- Last Update On : 2014-10-14
The introduction of an immunoassay for prostatic acid phosphatase (PAP) in 1977 was hailed as a breakthrough in monitoring prostate cancer. However, the popularity of PAP steadily waned following the development of increasingly more sensitive and specific immunoassays for prostate specific antigen (PSA). PAP is elevated in only 12% of men with stage A cancer, while PSA is elevated in 65%. Because of this poor sensitivity, the laboratory ceased performing prostatic acid phosphatase on May 1, 1994.