Prostate cancer disproportionately affects men of African descent, yet their representation in tissue-based studies is limited. This multinational, multicenter pilot study aims to establish the groundwork for collaborative research on prostate cancer in sub-Saharan Africa.
The Men of African Descent and Carcinoma of the Prostate network formed a pathologist working group representing eight institutions in five African countries. Formalin-fixed paraffin-embedded prostate tissue specimens were collected from Senegal, Nigeria, and Ghana. Histology slides were produced and digitally scanned. A central genitourinary pathologist (P.L.) and eight African general pathologists reviewed anonymized digital whole-slide images for International Society of Urological Pathology grade groups and other pathologic parameters. Discrepancies were re-evaluated, and consensus grading was assigned. A virtual training seminar on prostate cancer grading was followed by a second assessment on a subcohort of the same tissue set.
Of 134 tissue blocks, 133 had evaluable tissue; 13 lacked cancer evidence, and four were of insufficient quality. Post-training, interobserver agreement for grade groups improved to 56%, with a median Cohen's quadratic weighted kappa of 0.83 (mean, 0.74), compared with an initial 46% agreement and a quadratic weighted kappa of 0.77. Interobserver agreement between African pathologist groups was 40%, with a quadratic weighted kappa of 0.66 (95% CI, 0.51 to 0.76). African pathologists tended to overgrade (36%) more frequently than undergrade (18%) compared with the reference genitourinary pathologist. Interobserver variability tended to worsen with a decrease in tissue quality.
Tissue-based studies on prostate cancer in men of African descent are essential for a better understanding of this common disease. Standardized tissue handling protocols are crucial to ensure good tissue quality and data. The use of digital slide imaging can enhance collaboration among pathologists in multinational, multicenter studies.
JCO global oncology. 2024 Jun [Epub]
Abraham C van Wyk, Priti Lal, J Olufemi Ogunbiyi, Lynnette Kyokunda, Fred Hobenu, Cherif Dial, Mohamed Jalloh, Richard Gyasi, Olabode P Oluwole, Afua D Abrahams, Adam R Botha, Nompumelelo Zamokuhle Mtshali, Caroline Andrews, Sunny Mante, Ben Adusei, Serigne M Gueye, James E Mensah, Andrew Anthony Adjei, Yao Tettey, Akin Adebiyi, Oseremen Aisuodionoe-Shadrach, Sefiu Bolarinwa Eniola, Amparo Serna, Kosj Yamoah, Wenlong Carl Chen, Pedro Fernandez, Brian D Robinson, Juan Miguel Mosquera, Ann W Hsing, Ilir Agalliu, Timothy R Rebbeck
Stellenbosch University and National Health Laboratory Service, Tygerberg Hospital, Cape Town, South Africa., University of Pennsylvania, Philadelphia, PA., University College Hospital/University of Ibadan, Ibadan, Nigeria., University of Botswana, Gaborone, Botswana., 37 Military Hospital, Accra, Ghana., Hôpital Général Idrissa Pouye, Dakar, Sénégal., Korle-Bu Teaching Hospital, Accra, Ghana., University of Abuja, Abuja, Nigeria., Department of Anatomical Pathology, Faculty of Health Sciences, University of the Witwatersrand and the National Health Laboratory Service, Johannesburg, South Africa., Dana-Farber Cancer Institute, Boston, MA., Moffitt Cancer Center & Research Institute, Tampa, FL., National Cancer Registry, National Institute for Communicable Diseases a Division of the National Health Laboratory Service, Johannesburg, South Africa., Division of Urology, Department of Surgical Sciences, Stellenbosch University, Cape Town, South Africa., Weill Cornell Medical Center, New York, NY., Stanford Cancer Institute, Stanford School of Medicine, Palo Alto, CA., Albert Einstein College of Medicine, New York, NY.