Malignant melanoma is the cancer of the skin inwhich melanocytes develop into malignant cells.It accounts for about 4% of allskin cancers but responsible for 80% of cancer related deaths in the US. Malignantmelanoma is the 6th common cancers among women and 5thamong men in the United States Of America it usually detected or diagnosed atadult stage with a median age at the time of diagnosis being 58 years and only0.
9% of the cases before age of 20(1).Its incidence increased rapidly in the 1970s atabout 6% per year. It has been estimated that the annual incidence increase isabout 3-7%. The increase in incidence rate has been attributed to screeningand early detection of malignant melanoma and awareness (2).
This type ofskin cancer is more common amongst the Caucasian population when compared tothe black people. People with light skin are at increased risk of developingmelanoma, about 17-25 times (1). Melanoma is reported to be more extremely rare the blacksand most cases were acral lentiginous subtype (3, 4). Africans tend to haveprotection form the carcinogenic effects of UV radiation than Caucasians due togreater levels of melanin. The most common sites on which acral lentiginousmelanomas develop in Africans and African–Americans are nail beds, soles andpalms. In a retrospective analysis of melanoma in South Africans of mixedancestry showed histological type and anatomic distribution that ischaracteristic of black populations, yet the 5-year survival rate in thesepatients was similar to that seen in white populations (5).
Annual increase in the incidencerate of melanoma has been estimated to be 3–7% per year Caucasians (6).In most cases malignant melanoma is diagnosed atstage 3 or above, with a median survival of 6-9 months and 5 year survival rateof less than 5% (7, 8).The major predisposing factors are family history, exposureto UV radiation, either intermittent or chronic exposure, fair skin, history ofmelanoma. In a study done by Radespiel-Tröger, M., et al,confirmed that there is an increased risk of melanoma in outdoor workers (9). Outdoor workers had more riskbehaviour with similar constitutional skin cancer risk factors: more UVexposure (both occupational and leisure) and less sunscreen use and lowerhealth literacy). This results in higher exposure, more photodamage and anincreased risk of developing Basal Cell Carcinoma and Squamous Cell Carcinoma (10).
The high levels of sun exposure may be associated with with skin cancers inpeople who work outdoor, together with insufficient use and practise of sunprotective measures when working outside(11). A large number of people are exposedto varying levels of solar radiation at the workplace. In a study using theCAREX (carcinogen exposure) database designed to provide selected exposure dataand documented estimates of the number of workers exposed to carcinogen bycountry, reported that the most common occupational exposure to carcinogens inthe EU countries was solar radiation (12).