responders was rarely followed. Similarly, discontinuation of biologicals in nonresponders was not routine practice. This may indicate a reluctance of both patients and clinicians to withdraw an at least partly effective therapy from these refractory patients.

Axl promotes cutaneous squamous cell carcinoma survival through negative regulation of pro-apoptotic Bcl-2 family members

Expression of Axl, a receptor tyrosine kinase, is increased in cutaneous squamous cell carcinoma (SCC). Examination of a series of cutaneous SCC tumors revealed positive phospho-Akt (P-Akt) staining accompanied by weak TUNEL staining in Axl-positive tumors, suggesting an anti-apoptotic role for Axl in SCC survival. The role of Axl in UV-induced apoptosis was investigated in a cutaneous SCC cell line using retroviral short hairpin RNA sequences enabling stable Axl knock-down. We show that, although Axl knock-down has no effect on cell proliferation, it sensitizes cells to UV-induced apoptosis through increased activation of the pro-apoptotic protein Bad, a change in the conformation of Bax and Bak, release of cytochrome c into the cytosol, and activation of caspases. These events are accompanied by faster Akt dephosphorylation in UV-treated Axl knock-down cells and correlate with the degree of Axl knock-down. Treatment with the pan-caspase inhibitor zVAD-fmk partially rescued cells from UV-induced apoptosis but did not affect Bid cleavage or cytochrome c release, suggesting that cells die via the mitochondrial-mediated pathway. Thus, Axl confers resistance of SCC cells to apoptosis and displays potential as a target for therapeutic intervention in cutaneous SCC.

Desmoplastic trichoepithelioma confused with cutaneous squamous cell carcinoma in childhood

Squamous cell carcinoma of the skin is very rare in childhood, especially without predisposing factors or underlying diseases. We report the case of a desmoplastic trichoepithelioma misdiagnosed as cutaneous squamous cell carcinoma in a 12 years old boy Only accurate multiple reviews of the histological samples and repeated questioning of the mother could finally clarify the diagnostic dilemma. Desmoplastic trichoepithelioma is a quite uncommon benign adnexal tumor with a reported incidence, in adults, of 1 in 5000 skin biopsies. It usually affects the face of middle-aged women, but it has been reported at any age. The treatment of desmoplastic thricoepithelioma includes curettage and electrodesiccation or surgical removal. Recurrence or appearance of new lesions is rare. The diagnosis of squamous cell carcinoma in a child without predisposing factors should be accepted with great caution and only after expert histological review.

Mechanism of action and clinical benefits of colloidal oatmeal for dermatologic practice

Colloidal oatmeal has a long history of beneficial use in dermatology. It is a natural product that has an excellent safety record and has demonstrated efficacy for the treatment of atopic dermatitis, psoriasis, drug-induced rash and other conditions. In recent years, in vitro and in vivo studies have begun to elucidate the multiple mechanisms of action of naturally derived colloidal oatmeal. Evidence now describes its molecular mechanisms of anti-inflammatory and antihistaminic activity. The avenanthramides, a recently described component of whole oat grain, are responsible for many of these effects. Studies have demonstrated that avenanthramides can inhibit the activity of nuclear factor kappaB and the release of proinflammatory cytokines and histamine, well known key mechanisms in the pathophysiology of inflammatory dermatoses. Topical formulations of natural colloidal oatmeal should be considered an important component of therapy for atopic dermatitis and other conditions and may allow for reduced use of corticosteroids and calcineurin inhibitors.

Paraneoplastic Acanthosis Nigricans: The importance of exhaustive and repeated malignancy screening

Paraneoplastic acanthosis nigricans (P-AN) characteristically has a sudden onset, rapid progression, and extensive cutaneous involvement. The association between P-AN and internal malignancy is well established and the most common association is with adenocarcinoma of gastrointestinal origin. We present the case of an 81-year-old man with a 12-month history of anorexia, weight loss, and clinical evidence of extensive acanthosis nigricans. After exhaustive and repeated investigations a papillary thyroid carcinoma and a follicular adenoma were identified and he improved upon its resection. To our knowledge, P-AN in association with thyroid neoplasm has been reported on only one previous occasion.

Expression of DNA mismatch repair proteins and MSH2 polymorphisms in nonmelanoma skin cancers of organ transplant recipients

BACKGROUND

Organ transplant recipients (OTRs) have an increased risk of skin cancer. Treatment with azathioprine, commonly used in post-transplant immunosuppressive regimens, results in incorporation of 6-thioguanine (6-TG) into DNA. Mismatch repair (MMR)-defective cells are resistant to killing by 6-TG. Azathioprine exposure confers a survival advantage on MMR-defective cells, which are hypermutable and may therefore contribute to azathioprine-related nonmelanoma skin cancer, a phenomenon we have previously demonstrated in transplant-associated sebaceous carcinomas. The MSH2 protein is an important component of DNA MMR. The -6 exon 13 T>C MSH2 polymorphism is associated with impaired MMR, drug resistance and certain cancers.

OBJECTIVES

To investigate (i) whether loss of MMR protein expression and microsatellite instability are over-represented in squamous cell carcinomas (SCCs) from OTRs on azathioprine compared with SCCs from immunocompetent patients, and (ii) whether the MSH2 -6 exon 13 polymorphism is over-represented in OTRs with skin cancer on azathioprine.

METHODS

(i) Immunohistochemical staining was used to assess expression of the MMR proteins MSH2 and MLH1 in cutaneous SCCs from OTRs on azathioprine and from immunocompetent patients. (ii) Blood samples from OTRs on azathioprine with and without skin cancer were genotyped for the -6 exon 13 MSH2 polymorphism.

RESULTS

(i) MSH2 and MLH1 protein expression was not altered in SCCs from OTRs on azathioprine and there was no difference in expression between SCCs from OTRs and immunocompetent patients. (ii) There was no association between MSH2 polymorphism genotype frequency and OTR skin cancer status.

CONCLUSIONS

Despite previous findings in transplant-associated sebaceous carcinomas, defective MMR and the -6 exon 13 MSH2 polymorphism are unlikely to play a significant role in the development of SCC in OTRs on azathioprine.