Risk factors for non-melanomatous skin cancer in Alexandria, Egypt

Solar ultraviolet radiation in Africa: a systematic review and critical evaluation of the health risks and use of photoprotection

The majority of the African continent experiences high solar UVB radiation throughout the year. The adverse consequences of this on the health of populations living in Africa are reviewed.

The Epidemiology of Skin Cancer and its Trend in Iran

Background:

One of the most common cancers is skin cancer worldwide. Since incidence and cost of treatment of the cancer are increasing, it is necessary to further investigate to prevent and control this disease. This study aimed to determine skin cancer trend and epidemiology in Iran.

Methods:

This study was done based on existing data. Data used in this study were obtained from a national registry of cancer cases and the Disease Management Center of Ministry of Health in Iran. All cases registered in the country were included during 2004–2008. Incidence rates were reported based on the direct method and standard population of World Health Organization.

Results:

Based on the results of this study, the incidence of skin cancer is rising in Iran and the sex ratio was more in men than women in all provinces. The age-standardized incidence rate (ASR) of skin cancer was highest in males in Semnan, Isfahan, and Hamedan provinces (34.9, 30.80, and 28.84, respectively). The highest ASRs were seen in females in Semnan, Yazd, and Isfahan provinces (26.7, 24.14, and 18.97, respectively). The lowest ASR in male was observed in Sistan and Baluchestan, and in female in Hormozgan provinces.

Conclusions:

The incidence of skin cancer is increasing in the country. Therefore, the plan for the control and prevention of this cancer must be a high priority for health policy makers.

Breast cancer in postmenopausal women after non-melanomatous skin cancer: the Women's Health Initiative observational study

An increased risk of breast cancer has been reported in patients with non-melanomatous skin cancer (NMSC), but this association has not been studied in a large, multi-geographic population. We utilized data from the Women's Health Initiative observational study to assess whether history of NMSC is associated with breast cancer risk. This analysis included 70,246 postmenopausal White and Hispanic women aged 50-79, in which 4,247 breast cancer cases were identified over a mean (SD) of 11.3 (3.2) years. Baseline information was collected on demographics, medical history, sun exposure, and vitamin D intake. Cox proportional hazards regression was used to calculate hazard ratios (HRs) with 95 % confidence intervals (CIs). The relationship between NMSC and breast cancer was examined as a time-dependent exposure using updated information on NMSC gathered during follow-up visits. All statistical tests were two sided. There were 5,595 women diagnosed with NMSC at study entry. The annualized rate of breast cancer was 0.64 % among women with a history of NMSC and 0.55 % among women with no history of NMSC. The multivariable-adjusted HR for breast cancer among women with a history of NMSC versus no history of NMSC was 1.07 (95 % CI 0.95-1.20, P = 0.27). Further evaluation stratified by tumor characteristics showed an increased risk of lymph node-positive disease, HR = 1.30 (95 % CI 1.01-1.67, P = 0.04), and regional-stage disease, HR = 1.33 (95 % CI 1.05-1.70, P = 0.02), among women with NMSC. There was no significant overall association between NMSC and breast cancer; however, there was an increased risk of more advanced-stage breast cancer which needs further exploration.

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.

Ultraviolet action spectrum for cell killing in a human lens epithelial cell line

There are many sources of ultraviolet (UV) radiation in the workplace. Action spectrum data are necessary for establishing methods to evaluate UV hazards. We determined a UV action spectrum for cell killing in the human lens epithelial cell line SRA 01/04 by measuring the viability of cells exposed to UV at 8 different wavelengths ranging from 259.5 to 300.5 nm in a carefully designed and controlled experiment. The action spectrum based on LD50 is nearly flat or falls slightly with wavelength in the short-wavelength region and then rises increasingly steeply at longer wavelengths. UV at 267.5 nm is most effective in cell killing, with an LD50 of 8.86 Jm(-2). The action spectrum for killing lens epithelial cells in humans (in vivo action spectrum) derived from the present results falls monotonically with wavelength in the range studied, suggesting that UV at wavelengths longer than 300.5 nm may also be highly effective in killing lens epithelial cells in humans and, therefore, in causing cataract. Further studies should be conducted with UV at longer wavelengths.

Multiple nonmelanoma skin cancer in an exposed Australian population

BACKGROUND

Patients with nonmelanoma skin cancer (NMSC) frequently develop multiple skin cancers. The study presents incidence rates and rates of excision of NMSC for a population living in a high-risk environment for skin cancer.

METHODS

Between 1997 and 1999 a prospective population-based study collected information on all histologically confirmed NMSCs in Townsville, Australia.

RESULTS

Of the 6708 patients recorded with NMSC, 38.5% had multiple lesions. Yearly age-standardized incidence rates (per 100,000 inhabitants) of basal cell carcinoma (BCC) were 1444.8 for men, 942.7 for women, and of squamous cell carcinoma (SCC) were 805.0 for men, and 423.6 for women. Compared to incidence rates, age-standardized rates of lesions of BCC were 2.1 times higher in men, 1.6 times higher in women, and of SCC were 1.8 times higher in men and 1.4 times higher in women.

CONCLUSIONS

The occurrence of multiple NMSCs compromises results of short-term studies on incidence. Further discussions on the most appropriate strategies to describe the real burden of NMSC are warranted.

Biological effects of narrow-band (311 nm TL01) UVB irradiation: a review

The narrow-band UVB (TL01) lamp (311 nm emission) was developed for use in phototherapy, as an alternative to a broad-band UVB source and to photochemotherapy, both of which have significant side effects and carry a risk of carcinogenesis. This new lamp has proved to be particularly effective at clearing psoriasis. It is now acknowledged that the TL01 lamp is probably 2-3 times more carcinogenic per minimum erythema dose than broad-band UVB, but the cumulative dose required in therapy is considerably less than when using broad-band UVB sources. In terms of irradiation dose, the TL01 lamp is about 5-10-fold less potent than broad-band UVB for erythema induction, hyperplasia, oedema, sunburn cell formation and Langerhans cell depletion from skin. However, the broad-band UVB to TL01 potency ratio for cis-urocanic acid formation in the skin is approximately unity. In addition, the TL01 lamp, as used in phototherapy, has relatively more suppressive effects than broad-band UVB on systemic immune responses as judged by natural killer cell activity, lymphoproliferation and cytokine responses. However, the TL01 lamp is less effective at reducing epidermal antigen presentation, inducing dendritic cell migration to lymph nodes draining irradiated sites and suppressing contact hypersensitivity at the doses tested. Therefore the use of the TL01 lamp in phototherapy should be considered carefully after weighing up its diverse effects on the skin and immune system.