Racial differences in melanoma incidence

Abstract

Summary.-The incidences of malignant melanoma recorded by 59 populationbased cancer registries were investigated to determine the effects of racial and skincolour differences. White populations exhibited a wide range of melanoma incidences and females commonly, though not invariably, had a higher incidence than males. Non-white populations experienced in general a much lower incidence of melanoma although there was some overlap of white and non-white rates. No predominant sex difference emerged among non-whites.Populations of African descent were found to have a higher incidence than those of Asiatic origin, but it was concluded that this was due largely to the high frequency of tumours among Africans on the sole of the foot. A clear negative correlation between degree of skin pigmentation and melanoma incidence emerged for the exposed body sites. These data provide strong support for the hypotheses that UV radiation is a major cause of malignant melanoma and that melanin pigmentation protects against it. Further research is required to elucidate the aetiology of melanoma of the sole of the foot.

Variation of melanoma incidence with latitude in North America and Europe

“…Regression analyses showed that this trend with latitude was significant in both males and females (Table I). An earlier analysis of these data of the melanoma incidence among Caucasians indicated that the melanoma incidence was directly related to that of cancer of all sites (excluding non-melanoma skin tumours) (Crombie, 1979). It Within Europe the relationship between melanoma incidence and latitude takes a different form (Fig.…”

“…The incidence among darkskinned races is commonly low (Oettle, 1]966;Camain et al, 1972) and a clear relationship between the density of skin pigmentation and the incidence of melanoma on the exposed body sites has been demonstrated (Crombie, 1979). Melanin pigmentation is thought to afford protection by absorbing the UV (Quevedo et al, 1975) so that the degree of protection would be expected to depend on the concentration of pigment.…”

Incidence of eye cancer in Taiwan: an 18-year review

“…18,19 Nevertheless, the protection of increased pigmentation has been hypothesized to explain the less risk to ocular melanoma in darkly pigmented people when compared with whites people. 20 In the United States, uveal melanoma primarily affects patients between 60 and 70 years old. 6 However, it has been observed that Chinese patients with uveal melanoma tended to be younger than their Western counterparts.…”

Distribution of malignant melanoma on the body surface

“…An earlier paper in this series found that among the 48 "white" registries, females had a significantly higher incidence of melanoma than males (Crombie, 1979b). Details of the distribution of melanoma among the 4 major body sites (head, upper limb, lower limb and remainder) are available only for 37 "white" registries, but these also show that females have the significantly higher incidence (Table I).…”

“…It is well known that dark-skinned races have a low incidence of melanoma (Oettle, 1966;Camain et al, 1972) and a recent study (Crombie, 1979b) has demonstrated a clear relationship between the density of pigmentation and the incidence of melanoma on the exposed body sites. Melanin pigment is thought to protect by absorbing the UV (Quevedo et at., 1975) so that the degree of protection would depend on the density of pigment.…”