**2. Types of skin cancer**

**a.** Basal Cell Carcinoma (BCC): This is the most common form of skin cancer and accounts for more than 90% of all skin cancers in the United States. BCC causes damage by growing and invading the surrounding tissue and usually does not metastasize to other parts of the body. Intermittent sun exposure (especially early in life), age and light colored skin are important factors in the development of BCC. Approximately a fifth of BCCs, develop in regions that are not sun-exposed such as chest, arms, neck, back and scalp [2]. Weak‐ ening of the immune system on account of the disease or immune-suppressive drugs is known to promote the risk of developing BCCs. Usually BCC begins as a small, domeshaped bump and is covered by small superficial blood vessels called telangiectases and its texture is often shiny and translucent. Hereditary predisposition to BCC [3,4] occurs

© 2013 Tarapore; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

among individuals with albinism and Xeroderma Pigmentosum. These disorders can be linked to either instability of the skin or diminished pigmentation.

is on account of the larger, more melanized melanosomes located in the epidermis of dark skin individuals that absorb and scatter more light energy than the smaller, less melanized melanosomes of white skin. The incidence rate of skin cancer (both melanoma and nonmelanoma) has increased significantly in the last decade [15]; particularly among young women. For most individuals, exposure to UVR from the sun is the main source of skin cancer. Nonetheless, some individuals are exposed to high UV doses through artificial sources – sunbeds and sunlamps used for tanning purposes. Indoor tanning is widespread in most developed countries in Northern Europe, Australia and the United States [16]. Intense early sunburns and blistering sunburns are closely associated with melanoma development [17,18, 19]. Statistics indicate that one severe childhood sunburn is associated with a two-fold increase in melanoma risk [20]. Chronic UV exposure results in increased skin aging, wrinkles, uneven skin pigmentation, loss of elasticity and a distribution in the skin barrier function [21]. Chronic UVR exposure is an important risk factor in the development of actinic keratosis (precursor of

An Overview of Important Genetic Aspects in Melanoma

http://dx.doi.org/10.5772/55257

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**Ultraviolet (UV radiation)** UVA UVB

**Genetic syndromes** Xeroderma pigmentosum Oculocutaneous albinism Basal cell nevus syndrome

> **Ionizing radiation** X-rays

**Other risk factors** Artificial UV radiation (tanning) Smoking Color of skin (having fair skin, especially with blue or hazel eyes) History of precursor lesions Chronically injured or non-healing wounds Working outdoors Increasing age

SCCs).

**Table 1.** Risk factors for skin cancer [1-8]

