Actinic Keratosis: The Key Event in the Evolution from Photoaged Skin to Squamous Cell Carcinoma

Longitudinal Assessment of the Prevalence of Actinic Keratosis and Extensive Risk Factor Evaluation: An Update from the Rotterdam Study

Population-based studies available to analyze the prevalence, risk factors, and longitudinal outlook of actinic keratoses (AKs) are limited. These features mentioned earlier were assessed using Rotterdam study participants aged ≥40 years who underwent a full-body skin examination by a dermatology-trained physician. ORs with 95% confidence intervals were calculated for the associations between risk factors and the presence of AK. Among 8,239 eligible participants, the prevalence of one or more AKs was 21.1% (95% confidence interval = 20.2-22.0) and was higher in men. Male sex, age, lighter hair and eye color, baldness, genetic risk score, and digital photoaging measures (digitally assessed pigmented spots, telangiectasias, and global facial wrinkling) had a positive association with AK. Cigarette smokers had reduced odds of having AK, with current smokers having the lowest risk. Among patients with two AK assessments, there was no difference in the presence of AK during follow-up between treated and untreated participants. In conclusion, genetic risk score and digital photoaging measures showed associations with increased lesion count. At the individual level, patients were most likely to decrease in AK severity group over time, possibly regardless of whether or not participants were treated.

A Study of Efficacy and Safety of Ashwagandha (Withania somnifera) Lotion on Facial Skin in Photoaged Healthy Adults

Background Facial skin has an essential cosmetic function in both men and women, and photoaged skin can affect the quality of life in healthy people. Ashwagandha (Withania somnifera) which is also called Indian ginseng has adaptogenic properties and is used in traditional Indian medicine to maintain balance, energize, and rejuvenate. Objective This randomized, double-blind, and placebo-controlled study assessed the efficacy and safety of topical application of lotion containing 8% standardized Ashwagandha root extract on improvement of skin parameters in the photoaged facial skin of healthy subjects. Methods Fifty-six healthy men and women aged between 18 and 60 years with Fitzpatrick phototype III-VI skin grade were randomized to receive the topical application (lotion on facial skin) of either Ashwagandha 8% (AG, n=28), or an identical placebo (PL, n=28) for 60 days. The primary outcome was the change from baseline on day 60 in the scores for global physician assessment scoring for the five dermatological signs (skin wrinkles, pores, hydration/moisture, skin brightness/tone, and pigmentation) on facial skin. Secondary outcomes were changes from baseline in the transepidermal water loss (TEWL), melanin index, hydration, and skin elasticity (R2 ratio). Another efficacy outcome was quality of life using the health-specific Short Form Health Survey-12 (SF-12). Safety was assessed using local reactions and adverse events. Three (1 AG, 2 PL) patients were lost to follow-up and per-protocol (PP) data included 53 patients (27 AG, 26 PL). For measurement data, repeated measures analysis of variance (ANOVA) was used to assess treatment effect at different time periods in the PP dataset (n=53). Two groups were compared for differences using a t-test for continuous data or a Mann-Whitney 'U' test for ordinal data. Adverse events were compared between two groups using the chi-square test. Results Greater reduction (p<0.0001) in total physician assessment scores from baseline to day 60 was observed with AG (-74.69%) compared to PL (-48.68%). There was a greater improvement in TEWL, skin hydration, and skin elasticity (R2 ratio) with AG as compared to placebo (p<0.0001). However, the change in melanin index was similar in the two groups at the end of day 60 (p=0.969). The percentage increase in melanin index from baseline to day 60 in the PP dataset was by -2.82% with AG and -1.78% with PL, whereas the percentage reduction in TEWL from baseline to day 60 in the PP dataset was by -15.12% with AG and -8.34% with PL. Similarly, greater percentage improvements were seen with AG as compared to PL for skin hydration (20.66% with AG and 9.5% with PL) and elasticity was assessed by the R2 ratio (16.34% with AG and 3.73% with PL). Adverse events were comparable in the two groups. Conclusions Topical application of a lotion containing Ashwagandha standardized root extract improves the skin condition and quality of life in photoaged healthy individuals. Further studies with different skin types and standard comparators are warranted to substantiate these claims of benefit.

Gender differences in UV-induced skin inflammation, skin carcinogenesis and systemic damage

Ultraviolet (UV) radiation-induced chronic inflammation contributes to all stages of skin tumor development. In addition, gender plays an important role in inflammatory diseases or cancer. In this study, histopathology changes, hematology, oxidative stress and inflammatory response were used to evaluate sex differences in UV-induced chronic inflammation-associated cancer development. The results showed that the male and female mice had photoaging damage at the 9th week. However, skin tumors only appeared in male mice at 31st week. Furthermore, UV increased ROS production, p65, p-p65, IL-6 and TNF-α protein expressions in skin, and these factors elevated more in male mouse model. Hematology results showed that the parameters of blood systemic inflammation were changed in different degrees in model groups, while the pathological results showed inflammatory cell infiltration in the internal organs of both model groups in varying degrees. These results indicate that there are gender differences in UV-induced skin inflammation, carcinogenesis and systemic damage. Moreover, male mice are more sensitive to UV irradiation, which may be responsible to greater oxidative stress and inflammatory damage.

Predicting keratinocyte carcinoma in patients with actinic keratosis: development and internal validation of a multivariable risk-prediction model

BACKGROUND

Patients with actinic keratosis (AK) are at increased risk for developing keratinocyte carcinoma (KC) but predictive factors and their risk rates are unknown.

OBJECTIVES

To develop and internally validate a prediction model to calculate the absolute risk of a first KC in patients with AK.

METHODS

The risk-prediction model was based on the prospective population-based Rotterdam Study cohort. We hereto analysed the data of participants with at least one AK lesion at cohort baseline using a multivariable Cox proportional hazards model and included 13 a priori defined candidate predictor variables considering phenotypic, genetic and lifestyle risk factors. KCs were identified by linkage of the data with the Dutch Pathology Registry.

RESULTS

Of the 1169 AK participants at baseline, 176 (15·1%) developed a KC after a median follow-up of 1·8 years. The final model with significant predictors was obtained after backward stepwise selection and comprised the presence of four to nine AKs [hazard ratio (HR) 1·68, 95% confidence interval (CI) 1·17-2·42], 10 or more AKs (HR 2·44, 95% CI 1·65-3·61), AK localization on the upper extremities (HR 0·75, 95% CI 0·52-1·08) or elsewhere except the head (HR 1·40, 95% CI 0·98-2·01) and coffee consumption (HR 0·92, 95% CI 0·84-1·01). Evaluation of the discriminative ability of the model showed a bootstrap validated concordance index (c-index) of 0·60.

CONCLUSIONS

We showed that the risk of KC in patients with AK can be calculated with the use of four easily assessable predictor variables. Given the c-index, extension of the model with additional, currently unknown predictor variables is desirable. Linked Comment: Kim et al. Br J Dermatol 2020; 183:415-416.

Electrospun poly-l-lactide scaffold for the controlled and targeted delivery of a synthetically obtained Diclofenac prodrug to treat actinic keratosis

Actinic Keratosis' (AKs) are small skin lesions that are related to a prolonged sun-damage, which can develop into invasive squamous cell carcinoma (SCC) when left untreated. Effective, specific and well tolerable therapies to cure AKs are still of great interest. Diclofenac (DCF) is the current gold standard for the local treatment of AKs in terms of costs, effectiveness, side effects and tolerability. In this work, an electrospun polylactic acid (PLA) scaffold loaded with a synthetic DCF prodrug was developed and characterized. Specifically, the prodrug was successfully synthetized by binding DCF to a glycine residue via solid phase peptide synthesis (SPPS) and then incorporated in an electrospun PLA scaffold. The drug encapsulation was verified using multiphoton microscopy (MPM) and its scaffold release was spectrophotometrically monitored and confirmed with MPM. The scaffold was further characterized with scanning electron microscopy (SEM), tensile testing and contact angle measurements. Its biocompatibility was verified by performing a cell proliferation assay and compared to PLA scaffolds containing the same amount of DCF sodium salt (DCFONa). Finally, the effect of the electrospun scaffolds on human dermal fibroblasts (HDFs) morphology and metabolism was investigated by combining MPM with fluorescence lifetime imaging microscopy (FLIM). The obtained results suggest that the obtained scaffold could be suitable for the controlled and targeted delivery of the synthesized prodrug for the treatment of AKs.

STATEMENT OF SIGNIFICANCE

Electrospun scaffolds are of growing interest as materials for a controlled drug delivery. In this work, an electrospun polylactic acid scaffold containing a synthetically obtained Diclofenac prodrug is proposed as a novel substrate for the topical treatment of actinic keratosis. A controlled drug delivery targeted to the area of interest could enhance the efficacy of the therapy and favor the healing process. The prodrug was synthesized via solid phase, employing a clean and versatile approach to obtain Diclofenac derivatives. Here, we used multiphoton microscopy to image drug encapsulation within the fibrous scaffold and fluorescence lifetime imaging microscopy to investigate Diclofenac effects and potential mechanisms of action.

Design, synthesis and biological evaluation of novel hydroxy-phenyl-1H-benzimidazoles as radical scavengers and UV-protective agents

An ever-increasing incidence of skin neoplastic diseases is registered. Therefore, it is important to protect the skin from the UV radiation that reaches the epidermis and dermis but also to block ROS generated by them. Our attention was attracted in developing new compounds provided with both UV filtering and antioxidant capacities. To this end, 2-phenyl-1H-benzimidazole-5-sulfonic acid (PBSA), a known UV filter, was selected as lead compound for its lack of antioxidant activity, high water solubility and good safety profile. PBSA was sequentially modified introducing hydroxyls on the phenyl ring and also substituting the functional group in position 5 of the benzimidazole ring. At the end of the synthetic study, a new, very potent class of antioxidants has been obtained. Surprisingly some of the developed molecules, while devoid of significant UV-filtering activity was endowed with potent UV-filtering booster capability if associated with known commercial UVB and UVA filters.

Actinic keratosis: correlation between clinical and histological classification systems

BACKGROUND

There are several clinical and histological classification systems for grading actinic keratosis (AK) lesions. The Olsen clinical classification scheme grades AK lesions according to their thickness and degree of hyperkeratosis (grades 1-3). The Roewert-Huber histological classification system grades AK lesions based on the extent of epidermal atypical keratinocytes (AK I-III).

OBJECTIVE

The aim of this study was to determine whether there is a correlation between these clinical and histological AK classification schemes.

METHODS

One AK lesion from patients in three pivotal clinical studies and routine practice was assessed clinically and histologically. A match in grading was defined as Olsen grade 1 being classified histologically as AK I, Olsen grade 2 as AK II and Olsen grade 3 as AK III.

RESULTS

Of the 892 lesions included, 29.0% were classified as Olsen grade 1, 59.6% as Olsen grade 2 and 11.3% as Olsen grade 3; 19.2% were histologically classified as AK I, 69.6% as AK II and 11.2% as AK III. Only 480 lesions (53.8%) had a matching clinical and histological classification. Of these matches, most were 'Olsen grade 2 = AK II' (83.1%). The Spearman's rank correlation coefficient for clinical and histological classification was r = 0.0499 (P = 0.137).

CONCLUSIONS

Clinical classification of AK lesions using the system of Olsen does not accurately match histological classification of the same lesions using the system of Roewert-Huber. Consequently, it is not possible to draw conclusions about the histology of AK lesions from their clinical appearance. This finding reinforces the need to treat all AK lesions as well as field cancerization.

The collagen receptor uPARAP/Endo180 in tissue degradation and cancer (Review)

The collagen receptor uPARAP/Endo180, the product of the MRC2 gene, is a central component in the collagen turnover process governed by various mesenchymal cells. Through the endocytosis of collagen or large collagen fragments, this recycling receptor serves to direct basement membrane collagen as well as interstitial collagen to lysosomal degradation. This capacity, shared only with the mannose receptor from the same protein family, endows uPARAP/Endo180 with a critical role in development and homeostasis, as well as in pathological disruptions of the extracellular matrix structure. Important pathological functions of uPARAP/Endo180 have been identified in various cancers and in several fibrotic conditions. With a particular focus on matrix turnover in cancer, this review presents the necessary background for understanding the function of uPARAP/Endo180 at the molecular and cellular level, followed by an in-depth survey of the available knowledge of the expression and role of this receptor in various types of cancer and other degenerative diseases.

Development of a non-melanoma skin cancer detection model

BACKGROUND

The incidence and prevalence of skin cancer is rising. A detection model could support the (screening) process of diagnosing non-melanoma skin cancer.

METHODS

A questionnaire was developed containing potential actinic keratosis (AK) and basal cell carcinoma (BCC) characteristics. Three nurses diagnosed 204 patients with a lesion suspicious of skin (pre)malignancy and filled in the questionnaire. Logistic regression analyses generated prediction models for AK and BCC.

RESULTS

A prediction model containing nine characteristics correctly predicted the presence or absence of AK in 83.2% of the cases. BCC was predicted correctly in 91.4% of the cases by a model containing eight characteristics. The nurses correctly diagnosed AK in 88.3% and BCC in 90.9% of the cases.

CONCLUSIONS

Detection or screening models for AK and BCC could be made with a limited number of variables. Nurses also diagnosed skin lesions correctly in a high percentage of cases. Further research is necessary to investigate the robustness of these findings, whether the percentage of correct diagnoses can be improved and how best to implement model-based prediction in the diagnostic process.

Willingness-to-pay to access Ingenol Mebutate Gel for Actinic Keratosis Treatment in the U.S. Setting

Background: Currently available topical treatments for actinic keratosis (AK) adversely affect patients' quality of life because of long treatment durations and long-lasting local skin reactions (LSRs), which may result in poor treatment adherence and patient outcomes. Ingenol mebutate gel, a recently introduced treatment for AK, is administered for 2 or 3 days, and LSR's are predicable in onset and duration. Objectives: The objective of the study was to estimate the value of ingenol mebutate gel's shorter treatment duration and tolerability profile to potential patients, versus existing topical treatments (imiquimod 3.75%, imiquimod 5% and diclofenac 3%) in the United States. Methods: The open-ended Contingent Valuation (CV) approach was used to estimate incremental willingness-to-pay (WTP) for ingenol mebutate gel rather than treatment with imiquimod 5%, imiquimod 3.75% and diclofenac 3%. Profiles for each therapy differed in regards to treatment duration, time-to-LSR resolution, and price. Subjects were asked to state their maximum out-of-pocket WTP to receive ingenol mebutate gel instead of each of the three alternatives. Results: 103 subjects provided usable answers. Between 48% and 63% of subjects were willing to pay extra to gain access to treatment with the ingenol mebutate gel profile instead of the comparators, and the mean incremental WTP ranged from $475 to $518. Subjects with experience of topical treatment stated higher WTP for accessing ingenol mebutate gel. Subjects whose most bothersome AK area was the full scalp or forehead also claimed higher WTP for ingenol mebutate gel. Conclusions: Patients diagnosed with AK indicated an unmet need for fast-acting topical treatment with shorter LSR resolution time.

Perioral lesions and dermatoses

The purpose of this article is to review the common neoplasms, infections, and inflammatory dermatoses that may present around or near the mouth. Dental professionals are well positioned to evaluate perioral skin conditions, further contributing to patients' general health. This article includes a review of seborrheic keratosis, warts, actinic keratoses, actinic cheilitis, and squamous cell carcinoma, among several other perioral cutaneous lesions.

Randomized, vehicle-controlled trials of topical 5-fluorouracil therapy for actinic keratosis treatment: an overview

Actinic keratoses are common in older individuals and topical immunotherapy is an important treatment when multiple lesions are present. To assess the efficacy of 5-fluorouracil in treating actinic keratoses, a systematic review of randomized, vehicle-controlled trials was performed. Percentages of 5-fluorouracil and vehicle responders were determined by absolute clearance and mean percent reduction in lesion count. Four trials with 399 and 269 participants in active treatment and vehicle groups, respectively, were evaluated. After 4 weeks of treatment, total clearance and mean lesion count reduction were 52.6 and 90.2% in the treatment group versus 0.85 and 28.3% in the vehicle group, respectively. Topical 5-fluorouracil is efficacious in treating actinic keratoses; however, vehicle responses warrant further investigation of study design and disease severity scales.

The importance of early diagnosis and treatment of actinic keratosis

Chronic, long-term sun exposure results in genetic changes in epidermal keratinocytes and the development of various skin lesions ranging from actinic keratosis (AK) to skin cancer. AK lesions may first appear as rough, scaly spots on sun-exposed skin, and, although most individual AK lesions do not become invasive cancers, the majority of invasive squamous cell carcinomas originate from AK. Genetic analysis demonstrates that ultraviolet radiation-induced mutations and changes in gene expression are present in squamous cell carcinoma, AK, and clinically normal-appearing perilesional sun-exposed skin, which supports the progressive nature of keratinocyte transformation. The presence of certain clinical features, such as large size, ulceration, or bleeding, suggests an increased risk of disease progression. The risk is also increased by evidence of extensive solar damage, advanced age, and immunosuppression. Early diagnosis and consideration for treatment are indicated to clear actinically damaged sites and diminish the risk of invasive squamous cell carcinoma.

Prevalence and awareness of actinic keratosis: barriers and opportunities

Actinic keratoses (AKs) are common skin lesions that appear after long-term exposure to ultraviolet radiation. The presence of AKs is associated with an increased risk for development of nonmelanoma skin cancer. AKs vary widely in clinical and histologic presentation, which contributes to inadequate identification and presents challenges for consensus classification. Clinically adequate reduction in AK prevalence requires a multifaceted approach. There is a reasonable need to increase awareness and knowledge about AK, including symptoms, prevention, and associated risk of nonmelanoma skin cancer, especially among the public at large. Safe and effective treatment strategies are needed to optimize clearance of AKs, ideally to prevent progression to invasive cutaneous neoplasia.

1α,25(OH)₂-vitamin D and a nongenomic vitamin D analogue inhibit ultraviolet radiation-induced skin carcinogenesis

Exposure to ultraviolet radiation (UVR) can lead to a range of deleterious responses in the skin. An important form of damage is the DNA photolesion cyclobutane pyrimidine dimer (CPD). CPDs can be highly mutagenic if not repaired prior to cell division and can lead to UV-induced immunosuppression, making them potentially carcinogenic. UVR exposure also produces vitamin D, a prehormone. Different shapes of the steroid hormone 1α,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃] can produce biological responses through binding either to its cognate nuclear receptor (VDR) to regulate gene transcription or to the VDR associated with plasma membrane caveolae to produce, via signal transduction, nongenomic physiologic responses. Here, we show that both 1,25(OH)₂D₃ and 1α,25(OH)₂-lumisterol (JN), a conformationally restricted analogue that can generate only nongenomic responses, are effective inhibitors of UV damage in an immunocompetent mouse (Skh:hr1) model susceptible to UV-induced tumors. Both 1,25(OH)₂D₃ and JN significantly reduced UVR-induced CPD, apoptotic sunburn cells, and immunosuppression. Furthermore, these compounds inhibited skin tumor development, both papillomas and squamous cell carcinomas, in these mice. The observed reduction of these UV-induced effects by 1,25(OH)₂D₃ and JN suggests a role for these compounds in prevention against skin carcinogenesis. To the best of our knowledge, this is the first comprehensive report of an in vivo long-term biological response generated by chronic dosing with a nongenomic-selective vitamin D steroid.

Diclofenac gel in the treatment of actinic keratoses

Actinic keratoses are areas of intraepithelial neoplasia for which treatment is necessary. Because they arise in areas of sun damage, it is desirable to treat the entire damaged field to not only treat visible lesions, but also subclinical, emerging malignancies, ie, “field therapy”, 5-fluorouracil, imiquimod, and diclofenac are all treatment options, and are discussed and compared.

Solanum incanum extract (SR-T100) induces human cutaneous squamous cell carcinoma apoptosis through modulating tumor necrosis factor receptor signaling pathway

BACKGROUND

The Solanum species herbs have been used to treat cancer for centuries; however, the underlying mechanisms and effectiveness in vivo remain unclear.

OBJECTIVES

SR-T100, extracted from the Solanum incanum, contains solamargine alkaloid as the main active ingredient. Here, we investigated the apoptosis-inducing effects of SR-T100 for targeting squamous cell carcinoma (SCC) in vitro and in vivo.

METHODS

We elucidated the mechanism by which SR-T100 induces apoptosis of human SCCs (A431, SCC4, SCC9, and SCC25) cells. The efficacy and safety issues were addressed regarding topical treatment of SR-T100 on UVB-induced cutaneous SCC of hairless mice and actinic keratoses (AKs) of human.

RESULTS

SR-T100 induces apoptosis in human SCCs cell lines by up-regulating the expressions of tumor necrosis factor receptors (TNFRs) and Fas, and downstream adaptors FADD/TRADD of the TNF-α and Fas ligand signaling cascades. SR-T100 also triggered the mitochondrial apoptotic pathway, as up-regulated cytochrome c and Bax, down-regulated Bcl-X(L). Animal experiments showed that all papillomas (35/35) and 27 of 30 UVB-induced microinvasive SCCs in hairless mice disappeared within 10 weeks after once-daily application of topical SR-T100. Furthermore, 13 patients, who suffered with 14 AKs, were treated with once-daily topical SR-T100 gel and 10 AKs cured after 16 weeks, showing negligible discomforts.

CONCLUSION

Our studies indicate that SR-T100 induces apoptosis of SCC cells via death receptors and the mitochondrial death pathway. The high efficacy of SR-T100 in our preclinical trial suggests that SR-T100 is a highly promising herb for AKs and related disorders.

Fluorescence detection and diagnosis of non-melanoma skin cancer at an early stage

BACKGROUND

The occurrence of non-melanoma skin cancer (NMSC), including actinic keratosis (AK) is increasing all over the world. The detection and diagnosis of NMSC is not optimal in clinical practice. Complementary methods for detection and accurate demarcation of NMSC at an early stage are needed in order to limit the damage caused by tumours.

OBJECTIVE

The purpose of the present study was to use a large area skin fluorescence detection system to detect early NMSCs (clinical visible as well as non-visible lesions) in the face, neck, chest, back and hands of patients treated with UV and outdoor workers.

METHODS

Fluorescence detection with a purpose-made digital camera and software (Dyaderm combined with 5-aminolevulinic acid (5-ALA) encapsulated in liposomes.

RESULTS

In 93 consecutively referred patients positive skin fluorescence was detected in 61 patients. After histological examination the positive fluorescence appeared to be correlated to benign lesions in 28 patients (sebaceous gland hyperplasia in 22 patients) and to (pre-) malignant lesions in 33 patients (actinic keratosis in 29, BCC in 3 and SCC in 1 patient). False negative fluorescence was found in only one lesion. In five patients the FD technique used in this study appeared to be more sensitive for the identification of (pre-) malignant lesions than the clinical examination. This is in contrast with FD techniques used in previous studies.

CONCLUSION

Diagnostic skin fluorescence using liposomal encapsulated 5-ALA and a specialised computerised detection and visualisation system offers the possibility for detection of NMSC at an early, pre-clinical stage. The technique is well suited to examine large areas of skin. It also identifies areas of most interest for performing confirmatory skin biopsies, as well as pre-operative assessment of boundaries of skin malignancies, and finally, the technique is applicable in the control and follow-up of skin cancer treatment.

Retinoids in the treatment of skin aging: an overview of clinical efficacy and safety

Aging of skin is an intricate biological process consisting of two types. While intrinsic or chronological aging is an inevitable process, photoaging involves the premature aging of skin occurring due to cumulative exposure to ultraviolet radiation. Chronological and photoaging both have clinically differentiable manifestations. Various natural and synthetic retinoids have been explored for the treatment of aging and many of them have shown histological and clinical improvement, but most of the studies have been carried out in patients presenting with photoaged skin. Amongst the retinoids, tretinoin possibly is the most potent and certainly the most widely investigated retinoid for photoaging therapy. Although retinoids show promise in the treatment of skin aging, irritant reactions such as burning, scaling or dermatitis associated with retinoid therapy limit their acceptance by patients. This problem is more prominent with tretinoin and tazarotene whereas other retinoids mainly represented by retinaldehyde and retinol are considerably less irritating. In order to minimize these side effects, various novel drug delivery systems have been developed. In particular, nanoparticles have shown a good potential in improving the stability, tolerability and efficacy of retinoids like tretinoin and retinol. However, more elaborate clinical studies are required to confirm their advantage in the delivery of topical retinoids.

Expression of p53 in the evolution of squamous cell carcinoma: Correlation with the histology of the lesion

BACKGROUND

The evolution of squamous cell carcinoma (SCC) on sun-exposed areas is a multistep process triggered by ultraviolet radiation (UVR), in which precursor lesions exist. However, the exact classification of the various lesions in this process, mainly solar keratosis (SK), is still disputed, and its pathogenesis requires further clarification.

OBJECTIVE

To further elucidate the evolution of SCC on sun-damaged skin by correlating the levels of p53 protein expression, a parameter that reflects UVR damage to cells, and the morphology of the lesions that develop on sun-exposed areas.

METHODS

Biopsy specimens from normal skin (n = 4), normal skin with various degrees of solar elastosis (SE) (n = 16), various degrees of SK (n = 17) and SCCs from sun-exposed (n = 12) and sun-protected (n = 7) areas were stained with anti-p53 antibodies. A semiquantitative evaluation of the degree of staining was performed and correlated with the histological features.

RESULTS

Nuclear staining in keratinocytes was observed already in normal skin with mild SE and was increased gradually to its highest level of expression in advanced SK. It was also expressed in SCCs, but to a lesser degree. Statistical analysis revealed association between the morphology of the lesion and the level of p53 expression (P < .01); it also showed that in general the level of p53 is correlated with the histology of the lesion (P < .001). Furthermore, with regard to p53 expression, two groups of lesions exist: one showing a low level of expression of p53 that includes normal skin, skin with various degrees of SE and SCC from sun-protected areas, and a second group showing a high level of expression that includes SK and SCC occurring on sun-damaged skin.

LIMITATION

This is an immunohistochemical study of relatively few cases and in which the antibody detects all types of p53 protein.

CONCLUSIONS

This study furnishes further evidence that the development of SCC on sun-damaged skin is a gradual process not only morphologically but also on the molecular level. The process starts already in normal-appearing epidermis with SE. In that respect, SK should be regarded as a part of the continuum in the development of SCC, analogous to the situation in other epithelia. The molecular events involved in the development of SCC on sun-exposed areas may be different from those involving the development of SCC on sun-protected areas.

Actinic Keratoses and the Incidence of Occult Squamous Cell Carcinoma: A Clinical?Histopathologic Correlation

BACKGROUND

The ability to clinically diagnose actinic keratoses (AKs) lesions has been taken for granted for some time. The importance of the malignant potential of these lesions is well known. However, a recent Phase IV, multicenter study assessing the long-term benefit of aminolevulinic acid-based photodynamic therapy provided a unique opportunity to prospectively examine the clinical histopathologic correlation of AKs.

OBJECTIVE

The objective was to characterize the histopathology of clinically diagnosed AK lesions in the study population.

METHODS

Punch biopsies of 220 clinically diagnosed untreated AKs were performed at baseline plus 51 lesions unresponsive to treatment (total, 271).

RESULTS

Clinical diagnosis and histopathologic findings agreed in 91% (246/271) of the lesions biopsied. The balance of the biopsied lesions were: (1) benign changes 4% (11/271) and (2) occult cutaneous malignancy in 5% (14/271) of the cases, 12 squamous cell carcinomas and 2 basal cell carcinomas.

CONCLUSIONS

In this study, about 1 in 25 clinically diagnosed AK lesions identified by board-certified dermatologist investigator(s) were occult early-stage squamous cell carcinomas on histologic assessment, a fact surmised by the medical community that until now had not been well quantified. These findings should be considered when clinicians decide how to treat and manage AK patients.

Kryochirurgische Behandlung aktinischer Keratosen mit evidenzbasierter �bersicht

BACKGROUND

Actinic keratoses are focal epithelial carcinomas in situ, which are considered precursors of squamous cell carcinoma and must therefore be treated. In the USA, cryosurgery is the most frequent surgical procedure for the treatment of actinic keratoses and considered the treatment of choice.

METHODS

Our own results of cryosurgical treatment of actinic keratoses were evaluated. Original publications and reviews on the treatment of actinic keratoses with cryosurgery were retrieved from MEDLINE and classified according to their evidence level.

RESULTS

Two months after the procedure, 97.0% of the lesions (n=99) were considered sufficiently treated. Local pain during and shortly after treatment (15%) and pigmentary changes (5%) were the most frequent side effects. Recurrences were detected in 2.1% of the lesions during the 1st year and in 11,5% after 3 years. In 2 further monotherapy studies recurrences occurred in 1,2-9% of the lesions after one year in 30% after 3 years. Literature data suggest that photodynamic therapy is equally or even more effective than cryosurgery after a 3-month follow-up. The cryosurgical results were strongly dependent on the attending physician.

CONCLUSIONS

Cryosurgery is beneficial in the treatment of actinic keratoses. This method is equivalent to photodynamic therapy.

Hyaluronic acid in the treatment and prevention of skin diseases: molecular biological, pharmaceutical and clinical aspects

The glycosaminoglycan hyaluronic acid (HA), or hyaluronan, is a major component of the extracellular matrix of skin, joints, eye and many other tissues and organs. In spite of its simple structure, HA demonstrates remarkable rheological, viscoelastic and hygroscopic properties which are relevant for dermal tissue function. Biological activities in skin, however, are also due to its interaction with various binding proteins (hyaladherins). Due to an influence on signaling pathways, HA is involved in the wound-healing process and scarless fetal healing. Increased HA concentrations have been associated with inflammatory skin diseases. In clinical trials, topical application of HA improved wound healing; in particular, acute radioepithelitis, venous leg ulcers or diabetic foot lesions responded to HA treatment. Moreover, as a topical drug delivery system for diclofenac, an HA gel has recently been approved for the treatment of actinic keratoses. Finally, chemical modifications led to new HA derivates and biomaterials, which may be introduced into therapy in the future. Therefore, ongoing research offers new horizons for the therapeutic use of this glycosaminoglycan which has been regarded as an inert structural component until recently.