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There are carcinogenic effects of sun exposure that increase the risk for skin cancer, especially for fair-skinned individuals. Therefore, there are recommendations to avoid sun exposure and to apply sun blockers. A more nuanced and balanced message for sun safety guidelines is now advocated. Despite an increased risk of death due to skin cancer, fair skinned women seem to have an overall survival advantage. In addition, an inverse association between sun exposure and hypertension, thromboembolism, and type 2 diabetes mellitus has been shown. Furthermore, low sun exposure habits result in increased risk of cardiovascular disease (CVD), and non-CVD/non-cancer mortality among women. There are also data supporting that the prognosis of cancer is improved with increasing levels of vitamin D/sun exposure. In this narrative review we will provide a brief update of hazards and benefits of sun exposure focused on an updated, balanced, and evidence-based view., (Copyright © 2022 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background: Sun exposure in combination with skin pigmentation is the main determinant for vitamin D status. Human skin color seems to be adapted and optimized for regional sun ultraviolet (UV) intensity. However, we do not know if fair, UV-sensitive skin is a survival advantage in regions with low UV radiation., Methods: A population-based nested case-control study of 29,518 Caucasian women, ages 25 to 64 years from Southern Sweden who responded to a questionnaire regarding risk-factors for malignant melanoma in 1990 and followed for 25 years. For each fair woman, defined as having red hair or freckles (n = 11,993), a control was randomly selected from all non-fair women from within the cohort of similar age, smoking habits, education, marital status, income, and comorbidity, i.e., 11,993 pairs. The main outcome was the difference in all-cause mortality between fair and non-fair women in a low UV milieu, defined as living in Sweden and having low-to-moderate sun exposure habits. Secondary outcomes were mortality by sun exposure, and among those non-overweight., Results: In a low UV milieu, fair women were at a significantly lower all-cause mortality risk as compared to non-fair women (log rank test p = 0.04) with an 8% lower all-cause mortality rate (hazard ratio [HR] = 0.92, 95% CI 0.84‒1.0), including a 59% greater risk of dying from skin cancer among fair women (HR 1.59, 95% CI 1.26‒2.0). Thus, it seem that the beneficial health effect from low skin coloration outweigh the risk of skin cancer at high latitudes., Conclusion: In a region with low UV milieu, evolution seems to improve all-cause survival by selecting a fair skin phenotype, i.e., comprising fair women with a survival advantage., Competing Interests: The authors have declared that no competing interests exist.

Advanced basal cell carcinomas (BCCs) circumvent Smoothened (SMO) inhibition by activating GLI transcription factors to sustain the high levels of Hedgehog (HH) signaling required for their survival. Unfortunately, there is a lack of efficacious therapies. We performed a gene expression-based drug repositioning screen in silico and identified the FDA-approved histone deacetylase (HDAC) inhibitor, vorinostat, as a top therapeutic candidate. We show that vorinostat only inhibits proliferation of BCC cells in vitro and BCC allografts in vivo at high dose, limiting its usefulness as a monotherapy. We leveraged this in silico approach to identify drug combinations that increase the therapeutic window of vorinostat and identified atypical PKC Ɩ/ʎ (aPKC) as a HDAC costimulator of HH signaling. We found that aPKC promotes GLI1-HDAC1 association in vitro, linking two positive feedback loops. Combination targeting of HDAC1 and aPKC robustly inhibited GLI1, lowering drug doses needed in vitro, in vivo, and ex vivo in patient-derived BCC explants. We identified a bioavailable and selective small-molecule aPKC inhibitor, bringing the pharmacological blockade of aPKC and HDAC1 into the realm of clinical possibility. Our findings provide a compelling rationale and candidate drugs for combined targeting of HDAC1 and aPKC in HH-dependent cancers.

Human basal cell carcinomas (BCCs) very frequently carry p53 mutations, and p53 loss markedly accelerates murine BCC carcinogenesis. We report here our studies of the mechanism by which p53 is activated to suppress BCC carcinogenesis. We find that aberrant hedgehog signaling in microscopic BCCs activates p53 in part via Arf (that is, the oncogene-induced stress pathway) but not via the DNA damage response pathway. However, Arf loss and p53 loss produce differing outcomes-loss of p53 promotes both tumor initiation and progression; loss of Arf promotes tumor progression but not initiation. Intriguingly, increased expression of Arf in tumor stromal cells, as in tumor keratinocytes themselves, contributes to suppression of BCC carcinogenesis.

Skin cancers are a rising menace as their incidence increases, attributed in part to increasing ultraviolet radiation exposure. This increasing problem has stimulated efforts to devise useful preventive approaches. The uncertain efficacy of exhortations to avoid sun exposure and to use protective clothing and sunscreens to reduce damage when exposed argue for the development of an oral chemopreventive agent. Bickers and others have studied the effects and mechanisms of tea and of its putative active components on inhibition of skin cancer in experimental models. To continue this work, we have studied the effects of oral green tea and black tea on a new model of ultraviolet-induced skin carcinogenesis - the development of basal cell carcinomas in ptc1+/- mice. To our surprise, we have found that tea preparations which others have used to prevent squamous cell carcinoma formation in mice fail to inhibit basal cell carcinogenesis in our model, suggesting that prevention of this cancer may require special, tumor-specific approaches., (Copyright 2001 S. Karger AG, Basel)

Activation of the hedgehog pathway, through the loss of patched (PTC) or the activation of smoothened (SMO), occurs frequently in basal cell carcinoma (BCC), the most common human cancer. However, the molecular basis of this neoplastic effect is not understood. The downstream molecule Gli1 is known to mediate the biological effect of the pathway and is itself up-regulated in all BCCs. Gli1 can drive the production of BCCs in the mouse when overexpressed in the epidermis. Here we show that Gli1 can activate platelet-derived growth factor receptor alpha (PDGFRalpha) in C3H10T(1/2) cells. Functional up-regulation of PDGFRalpha by Gli1 is accompanied by activation of the ras-ERK pathway, a pathway associated with cell proliferation. The relevance of this mechanism in vivo is supported by a high level expression of PDGFRalpha in BCCs of mice and humans. In the murine BCC cell line ASZ001, in which both copies of the PTC gene are inactivated, DNA synthesis and cell proliferation can be slowed by re-expression of PTC, which down-regulates PDGFRalpha expression, or by downstream inhibition of PDGFRalpha with neutralizing antibodies. Therefore, we conclude that increased expression of PDGFRalpha may be an important mechanism by which mutations in the hedgehog pathway cause BCCs.

Basal cell carcinomas are can be induced by ionizing radiation, in particular in patients with the rare autosomal dominant basal cell nevus syndrome (BCNS). These patients also are prone to medulloblastomas, and curative ionizing radiation therapy for the latter is followed soon by the development of sheets of basal cell carcinomas in the overlying skin. Positional cloning of the gene mutant is BCNS patients has identified the hedgehog signaling pathway as crucial to the development of all basal cell carcinomas and presumably to this susceptibility to post-ionizing radiation carcinogenesis. Thus this pathway is a candidate for susceptibility to second, post-therapy cancers in the broader population., (Copyright 2001 Wiley-Liss, Inc.)

Mutations in hedgehog signaling pathway genes, especially PTC1 and SMO, are pivotal to the development of basal cell carcinomas. The study of basal cell carcinoma gene expression not only may elucidate mechanisms by which hedgehog signaling abnormalities produce aberrant tumor cell behavior but also can provide data on in vivo hedgehog target gene control in humans. We have found, in comparison with normal skin, that basal cell carcinomas have increased levels of mRNA for PTC1, GLI1, HIP, WNT2B, and WNT5a; decreased levels of mRNA for c-MYC, c-FOS, and WNT4; and unchanged levels of mRNA for PTC2, GLI2, WNT7B, and BMP2 and 4. These findings suggest that mutations in hedgehog signaling pathway genes may exert both cell autonomous and indirect effects and indicate that basal cell carcinoma tumor cells have a phenotype that at least in some aspects resembles that of epidermal stem cells.

Cyclooxygenase (COX) is the rate-limiting enzyme in the production of prostaglandins from arachidonic acid. This enzyme exists in at least two isoforms, COX-1 and COX-2. COX-1 is constitutively expressed in most tissues and plays various physiological roles. However, COX-2 expression is induced by a variety of agents, which include pro-inflammatory agents and mitogens. Evidence exists to indicate that increased expression of COX-2 occurs in several types of epithelial neoplasms. In this study, we show the effect of chronic exposure of murine skin to carcinogenic UVB on cutaneous COX-2 expression. SKH-1 mice were irradiated with 180 mJ/cm(2) UVB daily for five days a week for periods ranging from 1 to 20 weeks. Nontumor bearing skin areas of irradiated mice, skin of age-matched controls and benign papillomas and malignant tumors were assessed immunohistochemically for COX-2 expression in these mice. No epidermal staining occurred in any of the non-UVB-treated controls throughout the experiment. Epidermal COX-2 expression only occurred in UVB-irradiated mice. After 1 and 5 weeks of irradiation, patchy epidermal staining mostly confined to the granular layer and stratum corneum was observed. At week 9, staining intensity had increased, particularly in the granular layer. At week 13, staining was uniformly seen in all epidermal layers with particular prominence in the basal cell layer underlying areas of visible epidermal hyperplasia. It is of interest that the most intense staining was seen in the perinuclear region of keratinocytes and at the plasma membrane. At week 20, COX-2 staining was predominant in the granular layer, although in some tissue sections, the entire epidermis was positive. In benign papillomas, staining was confined to the superficial layers of the epidermis and in squamous cell carcinomas (SCCs), patchy staining in the granular and spinous layers predominated. In general, COX-2 expression was more intense in well-differentiated SCCs than in papillomas. In summary, our results indicate that COX-2 serves as an early marker of epidermal UVB exposure and its expression increases in benign papillomas and in SCCs. These results suggest that pharmacological intervention using specific COX-2 inhibitors could have anticarcinogenic effects in UVB-induced human skin cancer., (Copyright 2001 Academic Press.)

The identification of mutations in Hedgehog (HH) pathway genes in some basal cell carcinomas (BCC) and the detection of HH pathway dysregulation in almost all BCC confirms the importance of this developmental regulatory pathway in human BCC tumorigenesis. Moreover, the occurrence of UVB signature mutations in key HH pathway genes in BCC provides the first genetic evidence that UV radiation (UVR) may be the principal mutagen involved in BCC tumorigenesis. We review herein current advances in the understanding of the role of the HH pathway in BCC tumorigenesis including transgenic and knock-out animal models of HH pathway dysregulation. Furthermore, we summarize abnormalities in other tumor suppressors and oncogenes including ras and p53 and evidence for interactions between these regulatory genes and the HH pathway.

Mutations in PATCHED (PTC), the human homolog of the Drosophila patched gene, have been identified in most exons of the gene in patients with the basal cell nevus syndrome and in sporadic basal cell carcinomas. We have screened the 23 PTC exons for mutations using single strand conformation polymorphism analysis of DNA from 86 basal cell nevus syndrome probands, 26 sporadic basal cell carcinomas, and seven basal cell nevus syndrome-associated basal cell carcinomas. This screen identified mutations located in eight exons in 13 of the basal cell nevus syndrome patients and in three of the tumors. The most common mutations were frameshifts resulting in premature chain termination. These results provide further evidence for the crucial role of PTC as a tumor suppressor in human keratinocytes.

Basal-cell carcinomas (BCCs) are the commonest human cancer. Insight into their genesis came from identification of mutations in the PATCHED gene (PTCH) in patients with the basal-cell nevus syndrome, a hereditary disease characterized by multiple BCCs and by developmental abnormalities. The binding of Sonic hedgehog (SHH) to its receptor, PTCH, is thought to prevent normal inhibition by PTCH of Smoothened (SMO), a seven-span transmembrane protein. According to this model, the inhibition of SMO signalling is relieved following mutational inactivation of PTCH in basal-cell nevus syndrome. We report here the identification of activating somatic missense mutations in the SMO gene itself in sporadic BCCs from three patients. Mutant SMO, unlike wild type, can cooperate with adenovirus E1A to transform rat embryonic fibroblast cells in culture. Furthermore, skin abnormalities similar to BCCs developed in transgenic murine skin overexpressing mutant SMO. These findings support the role of SMO as a signalling component of the SHH-receptor complex and provide direct evidence that mutated SMO can function as an oncogene in BCCs.

Mutations in the tumor suppressor gene PATCHED (PTC) are found in human patients with the basal cell nevus syndrome, a disease causing developmental defects and tumors, including basal cell carcinomas. Gene regulatory relationships defined in the fruit fly Drosophila suggest that overproduction of Sonic hedgehog (SHH), the ligand for PTC, will mimic loss of ptc function. It is shown here that transgenic mice overexpressing SHH in the skin develop many features of basal cell nevus syndrome, demonstrating that SHH is sufficient to induce basal cell carcinomas in mice. These data suggest that SHH may have a role in human tumorigenesis.

Background: Patients with a basal cell carcinoma (BCC) are at increased risk for developing further BCCs, and long-term follow-up has been recommended to detect new cancers at an earlier, more easily treatable stage. The majority of BCCs are treated by dermatologists in their offices; we do not know to what extent they perform long-term follow up on their patients., Objective: To determine how practicing dermatologists follow up their BCC patients., Methods: A mailed questionnaire survey of 166 practicing members of a regional dermatologic society (the San Francisco Dermatological Society), to which 142 (85%) replied., Results: Two thirds of the respondents recalled BCC patients for screening examinations; of these, 58% followed up non-responders. Recall efforts were hampered by inefficient, unwieldy, and time-consuming techniques., Conclusion: Practicing dermatologists are motivated to recall BCC patients for examination, but guidelines and techniques for effective and efficient computerized recalling of skin cancer patients are needed. It is suggested that the American Academy of Dermatology set up a task force to develop guidelines and criteria for effective recall software.

Background: The identification of genes whose mutations underlie hereditary diseases has long been a holy grail and one whose satisfaction very recently has become a reality for a surprisingly large number of dermatologic diseases., Observations: This review summarizes in brief the chromosomal localization and, where known, the gene identification for diseases expressed primarily in the skin. These vary from skin cancer genes whose products control cell growth and carry out DNA repair to skin fragility genes whose products impart mechanical stability to the skin., Conclusions: The explosion of new data in the past several years summarized herein is nearly unprecedented and bodes well for the development of new therapeutic approaches to common as well as rare skin disorders.

One hundred forty-three patients with cutaneous T cell lymphoma were treated with topical carmustine (BCNU). A complete response was obtained in 86% of those with limited extent (less than 10%) plaques (T1 stage), in 48% of those with extensive (greater than or equal to 10%) plaques (T2 stage), and in 21% of those with erythroderma. The median time to achieve complete response was 11.5 weeks. Favorable results were obtained in patients with less than 5% involvement treated locally. Mild hematopoietic depression occurred in less than 10% of patients. Erythematous reactions were common, but no secondary cutaneous malignancies occurred. Differences in freedom from relapse or in survival between T2-stage patients with and those without clinical adenopathy were not statistically significant. The 5-year overall survival rate was 77%; the median survival time was 9.4 years.

Treatment of thin (superficial) basal cell carcinomas (BCCs) with topical fluorouracil is widely accepted despite the absence of published five-year cure rates. The published short-term data disclose treatment failure rates substantially higher than other modalities. In trials to improve and standardize topical fluorouracil therapy, thin BCCs were treated with 25% fluorouracil in petrolatum under occlusion for three weeks using weekly dressing changes. Of 44 thin BCCs treated only with 25% fluorouracil under occlusion for three weeks, the five-year cumulative recurrence rate was 21%. In a second series of 244 BCCs, light curettage preceded the 25% fluorouracil treatment to yield a five-year cumulative recurrence rate of 6%. Cosmetic results were good to excellent in more than 80% of both series. While fluorouracil by itself is not a satisfactory treatment for thin BCC, when combined with light curettage, topical fluorouracil therapy is capable of cure rates competitive with other modalities.

The Mycosis Fungoides Cooperative Group has been following patients with cutaneous T-cell lymphoma, including mycosis fungoides and the Sézary syndrome variant. Previous analyses identified the extent of skin involvement and the number of sites of clinically enlarged lymph nodes as important prognostic variables. These two variables were used to classify 340 patients into four clinical stages. Repeat analysis based on additional followup data shows the usefulness of this clinical staging system for identifying patients with differing survival experience. An alternative grouping suggested by fitting a survival model to the data also has been studied. Staging systems based only on skin involvement and lymph nodes are recommended for general use because the information needed is readily available, requiring only physical examination.

Twelve consecutive patients with advanced stage mycosis fungoides (MF) were treated with combined total body X ray irradiation (TBI) and total skin electron beam radiotherapy (EBRT). Six had generalized plaque disease and dermatopathic nodes, three had tumor stage disease and node biopsy positive for mycosis fungoides, and three had erythroderma/Sezary syndrome. The treatment regimen consisted of split course total body X ray irradiation, given in twice weekly 15 cGy fractions to 75 cGy, then total skin electron beam radiation therapy given in once weekly 400 cGy fractions to a total dose of 2400 cGy. Underdosed areas and areas of greatest initial involvement were boosted 400 cGy twice weekly for an additional 1200 cGy. This was followed by a second course of total body X ray irradiation, to a total dose of 150 cGy. The total skin electron beam radiotherapy technique is a modification of an established six position EBRT technique for mycosis fungoides. Measurements to characterize the beam with and without a lexan scattering plate, demonstrated that the combination of no-plate beams produced better dose uniformity with a much higher dose rate. This improved technique is particularly advantageous for elderly and/or frail patients. Nine (75%) of the 12 patients achieved complete response (CR). The other three had significant improvement with greater than 80% clearing of their disease and resolution of symptoms. All six patients with generalized plaque disease achieved complete response and remained free of disease from 2 to 16 months. Two of three node positive patients also achieved complete response; one, with massive biopsy-documented mycosis fungoides nodal disease and deep open tumors, remained relapse-free over 2 years. Only one of the three patients with erythroderma/Sezary syndrome achieved a complete response, which was short lived. Therapy was well tolerated. No significant hematological toxicity occurred. Although total body X ray irradiation and total skin electron beam radiotherapy produced excellent palliation of patients with advanced stage mycosis fungoides, new strategies to provide more effective systemic treatment are needed.

On the basis of a study of 193 patients with localized melanoma followed for 25 years, it appears that such tumors are curable, in about 75% of the cases, by surgical removal alone. Of the 41 patients who died from this tumor, 92% succumbed during the first decade and the rest during the next five years. There were no deaths due to melanoma after 15 years of observation. Prophylactic lymph node dissection on these localized cases improved the survival statistics, but this may have been due to the elimination from this series of those with microscopic nodal metastases. A hopeless prognosis is unjustified in patients with primary melanoma because approximately only 25% of the patients in this series succumbed to this tumor during the 25 years of observation. Therapy in such individuals should be conservative until the diagnosis has been established by histopathologic examination. This policy minimizes unnecessary multilation and morbidity in benign lesions. The diagnosis should be suspected early and established or eliminated at the earliest possible time.

Facial nerve paralysis developed in a man with tumor-stage mycosis fungoides (MF). Mastoidectomy disclosed that MF had involved the mastoid and middle ear. Meningeal lymphoma, confirmed by the finding of Sézary cells in the CSF, was subsequently established. Autopsy disclosed MF lymphoma in the leptomeninges, medulla, spinal cord, and cranial nerves. A unique feature was the formation of a communicating hydrocephalus. Case reports of 23 patients with MF of the CNS, including 21 autopsies, are reviewed. Practically all had tumor-stage or erythrodermic MF. Atypical mononuclear cells were found ante mortem in the CSF in eight patients. In contrast to other CNS lymphomas, bone marrow involvement was uncommon. Cranial, especially facial, nerve paralyses were often premonitory signs of meningeal lymphomas. Patients with MF having such symptoms should have cytologic examination of the CSF.

Mycosis fungoides is a lymphoma that appears to begin in skin. Although variable in its clinical course, it tends to affect middle-aged people, is present for a median of 4 yr before diagnosis, and generally results in death of the patient 4 to 5 yr after diagnosis. Cutaneous tumors and palpably enlarged lymph nodes are associated with shortened survival, and each of these frequently is accompanied by extracutaneous dissemination of the disease. The malignant cells are T lymphocytes with highly infolded nuclei, and they frequently express a helper cell function. Their chromosome complement has been found to be abnormal in karyotyping studies, and measurement of the amount of DNA by cytophotometry may permit diagnosis of the disease before the histological characteristics are detectable by light microscopy.

Twenty-six patients with mycosis fungoides were treated topically with three nitrosourea compounds: carmustine (BCNU), lomustine (CCNU), and 1-methyl-1-nitrosourea. A high percentage experienced good to excellent results. Remissions following treatment of individual lesions varied from one month to at least three years. Remissions following total body surface treatment varied from two weeks to at least four months. Two of 13 patients treated over the entire body suffered temporary bone marrow depression, indluding one with severe pancytopenia. This toxic effect was attributed to lomustine and was not seen in patients treated with carmustine alone. Thirteen patients highly allergic to mechlorethamine hydrochloride showed no cross-sensitivity to nitrosourea compounds. A primary irritant dermatitis occurred in about one half of the patients and telangiectasia in two. Two patients developed hypersensitivity to nitrosourea compounds. Carmustine is the preferred nitrosourea compound for topical therapy of mycosis fungoides.

In three patients with histologically documented mycosis fungoides, all or most of the lesions were hypopigmented. Unsuspected microscopic foci of mycosis fungoides were found in a purely macular hypopigmented area in one of these patients who had been treated with vitiligo 15 years earlier. Two of the patients were black, and one was Latin American. Repigmentation in all patients followed treatment with carmustine (BCNU) and mechlorethamine.

Mycosis fungoides is a T-cell lymphoma which is often localized to the skin in the early stages. Untreated, the process eventually progresses through eczematous, plaque, and tumor stages to systemic involvement. Its course, however, is unpredictable. Topical chemotherapy is effective in early stages of mycosis fungoides. Possibly prognostic benefits can occur from the early use of these agents. Nitrogen mustard and BCNU, both alkylating agents, have been used topically to control the disease. A dermatitis may develop in persons treated with nitrogen mustard but systemic side-effects are rare. However, BCNU may rarely lead to marrow depression when used topically. The use of these agents in mycosis fungoides is discussed herein.

Tattooing with India ink is a precise and practical method for identifying biopsy sites when there is a significant delay between biopsy and definitive surgery.

The frequency and prognostic importance of various characteristics of patients registered by the Mycosis Fungoides Cooperative Group between November 1974 and December 1977 are reported. Variables which were considered include demographic and historical factors, symptoms, extent of disease, and other physical findings. A staging system which is based on the extent of skin involvement and the number of nodal sites clinically involved is described. Finally, a description of therapeutic results to date for patients randomized into Mycosis Fungoides Cooperative Group protocols is presented.

Excision of primary malignant melanomas by a cautery (actual heat) or by endothermy (electric cutting current) is a simple method of management. It consists of excision of a disc of tissue that contains the evident malignancy plus some surrounding normal-appearing skin.

A 10-year experience in eighty-six patients confirms the effectiveness of topical carmustine (BCNU) in mycosis fungoides (MF). Complete remission (CR) was achieved in 84% of those with less than 10% involvement (stage IA), median CR, 12 months, and in 52% with greater than 10% involvement (stage IB), median CR, 23 months. The probability of freedom from relapse for 1 year was 72% in stage IA and 37% in stage IB. No deaths in stages IA or IB were attributable to MF. Including all causes of death, the probability of 5-year survival for stage IA was 93% and for stage IB, 48%. Good results were obtained with only local BCNU in fourteen patients with mostly less than 5% involvement. Five of seven with poikilodermatous MF, two with parapsoriasis en plaques (PEP), and three with lymphomatoid papulosis did well. Persistent local therapy cleared deeply infiltrated lesions in some patients. With present schedules, the hazard of bone marrow depression is slight. Erythematous reactions and telangiectasia are troublesome but have not been accompanied by premalignant changes.