Epidemiology and etiology of malignant melanoma

According to recent cancer epidemiology reports malignant melanoma in both sexes and lung carcinoma in females, are the only cancers of which the incidence continuously increases. In Australia, Northern Europe and Canada the incidence doubling time of malignant melanoma has been 10 to 20 years only. The highest incidence has been found in the State of Queensland, Australia, with an incidence of 32/100,000 inhabitants per year in males and 33.4/1000,000 in females. Moreover 1 of 3 persons is likely to develop skin cancer during life span in Queensland. The new habit of Whites to sun-bathe in sunny regions of the world seems to be in close relationship with the increased incidence of malignant melanoma. In addition, the hazard of skin cancer is higher in the south of U.S.A as compared with the north, where the UVB radiations is lower. Genetic factors seem to play a role in malignant melanoma. Patients having this tumour report sun-burn and freckling in a 4 fold higher frequency than non melanoma patients. Chemicals such as psoralens; used as photosensitizers, synthetic steroids and probably some cosmetics, may act as error prone carcinogenic agents in the presence of hv from UV light. This field of skin toxicology and carcinogenesis leads into to the way of new developments in cosmetics, including the design of efficient skin protectors. Therefore, future efforts in preventing further increase of malignant melanoma incidence should take into account the following: 1) UV irradiation is a causative factor of malignant melanoma; 2) the evidence of genetic propensity at developing malignant melanoma; 3) the increased use of chemicals and cosmetics with a photosensitizing effect - and possibly a photochemical carcinogenic effect - is an additional hazard; 4) the XXth century man will not give up sun-bathing. Therefore, future prevention of skin cancers will depend upon the development of new and efficient antisolar agents.SCOPUS: re.j