1. Department of Urology, Stellenbosch University, P.O. Box 19063, Cape Town 7505, South Africa
2. Department of Biostatistics and Epidemiology and Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
3. Department of Urology, Tygerberg Hospital, Cape Town 7505, South Africa
4. University Cheikh Anta Diop and Hôpital Général de Grand Yoff, Dakar, Senegal