Serum prostate specific antigen (PSA) as surrogate for the histological diagnosis of prostate cancer
The original publication is available at http://www.samj.org.za
Introduction. To determine whether there is a cut-off value of serum prostate-specific antigen (PSA) which can be used confidently to make the diagnosis of prostate cancer, thereby obviating the need for biopsy. Patients and methods. During the period October 1991 to March 1998 the Department of Chemical Pathology at Tygerberg Hospital performed a total of 6 733 serum PSA assays on 3 960 patients. The histopathological and clinical diagnoses of these patients were obtained from records in the departments of Anatomical Pathology, Urological Oncology and Radiation Oncology. The serum PSA levels were correlated with the histopathology reports, using different PSA cut-off values ranging from 5 to 500 ng/ml, to calculate the sensitivity, specificity, and positive and negative predictive values of each cut-off value of PSA in predicting the presence of prostate cancer.