Prostate specific antigen nadir determined using ultra-sensitive prostate specific antigen as a predictor of biochemical progression after radical prostatectomy in Japanese males

Prostate-Specific Antigen as an Ultrasensitive Biomarker for Patients with Early Recurrent Prostate Cancer: How Low Shall We Go? A Systematic Review

Serum prostate-specific antigen (PSA) needs to be monitored with ultrasensitive PSA assays (uPSAs) for oncologists to be able to start salvage radiotherapy (SRT) while PSA is <0.5 µg/L for patients with prostate cancer (PCa) relapsing after a radical prostatectomy (RP). Our systematic review (SR) aimed to summarize uPSAs for patients with localized PCa. The SR was registered as InPLASY2023110084. We searched for studies on Google Scholar, PUBMED and reference lists of reviews and studies. We only included studies on uPSAs published in English and excluded studies of women, animals, sarcoidosis and reviews. Of the 115 included studies, 39 reported PSA assay methods and 76 reported clinical findings. Of 67,479 patients, 14,965 developed PSA recurrence (PSAR) and 2663 died. Extremely low PSA nadir and early developments of PSA separated PSAR-prone from non-PSAR-prone patients (cumulative p value 3.7 × 1012). RP patients with the lowest post-surgery PSA nadir and patients who had the lowest PSA at SRT had the fewest deaths. In conclusion, PSA for patients with localized PCa in the pre-PSAR phase of PCa is strongly associated with later PSAR and survival. A rising but still exceedingly low PSA at SRT predicts a good 5-year overall survival.

Predictors of prostate bed recurrence on magnetic resonance imaging in patients with rising prostate-specific antigen after radical prostatectomy

INTRODUCTION

Radical prostatectomy (RP) is a standard treatment modality for localized prostate cancer. Biochemical failure after RP is usually evaluated with whole-body imaging to exclude distant metastatic disease, and pelvic magnetic resonance imaging (MRI) to detect local recurrence in the prostatectomy bed. The goal of this study is to correlate disease characteristics and demographic data in patients with rising prostate-specific antigen (PSA) after RP to determine association with MRI-detected cancer recurrence.

METHODS

Sixty-four patients who underwent pelvic MRI for rising PSA after RP and had complete clinical and pathological data available were included. Using Chi-squared testing, we analyzed PSA levels, pathological disease characteristics (prostate cancer risk group, Gleason score, extracapsular extension, positive surgical margin, seminal vesicle involvement, perineural invasion, lymphovascular invasion, and PSA level before MRI), time from surgery to biochemical failure, and patient demographic characteristics as potential predictors of MRI-detected local recurrence.

RESULTS

Definite MRI-detected local recurrence was observed in 17/64 patients (27%). Eleven (17%) patients had a suspicious lesion with the differential of scarring, retained seminal vesicle, or recurrent cancer. Thirty-six (56%) patients had no evidence of tumor in the prostate bed or pelvis on MRI. Patient race was associated with likelihood of detecting a prostate nodule on MRI (p=0.04), with African American patients having 82% lower odds of MRI-detected tumor recurrence compared with white patients (p=0.045). No other tumor or patient characteristic was significantly associated with MRI-detected recurrence.

CONCLUSIONS

African American patients with biochemical failure after RP are less likely to have MRI-detectable recurrence in the prostate bed compared with white patients.

Determining When to Stop Prostate Specific Antigen Monitoring after Radical Prostatectomy: the Role of Ultrasensitive Prostate Specific Antigen

PURPOSE

We analyzed long-term followup data after radical prostatectomy to determine how long we should follow patients in whom the serum prostate specific antigen level measured by an ultrasensitive assay was consistently low.

MATERIALS AND METHODS

We retrospectively reviewed clinicopathological data for 582 consecutive patients who underwent open or laparoscopic radical prostatectomy between 1995 and 2004, excluding 4 patients who received adjuvant therapy. We stratified the patients according to prostate specific antigen at 3 and 5 years after surgery, and examined subsequent biochemical recurrence (elevation of prostate specific antigen to greater than 0.2 ng/ml) during followup. Mean followup was 9.7 years.

RESULTS

At 3 years after surgery prostate specific antigen levels were measured by an ultrasensitive assay in 323 patients who had not experienced biochemical recurrence. In 187 patients with undetectable prostate specific antigen levels (less than 0.01 ng/ml) the 10 and 15-year biochemical recurrence-free survival rates were 99% and 96%, respectively. At 5 years after surgery prostate specific antigen was measured in 315 patients by the ultrasensitive assay. In 162 patients with undetectable prostate specific antigen levels the 10 and 15-year biochemical recurrence-free survival rates were both 100%. In this group the prostate specific antigen level at last followup was less than 0.01 ng/ml in 132 patients, 0.01 to 0.03 ng/ml in 27 patients, and 0.06 ng/ml, 0.07 ng/ml and 0.11 ng/ml in 1 patient each.

CONCLUSIONS

This long-term review indicates that if patients have continuously undetectable prostate specific antigen levels by an ultrasensitive assay for 5 years, prostate specific antigen monitoring can be stopped with an extremely low risk of subsequent biochemical recurrence.

Positive resection margins may not reflect the true margin in patients undergoing radical prostatectomy

The aim of the present study was to evaluate the hypothesis that a positive resection margin (RM1) of an excised specimen may not reflect the true margin in patients that have undergone radical prostatectomy (RP). Between September 2003 and March 2011, 370 Japanese patients underwent an antegrade RP at the National Kyushu Cancer Center (Fukuoka, Japan), however, 95 of these patients were excluded from the study due to a history of receiving hormonal therapy or insufficient preoperative clinical data. The incidence of biochemical failure (BCF) was evaluated using multivariate analysis, which revealed that the preoperative prostate-specific antigen (PSA) level, pathological tumor stage, RP Gleason score and a PSA nadir <0.008 ng/ml were significant predictors (P=0.0065, 0.0006, 0.0002 and <0.0001, respectively). By contrast, an RM1 was not found to be a significant predictor of BCF, while the parameter with the highest hazard ratio (HR) was a PSA nadir <0.008 ng/ml (HR, 10.055; 95% confidence interval, 5.005–20.200). From the 56 cases that were RM1, 41 cases (73.2%) exhibited a PSA nadir <0.008 ng/ml. There were 42 cases (75.0%) in which only one site was identified to be RM1; among these cases, no significant difference was observed between a PSA level <0.008 ng/ml and a PSA level ≥0.008 ng/ml at the RM1 site (apex, P=0.1460; base, P=0.1384; anterior, P=0.3870; and posterolateral, P=0.5040). There were 14 cases (25.0%) in which multiple sites were RM1; these cases were classified by the number of sites that were RM1 (one vs. multiple) and no significant difference was observed between a PSA level <0.008 ng/ml and a PSA level ≥0.008 ng/ml (P=0.6090). Based on these results, an RM1 of an excised specimen may not reflect the true margin in patients that are treated with RP, specifically in cases where the PSA level is identified to decrease to below the postoperative measurement threshold value (PSA nadir <0.008 ng/ml).

Usefulness of ultra-sensitive prostate-specific antigen following radical prostatectomy

This study aimed to evaluate the usefulness of ultra-sensitive prostate-specific antigen (PSA) following radical prostatectomy (RP). Between September, 2003 and March, 2009, a total of 311 prostate cancer patients underwent antegrade RP; following the exclusion of 111 patients due to prior hormonal therapy, 200 patients were finally included in this study. The results of the multivariate analysis identified RP Gleason score, extraprostatic extension, lymph node metastasis and PSA nadir as significant predictors of biochemical failure (P=0.0116, 0.0216, 0.0178 and <0.0001, respectively) and PSA nadir <0.008 ng/ml exhibited the highest hazard ratio (HR) [HR=26.34; 95% confidence interval (CI): 7.34-104.69]. After a median follow-up period of 52.2 months, the biochemical failure-free rate in the PSA nadir <0.008 and ≥0.008 ng/ml groups was 94.3 and 58.8%, respectively, with a statistically significant difference according to the log-rank test (P<0.001). In the multivariate analysis, statistically significant differences were observed only in pathological nodel stage within the PSA nadir <0.008 ng/ml group (P=0.0107). For this reason, postoperative follow-up using ultra-sensitive PSA is considered to be of value, since the use of high-sensitivity PSA to confirm a reduction to below postoperative measurement threshold value (PSA nadir <0.008 ng/ml) may avert administering unnecessary additional treatment, regardless of pathological reccurrence factors.

Prostate-specific antigen measured 3 months after radical prostatectomy as a new predictor of biochemical recurrence

BACKGROUND

This study was undertaken to investigate if the prostate-specific antigen (PSA) level measured 3 months after radical prostatectomy (RP) is a predictor of biochemical recurrence (BCR)-free survival.

METHODS

We retrospectively reviewed the clinicopathologic data of 174 patients with a follow-up of at least 3 years after RP for clinically localized prostate cancer. None of the patients received neoadjuvant/adjuvant therapy. Subjects were categorized according to PSA level 3 months after RP (3M-PSA): <0.010 ng/mL (group 1; n = 119) or 0.010-0.100 ng/mL (group 2; n = 55). BCR was defined as two consecutive rises in PSA level ≥0.2 ng/mL.

RESULTS

At a median follow-up of 69.5 months (range 36-113 months), 32 (18.4 %) patients experienced BCR. The median time to BCR was 16 months (range 4-98 months) after RP. The 5-year BCR-free survival rate was 92.6 and 57.4 % in groups 1 and 2, respectively. Patients in group 1 had a significantly higher BCR-free survival rate than those in group 2 (log-rank P < 0.001). According to the Cox proportional hazards model, patients with a 3M-PSA level of <0.010 ng/mL were at lower risk for BCR (P < 0.001), along with pathologic Gleason sum 6 (P = 0.028). PSA nadir level after RP was also a risk factor for BCR (log-rank P < 0.001). Area under the receiver operating characteristic curve for 3M-PSA to predict BCR was almost equivalent to that for the PSA nadir level (0.855 vs. 0.849).

CONCLUSIONS

3M-PSA is an independent predictor of BCR-free survival. Our findings might be used for a risk-adjusted follow-up protocol.

Risk factors predicting the outcome of salvage radiotherapy in patients with biochemical recurrence after radical prostatectomy

OBJECTIVES

Salvage radiotherapy is the only curative treatment for patients with prostate cancer showing biochemical progression after radical prostatectomy. In this study, we evaluated the clinicopathological parameters that influence the outcome of salvage radiotherapy.

METHODS

Medical records of 49 patients who underwent salvage radiotherapy after radical prostatectomy from 1997 to 2008 at the Graduate School of Medicine, Kyoto University, were retrospectively reviewed. Radiotherapy was carried out with 66 Gy on the prostatic bed.

RESULTS

Biochemical progression-free survival after salvage radiotherapy at 2, 5 and 7 years was 51.0%, 42.2% and 42.2%, respectively. Significant parameters predicting biochemical progression after salvage radiotherapy by Cox regression analysis were prostatectomy Gleason score sum ≥ 8 (hazard ratio 0.08; 95% confidence interval 0.03-0.22; P=0.001), prostate-specific antigen nadir after radical prostatectomy ≥ 0.04 ng/mL (hazard ratio 0.30; 95% confidence interval 0.13-0.69; P=0.005) and negative surgical margin (hazard ratio 0.28; 95% confidence interval 0.12-0.70; P=0.006). When the patients were subgrouped by these risk factors, the 5-year progression-free survival rates after salvage radiotherapy were 77.8%, 50.0% and 6.7% in patients with 0, 1 and ≥ 2 predictors, respectively.

CONCLUSION

In order to discriminate favorable candidates for salvage radiotherapy, Gleason score of prostatectomy, prostate-specific antigen nadir after prostatectomy and positive surgical margin represent independent predictors. Thus, progression-free survival might be more precisely predicted according to the presence/absence of these risk factors. The significance of this risk classification should be confirmed by large prospective studies.

Postoperative prostate-specific antigen nadir improves accuracy for predicting biochemical recurrence after radical prostatectomy: Results from the Shared Equal Access Regional Cancer Hospital (SEARCH) and Duke Prostate Center databases

OBJECTIVES

We previously showed that prostate-specific antigen (PSA) nadir after radical prostatectomy (RP) significantly predicts biochemical recurrence (BCR). Herein, we sought to explore the effect of including PSA nadir into commonly used models on their accuracy to predict BCR after RP.

METHODS

This was a retrospective analysis of 943 and 1792 subjects from the Shared Equal Access Regional Cancer Hospital (SEARCH) and Duke Prostate Cancer (DPC) databases, respectively. The discrimination accuracy for BCR of seven previously published models was assessed using concordance index and compared with and without adding PSA nadir level in SEARCH. Using data from SEARCH, we developed a new nomogram incorporating PSA nadir to other known predictors (preoperative PSA, pathological Gleason score, PSA nadir level, surgical findings, prostate weight, body mass index and race) of BCR and externally validated it in the DPC.

RESULTS

In SEARCH, the mean concordance index across all seven nomograms was 0.687. After the inclusion of PSA nadir, the concordance index increased by nearly 7% (mean=0.753). The concordance index of the new nomogram in SEARCH was 0.779 (bias-corrected=0.767), which was 5% better than the next best model. In DPC, the new nomogram yielded a concordance index of 0.778.

CONCLUSION

The addition of postoperative PSA nadir to commonly used nomograms increased their accuracies by nearly 7%. Based upon this, we developed and externally validated a new nomogram, which was well calibrated and highly accurate, and is a potentially valuable tool for patients and physicians to predict BCR after RP.