Objective: To analyse the increase of serum prostatic specific antigen (PSA) as a means of early detection of progression in hormonally untreated or androgen-deprived patients with T1-T4, pN+ and MO prostate cancer.
Patients and methods: From 1986 to 1992 40 patients with T1-T4 pN+ MO prostate cancer were either deprived of androgen at diagnosis (Group 1, 19 patients) or had no immediate hormone manipulation (Group 2, 21 patients) and were followed at 3-6-monthly intervals when determinations of PSA and routine clinical/radiological examinations were performed. A significant increase in PSA was defined as a > or = 50% increase of the baseline PSA value which was the either the lowest PSA value within 6 months from the start of androgen deprivation (Group 1) or the initial PSA value (Group 2).
Results: By June 1993 22 of the 40 patients had clinically progressed. In 12 patients the progression was preceded by a significant increase in PSA (Group 1, three of four progressing patients; Group 2, nine of 18 progressing patients). A PSA increase of > or = 50% was observed simultaneously with clinical progression in six patients, whereas clinical progression occurred in four patients with no previous or simultaneous significant increase in PSA. In four of nine hormonally untreated patients > or = 1 year elapsed between antecedent PSA increase and clinical progression.
Conclusion: In routine clinical practice PSA does not significantly increase (> or = 50% of baseline value and > 10 micrograms/L) before disease progression in about one third of patients with pN+ MO prostate cancer managed with or with no hormone manipulation. Future studies should be carried out to determine whether a lower rate of increase in PSA during follow-up has any clinical significance.