1. ¹MRC/NHLS/Wits Cancer Epidemiology Research Group, National Health Laboratory Service, PO Box 1038, Johannesburg 2000, South Africa
2. ²Cancer Epidemiology Research Unit, The Cancer Council NSW, PO Box 572, Kings Cross 1340, Australia
3. ³Division of Medical Oncology, Department of Medicine, Johannesburg Hospital and the University of the Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa
4. ⁴Department of Anatomical Pathology, Chris Hani Baragwanath Laboratory, School of Pathology, University of the Witwatersrand, and National Health Laboratory Service, PO Box 1038, Johannesburg 2000, South Africa
5. ⁵Division of Radiation Oncology, Department of Medicine, Johannesburg Hospital and the University of the Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa
6. ⁶Clinical Haematology Division, Department of Medicine, Chris Hani Baragwanath Hospital and the University of the Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa

Correspondence: Dr F Sitas, E-mail: freddys@nswcc.org.au

Received 22 November 2007; Revised 4 February 2008; Accepted 11 February 2008; Published online 25 March 2008.

Abstract

Demographic and lifestyle information from 9690 black patients diagnosed with cancer or cardiovascular disease was collected in an ongoing case–control study in Johannesburg, South Africa. Compared to never smokers, the odds ratio (OR) for lung cancer among current smokers was 16.3 (95% confidence interval (CI), 9.6–27.6) for men and 6.4 (95% CI, 4.0–10.4) for women. The corresponding OR for other smoking-related cancers was 4.6 (95% CI, 3.7–5.7) among men and 1.9 (95% CI, 1.6–2.2) among women, and for cardiovascular disease, 3.4 (95% CI, 2.1–5.4) among men and 1.5 (95% CI, 1.1–2.1) among women. Risks were higher among smokers than former smokers, and all risk estimates increased with increasing levels of smoking duration and intensity. Non-electric domestic fuel was associated with approximately 60% increase in the risk of smoking-related cancer, but not cardiovascular disease. Risks for cancers of cervix, oesophagus, oral cavity/pharynx, stomach, larynx, pancreas and anogenital region, as well as squamous cell carcinoma of skin were all significantly higher among current than never-smokers, with ORs ranging from 1.5 for cervix (95% CI, 1.2–1.8) to 14.7 for larynx (95% CI, 7.2–30). The risks of tobacco-related disease reported here are similar to that currently observed in Western countries, even though cigarette consumption is relatively low in this population.