Prognostic implications of an undetectable ultrasensitive prostate-specific antigen level after radical prostatectomy

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.

Establishment and Validation of a Novel Prediction Model for Early Natural Biochemical Recurrence After Radical Prostatectomy Based on Post-Operative PSA at Sixth Week

Objective

Based on post-operative PSA at 6th week (PSA6w) after radical prostatectomy to establish an optimal model for predicting natural biochemical recurrence (BCR).

Methods

A total of 742 patients with post-operative PSA6w from PC-follow database, between January 2003 and October 2022, were included. All the patients had not received any hormone therapy and radiotherapy before operation and BCR. Of these patients, 588 cases operated by one surgeon were enrolled for modelling and another 154 cases operated by other surgeons were for external validation. After screened by Cox regression, the post-operative PSA6w, pathological stage, Gleason Grade and positive surgical margins were adopted for modelling. The R software was used to plot the nomogram of the prediction model for BCR. C-index and calibration curve were calculated to evaluate the new model. Finally, integrated discrimination improvement was adopted to evaluate the prediction performances of the new nomogram model and the classical Kattan nomogram.

Results

The C-index of the new model was 0.871 (95% CI: 0.830-0.912). The calibration curve of the new model demonstrated superior consistency between the predicted and actual value. The C-index of the external validation group was 0.850 (95% CI: 0.742-0.958), which demonstrated perfect universality. The integrated discrimination improvement showed a 12.61% improvement in prediction performance over that of the classical Kattan nomogram (P < 0.01). Based on the new nomogram, patients were divided to high and low BCR group with a 3 year BCR-free cutoff probability as 74.72%. Low-risk patients, accounting for 77.89% of the patients, have no need to follow up frequently with a false-negative rate only 5.24%, which will save medical resources to a large extent.

Conclusion

Post-operative PSA6w is a sensitive risk biomarker for early natural BCR. The new nomogram model could predict BCR probability with a higher accuracy and will further simplify the clinical follow-up strategies.

Novel nomogram to predict biochemical recurrence-free survival after radical prostatectomy

PURPOSE

Conditional survival represents the probability of subsequent survival given that patients have already survived a certain length of time. Several models predict biochemical recurrence (BCR) after radical prostatectomy. However, none of them include postoperative prostate-specific antigen (PSA). We aimed to analyze BCR-free survival evolution over time and develop a nomogram incorporating the postoperative PSA value to predict BCR-free survival.

MATERIAL AND METHODS

We included patients treated with robot-assisted radical prostatectomy (RARP) for prostate cancer between 2009 and 2021 and calculated conditional survival. Cox proportional hazard regression analysis was used to assess the predictive variables of BCR. We developed a nomogram predicting BCR-free survival three and five years after RARP. We used c-index and decision curve analyses to compare the nomogram with the Cancer of the Prostate Risk Assessment post-Surgical (CAPRA-S) score.

RESULTS

We included 718 patients. The overall 3- and 5-year BCR-free survival rates were 85.1% and 75.7%, respectively. The 5-year BCR-free survival rates increased to 78.9%, 82.9%, 85.2%, and 84.7% for patients surviving 1, 2, 3, and 4 years without BCR, respectively. We developed a nomogram including the pathological Gleason score and T stage, positive surgical margin, PSA ≥ 0.05 ng/mL at one year, and lymph node involvement to predict BCR at 3 and 5 years postoperatively. Our nomogram presented a higher c-index (0.89) than the CAPRA-S score (0.78; p = 0.001) and a positive net benefit at 3 and 5 years postoperatively in the decision curve analyses.

CONCLUSION

The 5-year conditional BCR-free survival increased with survival without BCR. The developed nomogram significantly improved the accuracy in predicting BCR-free survival after RARP.

Clinicopathological and oncological significance of persistent prostate-specific antigen after radical prostatectomy: A systematic review and meta-analysis

Objective

To investigate the association of persistently elevated prostate-specific antigen (PSA) after radical prostatectomy (RP) with clinicopathological features and long-term oncological prognosis for the development of a potential management strategy.

Methods

A systematic literature search was performed using PubMed and Web of Science up to June 2021 to identify the eligible studies focusing on understanding the impact of persistent PSA in patients who underwent RP for localized prostate cancer. Meta-analyses were performed on parameters with available information.

Results

A total of 32 RP studies were identified, of which 11 included 26 719 patients with consecutive cohorts and the remaining 21 comprised 24 177 patients with cohorts carrying specific restrictions. Of the 11 studies with consecutive cohorts, the incidence of persistent PSA varied between 3.1% and 34.6% with a median of 11.0%. Meta-analyses revealed patients with persistent PSA consistently showed unfavorable clinicopathological features and a more than 3.5-fold risk of poorer biochemical recurrence, metastasis, and prostate cancer-specific mortality prognosis independently, when compared to patients with undetectable PSA. Similarly, cases with persistent PSA in different specific patient cohorts with a higher risk of prostate cancer also showed a trend of worse outcomes.

Conclusion

We found that the frequency of persistent PSA was about 11.0% in consecutive RP cohorts. Persistent PSA was significantly associated with unfavorable clinicopathological characteristics and worse oncological outcomes. Patients with persistent PSA after RP may benefit from early salvage treatment to delay or prevent biochemical recurrence, improving oncological outcomes for these patients. Further prospective randomized controlled trials are warranted to understand optimal systemic therapy in these patients.

Clinical and Biological Significance of DNA Methylation-Driven Differentially Expressed Genes in Biochemical Recurrence After Radical Prostatectomy

Background: Biochemical recurrence (BCR) after radical prostatectomy indicates poor prognosis in patients with prostate cancer (PCA). DNA methylation (DNAm) is a critical factor in tumorigenesis and has attracted attention as a biomarker for the diagnosis, treatment, and prognosis of PCA. However, the predictive value of DNAm-derived differentially expressed genes (DMGs) in PCA with BCR remains elusive.

Methods: We filtered the methylated genes and the differentially expressed genes (DGEs) for more than 1,000 clinical samples from the TCGA cohort using the chAMP and DESeq2 packages of R language, respectively. Next, we integrated the DNAm beta value and gene expression data with the Mithymix package of R language to obtain the DMGs. Then, 1,000 times Cox LASSO regression with 10-fold cross validation was performed to screen signature DMGs and establish a predictive classifier. Univariate and multivariate cox regressive analyses were used to identify the prognostic factors to build a predictive model, and its performance was measured by receiver operating characteristic, calibration curves, and Harrell’s concordance index (C-index). Additionally, a GEO dataset was used to validate the prognostic classifier.

Results: One hundred DMGs were mined using the chAMP and Methymix packages of R language. Of these, seven DMGs (CCK, CD38, CYP27A1, EID3, HABP2, LRRC4, and LY6G6D) were identified to build the prognostic classifier (Classifier) through LASSO analysis. Moreover, univariate and multivariate Cox regression analysis determined that the Classifier and pathological T stage (pathological_T) were independent predictors of BCR (hazard ratio (HR 2.2), (95% CI 1.4–3.5), p < 0.0012, and (HR 1.8), (95% CI 1.0–3.2), p < 0.046). A nomogram based on the Classifier was constructed, with high prediction accuracy for BCR-free survival in TCGA and GEO datasets. GSEA enrichment analysis showed that the DMGs were mainly enriched in the metabolism pathways.

Conclusion: We identified and validated the nomogram of BCR-free survival for PCA patients, which has the potential to guide treatment decisions for patients at differing risks of BCR. Our study deepens the understanding of DMGs in the pathogenesis of PCA.

Biochemical recurrence after radical prostatectomy according to nadir prostate specific antigen value

The hypersensitive prostate specific antigen (PSA) test can measure in 0.01 ng/mL units, and its efficacy for screening after radical prostatectomy (RP) has been reported. In this study, we assessed patients who underwent RP to evaluate whether the nadir value affects biochemical recurrence (BCR). From 1995 to 2014, patients classified as N0 who had negative resection margins and a nadir PSA of less than 0.2 ng/mL were evaluated. The characteristics, pathological outcomes, PSA after RP, and BCR were assessed. A total of 1483 patients were enrolled. Among them, 323 (21.78%) patients showed BCR after RP. The mean age of the BCR group was 63.86±7.31 years, and while that of the no-recurrence group was 64.06±6.82 years (P = 0.645). The mean preoperative PSA of the BCR group was 9.75±6.92 ng/mL and that of the no-recurrence group was 6.71±5.19 ng/mL (P < 0.001). The mean time to nadir (TTN) in the BCR group was 4.64±7.65 months, while that in the no-recurrence group was 7.43±12.46 months (P < 0.001). The mean PSA nadir value was 0.035±0.034 ng/mL in the BCR group and 0.014±0.009 ng/mL in the no-recurrence group (P < 0.001). In multivariable Cox regression analyses, Gleason score, positive biopsy core percentages, minimal invasive surgery, nadir PSA value, and TTN were independently associated with BCR. The mean BCR occurred at 48.23±2.01 months after RP, and there was a significant difference in BCR occurrence according to the nadir PSA value (P < 0.001). A high PSA nadir value and short TTN may predict the risk of BCR after successful RP, aiding the identification of candidates for adjuvant or salvage therapies after RP.

Tissue N-linked glycosylation as potential prognostic biomarker for biochemical recurrence-free survival

PURPOSE

Only few biomarkers have been evaluated for their prognostic value following radical prostatectomy. We explored if tissue N-glycosylation shows prognostic properties for biochemical recurrence (BCR)-free survival.

MATERIALS AND METHODS

Tissue N-glycosylation profile was determined from 82 prostate cancer (PCa) patients and prognostic features were compared to clinical and biochemical parameters for BCR-free survival.

RESULTS

Majority presented with Gleason score 3 + 4 (41%), extensive local disease (62%) and without pelvic lymph nodes invasion (83%). Several parameters (low T stage, low Gleason score, low EAU risk groups for BCR, absence of positive surgical margins, high ratio of fucosylated triantennary structures on total of multiantennary structures [3AFc/MA], low ratio of fucosylated biantennary with core-branched N-acetylglucosamine on total of biantennary structures, and high ratio of triantennary structures on total of multiantennary structures) proved to have a univariate beneficial effect on BCR-free survival. Multivariate analysis proved positive surgical margins and 3AFc/MA to be independent prognosticators.

CONCLUSIONS

Tissue N-glycans are a powerful prognostic tool and can be an asset in PCa as the ratio of 3AFc/MA is independently associated with BCR-free survival. This could be of clinical use in guiding patients following radical prostatectomy, e.g. referral to adjuvant radiotherapy. Further elaboration of this biomarker is warranted.

Management of Persistently Elevated Prostate-specific Antigen After Radical Prostatectomy: A Systematic Review of the Literature

CONTEXT

The prognosis and optimal management of pN0/pN1 patients with persistently elevated prostate-specific antigen (PSA) 6-8 wk after radical prostatectomy (RP) remain unclear.

OBJECTIVE

To perform a systematic review of oncologic outcomes and effectiveness of salvage therapies in men with a detectable PSA level after RP.

EVIDENCE ACQUISITION

A systematic review was performed in May 2020. A total of 2374 articles were screened, and 25 studies including 5217 men were selected and included in the systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines.

EVIDENCE SYNTHESIS

PSA persistence was most commonly defined as PSA >0.1 ng/ml. PSA persistence was significantly correlated with disease aggressiveness and associated with worse oncologic outcomes than in men with undetectable PSA levels. The 5-yr recurrence-free survival rates varied from 21.5% to 67.0%. The ≥10-yr cancer-specific survival was 75-88%. Salvage radiotherapy ± androgen deprivation therapy was associated with improved survival outcomes. Risk stratification according to pathologic features, PSA levels/kinetics, and genomic classifier may aid in personalization of treatment. The usefulness of molecular imaging in this setting remains underevaluated. Main limitations of this systematic review are the retrospective design of the included studies and the lack of randomized controlled trials (RCTs) focusing on this specific population.

CONCLUSIONS

PSA persistence after RP is strongly correlated with poor oncologic outcomes. Our review suggests a benefit from immediate radiotherapy; however, current evidence is still low. Indication of subsequent therapies should be based on individual discussions, taking into account all the prognostic factors and the efficacy/toxicity imbalance of proposed treatment. Results from ongoing RCTs are awaited to state on the role of more intensified systemic therapy in this population.

PATIENT SUMMARY

Patients with a detectable prostate-specific antigen level after surgery are at high risk of subsequent progression. Immediate radiotherapy might improve survival outcomes. Further research into the role of molecular imaging and genomic classifier is needed in this patient population.

A Dual-Sensing DNA Nanostructure with an Ultrabroad Detection Range

Despite considerable interest in the development of biosensors that can measure analyte concentrations with a dynamic range spanning many orders of magnitude, this goal has proven difficult to achieve. We describe here a modular biosensor architecture that integrates two different readout mechanisms into a single-molecule construct that can achieve target detection across an extraordinarily broad dynamic range. Our dual-mode readout DNA biosensor combines an aptamer and a DNAzyme to quantify adenosine triphosphate (ATP) with two different mechanisms, which respond to low (micromolar) and high (millimolar) concentrations by generating distinct readouts based on changes in fluorescence and absorbance, respectively. Importantly, we have also devised regulatory strategies to fine-tune the target detection range of each sensor module by controlling the target-sensitivity of each readout mechanism. Using this strategy, we report the detection of ATP at a dynamic range spanning 1-500 000 μM, more than 5 orders of magnitude, representing the largest dynamic range reported to date with a single biosensor construct.

Prognostic significance of a novel indicator (PSApostd3/PSApre) for PSA recurrence in patients after radical prostatectomy

Purpose

Radical prostatectomy (RP) is a common treatment for prostate cancer, but a fraction of patients may experience PSA recurrence after surgery, manifesting as an elevation in prostate specific antigen (PSA). Vast literature has reported different prognostic factors for PSA recurrence without reaching a consensus. This retrospective study investigated the efficacy of a new indicator in predicting PSA recurrence in patients after RP.

Patients and methods

From October 2000 to December 2015, 102 PCa patients who underwent laparoscopic prostatectomy in the Urology Department of Peking Union Medical College Hospital were analyzed. We calculated PSA_postd3/PSA_pre, defined as the ratio of the PSA on day 3 postop as the numerator and the pre-operative PSA as the denominator, in these patients to represent PSA decrement after surgery, and investigated its relationship with PSA recurrence during follow-up.

Results

The receiver operating characteristic (ROC) curve of PSA_postd3/PSA_pre derived a cut-off at 0.453 (sensitivity=0.704, specificity=0.853, P<0.0001), suggesting an increased risk of PSA recurrence in patients whose PSA on day 3 postop did not decrease to approximately half of their preoperative levels. Among several factors, PSA_postd3/PSA_pre (P<0.0001), pathological T stage (P=0.042) and Gleason Grade (P=0.021) were determined to be significantly associated with PSA recurrence by Fisher’s exact test, while only PSA_postd3/PSA_pre (P<0.001) was significantly related to PSA recurrence-free survival (PRFS) by multivariate logistic regression analysis.

Conclusion

These results imply that PSA_postd3/PSA_pre could provide substantial information for PSA recurrence prediction in patients after RP.

Ultrasensitive prostate-specific antigen level as a predictor of biochemical progression after robot-assisted radical prostatectomy: Towards risk adapted follow-up

BACKGROUND

Ultrasensitive prostate-specific antigen (USPSA) is useful for stratifying patients according to their USPSA-based risk. Aim of our study was to determine the usefulness of USPSA as predictor of biochemical recurrence (BCR) after robot-assisted radical prostatectomy (RARP).

METHODS

This retrospective study included 213 prostate cancer patients who had a postoperative USPSA between 0.01 and 0.2 ng/mL and at least 2 years of follow-up. We developed predictive models for BCR with PSA ≥0.2 and ≥0.5 ng/mL.

RESULTS

A total of 103 patients (48.3%) had BCR at a median follow-up of 13.3 months. Higher postoperative USPSA (odds ratio [OR] = 4.73, P < 0.01), bilateral positive surgical margin in both sides (OR = 1.32, P = 0.044), higher average PSA rise (OR = 1.67, P = 0.031), ISUP grade group ≥3 (OR = 1.48, P = 0.003), and shorter interval since RARP (OR = 0.58, P < 0.001) were independent predictors of BCR with PSA ≥0.2 ng/mL. Higher postoperative USPSA (OR = 3.85, P < 0.01), bilateral positive surgical margin (OR = 1.34, P = 0.011), ISUP grade group ≥3 (OR = 1.5, P = 0.002), and shorter interval since RARP (OR = 0.61, P = 0.001) were independent predictors of BCR with PSA ≥0.5 ng/mL. The areas under the curve for the first and second model were 0.865 and 0.834, respectively.

CONCLUSION

Ultrasensitive PSA after RARP is a useful prognostic indicator of BCR which could guide postoperative risk stratification and layout follow-up scheduling.

Prediction of biochemical failure using prostate-specific antigen half-life in patients with adverse pathologic features after radical prostatectomy

PURPOSE

Prostate-specific antigen nadir and time to prostate-specific antigen nadir are predictors of disease progression in patients who undergo radical prostatectomy. However, a mutually conflicting relationship exists between them. Thus, we compared postoperative prostate-specific antigen levels at the first follow-up with the expected levels while considering the half-life of prostate-specific antigen to improve the prediction of biochemical failure after radical prostatectomy in patients with adverse pathologic features.

METHODS

Patients treated with robot-assisted laparoscopic prostatectomy were enrolled. Patients with a follow-up duration of < 12 months or positive lymphadenectomy results were excluded. "Adverse prostate-specific antigen" was defined as a prostate-specific antigen level higher than the expected level at 6 weeks.

RESULTS

Among 450 patients, adverse pathologic features and adverse prostate-specific antigen were found in 260 (57.8%) and 245 (54.5%) patients, respectively. Analysis of patients with and without abnormal prostate-specific antigen level revealed significantly different biochemical failure-free survival outcomes. Patients with one adverse pathologic feature but without adverse prostate-specific antigen showed similar biochemical failure-free survival to those without adverse pathologic features. Adverse prostate-specific antigen was identified as an independent predictor for biochemical failure within 1 year after radical prostatectomy. The area under the curve when adding adverse prostate-specific antigen to the conventional factors was significantly higher than that for the conventional factors alone.

CONCLUSION

The difference between postoperative prostate-specific antigen levels at the first follow-up visit after radical prostatectomy and the expected level while considering the half-life of prostate-specific antigen is a predictive factor for treatment efficacy following radical prostatectomy.

First Postprostatectomy Ultrasensitive Prostate-specific Antigen Predicts Survival in Patients with High-risk Prostate Cancer Pathology

BACKGROUND

Ultrasensitive prostate-specific antigen (uPSA) has untapped potential for optimizing management following radical prostatectomy (RP) in terms of facilitating early salvage, minimizing overtreatment, and identifying those at risk of occult systemic disease.

OBJECTIVE

To test first postoperative uPSA for prediction of outcome in patients with adverse pathology after RP.

DESIGN, SETTING, AND PARTICIPANTS

Patients with extraprostatic extension and/or a positive margin who did not receive immediate adjuvant therapy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

First uPSA was measured at 3 mo after RP. The study endpoints were biochemical relapse (BCR), defined as PSA ≥0.2ng/ml, bone metastasis-free survival (BMFS), prostate cancer-specific survival (PCSS), overall survival (OS), and salvage radiation therapy (SRT) success. Outcome results were compared using the Kaplan-Meier method and multivariate analysis (MVA).

RESULTS AND LIMITATIONS

The cohort consisted of 269 RP patients from 1991-2015 with median follow-up of 77 mo. Sensitivity analysis identified first postoperative uPSA of ≥0.03ng/ml as the optimal threshold for predicting BCR. First postoperative uPSA ≥0.03 versus <0.03ng/ml was associated with worse 5-yr BCR (86%, 95% confidence interval [CI] 71-93% vs 39%, 95% CI 25-51%; p<0.00001), 10-yr BMFS (75%, 95% CI 62-92% vs 95%, 95% CI 88-100%; p=0.0001), 10-yr PCSS (84%, 95% CI 73-96% vs 100%, 95% CI 100-100%; p=0.005), and 10-yr OS (81%, 95% CI 70-93% vs 98%, 95% CI 94-100%; p=0.009). On MVA, first postoperative uPSA ≥0.03ng/ml was an independent predictor of BCR (hazard ratio [HR] 9.4, 95% CI 5.8-15.4; p<0.00001) and the only predictor for BMFS (HR 9.7, 95% CI 2.1-44.6; p=0.0034), PCSS (HR 13.5, 95% CI 1.7-107.9; p=0.014), and OS (HR 5.0, 95% CI 1.4-18.3; p=0.014). Following SRT, first postoperative uPSA ≥0.03ng/ml independently predicted worse BMFS (HR 5.9, 95% CI 1.3-26.9; p=0.021), PCSS (HR 6.9, 95% CI 0.9-55.8; p=0.07), and OS (4.5, 95% CI 1.0-20.1; p=0.057). Limitations include the retrospective design and potential selection bias.

CONCLUSIONS

First postoperative uPSA ≥0.03ng/ml independently predicts BCR, BMFS, PCSS, and OS better than traditional risk factors. SRT alone may be insufficient for patients with high-risk disease when first postoperative uPSA is ≥0.03ng/ml.

PATIENT SUMMARY

When the first postprostatectomy ultrasensitive prostate-specific antigen level is ≥0.03ng/ml, patients are at higher risk of recurrent and occult prostate cancer. They should be considered for early salvage radiotherapy, possibly with hormone therapy.

The significance of reporting to the thousandths place: Figuring out the laboratory limitations

OBJECTIVES

A request to report laboratory values to a specific number of decimal places represents a delicate balance between clinical interpretation of a true analytical change versus laboratory understanding of analytical imprecision and significant figures. Prostate specific antigen (PSA) was used as an example to determine if an immunoassay routinely reported to the hundredths decimal place based on significant figure assessment in our laboratory was capable of providing analytically meaningful results when reported to the thousandths places when requested by clinicians.

DESIGN AND METHODS

Results of imprecision studies of a representative PSA assay (Roche MODULAR E170) employing two methods of statistical analysis are reported. Sample pools were generated with target values of 0.01 and 0.20 μg/L PSA as determined by the E170. Intra-assay imprecision studies were conducted and the resultant data were analyzed using two independent statistical methods to evaluate reporting limits.

RESULTS

These statistical methods indicated reporting results to the thousandths place at the two assessed concentrations was an appropriate reflection of the measurement imprecision for the representative assay. This approach used two independent statistical tests to determine the ability of an analytical system to support a desired reporting level. Importantly, data were generated during a routine intra-assay imprecision study, thus this approach does not require extra data collection by the laboratory.

CONCLUSIONS

Independent statistical analysis must be used to determine appropriate significant figure limitations for clinically relevant analytes. Establishing these limits is the responsibility of the laboratory and should be determined prior to providing clinical results.

Impact of Postoperative Radiotherapy in Men with Persistently Elevated Prostate-specific Antigen After Radical Prostatectomy for Prostate Cancer: A Long-term Survival Analysis

BACKGROUND

Prostate cancer (PCa) patients with prostate-specific antigen (PSA) persistence after radical prostatectomy (RP) are at increased risk of mortality, although the natural history of these men is heterogeneous and the optimal management has not been established.

OBJECTIVE

To develop a model to predict cancer-specific mortality (CSM) and to test the impact of radiotherapy (RT) on survival in this setting.

DESIGN, SETTING, AND PARTICIPANTS

We identified 496 patients treated with RP and lymph node dissection at two referral centers between 1994 and 2014 who had PSA persistence, defined as a PSA level between 0.1 and 2 ng/ml at 6-8 wk after RP.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES

A multivariable model predicting CSM was developed. We assessed whether the impact of postoperative PSA levels on survival differed according to baseline CSM risk. The nonparametric curve fitting method was then used to explore the relationship between baseline CSM risk and 10-yr CSM rates according to postoperative RT.

RESULTS AND LIMITATIONS

Median follow-up for survivors was 110 mo. Overall, 49 patients experienced CSM. The 10-yr CSM-free survival was 88%. Pathologic grade group and pathologic stage were independent predictors of CSM (all p=0.01). The association between CSM-free survival and PSA at 6-8 wk differed by the baseline CSM risk, whereby the effect of increasing PSA was evident only in patients with a CSM risk of ≥10%. Postoperative RT was beneficial when the predicted risk of CSM was ≥30% (p=0.001 by an interaction test). Our study is limited by its retrospective design.

CONCLUSIONS

Increasing PSA levels should be considered as predictors of mortality exclusively in men with worse pathologic characteristics. Postoperative RT in this setting was associated with a survival benefit in patients with a CSM risk of ≥30%. Conversely, individuals with a CSM risk of <30% should be initially managed expectantly.

PATIENT SUMMARY

Not all patients with prostate-specific antigen persistence have a poor prognosis. Pathologic characteristics should be used to estimate the risk of cancer-specific mortality in these individuals and to identify patients who could benefit from postoperative radiotherapy.

Stratification model based on early postprostatectomy prostate-specific antigen kinetics may help to reduce the risk of overtreatment in candidates for adjuvant radiotherapy

OBJECTIVE

The aim of this study was to construct a stratification model based on early postoperative kinetics of prostate-specific antigen (PSA) to select the most suitable high-risk patients for early intervention after radical prostatectomy (RP).

MATERIALS AND METHODS

The study evaluated 205 men who had undergone RP without any adjuvant treatment. All of the patients had positive surgical margins, extracapsular extension and/or seminal vesicle invasion. The patients underwent multiple ultrasensitive PSA measurements on days 14, 30, 60 and 90 after RP, and subsequently at 3 month intervals. The ability of particular PSA measurements to predict biochemical recurrence (BCR) was assessed using the area under the curve (AUC). A sequential mathematical decision procedure was constructed to create a stratification model.

RESULTS

During the median follow-up of 45.9 months, 106 patients (51%) experienced BCR. Prediction of BCR in terms of the AUC for PSA measurements on days 14, 30, 60 and 90 after the surgery was 0.61, 0.70, 0.80 and 0.82, respectively. In the multivariate analysis, only PSA after RP remained as a predictor of progression-free survival (p < 0.001). The stratification model based on calculated cut-off values for PSA on day 30 (0.068 ng/ml) and PSA on day 60 (0.015 ng/ml) reduced the potential overtreatment rate by 37%.

CONCLUSIONS

The results imply that ultrasensitive PSA values obtained very early after RP correlate with the presence of recurrent disease in high-risk patients. Incorporating these readily available variables into risk stratification models may help to individualize the administration of adjuvant radiotherapy and thus to minimize overtreatment.

Longitudinal modeling of ultrasensitive and traditional prostate-specific antigen and prediction of biochemical recurrence after radical prostatectomy

Ultrasensitive prostate-specific antigen (u-PSA) remains controversial for follow-up after radical prostatectomy (RP). The aim of this study was to model PSA doubling times (PSADT) for predicting biochemical recurrence (BCR) and to capture possible discrepancies between u-PSA and traditional PSA (t-PSA) by utilizing advanced statistical modeling. 555 RP patients without neoadjuvant/adjuvant androgen deprivation from the Turku University Hospital were included in the study. BCR was defined as two consecutive PSA values >0.2 ng/mL and the PSA measurements were log₂-transformed. One third of the data was reserved for independent validation. Models were first fitted to the post-surgery PSA measurements using cross-validation. Major trends were then captured using linear mixed-effect models and a predictive generalized linear model effectively identified early trends connected to BCR. The model generalized for BCR prediction to the validation set with ROC-AUC of 83.6% and 95.1% for the 1 and 3 year follow-up censoring, respectively. A web-based tool was developed to facilitate its use. Longitudinal trends of u-PSA did not display major discrepancies from those of t-PSA. The results support that u-PSA provides useful information for predicting BCR after RP. This can be beneficial to avoid unnecessary adjuvant treatments or to start them earlier for selected 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.

Predictive factors and oncological outcomes of persistently elevated prostate-specific antigen in patients following robot-assisted radical prostatectomy

Our aim was to evaluate factors associated with persistently elevated prostate-specific antigen (PSA) and biochemical recurrence following robotic-assisted radical prostatectomy (RARP). The study population (N = 5300) consisted of consecutive patients who underwent RARP for localized prostate cancer by a single surgeon (VP) from January 2008 through July 2013. A query of our Institutional Review Board-approved registry identified 162 men with persistently elevated PSA (group A), defined as PSA level ≥0.1 ng/ml at 6 weeks after surgery, who were compared with rest of the cohort group having undetectable PSA, group B (<0.1 ng/ml). A univariate and multivariate logistic regression analysis was used to evaluate the significant association between various variables and the following: (1) persistently elevated PSA, (2) BCR (PSA value ≥0.2 ng/ml) on follow-up in the persistent PSA group. On multivariate analysis, only the following parameters were significantly associated with persistent PSA after RARP-preoperative [PSA >10 ng/ml (p = 0.01), Gleason Score ≥8 (p = 0.001) and clinical stage(p = 0.001)]; postoperative [pathologic stage (p = 0.001), extraprostatic extension (EPE, p = 0.01), lymph node positivity (p = 0.001), positive surgical margin (PSM, p = 0.02), Gleason score (p = 0.01) and tumor volume percent (p < 0.001)]. The mean follow-up was 38.1 months. The BCR was significantly higher in group A as compared to group B(52.47 vs 7.9 %) respectively; p = 0.01). The mean time to BCR was significantly lesser in group A as compared to group B(8.9 vs 21.1 months respectively; p = 0.01). The BCR-free survival rates at 1 year and 3 years were significantly lower statistically in the persistent PSA group in comparison to other groups (69.7 vs 97.3 % and 48.5 vs 92.1 %, respectively; p = 0.01). On multivariate logistic regression analysis in patients with persistent PSA on follow-up, preoperative PSA >10 ng/ml, postoperative Gleason score ≥8, postoperative stage ≥pT3, positive pelvic lymph nodes, PSM >3 mm and post-RARP PSA doubling time (DT) <10 months (p < 0.001) were significantly associated with BCR. In patients after RARP, factors associated with aggressive disease (high preoperative PSA, Gleason score ≥8, stage ≥T3, PSM, high tumor volume percent and EPE) predict PSA persistence. Although these patients with persistent PSA after RARP are more likely to have BCR and that too earlier than those patients with undetectable PSA after RARP, a significant proportion of these patients (47.53 %) remain free of BCR. This subset of patients is associated with these favorable parameters (preoperative PSA <10 ng/ml, post-RARP PSA DT ≥10 months, postoperative Gleason score <8, pathologic stage <pT3, PSM <3 mm and no lymph node involvement), thus potentially not requiring any adjuvant treatment.

Adverse pathology and undetectable ultrasensitive prostate-specific antigen after radical prostatectomy: is adjuvant radiation warranted?

OBJECTIVES

To determine if men with adverse pathology but undetectable ultrasensitive (<0.01 ng/mL) PSA are at high-risk for biochemical recurrence (BCR), or if there is a subset of patients at low-risk for whom the benefit of adjuvant radiation therapy might be limited.

PATIENTS AND METHODS

We evaluated 411 patients treated with RP from 2001 to 2013 without adjuvant radiation who had an undetectable (<0.01 ng/mL) PSA level after RP but with adverse pathology [positive surgical margins (PSMs), extraprostatic extension (EPE), and/or seminal vesicle invasion (SVI)]. Multivariable Cox regression analyses tested the relationship between pathological characteristics and BCR to identify groups of men at highest risk of early BCR.

RESULTS

On multivariable analysis, only pathological Gleason 7 (4 + 3), Gleason ≥8, and SVI independently predicted BCR (P = 0.019, P < 0.001, and P = 0.001, respectively), although on two-way analysis men with Gleason 7 (4 + 3) did not have significantly higher rates of BCR compared with patients with Gleason ≤6 (log-rank, P = 0.074). Men with either Gleason ≥8 (with PSMs or EPE) or SVI (15% of the cohort) defined a high-risk group vs men without these characteristics (3-year BCR risk of 50.4% vs 11.9%, log-rank, P < 0.001).

CONCLUSIONS

Among men with adverse pathology but an undetectable (<0.01 ng/mL) PSA level after RP, the benefits of adjuvant radiation are probably limited except for men with Gleason 8-10 (with PSMs or EPE) or SVI who are at high-risk of early BCR.

Oncological outcomes of cryosurgery as primary treatment in T3 prostate cancer: experience of a single centre

OBJECTIVE

To assess the oncological outcomes and determine prognostic factors for overall survival (OS), cancer-specific survival (CSS), and biochemical progression-free survival (BPFS) after cryosurgery for clinical stage T3 prostate cancer.

PATIENTS AND METHODS

Between 2002 and 2007, 75 patients with clinical stage T3 prostate cancer received cryosurgery as primary treatment in our institution. No adjuvant treatment was provided until biochemical failure. After biochemical failure, hormone therapy was administered. Kaplan-Meier analysis was used to calculate the OS, CSS, and BPFS. Cox regression was used to identify factors predictive of survival.

RESULTS

Clinical stage T3a (cT3a) was detected in 60% (45/75) of patients and cT3b detected in 40% (30/75). The 5-year OS, CSS, and BPFS rates were 85.3%, 92.0%, and 48%, respectively. There was a significant difference when comparing the pT3a with the pT3b group for 5-year OS (88.9% vs 80%, P = 0.02) and BPFS (55.6% vs 36.7%, P = 0.01), but there was no difference in CSS (93.3% vs 90%, P = 0.63). Stage, Gleason score, and nadir prostate-specific antigen (PSA) were associated with BPFS, while Gleason score and nadir PSA were the most significant predictors for CSS.

CONCLUSIONS

Cryosurgery can offer good 5-year OS, CSS, and BPFS rates for cT3 prostate cancer, and there was no difference between T3a and T3b for CSS. Gleason score and nadir PSA were the most significant predictors of survival. Further clinical trials are warranted for evaluating the role of cryosurgery for cT3 prostate cancer.

[Postoperative radiotherapy of prostate cancer]

Between 10 and 40% of patients who have undergone a radical prostatectomy may have a biologic recurrence. Local or distant failure represents the possible patterns of relapse. Patients at high-risk for local relapse have extraprostatic disease, positive surgical margins or seminal vesicles infiltration or high Gleason score at pathology. Three phase-III randomized clinical trials have shown that, for these patients, adjuvant irradiation reduces the risk of tumoral progression without higher toxicity. Salvage radiotherapy for late relapse allows a disease control in 60-70% of the cases. Several research in order to improve the therapeutic ratio of the radiotherapy after prostatectomy are evaluate in the French Groupe d'Étude des Tumeurs Urogénitales (Gétug) and of the French association of urology (Afu). The Gétug-Afu 17 trial will provide answers to the question of the optimal moment for postoperative radiotherapy for pT3-4 R1 pN0 Nx patients, with the objective of comparing an immediate treatment to a differed early treatment initiated at biological recurrence. The Gétug-Afu 22 questions the place of a short hormonetherapy combined with image-guided, intensity-modulated radiotherapy (IMRT) in adjuvant situation for a detectable prostate specific antigen (PSA). The implementation of a multicenter quality control within the Gétug-Afu in order to harmonize a modern postoperative radiotherapy will allow the development of a dose escalation IMRT after surgery.

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.

Obesity, prostate-specific antigen nadir, and biochemical recurrence after radical prostatectomy: biology or technique? Results from the SEARCH database

BACKGROUND

Obesity is associated with an increased risk of biochemical recurrence (BCR) after radical prostatectomy (RP). It is unclear whether this is due to technical challenges related to operating on obese men or other biologic factors.

OBJECTIVE

To examine whether obesity predicts higher prostate-specific antigen (PSA) nadir (as a measure of residual PSA-producing tissue) after RP and if this accounts for the greater BCR risk in obese men.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective analysis of 1038 RP patients from 2001 to 2010 in the multicenter US Veterans Administration-based Shared Equal Access Regional Cancer Hospital database with median follow-up of 41 mo.

INTERVENTION

All patients underwent RP.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We evaluated the relationship between body mass index (BMI) and ultrasensitive PSA nadir within 6 mo after RP. Adjusted proportional hazards models were used to examine the association between BMI and BCR with and without PSA nadir.

RESULTS AND LIMITATIONS

Mean BMI was 28.5 kg/m2. Higher BMI was associated with higher PSA nadir on both univariable (p=0.001) and multivariable analyses (p<0.001). Increased BMI was associated with increased BCR risk (hazard ratio [HR]: 1.06; p=0.007). Adjusting for PSA nadir slightly attenuated, but did not eliminate, this association (HR: 1.04, p=0.043). When stratified by PSA nadir, obesity only significantly predicted BCR in men with an undetectable nadir (p=0.006). Unfortunately, other clinically relevant end points such as metastasis or mortality were not available.

CONCLUSIONS

Obese men are more likely to have a higher PSA nadir, suggesting that either more advanced disease or technical issues confound an ideal operation. However, even after adjusting for the increased PSA nadir, obesity remained predictive of BCR, suggesting that tumors in obese men are growing faster. This provides further support for the idea that obesity is biologically associated with prostate cancer progression.

Parameters derived from the postoperative decline in ultrasensitive PSA improve the prediction of radical prostatectomy outcome

PURPOSE

Contemporary tools estimating increased risk of prostate cancer (PCa) relapse after radical prostatectomy (RP) are far from perfect and there has been an intensive search for additional predictive variables. We aimed to explore whether the parameters of postoperative ultrasensitive prostate-specific antigen (PSA) decline provide additional information for predicting PCa progression.

METHODS

A total of 319 consecutive men, with at least 2 years of follow-up after RP for clinically localized PCa were subjected to this study. Intensive postoperative measurements of ultrasensitive PSA resulted in total of 4028 PSA values available for statistical evaluation. Biochemical recurrence (BCR) was defined as PSA ≥0.2 ng/ml. The accuracy of predictive models was quantified with the area under the curve.

RESULTS

Over a median follow-up of 43 months (24-99 months), 107 patients (34%) experienced BCR after RP. In patients with BCR, significantly higher values of PSA nadir (p < 0.001) and a decreased time interval from surgery to reach PSA nadir (p < 0.001) were observed. A multivariable Cox regression model confirmed that PSA nadir >0.01 ng/ml (HR 6.01, 95% CI: 3.89-9.52) and time to PSA nadir <3 months (HR 2.86, 95% CI: 1.74-5.01) were independent predictors of BCR. The inclusion of PSA nadir and the time to PSA nadir into the model resulted in improvement of predictive accuracy by 16% over the model designed on the basis of established parameters.

CONCLUSIONS

Our results demonstrate that the level of PSA nadir and the time to PSA nadir determined by ultrasensitive assay significantly improve the identification of patients who are at high risk of disease recurrence after RP.

The impact of adjuvant therapy in patients with biochemical recurrence on prostate cancer progression and mortality five years after radical prostatectomy

INTRODUCTION

The clinical significance of biochemical recurrence (BCR) after radical prostatectomy (RP) due to prostate cancer (PCa) is not unambiguous, sometimes being independent from the real progression. BCR is followed by a greater risk of adverse events and almost always results with the necessity for implementation of adjuvant therapy (AT). The aim of the following study was to examine the impact of AT in patients with BCR together with PCa progression and mortality 5-years after RP.

MATERIAL AND METHODS

Two hundred forty-seven patients after RP, who were treated in the period from 1995 to 2009, underwent the retrospective analysis. They were divided into three groups according to the applied AT after prior BCR diagnosis. The first group (n - 39) included patients treated with radiotherapy, along with hormonotherapy. The second group (n - 63) covers patients receiving hormonotherapy only. The third group (n - 145) consists of patients without BCR. Five-year general and disease-specific survival was evaluated and choice prognostic factors were compared.

RESULTS

Five-year overall survival was 74.2% in group I, 88.3% in group II, and 98.7% in group III. Diseasespecific survival was: 76.9%, 90.5%, and 100% (p = 0.001), respectively. BCR was diagnosed in 102 (41.5%) patients; while in another 24 (23.5%) of them progression was diagnosed after the AT was applied.

CONCLUSIONS

The risk of BCR 5-years after RP is greater in patients with high initial concentration of PSA, higher Gleason score, and clinical advancement. Five-year overall and disease-specific survivals are higher among patients after hormonotherapy alone compared to those after both radio- and hormonotherapy.

Fifth-generation digital immunoassay for prostate-specific antigen by single molecule array technology

BACKGROUND

Measurement of prostate-specific antigen (PSA) in prostate cancer patients following radical prostatectomy (RP) has been hindered by the limit of quantification of available assays. Because radical prostatectomy removes the tissue responsible for PSA production, postsurgical PSA is typically undetectable with current assay methods. Evidence suggests, however, that more sensitive determination of PSA status following RP could improve assessment of patient prognosis and response to treatment and better target secondary therapy for those who may benefit most. We developed an investigational digital immunoassay with a limit of quantification 2 logs lower than current ultrasensitive third-generation PSA assays.

METHODS

We developed reagents for a bead-based ELISA for use with high-density arrays of femtoliter-volume wells. Anti-PSA capture beads with immunocomplexes and associated enzyme labels were singulated within the wells of the arrays and interrogated for the presence of enzymatic product. We characterized analytical performance, compared its accuracy with a commercially available test, and analyzed longitudinal serum samples from a pilot study of 33 RP patients.

RESULTS

The assay exhibited a functional sensitivity (20% interassay CV) <0.05 pg/mL, total imprecision <10% from 1 to 50 pg/mL, and excellent agreement with the comparator method. All RP samples were well within the assay measurement capability. PSA concentrations following surgery were found to be predictive of prostate cancer recurrence risk over 5 years.

CONCLUSIONS

The robust 2-log improvement in limit of quantification relative to current ultrasensitive assays and the validated analytical performance of the assay allow for accurate assessment of PSA status after RP.

Clinical evaluation of a novel method for the measurement of prostate-specific antigen, AccuPSA(TM) , as a predictor of 5-year biochemical recurrence-free survival after radical prostatectomy: results of a pilot study

Study Type - Diagnostic (validating cohort) Level of Evidence 1b What's known on the subject? and What does the study add? Nadir Ultrasensitive PSA levels has some value for predicting BCR following RD. AccuPSA assays lower limit of PSA quantification of <0.01 pg/ml greatly enhances sensitivity and specificity of nadir PSA to predict BCR following RP. Our pilot study shows an AccuPSA of 3 pg/ml has a sensitory and specificity of 100% and 75% respectively for predicting 5 year BCR following RP. OBJECTIVES • To conduct a proof of concept study to evaluate a novel digital single molecule immunoassay (AccuPSA(TM) ) that detects prostate-specific antigen (PSA) a thousandfold more sensitively than current PSA detection methods. • To determine the ability of the AccuPSA(TM) assay to predict 5-year biochemical recurrence (BCR)-free survival after radical prostatectomy (RP). PATIENTS AND METHODS • A total of 31 frozen serum specimens were obtained from specimen logs maintained at New York University Langone Medical Center and the Johns Hopkins University School of Medicine on men who had undergone RP. Those men without evidence of BCR had a minimum of 5 years' PSA follow-up. • In all cases, preoperative and pathological information were available, as was a serum specimen 3-6 months after RP, with a PSA level of <0.1 ng/mL measured by conventional PSA methods at the time of serum collection. • Specimens were tested using the AccuPSA(TM) method. • A Cox proportional hazard model and Kaplan-Meier analysis were used to determine whether AccuPSA(TM) predicted the risk of BCR. RESULTS • Overall, 11/31 (35.5%) men developed BCR. • Mean AccuPSA(TM) nadir levels were significantly different (P < 0.001) between the non-BCR group (2.27 pg/mL) and the BCR group (46.99 pg/mL). • Using a multivariate Cox proportional hazard model, AccuPSA(TM) nadir level was a significant predictor of BCR-free survival (P < 0.01). • Kaplan-Meier analysis of up to 5 years follow-up showed that 100% of men with AccuPSA(TM) nadir values <3 pg/mL did not develop BCR, whereas 62.5% of men with values >3 pg/mL developed BCR (P= 0.00024). • The sensitivity, specificity, positive predictive value and negative predictive value of the AccuPSA(TM) method was 100%, 75%, 69% and 100%, respectively. CONCLUSIONS • AccuPSA(TM) assay predicts 5-year BCR- free survival after RP. • Identifying a reliable predictor of BCR soon after RP has important implications for frequency of PSA testing, selection of candidates for adjuvant therapy, and reassuring a large subset of men that they are not at risk of recurrence. • Larger studies are needed to validate these findings.

[News and perspective in management of high-risk prostate cancer]

Advanced prostate cancers include situations involving the patient's survival in the medium or short run. They are responsible for the second leading cause of death by cancer in France. However, their management is poorly codified and confronts clinicians and researchers to therapeutic problems. Even if the main options remain surgery radiotherapy and hormone therapy, alone or in combination, their places tends to be clarified. The association radio-hormonotherapy is the gold standard, but surgery first has interesting results with the possibility of multi-modal salvage treatment if necessary. Similarly, improved diagnostic tools allow a more personal management of these patients and the search for predictive factors (early PSA assay, time to reach PSA nadir) contribute to provide better monitoring. The mortality of prostate cancer decreases by 2.5 % per year due to earlier detection of cancer and advances in treatment of advanced forms. Technical advances in surgery and radiotherapy, associated with new ways of androgeno-suppression should continue this trend.

Persistently elevated prostate-specific antigen at six weeks after radical prostatectomy helps in early identification of patients who are likely to recur

OBJECTIVE

To determine the prognostic factors of biochemical recurrence in patients who failed to achieve an undetectable prostate-specific antigen (PSA) after radical prostatectomy (RP) for prostate cancer.

MATERIALS AND METHODS

We reviewed data on 240 men who underwent RP as first-line treatment and who had a PSA assay available at 6 weeks after surgery. Persistent detectable PSA was defined as a PSA level ≥ 0.1 ng/ml at 6 weeks after surgery.

RESULTS

Overall, 83 men presented persistently elevated PSA after RP and 81 had a biochemical recurrence. Median follow-up was 44 months. In univariate analysis, these factors were associated with biochemical recurrence: preoperative PSA level (P < 0.0001), biopsy and pathologic Gleason score (P < 0.001), capsular involvement (P = 0.0001), positive surgical margins (P < 0.0001), pathological stage ≥ T3 (P = 0.0001), and detectable post-operative PSA ≥ 0.1 ng/ml (P = 0.0001). In a multivariate analysis, only the detectable post-operative PSA level ≥ 0.1 ng/mL (P = 0.001), positive surgical margins (P = 0.002), and pathological stage ≥ T3 (P < 0.001) were significant. The individual, five-year, PSA-free survival rate for men with post-operative PSA <0.1 ng/ml and ≥ 0.1 ng/ml were 59 and 42%, respectively (P < 0.001).

CONCLUSIONS

A majority of patients who failed to achieve an undetectable PSA after surgery had a subsequent biochemical recurrence in the outcome. A systematic PSA assay 6 weeks after RP could be useful to early identify patients who are likely to recur.

Three-year postoperative ultrasensitive prostate-specific antigen following open radical retropubic prostatectomy is a predictor for delayed biochemical recurrence

BACKGROUND

Prostate-specific antigen (PSA) is the only independent predictor of biochemical recurrence (BCR) following radical prostatectomy (RP) subject to change over time.

OBJECTIVE

To determine whether an ultrasensitive PSA measured at 3 yr following RP is a predictor of subsequent BCR.

DESIGN, SETTING, AND PARTICIPANTS

There were 1197 consecutive men with clinically localized prostate cancer who underwent an open radical retropubic prostatectomy (ORRP) at a tertiary referral academic medical center. Exclusions included 107 men (8.9%) who developed a PSA level ≥ 0.2 ng/ml or underwent hormone therapy or radiation therapy (RT) within the first 3 r after surgery, 191 men (16%) who did not undergo a 3-yr ultrasensitive PSA assay, and 98 men (8.2%) who had PSA levels ≥ 0.1 and <0.2 at 3 yr. The remaining 801 men were stratified into two groups based on their ultrasensitive PSA level at 3 yr postoperatively: group 1, which consisted of patients whose PSA was ≤ 0.04 (n = 765), and group 2, which consisted of patients whose PSA was >0.04 and <0.10 (n = 36).

MEASUREMENTS

Delayed BCR was the primary end point and represented those men in this cohort who developed a PSA level ≥ 0.2 or underwent salvage RT for a persistently rising PSA level after 3 yr of follow-up.

RESULTS AND LIMITATIONS

The 7-yr cumulative BCR-free survival rate for groups 1 and 2 was 0.957 (95% confidence interval [CI], 0.920-0.978) and 0.654 (95% CI, 0.318-0.855), respectively. In multivariable Cox proportional hazards models, ultrasensitive PSA level at 3 yr remained the only significant predictor of delayed BCR (likelihood ratio χ(2) for full model: 27.03; df = 1; p < 0.001). A limitation of the study is that no uniform PSA assay was obtained.

CONCLUSIONS

Our findings provide compelling evidence that an ultrasensitive PSA at 3 yr following RP provides useful insights into delayed BCR and is a source of reassurance for the overwhelming majority of men being followed for delayed recurrences.

Simultaneous detection of single molecules and singulated ensembles of molecules enables immunoassays with broad dynamic range

We report a method for combining the detection of single molecules (digital) and an ensemble of molecules (analog) that is capable of detecting enzyme label from 10(-19) M to 10(-13) M, for use in high sensitivity enzyme-linked immunosorbent assays (ELISA). The approach works by capturing proteins on microscopic beads, labeling the proteins with enzymes using a conventional multistep immunosandwich approach, isolating the beads in an array of 50-femtoliter wells (Single Molecule Array, SiMoA), and detecting bead-associated enzymatic activity using fluorescence imaging. At low concentrations of proteins, when the ratio of enzyme labels to beads is less than ∼1.2, beads carry either zero or low numbers of enzymes, and protein concentration is quantified by counting the presence of "on" or "off" beads (digital regime). (1) At higher protein concentrations, each bead typically carries multiple enzyme labels, and the average number of enzyme labels present on each bead is quantified from a measure of the average fluorescence intensity (analog regime). Both the digital and analog concentration ranges are quantified by a common unit, namely, average number of enzyme labels per bead (AEB). By combining digital and analog detection of singulated beads, a linear dynamic range of over 6 orders of magnitude to enzyme label was achieved. Using this approach, an immunoassay for prostate specific antigen (PSA) was developed. The combined digital and analog PSA assay provided linear response over approximately four logs of concentration ([PSA] from 8 fg/mL to 100 pg/mL or 250 aM to 3.3 pM). This approach extends the dynamic range of ELISA from picomolar levels down to subfemtomolar levels in a single measurement.