Correlation between postoperative prostate-specific antigen and biochemical recurrence in positive surgical margin patients: Single surgeon series

BACKGROUND To evaluate the relationship between postoperative prostate-specific antigen (PSA) levels and biochemical recurrence (BCR) after radical prostatectomy, especially in patients with positive surgical margins (PSMs). MATERIALS AND METHODS A total of 144 patients who underwent radical prostatectomies performed by a single surgeon without any neoadjuvant or adjuvant treatment were analyzed. Differences in clinicopathological factors were compared by surgical margin status, and the relationship between postoperative PSA level and BCR in patients with PSMs was evaluated. RESULTS Fifty of the 144 patients (34.7%) had PSMs. Of these, 74% experienced BCR. The negative surgical margins and PSMs groups differed significantly in terms of PSA level at diagnosis, clinical T stage, and risk group by the cancer of the prostate risk assessment score (P = 0.002, P = 0.002, and P = 0.004, respectively). Also, the nadir PSA level, tumor volume, and BCR rate differed between the two groups (P = 0.007, P = 0.015, and P = 0.005, respectively) On Kaplan-Meier analysis, BCR-free survival was better in the negative surgical margins than the PSMs group (64.1 vs. 55.4 months, log-rank test, P = 0.011). BCR-free survival did not differ significantly in PSMs patients according to whether PSA level was or was not detectable at 1 month postoperatively. However, BCR-free survival improved when the nadir PSA level was undetectable (compared to detectable) in PSMs patients (64.3 vs. 26.1 months, log-rank test, P < 0.001). In PSMs patients belonging to the high risk group by cancer of the prostate risk assessment score, BCR-free survival was significantly better when the PSA level attained the nadir within 3 months, compared to > 6 months, postoperatively (64.2 vs. 29.5 months, log-rank test, P = 0.022). CONCLUSION If PSA is detectable in PSMs patients until 1 month after operation, cautious observation may be possible. If the nadir is attained within 3 months postoperatively in high-risk patients with PSMs, better BCR-free survival may be expected.