<prompt> True about PSA is all exceptLevels increase in BPHLevels increase with ageFinasteride increases PSA levelMetastatic prostate cancer increase PSA level  <response>: Prostate-specific antigen PSA is a glycoprotein that is a serine protease.Its function may be to facilitate liquefaction of semen, but it is a marker for prostatic disease.The levels increase with age, with prostate cancer and with BPH. There are age-related values but, in general, in men aged 50-69 years, a level of about 3-4 ngmL would prompt a discussion about the need for prostate biopsy Its level in men with metastatic prostate cancer is usually increased to 30 ngmL and falls to low levels after successful androgen ablation. Men with locally confined prostate cancer usually have serum PSA levels 10-15 ngmL.Finasteride and dutasteride, which are used to treatBPH--lower a mans PSA levelPSA is a useful tumour marker in the postsurgery setting, where a supersensitive assay, with sensitivity to 0.02 ngmL, facilitates early detection of biochemical recurrence.Bailey and Love 27e pg: 1457 