Background
Racial disparities associated with pathogenesis and progression of prostate cancer makes a global diagnostic prostate-specific antigen (PSA) cut-off value inappropriate. Our review aimed to evaluate the pooled sensitivity and specificity of PSA and its surrogates, and to systematically synthesize the optimum thresholds for the detection of prostate cancer in sub-Saharan Africa.
Methods
This was a systematic review of 6861 peer-reviewed literature from five databases: MEDLINE, PubMed, CINAHL, African Journal Online and Academic Search Complete, last search was in September 2022. Studies reporting the diagnostic accuracy of PSA and/or its surrogates towards the detection of prostate cancer in patients, using histology of prostate biopsy as the reference test for cancer diagnosis, were included. Studies that did not report sensitivity and/or specificity, or histology diagnosis of prostate cancer were excluded. Risk of bias assessment was conducted using quality assessment of diagnostic accuracy studies (QUADAS) by two independent investigators. Random effect model of meta-analysis was performed using Comprehensive Meta-Analysis version 3.
Results
Thirteen (13) studies of males diagnosed with prostate cancer were included—10 studies reported PSA sensitivity/specificity/both; 4 reported on PSA surrogates (3 reported %freePSA, and 1 reported PSA density). We conducted 2 meta-analyses to pool the diagnostic accuracy of PSA and %freePSA. The sensitivity of PSA (n = 10) at the cut-off values of < 4 ng/ml, 4–10 ng/ml, > 10 ng/ml were 86.8%, 93.1%, and 76.0% respectively; while specificity (n = 8) were 42.3%, 29.3%, and 28.8% respectively. The PSA cut-off of 4–10 ng/ml possessed the highest diagnostic accuracy (55.7%). The specificity (91.5%) and diagnostic accuracy (84%) of %freePSA (n = 3) was best at cut-off value ≤ 10%.
Conclusion
Having the highest diagnostic accuracy individually, a combination of PSA 4–10 ng/ml and %freePSA ≤ 10% may be a more appropriate criteria for deciding eligibility for prostate biopsy among males in sub-Saharan Africa.