Genetics and risk factors for basal cell carcinoma

Is there any gender-specific impact in the treatment of patients with basal cell carcinoma in the head and neck region?

Background

There are no current studies concerning gender-specific impact on the treatment of BCCs. We performed a retrospective analysis with the aim of showing that selection of treatment by physician and patients' evaluation concerning quality of life and aesthetic outcome has a gender-specific impact.

Methods

Overall, 47 patients treated by excision of BCC from the head and neck region at our department from 2015 to 2020 were included. Defects were closed via flap, split-thickness skin graft. or primary closure. Pain, scar quality, patient satisfaction and quality of life were ascertained by the Skin Cancer Index (SCI), the Basal and Squamous Cell Carcinoma Quality of Life (BaSQoL) questionnaire, Patient and Observer Scar Assessment Scale (POSASv2.0EN) and Vancouver Scar Scale (VSS).

Results

Women received significantly more flaps than split-thickness skin grafts (p = 0.025). The coverage method was independent of surgeons' gender.Patient's POSAS were higher in women (p = 0.087), and observer's POSAS (p = 0.229) and VSS (p = 0.7) showed no significant difference between genders.SCI and BaSQoL scores showed that women are significantly more critical than men after BCC treatment (SCI p = 0; BaSQoL p = 0.022). Furthermore, dermatological follow-up frequency was significantly higher in women (p = 0.035).

Conclusion

We determined the gender-specific impacts on the treatment of patients with BCCs regarding methods of closure, post-interventional dermatological follow-ups, quality of life, scar quality, and overall patient satisfaction. No difference in scar quality was found when assessed by physicians.

The Association Between Aspirin and Basal Cell Carcinoma: A Clinical and Financial Analysis

Background

Nonmelanoma skin cancer (NMSC) is the most common malignancy. Basal cell carcinoma (BCC) comprises about 80% of all NMSCs and its incidence continues to rise. Although BCC rarely leads to metastases or increased mortality, its effects on healthcare costs and quality of life are substantial. Aspirin may prevent the development of basal cell carcinoma (BCC) by the inhibition of cyclooxygenase (COX) enzymes, which are associated with carcinogenesis and inflammation. This study therefore examined the effect of aspirin on the risk of BCC, its clinical outcomes, and its treatment costs.

Methods

A retrospective study (2010 - 2018) was conducted using the Humana Health Insurance Database. International Classification of Disease ninth and 10th codes and National Drug Codes were used to identify BCC diagnoses and aspirin prescriptions. Patients were matched for age, sex, Charlson Comorbidity Score (CCI), and region of residence. Chi-squared, logistic regression, and odds ratio (OR) analyses were utilized to test for significance and to estimate relative risk.

Results

Aspirin use was associated with a decreased incidence of BCC in unmatched (OR = 0.658, 95% confidence interval (CI) 0.526 - 0.820) and matched (OR = 0.54, 95% CI 0.47 - 0.61) analyses. Aspirin was also associated with a decreased BCC risk when stratified by hypertension (P = 3.888 × 10^-5), chronic obstructive pulmonary disease (COPD) (P = 0.014), diabetes (P = 0.049) and tobacco use (P = 0.017). Aspirin use was not associated with risk of BCC when stratified by obesity (P = 0.408). The average paid per patient for BCC treatment was significantly higher for patients in the aspirin use group than in the aspirin nonuse group (P = 0.0087).

Conclusions

While the high incidence and cost of treatment of BCC are demanding both clinically and financially, the low cost of aspirin and its widespread use may have vital implications for its preventative role in this disease. This study concluded that aspirin use was associated with a significantly decreased risk of BCC.

Associations of keratinocyte cancers with snp variants in the sonic hedgehog pathway

BACKGROUND

Sonic Hedgehog (SHH) pathway dysregulation is implicated in basal cell carcinoma (BCC) development. To evaluate the possible wider role of SHH gene variants in skin carcinogenesis, we assessed associations of genes in the SHH pathway with lifetime development of any keratinocyte cancer (KC), and with developing either BCCs or squamous cell carcinomas (SCCs) exclusively, in a 25-year prospective, population-based study of 1,621 Australians.

METHODS

We genotyped 795 unrelated adults with available blood samples: 311 cases with any KC (186 developing BCCs-only, 55 SCCs-only, 70 BCCs and SCCs) and 484 controls. We compared allele frequencies of 158 independent SNPs across 43 SHH genes between cases and controls, and performed a gene-based analysis.

RESULTS

We found associations between SNP rs4848627 (GLI2) (related to DNA synthesis in keratinocytes) and development of any KC (OR = 1.53; 95% CI = 1.06-2.13, P < 0.01) and SCCs exclusively (OR = 2.12; 95%CI = 1.39-3.23, P < 0.01). SNP rs3217882 located in CCND2 was associated with exclusive BCC development (OR = 1.43, CI = 1.12-1.82, P < 0.01). The gene-based analysis suggested an association of PRKACG (protein kinase cAMP-activated catalytic subunit gamma) with any KC (P = 0.013).

CONCLUSION

We conclude that variants located in genes in the SHH pathway may are involved in SCC as well as BCC development.

Anatomical distribution of basal cell carcinoma in Israel using relative tumor density scores

BACKGROUND

Ultraviolet radiation (UVR) is considered a major risk factor for the development of basal cell carcinoma (BCC). Calculating the relative tumor density (RTD) by adjusting the proportion of BCC lesions relative to the skin surface area at a specific site enables comparison of the proportion of tumors at different anatomical sites and better understanding of the association with sun exposure.

OBJECTIVES

To characterize anatomical distribution of BCC in the Israeli population using RTD score.

METHODS

A retrospective, cross-sectional study that includes all histologically confirmed BCC samples obtained from a major national pathological institute, which receives specimens from numerous surgeons throughout Israel, during the first trimester of 2012.

RESULTS

A total of 1,712 skin lesions were diagnosed as BCC during the study period. RTD in the head and neck area was the highest over the body (RTD = 6.6). We found that RTD over the upper arms in males was higher than the proportion of skin surface area (RTD = 1.1). A comparison of RTD values in subsites of the head and neck region indicates that men have higher RTD values for the ears, neck, and scalp than women. However, the nose and eyes areas have female predominance.

CONCLUSIONS

Using RTD scores, our study demonstrates the unique UVR exposure pattern in the Mediterranean climate of Israel and supports the notion that UVR is an important risk factor for the development of BCC lesions.

Basal cell carcinomas of the scalp after radiotherapy for tinea capitis in childhood: A genetic and epigenetic study with comparison with basal cell carcinomas evolving in chronically sun-exposed areas

BACKGROUND

Basal cell carcinoma (BCC) has been mostly associated with sun exposure, but ionizing radiation is also a known risk factor. It is not clear if the pathogenesis of BCC, namely at a genomic and epigenetic level, differs according to the underlying triggering factors.

OBJECTIVE

The present study aims to compare genetic and epigenetic changes in BCCs related to ionizing radiation and chronic sun exposure.

METHODS

Tumor samples from BCCs of the scalp in patients submitted to radiotherapy to treat tinea capitis in childhood and BCCs from sun-exposed areas were analysed through array comparative genomic hybridization (array-CGH) and methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) to detect copy number alterations and methylation status of specific genes.

RESULTS

Genomic characterization of tumor samples revealed several copy number gains and losses in all chromosomes, with the most frequent gains observed at 2p, 6p, 12p, 14q, 15q, 18q, Xp and Yp, and the most frequent losses observed at 3q, 14q, 16p, 17q, 22q, Xp, Yp and Yq. We developed a statistical model, encompassing gains in 3p and 16p and losses in 14q and 20p, with potential to discriminate BCC samples with sporadic aetiology from BCC samples that evolve after radiotherapy in childhood for the treatment of tinea capitis, which presented statistical significance (P = 0.003). Few methylated genes were detected through MS-MLPA, most frequently RARB and CD44.

CONCLUSIONS

Our study represents a step forward in the understanding of the genetic mechanisms underlying the pathogenesis of BCC and suggests potential differences according to the underlying ris k factors.

Circular RNA hsa_Circ_0005795 mediates cell proliferation of cutaneous basal cell carcinoma via sponging miR-1231

Growing evidence has revealed that circular RNAs (circRNA) play critical roles in cancer progression. Here, we examined the function of a novel circRNA, Circ_0005795, in basal cell carcinoma (BCC) and explored the possible molecular mechanism. Nodular BCC and adjacent non-tumor tissues derived from 30 patients and 2 BCC cell lines were applied to analyze gene expression. Circ_0005795 loss- and gain-of-function were constructed to investigate BCC progression. Nuclear and cytoplasmic fractionation and luciferase assay were carried out to determine cellular localization and molecular interaction of Circ_0005795. Circ_0005795 expression was significantly elevated in BCC tissues and cells. Knockdown of Circ_0005795 dramatically reduced cell viability, colony formation, and anti-apoptotic protein levels, while increased caspase-3 activity. Circ_0005795 located in cytoplasm, which exerted its tumor-promoting effect through targeting and sponging miR-1231 in BCC cells. In summary, Circ_0005795 works as an oncogene in BCC, which might be used as a promising biomarker and a potential therapeutic target for BCC diagnosis and treatment.

Eruptive Basaliomas: "Why we have to Perform Surgery?" Or Said Otherwise: "Catch The Metatypical!"

BACKGROUND

Keratinocyte cancers are malignant diseases with a broad incidence of spread which tends to increase during the last couple of decades. The solar radiation plays a dominant role in the occurrence of BCC, but certain genetic phenotypes appear to be risky from an etiological point of view. Metatypical basal cell carcinoma (MTBCC) is a rare variant of BCC which combines the clinical and histological characteristics of BCC and SCC. Clinically they are indistinguishable from the conventional BCC, and only the histological examination can differentiate them. The MTBCC is a histological subtype which is considered more aggressive due to its ability to produce local recurrences or distant metastases.

CASE REPORT

We present a 44-year old patient with multiple BCCs disseminated on the face and body. The biopsy established mixed type histology: three metatypical and four solid BCCs. The lesions were removed via elliptical excision with a field of operational security of 0.5 cm in all directions.

CONCLUSIONS

The eruptive (multiple) BCCs are a challenge about the choice of a therapy option. This is because clinically completely identical tumours show different histopathological characteristics, namely those with a tendency to metastasise. Having in mind one of the hypotheses of metatypical BCC emergence - the improper or inadequate radiotherapy (as a choice of therapy) could trigger the transition of a conventional tumour to a metastasising one, the surgical treatment appears to be the most secure treatment method.

Molecular basis of basal cell carcinoma

Basal cell carcinoma is the most common cancer, presenting low mortality but high morbidity, and it has as risk factor exposure to sunlight, especially UVB spectrum. The most important constitutional risk factors for basal cell carcinoma development are clear phototypes (I and II, Fitzpatrick classification), family history of basal cell carcinoma (30-60%), freckles in childhood, eyes and light hair. The environmental risk factor better established is exposure to ultraviolet radiation. However, different solar exposure scenarios probably are independent risk factors for certain clinical and histological types, topographies and prognosis of this tumor, and focus of controversy among researchers. Studies confirm that changes in cellular genes Hedgehog signaling pathway are associated with the development of basal cell carcinoma. The cellular Hedgehog signaling pathway is activated in organogenesis, but is altered in various types of tumors.

Multiple nonsyndromic acquired basal cell carcinomas : Uncommon clinical presentation in a Bulgarian patient

Basal cell carcinoma is the most frequent cutaneous neoplasm, with slowly progressive nature and locally invasive behavior. Despite the low metastatic potential, local tissue destruction and disfigurement caused by the tumor can be large if not eradicated in time by early diagnosis and treatment. Both genetic predisposition and exposure to environmental risks are involved in the pathogenesis of the malignant transformation in BCC. The total number of nonmelanocytic skin cancers is a risk factor for recurrence of previous tumor, on the one hand, as well as for the formation of new ones, on the other. It is still unclear what environmental and genetic factors contribute to the development of multiple nonsyndromic BCCs. We present a man with multiple sporadic, nonsyndromic BCCs, with a history of even more lesions, removed earlier, as we discuss the potential triggering risk factors and pathogenic mechanisms of malignant transformation and the further appropriate therapeutic options. The early detection and eradication of these tumors are of importance for treatment effectiveness and quality of life because although rarely metastatic, BCCs could have an aggressive course and behavior which can lead to severe disfiguration and destruction.

Factors influencing and modifying the decision to pursue genetic testing for skin cancer risk

BACKGROUND

Across cancers, the decision to pursue genetic testing is influenced more by subjective than objective factors. However, skin cancer, which is more prevalent, visual, and multifactorial than many other malignancies, may offer different motivations for pursuing such testing.

OBJECTIVES

The primary objective was to determine factors influencing the decision to receive genetic testing for skin cancer risk. A secondary objective was to assess the impact of priming with health questions on the decision to receive testing.

METHODS

We distributed anonymous online surveys through ResearchMatch.org to assess participant health, demographics, motivations, and interest in pursuing genetic testing for skin cancer risk. Two surveys with identical questions but different question ordering were used to assess the secondary objective.

RESULTS

We received 3783 responses (64% response rate), and 85.8% desired testing. Subjective factors, including curiosity, perceptions of skin cancer, and anxiety, were the most statistically significant determinants of the decision to pursue testing (P < .001), followed by history of sun exposure (odds ratio 1.85, P < .01) and history of skin cancer (odds ratio 0.5, P = .01). Age and family history of skin cancer did not influence this decision. Participants increasingly chose testing if first queried about health behaviors (P < .0001).

LIMITATIONS

The decision to pursue hypothetical testing may differ from in-clinic decision-making. Self-selected, online participants may differ from the general population. Surveys may be subject to response bias.

CONCLUSION

The decision to pursue genetic testing for skin cancer is primarily determined by subjective factors, such as anxiety and curiosity. Health factors, including skin cancer history, also influenced decision-making. Priming with consideration of objective health factors can increase the desire to pursue testing.

[Therapy of basal cell carcinoma]

Basal cell carcinoma (BCC) represents the most common malignant skin tumour in fair-skinned people. Despite low metastatic potential, BCC can cause decisive tissue destruction and disfigurement by invasive growth. In addition to clinical and histologic diagnosis modern imaging techniques as optical coherence tomography and confocal laser microscopy have been introduced. BCCs with aggressive growth pattern and/or increased risk of relapse are preferentially treated surgically. For superficial BCCs various topical treatments and photodynamic therapy are available. Inhibitors of the sonic hedgehog pathway have been approved for symptomatic treatment of metastatic BCC and locally advanced BCC inappropriate for surgery or radiotherapy. Detailed knowledge of the clinical spectrum of BCC and an appropriate choice of therapy are mandatory for the successful treatment of BCC.

High mobility group box 1 regulates tumor metastasis in cutaneous squamous cell carcinoma via the PI3K/AKT and MAPK signaling pathways

The present study examined the mechanisms of high mobility group box 1 (HMGB1)-induced cell migration in human cutaneous squamous cell carcinoma (CSCC) SCC13 cells. Western blotting, a chemotaxis assay and ELISA were performed to analyze HMGB1 level in SCC13 cells and its ability to regulate tumor metastasis. The results demonstrated a significantly higher level of HMGB1 in the SCC13 cell supernatant compared with the human epidermoid carcinoma A431 cell supernatant. Administration of HMGB1 to the SCC13 cells caused cell migration, which occurred in a time- and dose-dependent manner. Moreover, HMGB1 significantly activated the phosphosphoinositide 3-kinase (PI3K)/AKT and mitogen-activated protein kinase (MAPK) signaling pathways by an increased level of phosphorylation in p85PI3K, AKT, p38 and p42/44 MAPK. Taken together, these data suggest that HMGB1 regulates tumor metastasis in CSCC via the PI3K/AKT and MAPK signaling pathways.

Tanning beds: A call to action for further educational and legislative efforts

BACKGORUND AND OBJECTIVES

Melanoma is steadily increasing over the past decade. Recent studies confirmed a link between tanning bed use and melanoma. We sought to determine the prevalence and frequency of tanning bed among young patients with melanoma.

METHODS

We retrospectively analyzed tanning bed use among young melanoma patients compared to controls selected from the hospital medical records. A telephone survey investigated family history of melanoma or skin cancer, hair color, eye color, skin type, tanning bed use, and patient awareness of dangers of tanning bed use.

RESULTS

A total of 601 melanoma cases were identified; 265 (44%) completed the telephone survey as did 195 (31%) controls. Of these 460 subjects, 260 were female. Females were 3.0 times more likely to have used a tanning bed. Melanoma patients had natural light color hair, blue-green eyes, and 2.0 times more likely to use a tanning bed than controls. Among the tanning bed users, 90% were aware of danger of tanning bed.

CONCLUSIONS

Our study found that tanning beds were more likely to be used by young women, the majority of whom are aware of the associated risks. Eliminating the use of tanning beds should be considered to decrease the incidence of melanoma.

Cellular and biological evaluation and diagnostic immunohistochemistry of cytokeratin 15/19 expression in distinguishing cutaneous basal cell carcinoma

Recent studies have investigated the expression of proliferative markers, but little is known about the expression of cytokeratin 15 and 19 in different histological subtypes of basal cell carcinoma (BCC). We conducted cellular, biological, clinicopathological and immunohistochemical analysis on the manifestations of 8 BCC by hematoxylin and eosin stain (H&E) staining and immunohistochemistry and reviewed relevant literature. Microscopically, the tumor cells were multiple remarkable foci of epidermolytic hyperkeratosis with large pleomorphic nuclei and scant cytoplasm together with peripheral palisading and forming solid nests. Furthermore, the most tumors were composed of highly cellular areas with a homogenous population of round, ovoid and spindle cells, hyperchromatic nuclei, high cellular pleomorphism, high mitotic index and various morphologic patterns. Moreover, the tumors displayed an invasive growth, with positive expression of Cytokeratin 19 (CK19) and negative expression of CK15. Our study revealed that the expression of CK19 was associated with progression and invasion in cases with BCC and immunohistochemistry is indispensable in distinguishing this tumor from other types of cutaneous carcinoma. To our best knowledge, it may be a considerable biomarker to assess invasiveness of cutaneous-surface BCC and to guide clinical management of such tumors.

S100A7 acts as a dual regulator in promoting proliferation and suppressing squamous differentiation through GATA-3/caspase-14 pathway in A431 cells

S100A7 is expressed in many squamous cell carcinomas (SCCs), such as SCC of the skin, and well-differentiated SCC always displays stronger staining of this protein. A431 cells, an epidermal cancer cell line, were selected as a cell model to investigate the roles and mechanism of S100A7 in SCC of the skin. In this study, we demonstrated that the overexpression of S100A7 in A431 cells significantly promoted cell proliferation in vitro and tumor growth in vivo, whereas it suppressed the expression of GATA-3, caspase-14 and three squamous differentiation markers, keratin-1, TG-1 and involucrin. Conversely, the overexpression of caspase-14 not only significantly decreased cell proliferation and delayed tumor growth but also markedly induced the expression of three squamous differentiation markers, whereas S100A7 and GATA-3 were not influenced. Further evidence showed that silencing GATA-3 greatly inhibited the expression of caspase-14 and three differentiation markers, while the expression of S100A7 was not changed; contrary results were obtained when overexpressing GATA-3. Importantly, restoring the expression of GATA-3 and caspase-14 in A431-S100A7 cells could bypass the ability of S100A7 to increase cell viability and repress squamous differentiation. These data suggested that S100A7 expression in SCC may play an important role in the maintenance of SCC cell dedifferentiation, at least in SCC of the skin.

Overexpression of p300 correlates with poor prognosis in patients with cutaneous squamous cell carcinoma

BACKGROUND

It has been suggested that the p300 transcriptional coactivator participates in the regulation of a wide range of cell biological processes, and mutations in p300 have been identified in various cancers.

OBJECTIVES

To investigate p300 expression in cutaneous squamous cell carcinoma (cSCC) tissues and its effect on the outcome of patients with cSCC.

METHODS

Immunohistochemistry (IHC) was performed on a tissue microarray to investigate p300 expression levels in cSCC tissues. Receiver operating characteristic (ROC) curve analysis, Kaplan-Meier plots and a Cox proportional hazards regression model were used to analyse the data.

RESULTS

Based on the ROC curves, we defined the cut-off score for high p300 expression as > 55% of tumour cells positively stained. High expression of p300 was observed in 86 of 165 (52·1%) of the cSCC samples and six of 30 (20%) of the adjacent normal skin tissue samples (P < 0·001). High expression of p300 was positively correlated with lymph node metastasis (P = 0·006) and advanced clinical stage (P < 0·001). In univariate survival analysis, high expression of p300 was correlated with poor patient outcomes in terms of recurrence-free survival (P = 0·006) and overall survival (P < 0·001). Moreover, p300 expression was evaluated as an independent prognostic factor in a multivariate analysis (P = 0·004).

CONCLUSIONS

Our results indicate that high p300 expression is associated with aggressive features of cSCC and suggest that p300 expression, as examined by IHC, will be a promising biomarker for predicting clinical outcomes in patients with cSCC.

Epidemiology of basal cell carcinoma

Basal cell carcinoma is the most common malignant neoplasm in humans and its incidence has increased over the last decades. Its high frequency significantly burdens the health system, making the disease a public health issue. Despite the low mortality rates and the rare occurrence of metastases, the tumor may be locally invasive and relapse after treatment, causing significant morbidity. Exposure to ultraviolet radiation is the main environmental risk factor associated with its cause. However, other elements of risk are described, such as light skin phototypes, advanced age, family history of skin carcinoma, light eyes and blond hair, freckles in childhood and immunosuppression. Behavioral aspects such as occupational sun exposure, rural labor and sunburns at a young age also play a role. Between 30% and 75% of the sporadic cases are associated with patched hedgehog gene mutation, but other genetic changes are also described. The tumor is commonly found in concomitance with skin lesions related to chronic sun exposure, such as actinic keratoses, solar lentigines and facial telangiectasia. The prevention of basal cell carcinoma is based on the knowledge of risk factors, early diagnosis and treatment, as well as on the adoption of specific measures, particularly in susceptible populations. The authors present a review of the epidemiology of basal cell carcinoma.

Indoor tanning and risk of early-onset basal cell carcinoma

BACKGROUND

Despite an increase in incidence of basal cell carcinoma (BCC) among young people and the ubiquity of indoor tanning in this population, few epidemiologic studies have investigated this exposure-disease relationship.

OBJECTIVE

We sought to evaluate the association between indoor tanning and early-onset BCC.

METHODS

Patients with BCC (n = 376) and control subjects with minor benign skin conditions (n = 390) who were younger than 40 years of age were identified through Yale Dermatopathology. Participants provided information on ever indoor tanning, age of initiation, frequency, duration, burns while tanning, and type of tanning device during an in-person interview. We calculated odds ratios (OR) and 95% confidence intervals (CI) using multivariate logistic regression with never indoor tanners as the referent group.

RESULTS

Ever indoor tanning was associated with a 69% increased risk of early-onset BCC (95% CI 1.15-2.48). This association was stronger among females (OR 2.14, 95% CI 1.31-3.47), for multiple BCCs (OR 2.16, 95% CI 1.26-3.70), and for BCCs on the trunk and extremities (OR 2.81, 95% CI 1.57-5.02). Risk increased dose dependently with years using regular indoor tanning devices (P trend = .003), number of overall burns (P trend < .001), and burns to biopsy site (P trend < .001) from indoor tanning. Approximately one quarter (27%) of early-onset BCCs (or 43% among women) could be prevented if individuals never tanned indoors.

LIMITATIONS

Potential recall bias of indoor tanning by patients and generalizability of the control population suggest replication in other studies is warranted.

CONCLUSIONS

Indoor tanning was a strong risk factor for early-onset BCC, particularly among females. Indoor tanning should continue to be targeted by both policy-based and behavioral interventions, as the impact on BCC-associated morbidity may be substantial.

Comparison of risk factors of single Basal cell carcinoma with multiple Basal cell carcinomas

Background:

Basal cell carcinoma (BCC) is the most common malignant skin tumor. Although mortality attributable to BCC is not high, the disease is responsible for considerable morbidity. There is evidence that the number of patients who develop more than one BCC is increasing.

Aims:

The aim of this study was to elucidate possible risk factors for developing Multiple BCC.

Patients and Methods:

Patients with histologically proven BCC (n = 218) were divided into two groups (single BCC and Multiple BCC) according to the number of their tumors and their profile were reviewed. Probable risk factors were compared between these two groups.

Results:

Among 33 evaluated risk factors, mountainous area of birth, past history of BCC, history of radiotherapy (in childhood due to tinea capitis), abnormal underlying skin at the site of tumor, and pigmented pathologic type showed significant differences between the two groups.

Conclusions:

The high rate of additional occurrences of skin cancers among patients with previously diagnosed BCC emphasizes the need of continued follow-up of these individuals. Those with higher risk require closest screening.

Liver kinase B1 (LKB1) in the pathogenesis of UVB-induced murine basal cell carcinoma

LKB1, a known tumor suppressor, is mutated in Peutz-Jeghers Syndrome (PJS). It is responsible for the enhanced cancer risk in patients with PJS. Dysregulation of LKB1-dependent signaling also occurs in various epithelial cancers. UVB alters the expression of LKB1, though its role in the pathogenesis of skin cancer is unknown. Here we describe upregulation of LKB1 expression in UVB-induced murine basal cell carcinoma (BCC) and in human skin tumor keratinocytes. AMP-kinase and acetyl Co-A carboxylase, the downstream LKB1 targets, are also enhanced in this neoplasm. In addition, p-Akt, a kinase which inactivates GSK3β by its phosphorylation, is enhanced in BCCs. Consistently, an accumulation of p-GSK3β and an increase in activated nuclear β-catenin are found. mTOR signaling, which is also inhibited by LKB1, remains upregulated in BCCs. However, a marked decrease in the expression of sestrins, which function as potent negative regulators of mTOR is observed. Metformin, a known chemical inducer of this pathway, was found effective in immortalized HaCaT keratinocytes, but failed to activate the LKB1-dependent signaling in human carcinoma A431 cells. Thus, our data show that the LKB1/AMPK axis fails to regulate mTOR pathway, and a complex regulatory mechanism exists for the persistent mTOR activation in murine BCCs.

Genetics of basal cell carcinoma

Basal cell carcinoma is the most common human malignancy in populations of European origin, and Australia has the highest incidence of basal cell carcinoma in the world. Great advances in the understanding of the genetics of this cancer have occurred in recent years. Mutations of the patched 1 gene (PTCH1) lead to basal cell carcinoma predisposition in Gorlin syndrome. PTCH1 is part of the hedgehog signalling pathway, and derangements within this pathway are now known to be important in the carcinogenesis of many different cancers including sporadic basal cell carcinoma. The molecular biology of the hedgehog pathway is discussed, and mouse models of basal cell carcinoma based on this pathway are explored. New developments in non-surgical treatment of basal cell carcinoma are based on this knowledge. Other genes of importance to basal cell carcinoma development include the tumour suppressor gene P53 and the melanocortin-1 receptor gene. In addition, we discuss molecules of possible importance such as the glutathione-S-transferases, DNA repair genes, cyclin-dependent kinase inhibitor 2A, Brahma and connexins. Evidence of familial aggregation of this cancer is explored and supports the possibility of genetic predisposition to this common malignancy.

Risk factors for basal cell carcinoma: Results from the case-control study

The aim of the present case-control study was to assess the risk factors for Basal cell carcinoma (BCC) in the Montenegrin population. The study group was comprised of 100 consecutive patients with a diagnosis of BCC, while the control group consisted of patients who did not present skin cancer and who were individually matched to the cases by sex and age. The increased risk for BCC was associated with: the presence of nevi (odds ratio [OR] = 3.77; 95% confidence interval [CI] = 1.12–12.73), type of skin concerning to burn rather than to tan after repeated sun exposure in childhood or adolescence (OR = 3.14; 95% CI = 1.59–6.18), the skin reaction to burn after two or more hours of sunlight during childhood or adolescence (OR = 4.53; 95% CI = 2.37–8.63), the number of severe and painful sunburns during their lifetime(OR = 3.52; 95% CI = 1.68–7.38), outdoor work during the summer-time (OR = 2.73; 95% CI = 1.00–7.45), occupational exposure to chemicals (OR = 17.89; 95% CI = 2.82–113.52), history of eczema (OR = 4.17; 95% CI = 1.53–11.39), and history of previous BCC (OR = 3.86; 95% CI = 1.40–10.65). Our study confirms the role of environmental and constitutional factors in development of BCC.

Focus on Basal cell carcinoma

Nonmelanoma skin cancers (NMSCs), which include basal and squamous cell cancers are the most common human cancers. BCCs have a relatively low metastatic rate and slow growth and are frequently underreported. Whilst there is a definite role of sunexposure in the pathogenesis of BCC, several additional complex genotypic, phenotypic and environmental factors are contributory. The high prevalence and the frequent occurrence of multiple primary BCC in affected individuals make them an important public health problem. This has led to a substantial increase in search for newer noninvasive treatments for BCC. Surgical excision with predetermined margins remains the mainstay treatment for most BCC. Of the newer non-invasive treatments only photodynamic therapy and topical imiquimod have become established in the treatment of certain BCC subtypes, while the search for other more effective and tissue salvaging therapies continues. This paper focuses on the pathogenesis and management of BCC.

Basal cell carcinoma: what's new under the sun

Basal cell carcinoma (BCC) is the most common skin cancer in white populations with an increasing incidence worldwide, thereby imposing an important public health problem. Its etiology is still unclear, but existing data indicate that the risk for BCC development is of multifactorial origin and results from the interplay of both constitutional and environmental factors. Yet, UV radiation (UVR) is believed to be the predominant causative risk factor in the pathogenesis of BCC. For years, BCC and squamous cell carcinoma (SCC) have been grouped together as "nonmelanoma skin cancer." However, it seems that there are considerable biologic differences between BCC and SCC, and thus each type of epithelial cancer should be addressed separately. The present review provides an overview of the intriguing etiologic link of BCC with UVR and attempts a comprehensive review of recent epidemiologic and molecular evidence that supports this association.

Nonmelanoma skin cancer

This article provides readers with a comprehensive review of the evaluation and management of nonmelanoma skin cancers. Treatment recommendations are heavily based on the most recent guidelines from the National Comprehensive Cancer Network. Merkel cell carcinoma and dermatofibrosarcoma protuberans are also discussed. After reviewing this article, readers should be equipped with a better understanding of these entities and the current recommendations for their management.

Management of nevus sebaceous and the risk of Basal cell carcinoma: an 18-year review

Nevus sebaceous (NS) is a common congenital hamartoma of the skin, usually found on the head and neck. It may undergo malignant transformation to basal cell carcinoma (BCC). However the incidence and lifetime risk of malignant transformation is unknown. We performed an 18-year review of all NS excisions at our institution, to report the number of cases of BCC and other neoplasms within excised NS. The aim is to inform physicians who must weigh the risks in recommending excision of a NS in a pediatric patient population with the risk of malignancy. After a database query for years 1990-2008, charts were reviewed and data were extracted on demographics and surgical history relating to NS. Thirty-one NS with abnormal findings were reviewed microscopically by a dermatopathologist. There were 651 NS distinct lesions among 631 patients and 690 excisions. Twenty-one intralesional diagnoses were found in 18 patients. Five patients (0.8%) had BCC (mean age 12.5 yrs, range 9.7-17.4 yrs). Seven (1.1%) had syringocystadenoma papilliferum (SP) (mean age 8.8 yrs, range 1.7-16.9 yrs), a lesion that may undergo malignant transformation. Malignant transformation of NS can occur in childhood or adolescence. We believe all NS should be excised, however timing of excision can be flexible. Our data do not support age cutoffs or morphologic changes to determine optimal excision time. In conjunction with the treating physician, the parent and patient may weigh the small risk of malignant transformation of NS against the morbidity associated with excision and anesthesia.

Risk of nonmelanoma skin cancer with azathioprine use

While often life-saving for many complex diseases, iatrogenic immunosuppression has been associated with life-threatening infections and malignancies. Among these malignancies is skin cancer. Skin cancer is the most common form of cancer in the United States; the nonmelanoma skin cancers have an annual incidence of greater than 1,000,000 people in the US. It is well documented that the risk of nonmelanoma skin cancer (NMSC) is increased in those who are immunosuppressed. While many articles have been published on skin cancer risk in organ transplant recipients, little has been written regarding the incidence of nonmelanoma skin cancer in inflammatory bowel disease. A review of the literature of patients who are immunosuppressed for autoimmune disorders, and specifically, inflammatory bowel diseases, is discussed, as well as clinical presentations and treatment options.

[Ultraviolet: a regulator of immunity]

Humans establish acquired immune systems during the growth, which can sufficiently eliminate pathogen avoiding immune responses to self, such as allergy and autoimmunity. An imbalance of the acquired immune system leads up to immune-mediated disorders. Ultraviolet (UV) exposure helps to establish the normal peripheral tolerance to contact allergen avoiding excessive immune responses. By contrast, UV develops kinds of autoimmune diseases on rare occasions, suggesting that abnormality in the process of UV-induced peripheral tolerance may induce these diseases. To elucidate the mechanism of UV-induced tolerance is possible to provide a new approach for the management of immune diseases. In the current review, focus is on the suggested players of UV-induced tolerance, blocking mechanisms on the elicitation phase of contact hypersensitivity, and the association between UV and autoimmunity. The major impact in basic immunology in this area is the discovery of cell surface marker of regulatory T cells. Therefore, we first discuss about the association of regulatory/suppressor T cells with UV-induced tolerance. Since the elicitation phase depends on cellular influx into the inflammatory sites, which is tightly regulated by adhesion molecules, we also focused on the role of adhesion molecules. Finally, this paper also includes statistical findings concerning the association between UV-radiation and the prevalence of a myositis specific autoantibody. Thus, UV is one of the nice regulators of an immune network and the knowledge of UV-mediated immune regulation will be translated into new therapeutic strategies to human immune-mediated disorders.

ASIP and TYR pigmentation variants associate with cutaneous melanoma and basal cell carcinoma

Fair color increases risk of cutaneous melanoma (CM) and basal cell carcinoma (BCC). Recent genome-wide association studies have identified variants affecting hair, eye and skin pigmentation in Europeans. Here, we assess the effect of these variants on risk of CM and BCC in European populations comprising 2,121 individuals with CM, 2,163 individuals with BCC and over 40,000 controls. A haplotype near ASIP, known to affect a similar spectrum of pigmentation traits as MC1R variants, conferred significant risk of CM (odds ratio (OR) = 1.45, P = 1.2 x 10(-9)) and BCC (OR = 1.33, P = 1.2 x 10(-6)). The variant in TYR encoding the R402Q amino acid substitution, previously shown to affect eye color and tanning response, conferred risk of CM (OR = 1.21, P = 2.8 x 10(-7)) and BCC (OR = 1.14, P = 6.1 x 10(-4)). An eye color variant in TYRP1 was associated with risk of CM (OR = 1.15, P = 4.6 x 10(-4)). The association of all three variants is robust with respect to adjustment for the effect of pigmentation.

Gene silencing of transcription factor Gli2 inhibits basal cell carcinomalike tumor growth in vivo

Basal cell carcinoma (BCC) belongs worldwide to the most frequent malignancy among Caucasians. The understanding of the molecular mechanisms of BCC formation, which is a prerequisite for the development of efficient new therapies, is still incomplete. The formation of sporadic BCCs in the skin is associated with uncontrolled hedgehog signaling, and the transcription factor Gli2 has been identified as a key mediator or effector of this signaling. There is indication in the literature that preventing Gli2 function may inhibit BCC formation and growth in vivo; however, the mechanism is unclear and difficult to study in humans. Therefore, we used a mouse tumor allograft model to investigate the role of Gli2 in tumor formation. A constitutively Gli2 expressing mouse tumor cell line was stably transfected with Gli2-specific shRNA to induce Gli2 gene silencing or with control shRNA. Injecting the Gli2 gene silenced cells into nude mice for tumor formation we detected a strongly retarded tumor growth compared with control tumor cells. Investigating the mechanisms, we found that Gli2 gene silencing has led to the disruption of the tumor structure as demonstrated by staining tumor sections with hematoxylin. Two main reasons for the tumor destruction were identified. We found that apoptosis was markedly increased while vascularization was strongly decreased in these tumors. Thus, important functions of the transcription factor Gli2 in this tumor model are the prevention of apoptosis and the promotion of microvascularization.

Models and mechanisms in malignant melanoma

Human melanoma represents the fastest growing malignancy in the US. The etiology of melanoma is highly debated as is the role of ultraviolet (UV) radiation in the initiation and progression of melanoma. This article discusses data from UV exposure and its relationship to the development of melanoma from various models of melanoma as well as various genetic alterations seen in oncogenic transformation of melanocytes. Genetic alterations such as the p16(INK4a) deletion, melanocortin 1 receptor (MC1R), RAS, and v-raf murine sarcoma viral oncogene homolog B1 (BRAF) may be indicative of a predisposition to melanoma development. Historical research as well as current data on the significance of the hot spot mutation in BRAF is discussed in its relative potential to the activating mutation in RAS.

Photoprotection

Sun exposure is the main cause of photocarcinogenesis, photoageing, and photosensitivity; thus, photoprotection is an important issue. In a skin cancer prevention strategy, behavioural measures--eg, wearing sun protective clothes and a hat and reducing sun exposure to a minimum--should be preferred to sunscreens. Often this solution is deemed to be unacceptable in our global, outdoor society, and sunscreens could become the predominant mode of sun protection for various societal reasons (eg, healthiness of a tan, relaxation in the sun). The application of a liberal quantity of sunscreen has been shown to be by far the most important factor for effectiveness of the sunscreen, followed by the uniformity of application and the specific absorption spectrum of the agent used. The sunscreen market--crowded by numerous products--shows various differences worldwide. Nevertheless, sunscreens should not be abused in an attempt to increase time in the sun to a maximum. Controversies about safety of sunscreens and clinical recommendations are discussed.

Association of functional gene variants in the regulatory regions of COX-2 gene (PTGS2) with nonmelanoma skin cancer after organ transplantation

BACKGROUND

Overexpression of cyclooxygenase-2 (COX-2), resulting in excessive prostaglandin production, has been observed in human epidermal keratinocytes after ultraviolet B injury, in squamous cell skin carcinoma (SCC), in actinic keratoses, and in the early stages of carcinogenesis in a wide variety of tissues. The dysregulation of COX-2 expression can in part be due to functional changes affecting regulatory elements in the promoter or 3' untranslated region (UTR) of the gene. Two common polymorphisms (-765G-->C, and -1195A-->G) in the promoter region of the COX-2 gene (now PTGS2), and one common polymorphism in the 3' UTR (8473T-->C) have been described, and reported as associated with various malignancies.

OBJECTIVES

To determine if common known polymorphisms in the regulatory region of the COX-2 gene (PTGS2) can be associated with nonmelanoma skin cancer (NMSC) predisposition after organ transplantation, to evaluate if cancer risks are associated with specific COX-2 gene (PTGS2) haplotypes containing these polymorphisms, and to identify possible new genetic polymorphisms in the proximal 5' or 3' regulatory regions of the gene associated with disease.

METHODS

The frequency of the three polymorphisms was determined in 240 Northern Italian transplant recipient patients (107 cases and 133 controls) with polymerase chain reaction-restriction fragment length polymorphism analysis. The proximal 5' and 3' regulatory regions of the gene were screened by heteroduplex analysis.

RESULTS

Stratification by age at transplant and type of tumours [SCC or basal cell carcinoma (BCC)] demonstrated that allele -765C represented a protective factor in BCC cases undergoing transplantation before 50 years of age (CC + CG vs. GG, Fisher exact test P = 0.003). One rare polymorphism, -62C-->G, was detected in the 5' flanking region. The allele frequency of -62G was 0.019, and no difference in genotype between cases and controls was observed. No other variants were found, suggesting that sequence variations in these regions are not likely to contribute to NMSC risk in this population. Haplotype analysis showed that the haplotype containing all major alleles represents a protective factor in patients with SCC undergoing transplantation after 50 years of age [P = 0.009; OR = 0.37 (0.18-0.79)] and that variant -1195A-->G may represent a risk factor in this subgroup of patients [P = 0.01; OR = 4.77 (1.47-16.41)]. Haplotype analysis in patients with BCC revealed that variant -765C might be a protective factor in patients undergoing transplantation before 50 years of age. Variant 8473T-->C, located in the 3' UTR region of the gene, showed no association with NMSC risk after transplantation.

CONCLUSIONS

COX-2 common variants -765G-->C and -1195A-->G appear to be associated with risk of NMSC, although in different ways in the SCC and BCC subgroups, indicating that environmental and genetic risk factors may play different roles in the outcome leading to these two phenotypes.

Psoriasin (S100A7) is significantly up-regulated in human epithelial skin tumours

PURPOSE

Psoriasin (S100A7) has originally been described to be expressed by psoriatic keratinocytes possibly as a result of altered differentiation and inflammation. As psoriasin was found to be overexpressed in human breast and bladder cancer suggesting a role in tumour progression, we investigated the expression of psoriasin in human epithelial skin tumours.

METHODS

Realtime reverse transcription-polymerase chain reaction experiments were performed to analyse the mRNA-expression levels of psoriasin together with involucrin as a marker for epithelial differentiation and interleukin-8 (IL-8) as a marker for inflammation in skin biopsy samples from patients with precancerous skin lesions (PSL, n = 6), squamous cell carcinoma (SCC, n = 11), basal cell carcinoma (BCC, n = 17), and healthy controls (n = 10).

RESULTS

Unexpectedly, mRNA expression levels for Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) revealed a variation of up to 600-fold in all cDNA-samples under investigation, indicating that GAPDH is not suitable as a housekeeping gene in human skin samples. Psoriasin mRNA expression was significantly up-regulated in samples of PSL, SCC and BCC. In situ hybridisation and immunohistochemical examinations identified psoriasin mRNA and protein expression in the differentiated layers of the epidermis. IL-8 mRNA expression was significantly up-regulated in SCC, however, there was no correlation between elevated levels of psoriasin and the expression of IL-8.

CONCLUSION

Similar to the findings in breast and bladder cancer, the up-regulation of psoriasin might play a role in the progression of skin cancer. The expression of psoriasin in human skin tumours seems to be independent from differentiation and inflammation.