Relationship between p53 codon 72 polymorphism and susceptibility to sunburn and skin cancer.
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Upregulation of p53 protein induces either growth arrest or apoptosis in response to cellular injury This is signaled from a highly conserved p53 domain between codons 64 and 92, where a functional polymorphism results in either a proline (p53-72P) or an arginine (p53-72R) at codon 72. Preliminary studies suggest that p53-72R may be a risk factor for cervical cancer and, consistent with this, preferential mutation and retention of the p53-72R allele has also been demonstrated in other cancers of squamous cell origin. Here we examine the relationship between allelic forms of p53 and nonmelanoma skin cancer, by determining the correlation with susceptibility to sunburn, which is a known risk factor, and then by p53 sequence analysis of a large series of tumors. We found a significant positive association between p53-72R and susceptibility to sunburn, as assessed by skin phototype and minimal erythemal dose following solar-simulated radiation (p = 0.0001 for trend). We also found a significant association between p53-72R homozygosity and nonmelanoma skin cancer in renal transplant recipients (basal cell carcinoma, p < 0.01; squamous cell carcinoma, p < 0.05) but not in immunocompetent patients compared with skin type matched controls. p53 sequence data revealed mutations in 30 of 70 (42.9%) nonmelanoma skin cancers, 28 (93%) of which were in the p53-72R allele. Loss of heterozygosity occurred more frequently in p53-72RP than in p53-72RR tumors (p = 0.0001) with preferential loss of p53-72P in heterozygotes (p = 0.016), irrespective of the mutant status of the concomitant allele. Together these data infer functional differences between polymorphic forms of p53 that are likely to be relevant to skin carcinogenesis. (+info)
Behavior of caregivers to protect their infants from exposure to the sun in Queensland, Australia.
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Exposure to the sun by infants has been demonstrated to increase the risk of the development of melanoma and other skin cancers later in life. A cohort of 508 women who delivered healthy Caucasian babies were followed up at 1 year to determine their knowledge, attitudes and practices regarding sun protection towards themselves and their child. In addition, the 1-year-old infants were assessed by a trained nurse for the number of nevi they had on their skin. Results indicate caregivers reported a high level of sun-protection practices towards their child, with 93% of the caregivers reporting usually or always placing the child in the shade when going outside. Further, 81% of the caregivers reported usually or always placing a hat on the child, while 64% reported usually or always applying sunscreen to the child's exposed skin. Interestingly, only 61% of the caregivers reported that they stayed in the shade to reduce sun exposure and only 42% wore a hat when out in the sun. Mother's own personal sun-protection methods predicted the method of sun protection that she would most likely use for the child. While children appear to be reasonably protected from the sun, they are influenced by their mother's own behaviors. (+info)
BACKGROUND: Public awareness and education may lead to the detection of thinner melanomas, which may result in a decrease in morbidity and mortality rates. Which detection patterns, lesion, and patient characteristics are associated with early detection? METHODS: Using the University of Michigan prospective melanoma database, the detection patterns, lesion characteristics, and patient characteristics of 1515 consecutive patients with in situ or invasive cutaneous melanomas were reviewed. Tumor thickness (measured in millimeters) was evaluated in relationship to detection patterns (patient, physician, spouse), lesion characteristics (change in color, size, shape/elevation, ulceration, bleeding, tenderness, itching), and patient characteristics (gender, skin type, number of atypical and clinically benign nevi, history of sunburn, personal and family history of melanoma). RESULTS: Patient characteristics associated with early detection included female gender, at least one atypical nevus, greater than 20 clinically benign nevi, and/or a personal history of melanoma. Skin types I, II, and III, a history of sunburn, and/or a family history of melanoma were also associated with thinner lesions, but these associations were not statistically significant. Lesion characteristics associated with earlier detection included a change in color, size, shape/elevation, and/or itching. Physician-detected melanomas were significantly thinner than patient or spouse-detected lesions. CONCLUSIONS: Educational campaigns should include increasing melanoma awareness in males and educating the public on the early signs and symptoms. Education should be directed at both high and low-risk groups. Physicians should consider performing total skin examinations routinely on patients. Although they detect a relatively small percentage of all melanomas, physicians detect significantly thinner lesions. (+info)
Cancer screening practices from National Health Interview Surveys: past, present, and future.
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The National Health Interview Survey (NHIS) has provided data about health behaviors at the national level since 1957. The 1987 and 1992 Cancer Control Supplements to the NHIS, along with other supplemental surveys administered intermittently on self-reported cancer-related behaviors, have contributed to important research and public health purposes. In this article, we reviewed 73 papers published between 1980 and 2001 that used NHIS data, including the first report from the 1998 NHIS, to examine what has been learned from past surveys. Our goal was to facilitate future analyses of recently released data on cancer screening practices from the Cancer Control Supplement to the 2000 NHIS, which is now known as the Cancer Control Module. We categorized the papers according to which of the following three study approaches they used: trends in screening rates, correlates of these rates with factors that may influence screening, and linkages or comparisons of NHIS data with other surveys or sources of information. We summarize knowledge gained in cancer screening for each of these three categories and identify areas that could benefit from more research. We highlight some of the new information available for the first time on the Cancer Control Module of the 2000 NHIS as fresh opportunities for cancer control research. Finally, we describe how the Cancer Control Supplements to the NHIS are integrated with the objectives of and developments in national cancer surveillance research that have emerged from federal planning efforts and collaborations with national partners in cancer surveillance in recent years. (+info)
Current action for skin cancer risk reduction in English schools: pupils' behaviour in relation to sunburn.
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In a random sample of schools distributed throughout all areas of England, 2703 primary school pupils from 46 schools and 2692 secondary school pupils from 32 schools were surveyed regarding behaviour in the sun, and opinions and experience of sunburn. Seventy percent (1879) of primary and 36.5% (982) of secondary pupils recalled hearing about protecting themselves from the sun at school. Primary school pupils who recalled they were told to 'stay in the shade' were more likely say they did so; 27.3% (739) of primary and 20.7% (556) of secondary school pupils reported getting sunburnt; and 53.2% (393/739) primary school pupils and 52.5% (292/556) secondary school pupils reporting sunburn said their sunburn peeled. The most common time both primary and secondary pupils said they got sunburnt at school was at lunchtime (mid-day break); the next most common time was during sports day. Pupils saying they did not protect their skin because they wanted a tan were more likely to report sunburn (41.7% primary and 29.5% secondary) than those giving other reasons. Primary school pupils who said they used sun screen frequently (285/847) were more likely than 'never users' (178/813) to report sunburn, as were secondary school pupils (53/192 and 264/1565 for frequent and 'never users', respectively). Dark- and light-skinned pupils at primary school (27.3 and 27.4%, respectively) were equally likely to say they had been sunburnt. At secondary school, only 10.6% of dark-skinned compared with 22.3% of light-skinned pupils reported sunburn. The last two findings might be related to cultural behaviours and are discussed later. Pupils of all ages need encouragement to protect their skin at mid-day break, to use sunscreens correctly and be aware of alternative sun-protection methods. Education is needed which challenges the notion that a 'tan is beautiful' and uses social teaching methods to empower pupils to carry out sun protection in real life. (+info)
A commercial sunscreen's protection against ultraviolet radiation-induced immunosuppression is more than 50% lower than protection against sunburn in humans.
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Ultraviolet radiation (280-400 nm)-induced suppression of cutaneous cell-mediated immunity plays an important part in the development of skin cancer. Sunscreens are widely advocated to protect against skin cancer but if they offer insufficient protection against immunosuppression they may inadvertently increase skin cancer risk. This human study evaluated immunoprotection afforded by a commercial sunscreen preparation (labeled sun protection factor 15) offering primarily ultraviolet B (280-320 nm) protection. Indirectly, it also investigated whether ultraviolet A (320-400 nm) plays a part in ultraviolet radiation-induced immunosuppression. Healthy white-skinned volunteers were used (n=119). Ultraviolet radiation exposures were on previously unexposed buttock skin with an ultraviolet radiation source that complied with European recommendations for sunscreen testing. Ultraviolet radiation dose-response curves for sunburn/erythema and suppression of the contact hypersensitivity response were generated either with or without sunscreen in vivo and protection factors were derived for both end-points. The ultraviolet radiation wavelengths transmitted by the sunscreen were determined in vitro and showed that the sunscreen was primarily an ultraviolet B absorber, with relatively poor absorption in the ultraviolet A region. The sun-screen protected against both erythema and immunosuppression but protection against immunosuppression (IPF=4.9, 95% confidence interval: 2.3-10.6) was less than half that for erythema (Ery-PFg=14.2, 95% confidence interval: 10.2-19.8). Failure of the sunscreen to afford comparable protection against both end-points was probably due to immunosuppression by ultraviolet A, a part of the solar spectrum that does not readily cause sunburn. The sunscreen protected against both end-points, which supports the use of sunscreens to reduce immunosuppression but protection against immunosuppression may be improved if sunscreens are formulated to offer equivalent protection against ultraviolet B and ultraviolet A. (+info)
Validity and reliability of the parental sun protection scales.
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Skin cancer is the most common cancer diagnosed in the US and its incidence continues to rise. Epidemiological studies have shown that excessive sun exposure received during childhood may increase the risk of developing skin cancer later in life. Yet, there are few published reports on the development of reliable and valid theory-based scales that assess the factors associated with parental sun-protection practices to reduce sun exposure in preschool children. To fill this gap, the Parental Sun Protection Scales were developed and validated. Two series of confirmatory factor analytic models were employed to test the factor structure of the scales and to examine the inter-relationships among the proposed psychosocial factors. Sunscreen-use and sun-avoidance behavioral models were tested in a sample of 384 parents. The results provided a basis for the reliable and valid measurement of psychosocial factors related to parental sun-protection practices. These scales may be useful in more fully understanding the determinants of sun-protection behaviors and in evaluating intervention programs designed to improve such behaviors. (+info)
The influence of painful sunburns and lifetime sun exposure on the risk of actinic keratoses, seborrheic warts, melanocytic nevi, atypical nevi, and skin cancer.
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Painful sunburns are implicated in the pathogenesis of squamous cell carcinoma, basal cell carcinoma, and malignant melanoma. Chronic exposure to ultraviolet radiation is known as the most important risk factor for the development of actinic keratoses and squamous cell carcinoma. The purpose of the study was to assess the effect of painful sunburns and lifetime sun exposure on the development of actinic keratoses and seborrheic warts in relation to the development of squamous cell carcinoma and basal cell carcinoma, and on the development of melanocytic nevi and atypical nevi in relation to the development of malignant melanoma. We made use of a cohort of 966 individuals who participated in a case-control study to investigate environmental and genetic risk factors for skin cancer. Exposure measurements for sunlight were collected and actinic keratoses, seborrheic warts, melanocytic nevi, and atypical nevi were counted. Relative risks were estimated using exposure odds ratios from cross-tabulation. Multivariate logistic regression was used to adjust for potential confounders. The recall of painful sunburns before the age of 20 y was associated with an increased risk of squamous cell carcinoma, nodular basal cell carcinoma, and multifocal superficial basal cell carcinoma as well as actinic keratoses. Odds ratios with 95% confidence intervals adjusted for age, sex, and skin type were 1.5 (0.97; 2.3); 1.6 (1.1; 2.2); 2.6 (1.7; 3.8); and 1.9 (1.4; 2.6) for the three types of nonmelanoma skin cancer and actinic keratoses, respectively. Painful sunburns before the age of 20 y were also associated with an increased risk of malignant melanoma and the development of its precursors, melanocytic nevi and atypical nevi. Odds ratios with 95% confidence intervals adjusted for age, sex, and skin type were 1.4 (0.86; 2.1); 1.5 (1.1; 2.0); and 1.4 (0.88; 2.3) for malignant melanoma and the two types of precursors, respectively. Lifetime sun exposure was predominantly associated with an increased risk of squamous cell carcinoma (p-value for trend=0.03) and actinic keratoses (p-value for trend <0.0001) and to a lesser degree with the two types of basal cell carcinoma. By contrast, lifetime sun exposure appeared to be associated with a lower risk of malignant melanoma, despite the fact that lifetime sun exposure did not diminish the number of melanocytic nevi or atypical nevi. Neither painful sunburns nor lifetime sun exposure were associated with an increased risk of seborrheic warts. (+info)