Skin cancer risk factors among Black South Africans-The Johannesburg Cancer Study, 1995-2016

Babongile C Ndlovu; Mazvita Sengayi-Muchengeti; Caradee Y Wright; Wenlong C Chen; Lazarus Kuonza; Elvira Singh

doi:10.1002/iid3.623

Skin cancer risk factors among Black South Africans-The Johannesburg Cancer Study, 1995-2016

Immun Inflamm Dis. 2022 Jul;10(7):e623. doi: 10.1002/iid3.623.

Authors

Babongile C Ndlovu^{1

2

3}, Mazvita Sengayi-Muchengeti^{2

3

4}, Caradee Y Wright^{5

6}, Wenlong C Chen^{2

7}, Lazarus Kuonza^{1

3}, Elvira Singh^{2

3}

Affiliations

¹ South African Field Epidemiology Training Program, National Institute for Communicable Diseases, Division of the National Health Laboratory Service, Johannesburg, South Africa.
² National Cancer Registry, National Health Laboratory Service, Johannesburg, South Africa.
³ School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
⁴ South African DSI-NRF Centre of Excellence in Epidemiological Modeling and Analysis (SACEMA), Stellenbosch University, Stellenbosch, South Africa.
⁵ Environment and Health Research Unit, South African Medical Research Council, Pretoria, South Africa.
⁶ Department of Geography, Geoinformatics and Meteorology, University of Pretoria, Pretoria, South Africa.
⁷ Sydney Brenner Institute for Molecular Bioscience, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.

Abstract

Background: The Black population has lower skin cancer incidence compared to White, Indian/Asian, and Mixed-race populations in South Africa; however, skin cancer still exists in the Black population. The aim of this study is to identify risk factors associated with skin cancer among Black South Africans.

Materials and methods: A case-control study was conducted. Cases were patients with keratinocyte cancers (KCs) and/or melanoma skin cancers (MSCs) and controls were cardiovascular patients. Sociodemographic exposures, environmental health variables, smoking, and HIV status were assessed. Stepwise logistic regression was used to identify risk factors associated with KCs and MSCs.

Results: The KCs histological subtypes showed that there were more squamous cell carcinomas (SCCs) (78/160 in females, and 72/160 in males) than basal cell carcinomas (BCCs). The SCC lesions were mostly found on the skin of the head and neck in males (51%, 38/72) and on the trunk in females (46%, 36/78). MSC was shown to affect the skin of the lower limbs in both males (68%, 27/40) and females (59%, 36/61). Using females as a reference group, when age, current place of residency, type of cooking fuel used, smoking, and HIV status were adjusted for, males had an odds ratio (OR) of 2.04 for developing KCs (confidence interval [CI]: 1.08-3.84, p = .028). Similarly, when age, current place of residency, and place of cooking (indoors or outdoors) were adjusted for, males had an OR of 2.26 for developing MSC (CI: 1.19-4.29, p = .012).

Conclusions: Differences in the anatomical distribution of KCs by sex suggest different risk factors between sexes. There is a positive association between being male, smoking, rural dwelling, and a positive HIV status with KCs and being male and rural dwelling with MSC. The rural dwelling was a newly found association with skin cancer and warrants further investigation.

Keywords: Black population; South Africa; keratinocyte skin cancer; melanoma skin cancer; risk factors.

MeSH terms

Case-Control Studies
Female
HIV Infections* / epidemiology
Humans
Male
Melanoma
Melanoma, Cutaneous Malignant
Risk Factors
Skin Neoplasms* / epidemiology
South Africa / epidemiology