[PSA-doubling time immediately before the diagnosis of prostate cancer]

PSA-doubling time (PSA-DT) immediately before the diagnosis of prostate cancer was calculated in 8 prostate cancer patients in whom PSA was checked three or more times with the same kit during a period of 6 months or more. The correlation between PSA-DT and clinical stage or pathological differentiation was analyzed. In most patients, PSA correlated well showing a straight regression line to the observation period on a hemi-logarithmic scale. The correlation coefficient was high, almost 0.9 or more except in one patient. PSA-DT ranged from 5.1 to 64.9 months, averaging 23.1 months. There was no significant correlation between clinical stage or pathological differentiation and PSA-DT. However, PSA-DT in stage D patients tended to be shorter than that of stage B + C patients. One patient who had stage D poorly differentiated carcinoma died of cancer recurrence. In this patient, PSA-DT was short (5.1 months).