Clinical interpretation of prostate-specific antigen values: Type of applied cut-off value exceeds methods bias as the major source of variation

Mining laboratory data to describe prostate specific antigen testing and prostate cancer in Johannesburg, South Africa

Introduction

guidelines issued by different organizations worldwide differ on the use of prostate specific antigen (PSA) in prostate cancer. However, no local data is available describing how PSA testing is offered by our healthcare facilities in the country. The objectives of this study were to describe PSA testing and subsequent prostate biopsy uptake in a South African urban population.

Methods

this was a descriptive retrospective study. Data of all PSA tests and prostate biopsies performed at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH) laboratory for 2013 calendar year was extracted from the laboratory information system.

Results

a total of 20 365 PSA tests were performed on 17 481 men during the study period. The majority of men were Black African (79%). The mean age for Black Africans (55.5 years, SD 13.3) was significantly lower than other racial groups (62.9 years, SD 12.6, p < 0.0005). PSA level was lower in Black Africans compared to others. Prostate biopsy uptake across all age groups was lower in Black African men compared to others (2% versus 4%, p = 0.01). Of the 423 men who had a prostate biopsy, 50% had prostate cancer. More Black African men were diagnosed with prostate cancer on biopsy compared to men of other racial groups (54% versus 43%, p = 0.03).

Conclusion

our study confirms that PSA testing is prevalent in healthcare facilities in South Africa. Black African men are tested for PSA levels but have low biopsy uptake and are more likely to be diagnosed with prostate cancer.