When all three values were considered individually, in only 2. The factor which induces increases in PSA levels, is deterioration of the architecture of the prostate gland caused by prostate cancer. For instance, in men aged years or younger, both no change and a significant decrease have been reported. And with all the nonmalignant factors that can boost a man's PSA, it's hard to be sure if a single reading is the "real" result. Similarly, a vigorous workout on an exercise bike may produce a temporary PSA bump. The participants were between the ages of 55 and 70, and they lived in two regions of France, one rural and the other partially urban. All patients were interrogated using International Prostate Symptom Scoring System IPSS , and subjected to complete urinalysis, digital rectal examination, serum total, free, and complexed PSA, and residual urine measurements, and uroflowmetric examinations. PSA 24hrs , and Technical factors may also explain short-term PSA variability. Since all prostate cells, both benign and malignant, produce the controversial protein, in most cases the swings have nothing to do with prostate cancer. David Samadi Jun 16, 7: For those with prostate cancer risk factors — a family history of the disease or African American men — screening should begin earlier. Avoiding ejaculation for 48 hours before a prostate-specific antigen PSA test is thus prudent. Both regions have temperate climates, and in both, PSA levels held steady in autumn, winter, and spring. However, in the age group in which PSA testing is primarily used for early detection of prostate cancer 50 years and older , ejaculation can lead to an increase in PSA level but could result in a false positive elevation.