Prostate cancer of Indigenous men in Canada – identifying differences in diagnosis and treatment within a universal healthcare system
Alexander Kiciak1, Raja Singh2, John Lewis2,3, Wayne Clark4, Sunita Ghosh3,5, Adam Kinnaird1,2.
1Division of Urology, University of Alberta, Edmonton, AB, Canada; 2Alberta Prostate Cancer Research Initiative, University of Alberta, Edmonton, AB, Canada; 3Department of Oncology, University of Alberta, Edmonton, AB, Canada; 4Indigenous Health Initiatives Program, University of Alberta, Edmonton, AB, Canada; 5Department of Mathematical and Statistical Sciences, University of Alberta, Edmonton, AB, Canada
Introduction: In Canada, Indigenous Peoples have higher morbidity rates and a lower life expectancy than non-Indigenous Canadians.1 Prostate cancer (PCa) detection occurs less often and with worse overall survival in Indigenous men than other Canadians.2 Data from the Alberta Prostate Cancer Research Initiative (APCaRI) shows ~1% of men diagnosed and treated for PCa in Alberta are Indigenous, despite Indigenous Peoples comprising 5.1% of Alberta's population. The objective of this study was to identify differences in PCa diagnosis and treatment between Indigenous and non-Indigenous men.
Methods: Men were prospectively enrolled in the APCaRI registry between June 2014 and July 2021. We compared the age, prostate-specific antigen (PSA), and Gleason grade group (GGG) at diagnosis, time from biopsy to treatment decision, treatment choices, and number of patients with metastases between Indigenous and non-Indigenous men with PCa in Alberta. Statistics were calculated using SPSS version 25 (Armonk, NY: IBM Corp.).
Results: A total of 64 Indigenous patients and 6242 non-Indigenous patients had data available for analysis. The mean age was 63.7 (standard deviation [SD] 7.2) vs. 64.3 (SD 7.8) years (p=0.26), and the median PSA was 8.7 vs. 7.4 ng/mL (p=0.02) between Indigenous and non-Indigenous men, respectively. Time from biopsy to treatment decision was 10.7 (SD 6.6) vs. 12.1 (SD 9.6) weeks (p=0.33). GGG stratification revealed 20.4% vs. 36.7% GGG 1, and 79.6% vs. 63.3% GGG 2–5 (p=0.01), respectively. Active surveillance was less common (18.4% vs. 30.5%), while radiation therapy was more common (44.9% vs. 28.7%) in Indigenous men, with pooled analysis of treatment choices significantly differing between groups (p<0.01). Indigenous men were more than twice as likely to be diagnosed with metastases (odds ratio 2.25, 95% confidence interval 1.11–4.60).
Conclusions: PCa diagnosis and treatment differ between Indigenous and non-Indigenous men. Indigenous men present with higher-grade tumors and increased rates of metastasis. Despite similar age, Indigenous men presented with higher median PSA at the time of PCa diagnosis. These data suggest potential differences in rates of PCa screening between Indigenous and non-Indigenous men.
[1] King M. Chronic diseases and mortality in Canadian Aboriginal peoples: learning from the knowledge. Prev Chronic Dis, 2011; 8(1):A07.
[2] Wong, E. C. L., & Kapoor, A. Epidemiology of prostate and kidney cancer in the Aboriginal population of Canada: A systematic review. Canadian Urological Association Journal, 2016; 11(5), E222–32. https://doi.org/10.5489/cuaj.4185
