Serum concentrations of prostate specific antigen and its complex with α1-antichymotrypsin before diagnosis of prostate cancer

摘要: Prostate cancer can be detected at an early, potentially curable stage by screening based on digital rectal examination and serum prostate specific antigen (PSA). The value of appears doubtful, high 10-year survival rates in selected cases early cancer, but this follow-up time may insufficient. By linking the information 21172 men who took part a Finland, 1968-73, with data from Finnish Cancer Registry, 44 diagnosed up to 1980 were identified. Serum samples 74 controls matched for age sampling assayed PSA its complex alpha 1-antichymotrypsin (PSA-ACT). With cut-off 2.5 micrograms/L giving 92% specificity, 95% cancers developing within first 5 years, 52% 6-10 years tested positive. As potential test 5-year interval under 65, sensitivity would specificity 97%. ratio PSA-ACT total was lower than patients cancer. Using ratio, we could eliminate half false-positive results range 2.5-25 without loss sensitivity. typically 5-10 after exceeded micrograms/L, median diagnosis 3.6 years. drawing sample 71% concentration less 4 48% those higher concentrations. corresponding figures 15 53% 27%, 20 43% 18%, respectively. These suggest it is advisable confine life expectancy clearly more 10 years--ie, younger men, have greatest chance benefit detection.