Risk Factors For Melanomas

Seventy-nine percent of skin-cancer-related deaths are caused by cutaneous malignant melanoma. During the last decades, the incidence of malignant melanoma has raised in all developed countries independently of sex . In 2005, the American Cancer Society estimated that there were 59,580 new cases of melanoma in the USA .The prognosis of cutaneous malignant melanoma strongly depends on the stage of detection . Whereas the prognosis is excellent for thin melanoma diagnosed early and treated with adequate surgical excision , the 5-year overall survival declines to 60% for patients with lymph node metastases . The overall survival of patients with advanced malignant melanoma is most unfavorable with a 5-year survival rate of 5–14% . Fortunately, about 82% of all cutaneous melanomas are detected at a localized stage of the disease . During the last decades, the importance of prognostic indicators played a central role in scientific reports on malignant melanoma. Numerous analyses led to continuous modification of the American Joint Committee on Cancer (AJCC) classification of cutaneous melanoma .

The most important risk factor for the development of melanoma is the number of melanocytic nevi on the body .The risk for melanoma development increases almost linearly within creasing numbers of melanocytic nevi. Numerous epidemiological risk factor studies, from various countries with Caucasian populations, have assigned a riskof 1-fold to individuals with 0–10 melanocytic nevi but an 8-to10-fold increase in relativenrisk for those with 100 or more melanocytic nevi. The second most important risk factor for melanoma development is the presence of atypical melanocytic nevi .These lesions are clinically well defined and should display at least three of the 5 following clinical features:

A: Ill-defined border
B: Irregular border,
C: Color varying within the lesio

D: Diameter of 5 mm or more
E: Presence of a macular component.

If a certain number of these atypical lesions is present then there is a 4-to 6-fold increase of the relative risk for melanoma development.These risk factors interact with each other in a multiplicative fashion.This means that persons having 100 melanocytic nevi or more, among which five or more are atypicalnmelanocytic nevi,have an about 50-fold relative risk for melanoma development. Knowing this enables dermatologists to identify persons at risk. Melanocytic nevi develop mainly during childhood and adolescence. Epidemiological studies in children have identified those factors associated with the developmentnof high numbers of common and atypical melanocytic nevi. Such as tudy was performed in 1812 kindergartenchildreni
Germany.This study analyzed risk factors that were associated with highnnumbers of melanocytic nevi at the initial examination, and those factors associated with high numbers of newly developed melanocytic nevi during a 3-yearfollow-up. Interestingly, almost the same risk factors were identified for both end points. The number of melanocytic nevi in children increases with age.Whereas an average of three melanocytic nevi has been detected at 2 years of age, an average of 19 was found at the age of seven.The most important risk factor for the development of melanocytic nevi was the number of weeks on holiday in sunny climates.This refers to the type of intermittent sun exposure that can cause sun burn in a certain percent age of children.
Additionally, sun burn was a significant risk factor in the longitudinal study. However, sun burn seems not to be required for the development of melanocytic nevi; moderate sun exposure seems to be sufficient for this. Outdoor activities at homeni
Germany, as recorded by as core combining different activities (e.g. bathing, playing games outdoors) werenlikewise significantly associated with melanocytic nevus development. Other risk factors for nevus development are pigmentntraits. A child’s skin type indicates there action to sun exposure, i.e. whether the child burns or tans, and is ansignificant risk factor. Additionally, a tendency to freckling is like wise associated with the development of melanocytic nevi. Another clue to hereditary factors is the significant association between numbers of melanocytic nevi innparents and nevus counts in children. The numbers of melanocytic nevi in both fathers and mothers were significantly associated to nevus development in their children. Finally, we evaluated the effects of preventive measures like sun screens and clothing. Interestingly, no degree of sun screen use (everused, never used, frequency of sunscreen application, sun protection factor, etc.) had any significant association with nevus development. On the contrary, clothing habits were significantly associated with protection from nevus development. Thenmore clothes children wore in the sun, the fewer nevi they developed.
Finally: Sunscreens alone are not sufficient; sun avoidance and clothing are required for primary prevention in children.
Risk factors are responsible for rising melanoma incidence.