Does intermittent sun exposure cause basal cell carcinoma? a case-control study in Western Australia

Ultraviolet light and ocular diseases

The objective of this study is to review the association between ultraviolet (UV) light and ocular diseases. The data are sourced from the literature search of Medline up to Nov 2012, and the extracted data from original articles, review papers, and book chapters were reviewed. There is a strong evidence that ultraviolet radiation (UVR) exposure is associated with the formation of eyelid malignancies [basal cell carcinoma (BCC) and squamous cell carcinoma (SCC)], photokeratitis, climatic droplet keratopathy (CDK), pterygium, and cortical cataract. However, the evidence of the association between UV exposure and development of pinguecula, nuclear and posterior subcapsular cataract, ocular surface squamous neoplasia (OSSN), and ocular melanoma remained limited. There is insufficient evidence to determine whether age-related macular degeneration (AMD) is related to UV exposure. It is now suggested that AMD is probably related to visible radiation especially blue light, rather than UV exposure. From the results, it was concluded that eyelid malignancies (BCC and SCC), photokeratitis, CDK, pterygium, and cortical cataract are strongly associated with UVR exposure. Evidence of the association between UV exposure and development of pinguecula, nuclear and posterior subcapsular cataract, OSSN, and ocular melanoma remained limited. There is insufficient evidence to determine whether AMD is related to UV exposure. Simple behaviural changes, appropriate clothing, wearing hats, and UV blocking spectacles, sunglasses or contact lens are effective measures for UV protection.

Ultraviolet Radiation and the Skin

Ultraviolet radiation (UVR) has many interactions with the skin, which are explored in detail in this review. Both ultraviolet A (UVA) and ultraviolet B (UVB) wavelengths are absorbed by chromophores in the skin, resulting in important biologic effects. Exposure to UVR can result in sunburn, immediate and delayed skin pigmentation, photoaging, and immunosuppression. In addition, exposure to UVA and UVB is an important risk factor for melanoma, squamous cell carcinoma, and basal cell carcinoma. Because endogenous vitamin D synthesis requires UVB, concerns have been raised about the possibility that photoprotection might contribute to vitamin D deficiency; however, vitamin D supplementation is a safer and more reliable method for maintaining adequate vitamin D levels than UVR exposure. Protection from UVR is critical and involves several factors. These elements include sun avoidance during peak hours of UVR exposure (10 am to 2 pm), proper application of a broad-spectrum sunscreen with adequate sun protection factor, and wearing protective clothing, a wide-brimmed hat, and protective eyewear. Indoor tanning is a high-risk activity that is likely contributing to recent increases in melanoma and nonmelanoma skin cancer in young women, and efforts are ongoing to ban minors from engaging in indoor tanning.

Sunlight and Vitamin D: A global perspective for health

Vitamin D is the sunshine vitamin that has been produced on this earth for more than 500 million years. During exposure to sunlight 7-dehydrocholesterol in the skin absorbs UV B radiation and is converted to previtamin D3 which in turn isomerizes into vitamin D3. Previtamin D3 and vitamin D3 also absorb UV B radiation and are converted into a variety of photoproducts some of which have unique biologic properties. Sun induced vitamin D synthesis is greatly influenced by season, time of day, latitude, altitude, air pollution, skin pigmentation, sunscreen use, passing through glass and plastic, and aging. Vitamin D is metabolized sequentially in the liver and kidneys into 25-hydroxyvitamin D which is a major circulating form and 1,25-dihydroxyvitamin D which is the biologically active form respectively. 1,25-dihydroxyvitamin D plays an important role in regulating calcium and phosphate metabolism for maintenance of metabolic functions and for skeletal health. Most cells and organs in the body have a vitamin D receptor and many cells and organs are able to produce 1,25-dihydroxyvitamin D. As a result 1,25-dihydroxyvitamin D influences a large number of biologic pathways which may help explain association studies relating vitamin D deficiency and living at higher latitudes with increased risk for many chronic diseases including autoimmune diseases, some cancers, cardiovascular disease, infectious disease, schizophrenia and type 2 diabetes. A three-part strategy of increasing food fortification programs with vitamin D, sensible sun exposure recommendations and encouraging ingestion of a vitamin D supplement when needed should be implemented to prevent global vitamin D deficiency and its negative health consequences.

Dermatology of the head and neck: skin cancer and benign skin lesions

Skin lesions are extremely common, and early detection of dangerous lesions makes skin cancer one of the most highly curable malignancies. By simply becoming aware of common lesions and their phenotypic presentation, dental professionals are empowered to detect suspicious dermatologic lesions in unaware patients. This article serves as an introduction to skin cancer and benign skin lesions for dental professionals.

Patterns and timing of sunlight exposure and risk of basal cell and squamous cell carcinomas of the skin--a case-control study

BACKGROUND

Non-melanoma skin cancer (NMSC), comprised of basal (BCC) and squamous (SCC) cell carcinomas, is the most common cancer in Caucasians. Ultraviolet radiation (UVR) exposure is the most important environmental risk factor for NMSC. However, the precise relationship between UVR and the risk of NMSC is complex, and the relationship may differ by skin cancer type.

METHODS

A case-control study was conducted among Florida residents to investigate measures of patterns (intermittent vs. continuous) and timing (childhood vs. adulthood) of sunlight exposure in BCC and SCC. Participants included 218 BCC and 169 SCC cases recruited from a university dermatology clinic and 316 controls with no history of skin or other cancers.

RESULTS

A history of blistering sunburn (a measure of intermittent sunlight exposure) was associated with both BCC (OR = 1.96, 95% CI = 1.27-3.03) and SCC (OR = 2.02, 95% CI = 1.22-3.33). Additionally, having a job in the sun for ≥ 3 months for 10 years or longer (a measure of continuous sunlight exposure) was also associated with both BCC and SCC in our study population. With the exception of younger age at first blistering sunburn, measures of younger age at sunlight exposure tended to be associated with SCC, but not BCC risk.

CONCLUSIONS

Results from the current study suggest that sunlight exposure is associated with both BCC and SCC risk regardless of the pattern in which the exposure was received (i.e. intermittent vs. continuous). The data also suggest that sunlight exposure at a younger age may be more important for SCC but not BCC, however additional studies are needed to further characterize sunlight exposure-response relationships in different types of NMSC.

40-year trends in skin cancer in British Columbia, Canada, 1973 to 2003

BACKGROUND

Skin cancer is common in North America. Incidence rate trends are potentially important in the assessment of the effects of measures to increase sun awareness in the population as well as measures to reduce sun damage.

OBJECTIVE

To determine the incidence of basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and cutaneous malignant melanoma (CMM) in a geographically defined Canadian population over a 40-year period.

METHODS

Data were obtained from the BC Cancer Registry for the calendar years 1973, 1983, 1993, and 2003.

RESULTS

Age-standardized incidence rates increased significantly from 1973 to 2003 for BCC, SCC, and CMM.

LIMITATIONS

The ethnic makeup of British Columbia has changed over time, and a novel method of accounting for the effect of this on skin cancer rates is presented.

CONCLUSION

The incidence rate for skin cancers continued to rise in British Columbia, but there appears to have been a decline in the incidence of CMM and BCC in the youngest cohorts.

Nonmelanoma skin cancer

Nonmelanoma skin cancer (NMSC) represents the most common form of cancer in Caucasians, with continuing increase in incidence worldwide. Basal cell carcinoma (BCC) accounts for 75% of cases of NMSC, and squamous cell carcinoma (SCC) accounts for the remaining majority of NMSC cases. Whilst metastasis from BCC is extremely rare, metastasis from high-risk SCC may be fatal. In this article, we review the aetiology, diagnosis and management of NMSC.

Skin cancers and their etiologies

Skin cancers are the most common form of malignancy. Early diagnosis and treatment provides the best chance for survival and reduced morbidity. However, some patients have recurrent or resistant lesions. In patients with basal cell carcinoma (BCC), prognosis is relatively good for all four types of lesions (superficial, nodular, infiltrative, and morpheaform), but the highest recurrence rates and greatest morbidity are associated with infiltrative and morpheaform BCC, and prognosis is least favorable when perineural invasion has occurred. Research into the etiology of BCC and other skin cancers has led to the identification of several genetic mutations-those of the Patched and Hedgehog genes. By targeting these pathways, treatments aimed at driver mutations hold promise for new nonsurgical treatments.

Obesity and the incidence of skin cancer in US Caucasians

BACKGROUND

Limited information is available on the potential link between obesity and either melanoma or non-melanoma skin cancers.

OBJECTIVE

To conduct a prospective study to examine the association between obesity and the risk of both melanoma and non-melanoma skin cancers.

METHODS

Using pooled data from two large national cohorts in the US, the Nurses' Health Study (NHS) and the Health Professionals Follow-up Study (HPFS), we prospectively examined the incidence of melanoma, squamous cell carcinoma (SCC), and basal cell carcinoma (BCC) among participants grouped according to body mass index (BMI).

RESULTS

Compared to participants with an updated BMI in the normal range, those with a BMI in the obese range had a 32 % lower risk of developing SCC, and those with a BMI in the morbidly obese category had a 37 % lower risk of developing SCC. The decrease in SCC risk was limited to women. Compared to participants with a BMI in the normal range, those with a BMI in the obese range had a 19 % lower risk of developing BCC, and those with a BMI in the morbidly obese category had a 29 % lower risk of developing BCC. The risk of developing melanoma did not statistically differ by BMI grouping. The results were similar using BMI measurements obtained 10 years prior to the diagnosis of skin cancer.

CONCLUSION

Obesity appears to be inversely associated with the development of non-melanoma skin cancers. Obesity is most likely a surrogate marker for lack of chronic sun exposure, which is a risk factor for non-melanoma skin cancers.

Sun protection--do we know enough?

INTRODUCTION

Sun protection, particularly the appropriate use of sunscreens is an important modifiable risk factor in the prevention of skin cancers. Our aim was to assess the current knowledge levels regarding sun protection, across plastic surgeons in the UK.

METHODS

A 12-point questionnaire based on the points contained in the patient information packs on sun protection produced by the British Association of Dermatology was circulated electronically amongst 551 BAPRAS members. We received 73 responses (13.3%). Questions were formulated around the basic information patients would expect to receive from a skin cancer specialist at the time of the diagnosis.

RESULTS

On average, participants could answer only 52.4% of the questions correctly. Only 9.7% (95% CI 3-17) of participants could accurately quantify the role of UV exposure in causation of melanoma. A total of 37.5% correctly identified the duration of action of sunscreen to be 3-4 h. Half of the participants were not aware that geographical conditions like altitude and latitude, as well as shade, could alter sun protection. A similar number could not answer questions related to the protective action of clothing.

CONCLUSION

As principal stakeholders in the treatment and outcomes of skin cancer patients, plastic surgeons could be at the forefront of influencing patients' behaviour regarding sun protection measures. The results demonstrate a need for better awareness and education regarding the knowledge of sunscreens and UV protection. Improved education would lead to health benefits for patients and their relatives and influence the primary prevention of this enlarging health issue of skin cancer.

Risk factors for basal cell carcinoma in a southern Brazilian population: a case-control study

BACKGROUND

Basal cell carcinoma (BCC) is the most common cancer to occur in Caucasian populations, and its incidence is increasing. Despite its frequency, there is a paucity of data on risk factors for BCC in some regions.

OBJECTIVES

This study investigated the association between pigmentary characteristics, distinctive patterns of solar exposure, habits and lifestyle, and risk for BCC among patients attending a dermatology center in a region in southern Brazil.

METHODS

We conducted a hospital-based, case-control study that included 127 case patients with histologically confirmed BCC and 280 cancer-free control subjects with other dermatologic conditions, observed between January 2006 and December 2007. The study was conducted using a questionnaire and physical examination by a dermatologist. Relative risks were estimated using exposure odds ratios generated by cross-tabulation and logistic regression models.

RESULTS

Risk for BCC was associated with family history of skin cancer, Fitzpatrick skin type I, and the presence of actinic keratoses, solar lentigines, leukoderma, and elastosis romboidalis nuchae. No effect was found for different patterns of solar exposure, eye, hair or skin color, exposure to non-solar ultraviolet radiation (UVR), or lifestyle-related habits such as sunscreen use and cigarette smoking.

CONCLUSIONS

The results of this study suggest that skin type and family history of skin cancer may be important in establishing risk for developing BCC. Additionally, the detection by clinical examination of skin markers related to UVR action is important in establishing which patients are more likely to develop BCC.

Lack of increased P15INK4B protein expression in basal cell carcinomas

BACKGROUND

The basal cell carcinoma (BCC) is the most common non-melanoma skin cancer (NMSK). BCC might develop because of the faulty cell cycle arrest. P15INK4b is a tumor suppressor gene, involved in cell cycle arrest and inactivated in most human cancers. The role of p15INK4b protein expression in the genesis of BCC is as yet unknown. In a previous study we showed the absence of p15INK4b expression in the majority of tissue microarray cores of cutaneous squamous cell carcinoma (SCCs), another type of non-melanoma skin cancer, indicating that p15INK4b could possibly be involved in the pathogenesis of cutaneous SCC. The aim of this study was to investigate p15INK4b protein expression in BCCs.

MATERIALS AND METHOD

Protein expression of p15INK4b in 35 cases of BCC tissue arrays and 19 cases of normal human skin tissue was studied using an immunohistochemical approach.

RESULTS

The expression of p15INK4b was not significantly different in the BCC cases as compared with normal human skin (p=0.356; p>0.05). In addition, there were no significant relationship between clinicopathologic variables of patients (age and sex) and p15INK4b protein expression.

CONCLUSIONS

Our finding may indicate that p15INK4b protein expression does not play a role in the genesis of BCC.

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.

Anatomic location of Basal cell carcinomas may favor certain histologic subtypes

BACKGROUND

Differences in age, site, and subtype exist in basal cell carcinoma (BCC).

OBJECTIVE

To evaluate whether an independent association exists between the anatomic location and the histologic subtype of BCC.

MATERIALS AND METHODS

A series of 3,254 BCCs was examined. The location was the head/neck (n  =  1,766), limbs (n  =  362), trunk (n  =  1,113), or genitals (n  =  13). Subtype was classified as superficial, nodular, micronodular, morpheic-infiltrative, or fibroepithelial.

RESULTS

Prevalence of BCCs on the head/neck or chest/abdomen increased with age (p < .001). The prevalence of superficial subtype decreased with age (p < .0001), whereas the prevalence on nodular subtype increased (p < .0001). Subtype was associated with location (p < .0001). The prevalence of superficial subtype was lower among BCCs on the head/neck than other locations (24.9% vs 64.4%, OR 0.18, 95% CI 0.16-0.21). The prevalence of nodular or morpheic/infiltrative subtype was higher among BCCs on the head/neck than other locations, that is, 57.1% versus 29.2%, OR 3.23, 95% CI 2.79 to 3.74 (nodular) and 16.1% versus 4.0%, OR 4.56, 95% CI 3.42 to 6.08 (morpheic/infiltrative).

CONCLUSION

Anatomic location and subtype of BCC were associated with age, but the anatomic location was the only independent predictor of histologic subtype. Although a bias by referral patterns may not be excluded, the results suggest that the anatomic location may favor the development of particular BCC subtypes.

FDA-sunlamp recommended Maximum Timer Interval And Exposure Schedule: consensus ISO/CIE dose equivalence

The authors compared calculations of sunlamp maximum exposure times following current USFDA Guidance Policy on the Maximum Timer Interval and Exposure Schedule, with USFDA/CDRH proposals revising these to equivalent erythemal exposures of ISO/CIE Standard Erythema Dose (SED). In 2003, [USFDA/CDRH proposed replacing their unique CDRH/Lytle] erythema action spectrum with the ISO/CIE erythema action spectrum and revising the sunlamp maximum exposure timer to 600 J m(-2) ISO/CIE effective dose, presented as being biologically equivalent. Preliminary analysis failed to confirm said equivalence, indicating instead ∼38% increased exposure when applying these proposed revisions. To confirm and refine this finding, a collaboration of tanning bed and UV lamp manufacturers compiled 89 UV spectra representing a broad sampling of U.S. indoor tanning equipment. USFDA maximum recommended exposure time (Te) per current sunlamp guidance and CIE erythemal effectiveness per ISO/CIE standard were calculated. The CIE effective dose delivered per Te averaged 456 J(CIE) m(-2) (SD = 0.17) or ∼4.5 SED. The authors found that CDRH's proposed 600 J(CIE) m(-2) recommended maximum sunlamp exposure exceeds current Te erythemal dose by ∼33%. The current USFDA 0.75 MED initial exposure was ∼0.9 SED, consistent with 1.0 SED initial dose in existing international sunlamp standards. As no sunlamps analyzed exceeded 5 SED, a revised maximum exposure of 500 J(CIE) m(-2) (∼80% of CDRH's proposal) should be compatible with existing tanning equipment. A tanning acclimatization schedule is proposed beginning at 1 SED thrice-weekly, increasing uniformly stepwise over 4 wk to a 5 SED maximum exposure in conjunction with a tan maintenance schedule of twice-weekly 5 SED sessions, as biologically equivalent to current USFDA sunlamp policy.

The challenges of UV-induced immunomodulation for children's health

Exposure to solar ultraviolet radiation (UVR) is recognised to have both beneficial and harmful effects on human health. With regard to immune responses, it can lead to suppression of immunity and to the synthesis of vitamin D, a hormone that can alter both innate and adaptive immunity. The consequences in children of such UV-induced changes are considerable: first there are positive outcomes including protection against some photoallergic (for example polymorphic light eruption) and T cell-mediated autoimmune diseases (for example multiple sclerosis) and asthma, and secondly there are negative outcomes including an increased risk of skin cancer (squamous cell carcinoma, basal cell carcinoma and cutaneous malignant melanoma) and less effective control of several infectious diseases. Many uncertainties remain regarding the amount of sun exposure that would provide children with the most effective responses against the variety of immunological challenges that they are likely to experience.

New insights about infant and toddler skin: implications for sun protection

The skin is increasingly recognized as a component of the innate immune response, in addition to its role as a physical barrier. Although the deleterious effects of solar ultraviolet radiation (UVR), including immunosuppression and cutaneous tumorigenesis, are widely acknowledged, most studies to date have concentrated on adult skin. Despite the more sensitive nature of infant and toddler skin, little is known about its responses to UVR exposure, whether acute or long-term. Accumulating evidence suggests not only that the skin's barrier protection remains immature throughout at least the first 2 years of life but also that accumulation of UVR-induced changes in the skin may begin as early as the first summer of life. Such evidence not only affirms the importance of sun protection during the infant and toddler years but underscores the need for more research to establish evidence-based standards of care in this area. In this article we review recent studies in which differences between the skin properties of infants and young children and those of adults were compared, and we discuss the implications of these differences for sun-protection practices.

Vitamin D3 inhibits hedgehog signaling and proliferation in murine Basal cell carcinomas

Constitutive Hedgehog (HH) signaling underlies several human tumors, including basal cell carcinoma (BCC). Recently, Bijlsma and colleagues reported a new biologic function for vitamin D3 in suppressing HH signaling in an in vitro model system. On the basis of that work, we have assessed effects of vitamin D3 on HH signaling and proliferation of murine BCCs in vitro and in vivo. We find that indeed in BCC cells, vitamin D3 blocks both proliferation and HH signaling as assessed by mRNA expression of the HH target gene Gli1. These effects of vitamin D3 on Gli1 expression and on BCC cell proliferation are comparable to the effects of cyclopamine, a known inhibitor of the HH pathway. These results are specific for vitamin D3, because the precursor 7-dehydrocholesterol and the downstream products 25-hydroxy vitamin D3 [25(OH)D] and 1,25-dihydroxy vitamin D3 [1,25(OH)(2)D] are considerably less effective in reducing either Gli1 mRNA or cellular proliferation. Moreover, these effects seem to be independent of the vitamin D receptor (VDR) because short hairpin RNA knockdown of VDR does not abrogate the anti-HH effects of D3 despite reducing expression of the VDR target gene 24-hydroxylase. Finally, topical vitamin D3 treatment of existing murine BCC tumors significantly decreases Gli1 and Ki67 staining. Thus, topical vitamin D3 acting via its HH inhibiting effect may hold promise as an effective anti-BCC agent.

Importance of hereditary factors in synchronous development of Basal cell carcinoma in two albino brothers: case report

Oculocutaneous albinism is an autosomal recessive disease associated with hypomelanosis of the skin, hair, and eyes. Squamous cell carcinoma is the most common malignant neoplasm in this group. Those affected in the tropical populations have higher rates of metastatic lesions. Basal cell carcinoma (BCC) is the most common human cancer. Its incidence is steadily increasing. The etiology of BCC of the skin is characterized by a complex interaction of environmental, genetic, and lifestyle factors. The results of family and genetic studies provide support for the role of genetic factors in BCC, but most cases of BCC of the skin appear to be sporadic, and possible gene-environment interactions remain unknown. We have reported 2 brothers who have albinism and synchronous developed BCC on their trunk region. Unlike most of the albino patients, our cases have BCC instead of squamous cell carcinoma. Development of the same malignancy in the same life period at the similar localizations reminds the importance of genetic predisposition.

A numeric model to simulate solar individual ultraviolet exposure

Exposure to solar ultraviolet (UV) light is the main causative factor for skin cancer. UV exposure depends on environmental and individual factors. Individual exposure data remain scarce and development of alternative assessment methods is greatly needed. We developed a model simulating human exposure to solar UV. The model predicts the dose and distribution of UV exposure received on the basis of ground irradiation and morphological data. Standard 3D computer graphics techniques were adapted to develop a rendering engine that estimates the solar exposure of a virtual manikin depicted as a triangle mesh surface. The amount of solar energy received by each triangle was calculated, taking into account reflected, direct and diffuse radiation, and shading from other body parts. Dosimetric measurements (n = 54) were conducted in field conditions using a foam manikin as surrogate for an exposed individual. Dosimetric results were compared to the model predictions. The model predicted exposure to solar UV adequately. The symmetric mean absolute percentage error was 13%. Half of the predictions were within 17% range of the measurements. This model provides a tool to assess outdoor occupational and recreational UV exposures, without necessitating time-consuming individual dosimetry, with numerous potential uses in skin cancer prevention and research.

Environmental cues to UV radiation and personal sun protection in outdoor winter recreation

OBJECTIVE

To predict the prevalence of UV radiation (hereinafter, UV) at North American ski resorts using temporal, seasonal, altitudinal, and meteorological factors and associate UV with a set of adult sun protection behaviors.

DESIGN

Ultraviolet radiation observations and cross-sectional survey of adults on sun protection were collected.

SETTING

Data were collected at 32 high-altitude ski areas located in western North America from 2001 through 2003.

PARTICIPANTS

The sample consisted of 3937 adult skiers or snowboarders.

MAIN OUTCOME MEASURES

Measurements of direct, reflected, and diffuse UV were performed at 487 measurement points using handheld meters and combined with self-reported and observed sun protection assessed for adults interviewed on chairlifts.

RESULTS

The strongest predictors of UV were temporal proximity to noon, deviation from winter solstice, and clear skies. By contrast, altitude and latitude had more modest associations with UV and temperature had a small positive relationship with UV. Guest sun safety was inconsistently associated with UV: UV was positively related to adults wearing more sunscreen, reapplying it after 2 hours, and wearing protective eyewear, but fewer adults exhibited many of the other sun protection behaviors, such as wearing hats and protective clothing or using lip balm, on days when UV was elevated. Guests took more sun safety precautions on clear-sky days but took steps to maintain body warmth on inclement days.

CONCLUSIONS

In future sun safety promotions, adults should be encouraged to wear sunscreen on cloudy days because UV is still high and conditions can change rapidly. They need reminders to rely more on season and time of day when judging UV and the need for sun safety.

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.

Subsequent squamous- and basal-cell carcinomas in kidney-transplant recipients after the first skin cancer: cumulative incidence and risk factors

BACKGROUND

The risk of skin cancer is highly increased in kidney-transplant recipients (KTR), but the risk of subsequent skin cancers is less well studied. The aim of this study was to estimate the cumulative incidence of subsequent squamous- and basal-cell carcinomas (BCCs) and to analyze potential risk factors.

METHODS

All histologically confirmed skin cancers between 1966 and 2006 were included in the study and counted. Cumulative incidences of subsequent squamous- and BCCs were calculated using Kaplan-Meier survival analyses. For the analyses of risk factors, we used Cox proportional hazard analyses.

RESULTS

A total of 239 (13%) of 1906 KTR developed skin cancer of whom 222 were diagnosed in our hospital. Altogether 167 (75%) of these 222 patients developed multiple skin cancers. The cumulative incidence of a second skin cancer increased from 32%, 1 year, to 59%, 3 years, and 72%, 5 years after the first skin cancer. KTR who started with squamous-cell carcinoma (SCC) mainly developed SCC and recipients who started with BCC mainly developed BCC as second skin cancer. Immunosuppression with azathioprine in combination with prednisone was associated with a significantly increased risk of subsequent SCCs but not with subsequent BCCs.

CONCLUSION

Skin cancer multiplicity is common in KTR. Patients with a first skin cancer are at increased risk for more skin cancers and need to be carefully checked for subsequent skin cancers.

Predictors of summer sun safety practice intentions among rural high school students

OBJECTIVE

To investigate the association between theoretically grounded psychosocial motivators and the sun safety practice intentions of rural youth.

METHODS

A survey was given to 219 members of FFA (Future Farmers of America) at high schools in the rural Midwest (average age = 16).

RESULTS

Perceived self-efficacy, peer norms, response efficacy, and susceptibility predicted protective clothing and sunscreen use intentions. Among boys, perceived norms among same-sex peers; but among girls, norms among both same- and opposite-sex peers, were significant.

CONCLUSIONS

Self-efficacy should be an important component of sun safety education for rural youth. Gender-specific peer norms should also be addressed.

Risk factors in Central Poland for the development of superficial and nodular basal cell carcinomas

INTRODUCTION

In the last decades the number of skin carcinomas has dramatically increased, which is mainly connected with changes in lifestyle, especially with common use of artificial light sources such as sunbeds. Basal cell carcinoma (BCC) is the most common form of skin cancer in white populations. Basal cell carcinomas are divided into subtypes, depending on their clinical picture and histology. The main groups are nodular (nBCC) and superficial (sBCC) ones. The major recognized risk factors for basal cell carcinoma (BCC) are exposure to chronic and intermittent burning doses of sunlight. Other risk factors leading to the development of the nBCC and sBCC subtypes of BCC are not well established.

MATERIAL AND METHODS

An analysis of 123 patients with either nBCC or sBCC, living in Lodz, Poland, regarding various intrinsic and environmental parameters was undertaken following the histological diagnosis of BCC.

RESULTS

No statistical differences were observed between the BCC subtype and sex, age, hair colour, eye colour, smoking, family history of skin cancer, occupation, or past episodes of sunburn. While sBCCs tended to occur on unexposed body sites in phototype I/II subjects who mainly avoided direct sunlight, nBCCs tended to occur on sun-exposed body sites in phototype III subjects who were frequently in direct sunlight.

CONCLUSIONS

Thus the development of particular BCC subtypes is partially dependent on phototype and personal sun behaviour.

Prevention of non-melanoma skin cancer in organ transplant patients by regular use of a sunscreen: a 24 months, prospective, case-control study

BACKGROUND

Skin cancers represent a major challenge within the ever growing group of long time surviving organ transplant recipients (OTR) world wide. Especially UV-induced non-melanoma skin cancers (NMSC) like invasive squamous cell carcinomas (SCC) and actinic keratoses (AK), and basal cell carcinoma (BCC), outnumber every other form of cancer in organ transplant recipients. Despite encouraging reports of protective effects of broad-spectrum sunscreens in immunocompetent patients, evidence for the prevention of NMSC in immunocompromised patients is still missing.

OBJECTIVES

To assess preventive effects of regular sun-screen use on AK, SCC and BCC in chronically immunocompromised organ transplant recipients.

METHODS

Hundred and twenty matched (age, sex, skin type, graft, transplant duration, previous post-transplant skin malignancies) organ transplant recipients (40 heart, 40 kidney, 40 liver grafted) were recruited for this prospective, single-center study. Both groups received equally written and oral information on sun protection measures. Sixty patients were provided with a free broad spectrum study-sunscreen (SPF>50, high-UVA absorption) for daily application of 2 mg cm(-2) to the head, neck, forearms, and hands.

RESULTS

All 120 patients completed the 24 months study. Within this 24 month study interval 42 of the 120 patients developed 82 new AK (-102 sunscreen group vs. +82 control; P<0.01), 8 new invasive SCC (0 vs. 8; P<0.01) and 11 BCC (2 vs. 9; ns). In spite of equal numbers of AK at baseline, a marked difference in favor of the intent-to-treat sunscreen group was recorded after 24 months (89 vs. 273; P<0.01, mean difference 3.07 [1.76-4.36]) and the lesion count was significantly lower as compared to the initial visit (89 vs. 191; P<0.01, mean difference 1.7 [0.68-2.72]). With an average of 5.6 applications per week throughout the 24 months the study sunscreen was generally well tolerated. Serum 25-hydroxy vitamin D levels as marker for vitamin D status were decreased in all patients without adequate substitution and 25(OH)D was found to be lower in the sunscreen-group as compared to the control group (mean value 53 ng mL(-1) vs. 60 ng mL(-1)).

INTERPRETATION

Regular use of sunscreens, as part of a consequent UV-protection strategy, may prevent the development of further AK and invasive SCC and, to a lesser degree, BCC in immune-compromised organ transplant recipients.

Non-melanoma skin cancer

The rising incidence and morbidity of non-melanoma skin cancers has generated great interest in unravelling of their pathogenesis and in the search for new non-invasive treatments. Whereas the role of cumulative sun exposure in pathogenesis of squamous-cell carcinoma seems clear, the relation between sun-exposure patterns and subtypes of basal-cell carcinoma remains undetermined. Several complex genotypic, phenotypic, and environmental factors contribute to pathogenesis of non-melanoma skin cancers. Unlike basal-cell carcinoma, squamous-cell carcinomas can arise from precursor lesions. Diagnosis of non-melanoma skin cancer is made clinically and confirmed by histological testing. Prognosis depends on lesion and host characteristics, which also dictate choice of treatment. Prevention strategies aim at reduction of sun exposure, but are of unproven benefit, especially for basal-cell carcinoma. Surgical excision with predetermined margins is the mainstay of treatment for squamous-cell carcinoma and for most basal-cell carcinomas. Of the new non-invasive treatments, only photodynamic therapy and topical imiquimod have become established treatments for specific subtypes of basal-cell carcinoma, and the search for more effective and tissue-salvaging therapies continues.

Association of prediagnostic serum vitamin D levels with the development of basal cell carcinoma

We investigated the association between serum 25-hydroxyvitamin D (25(OH)D) levels and basal cell carcinoma (BCC) risk in a nested case-control study at Kaiser Permanente Northern California (KPNC). A total of 220 case patients with BCC diagnosed after serum collection were matched to 220 control subjects. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) using conditional logistic regression. Fully adjusted models included body mass index (BMI), smoking, education, sun-exposure variables, X-ray exposure, and personal history of cancer. For each measure of serum 25(OH)D (continuous, clinically relevant tertiles, quintiles), we found an increased risk of BCC in unadjusted models (OR=1.03, 95% CI 1.00-1.05, P<0.05; OR=3.98, 95% CI: 1.31-12.31, deficient vs. sufficient, test for trend P-value <0.01; OR=2.32, 95% CI: 1.20-4.50, 1st vs. 5th quintile, test for trend P-value 0.03). In fully adjusted models, the values attenuated slightly (OR=1.02, 95% CI 1.00-1.05, P<0.05; OR=3.61, 95% CI: 1.00-13.10, deficient vs. sufficient, t-trend P=0.03; OR=2.09 1st vs. 5th quintile, 95% CI: 0.95-4.58, t-trend P=0.11). Our findings suggest that higher prediagnostic serum 25(OH)D levels may be associated with increased risk of subsequent BCC. Further studies to evaluate the effect of sun exposure on BCC and serum 25(OH)D levels may be warranted.

Adolescent attitudes towards tanning: does age matter?

Adolescents seem to be obsessed with tanning. One third of both adolescents and adults report sunbathing. On average, about 20% of adolescents report ever-using of artificial UV tanning devices with 15% currently using them. Tanning attitudes appear similar for adolescents and adults. The top three reasons for tanning included beliefs that a tan makes them more comfortable socializing with friends, looks better and is attractive. The top reason for using artificial UV tanning devices is also aesthetics, followed by relaxation. Other reasons for using artificial UV tanning devices include vacation preparation and to gain a protective base. Attitudes related to appearance that result in more frequent tanning may be difficult to change.

Malignant skin neoplasms

Skin cancers may be derived from any part of the skin, and the classification of all variants is extensive. Overall they are the most common cancers of the body, and include those that are highly mortal and those that are associated with an increased morbidity. In this review the most common skin cancers confronted by the clinician and their management are discussed. New associations are highlighted, as well as new information that can help the clinician to better understand the pathogenesis of many of these entities.

Behaviors associated with ultraviolet radiation exposure in a cohort of adult survivors of childhood and adolescent cancer: a report from the Childhood Cancer Survivor Study

BACKGROUND

Previous research from the Childhood Cancer Survivor Study (CCSS) has shown that risk of skin cancer is strongly associated with exposure to radiation therapy. The potential role of ultraviolet radiation exposure in survivors has not been described.

METHODS

The CCSS is a retrospective cohort study designed to investigate late effects among 5-year survivors of children and adolescents diagnosed with cancer between 1970-1986. Data regarding current sun protection behavior were collected on 9298 survivors and 2950 sibling controls. Median age at follow-up was 31 years (range, 17-54).

RESULTS

In this cohort, childhood cancer survivors and siblings showed similar patterns of sunscreen use (67% vs 66%). Survivors were significantly less likely to report having sunbathed in the previous year (none vs any in previous year: relative risk (RR)=0.92; 95% confidence interval (CI)=0.89-0.95) or use artificial tanning (none vs any in previous year: RR=0.76; 95% CI=0.70-0.83). Compared with survivors without radiation therapy, survivors with radiation exposure showed increased use of sunscreen (RR=1.06; 95% CI=1.03-1.10), and less sunbathing (none vs any in previous year: RR=0.89; 95% CI=0.86-0.92) or artificial tanning (none vs any in previous year: RR=0.62; 95% CI=0.56-0.69). In adjusted multivariable analysis, statistically significant factors for regular sunscreen use in the past summer (vs never/rarely) in the survivor population were being female, having lighter skin complexions, having previously been examined for skin cancer, and having skin that burned when in the sun unprotected.

CONCLUSIONS

Survivors of childhood cancer self-reported lower tanning practices than siblings. However, because of the potential increased risk of skin cancer from therapy-related exposures, future research should be directed at intervention studies to further reduce UV exposures.