Case report
The Role of UV Radiation in the Development of Basal Cell Carcinoma
Mirna Šitum
Marija Buljan
Vedrana Bulat
Liborija Lugović Mihić
Željana Bolanča
Dubravka Šimić
Abstract
Basal cell carcinoma (basalioma, BCC) is undoubtedly the most common malignant skin cancer and the most common
human malignancy in general, with the continuous increase in its incidence. BCC is generally a disorder of white
individuals, especially those with fair skin. UV radiation is the most important risk factor in the development of BCC.
Short-wavelength UVB radiation (290–320 nm, sunburn rays) is believed to play a greater role in BCC formation than
long-wavelength UVA radiation (320–400 nm, tanning rays). A latency period of 20–50 years is typical between the time
of UV damage and the clinical onset of BCC. Therefore, in most cases BCC develops on chronically sun-exposed skin in
elderly people, most commonly in the area of head and neck. UVB radiation damages DNA and its repair system and alters
the immune system resulting in a progressive genetic alterations and formation of neoplasm. UV-induced mutations
in the TP53 tumor-suppressor gene have been found in about 50% of BCC cases. The mutations that activate the Hedgehog
intercellular signaling pathway genes, including PTCH, Sonic hedgehog (Shh) and Smoothened (Smo) play a significant
role in cutaneous carcinogenesis. Epidemiologic studies demonstrate the higher incidence of the BCC in more
equatorial latitudes than in polar latitudes. Other risk factors for the development of BCC include sun bed use, family
history of skin cancers, skin type 1 and 2, immunosuppression, previous radiotherapy, and chronic exposure to toxic substances
such as inorganic arsenic. Although rarely metastatic, its malignant nature is sometimes emphasized by the local
tissue destruction, disfigurement, and even death if left untreated. Due to extremely high incidence of BCC medical
professionals should be aware of the importance of the public education on the etiology of this tumor and the importance
of the UV protection.
Keywords
basal cell carcinoma; basalioma; UV radiation; photoimmunology; carcinogenesis
Hrčak ID:
34646
URI
Publication date:
1.10.2008.
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