Malignant melanoma in Cape Town, South Africa

Abstract

There is a world-wide increase in the incidence of cutaneous malignant melanoma among white people. Absence of accurate population-based data on the incidence of melanoma in South Africa prompted a study to determine the incidence, anatomical sites and pathological details of melanoma in Cape Town. In a prospective study from 1 January 1990 to 31 December 1995, all the histopathology reports of melanoma presenting in a geographically defined area of Cape Town, were actively retrieved from every pathologist practising in this area. The data evaluated included information on age, sex, ethnic group and location of residence. Details of melanoma comprised body site, Clark level of invasion, Breslow thickness in millimetres and histogenetic type. The histology slides were reviewed by a panel in those cases where the recorded information was ambiguous or incomplete. A final number of 595 reports of primary invasive cutaneous melanomas in white people was analysed. Of these 50.3% were men and 49.7% women. The overall age-standardized incidence rate was 24.4 per 100,000 per annum (27.5 for men and 22.2 for women). There was no change in the incidence rate over the study period. Most melanomas in both sexes (74% of women and 71% of men) were < 1.5 mm Breslow thickness. Results of this study indicate a high incidence rate of melanoma in white South Africans, comparable with that in Australia, which demands urgent preventive health measures.

The Epidemiology of Cutaneous Melanoma in the White and Black African Population Groups in South Africa

“…It can be seen that there was a reasonably even distribution throughout the body in White males and females although, as also reported by Saxe et al (10), in Whites living in Cape Town, the trunk was the predominant site in males and the lower limb and/or hip in females. The situation was markedly different in Black Africans as more than two-thirds of the CMs occurred on the lower limb and/or hip in both sexes.…”

“…This is thought to be due to the many genetic changes involved in carcinogenesis, in addition to age-related reductions in the efficacy of the immune system. With regard to South Africa, among 595 Whites diagnosed with primary CM, the median age at diagnosis was 51 years in women and 56 years in men (10). Age-specific rates increased with age among the study sample with the steepest trends in the age group of 55 years and above.…”

“…Superficial spreading melanoma (Figure 2) is the commonest subtype in the White population of South Africa (9,10). Data from the NCR in 2000-2004 revealed that, when reported, the percentage of melanomas presenting as acral lentiginous melanoma (ALM) (Figure 3) was 16.6% in the Black African population compared with 0.8% in the White population (13).…”

“…This was followed by two studies in Whites in Cape Town which showed an increase in incidence in both men and women when figures from 1990 to 1995 were compared with that from 2001 to 2003 (10,11). Reported data from all of South Africa indicate that the incidence in the White population is similar to that found in European countries (18) …”

Is superficial spreading melanoma still the most common form of malignant melanoma?

“…[1][2][3] Most epidemiological studies over the past 40 years suggest that SSM is by far the most prevalent histological subtype of MM. 1,2,[4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] In populations with darker skin types, ALM is the most prevalent form of MM. [21][22][23][24][25][26] In an effort to determine the current prevalence of histologic subtypes of MM, we reviewed 771 consecutive cases of MM from the archives at the Brooke Army Medical Center in San Antonio, Texas.…”