Prostate specific antigen versus prostate specific antigen density as a prognosticator of pathological characteristics and biochemical recurrence following radical prostatectomy

Oncological outcomes in robot-assisted radical prostatectomy: the value of PSA density as a preoperative predictive factor

Background

Pretreatment assessment of patients diagnosed with localized prostate cancer (PCa) is essential for therapeutic decision-making. Currently available staging systems based on prostate-specific antigen (PSA), Gleason score, and clinical stage allow for determining the prognostic characteristics of these patients. Several studies have evaluated the preoperative use of prostate-specific antigen density (PSAD) as a prognostic factor for further risk stratification. To date, the role of PSAD in this setting is still an object of debate.

Objectives

The present analysis aimed to assess the predictive potential of PSAD for adverse oncological outcomes after robot-assisted radical prostatectomy (RARP) and to compare its accuracy to preoperative PSA (pPSA).

Design and methods

We retrospectively reviewed 427 patients diagnosed with localized PCa who underwent RARP at a single institution between January 2015 and January 2020. Generating receiver operator characteristic (ROC) curves, calculating areas under the curves (AUCs), and using a linear regression model, we analyzed the association of PSAD and pPSA with postoperative positive surgical margins (PSM), Gleason score ⩾ 7, persistent PSA, and biochemical recurrence (BCR), with a median follow-up of 47 months.

Results

PSAD showed a significant association with PSM (p < 0.0001), PSA persistence (p < 0.0001), and Gleason ⩾ 7 (p < 0.0001), without being statistically significant in predicting BCR (p = 0.098). The predictive value of PSAD was comparable to pPSA for outcomes of PSA persistence (AUC 0.727 versus 0.771) and Gleason ⩾ 7 (AUC 0.683 versus 0.649).

Conclusion

PSAD is a predictive factor for postoperative oncological outcomes of PSM, Gleason score ⩾ 7, and persistence of PSA. Despite the need for further studies, PSAD could be useful as a prognostic parameter in conjunction with established staging systems.

Determination of Whether Apex or Non-Apex Prostate Cancer Is the Best Candidate for the Use of Prostate-Specific Antigen Density to Predict Pathological Grade Group Upgrading and Upstaging after Radical Prostatectomy

Objective: Previous studies have demonstrated that prostate-specific antigen density (PSAD) may aid in predicting Gleason grade group (GG) upgrading and pathological upstaging in patients with prostate cancer (PCa). However, the differences and associations between patients with apex prostate cancer (APCa) and non-apex prostate cancer (NAPCa) have not been described. The aim of this study was to explore the different roles of PSAD in predicting GG upgrading and pathological upstaging between APCa and NAPCa. Patients and Methods: Five hundred and thirty-five patients who underwent prostate biopsy followed by radical prostatectomy (RP) were enrolled. All patients were diagnosed with PCa and classified as either APCa or NAPCa. Clinical and pathological variables were collected. Univariate, multivariate, and receiver operating characteristic (ROC) analyses were performed. Results: Of the entire cohort, 245 patients (45.8%) had GG upgrading. Multivariate analysis revealed that only PSAD (odds ratio [OR]: 4.149, p < 0.001) was an independent, significant predictor of upgrading. A total of 262 patients (49.0%) had pathological upstaging. Both PSAD (OR: 4.750, p < 0.001) and percentage of positive cores (OR: 5.108, p = 0.002) were independently significant predictors of upstaging. Of the 374 patients with NAPCa, 168 (44.9%) displayed GG upgrading. Multivariate analysis also showed PSAD (OR: 8.176, p < 0.001) was an independent predictor of upgrading. Upstaging occurred in 159 (42.5%) patients with NAPCa, and PSAD (OR: 4.973, p < 0.001) and percentage of positive cores (OR: 3.994, p = 0.034) were independently predictive of pathological upstaging. Conversely, of the 161 patients with APCa, 77 (47.8%) were identified with GG upgrading, and 103 (64.0%) patients with pathological upstaging. Multivariate analysis demonstrated that there were no significant predictors, including PSAD, for predicting GG upgrading (p = 0.462) and pathological upstaging (p = 0.100). Conclusions: PSAD may aid in the prediction of GG upgrading and pathological upstaging in patients with PCa. However, this may only be practical in patients with NAPCa but not with APCa. Additional biopsy cores taken from the prostatic apex region may help improve the accuracy of PSAD in predicting GG upgrading and pathological upstaging after RP.

Prostate gland volume estimation: anteroposterior diameters measured on axial versus sagittal ultrasonography and magnetic resonance images

PURPOSE

The aim of this study was to evaluate the accuracy of prostate volume estimates calculated from the ellipsoid formula using the anteroposterior (AP) diameter measured on axial and sagittal images obtained through ultrasonography (US) and magnetic resonance imaging (MRI).

METHODS

This retrospective study included 456 patients with transrectal US and MRI from two university hospitals. Two radiologists independently measured the prostate gland diameters on US and MRI: AP diameters on axial and sagittal images, transverse, and longitudinal diameters on midsagittal images. The volume estimates, volumeax and volumesag, were calculated from the ellipsoid formula by using the AP diameter on axial and sagittal images, respectively. The prostate volume extracted from MRI-based whole-gland segmentation was considered the gold standard. The intraclass correlation coefficient (ICC) was used to evaluate the inter-method agreement between volumeax and volumesag, and agreement with the gold standard. The Wilcoxon signedrank test was used to analyze the differences between the volume estimates and the gold standard.

RESULTS

The prostate gland volume estimates showed excellent inter-method agreement, and excellent agreement with the gold standard (ICCs >0.9). Compared with the gold standard, the volume estimates were significantly larger on MRI and significantly smaller on US (P<0.001). The volume difference (segmented volume-volume estimate) was greater in patients with larger prostate glands, especially on US.

CONCLUSION

Volumeax and volumesag showed excellent inter-method agreement and excellent agreement with the gold standard on both US and MRI. However, prostate volume was overestimated on MRI and underestimated on US.

Prostate weight and prostate cancer outcomes after radical prostatectomy: Results from the SEARCH cohort study

BACKGROUND

Smaller prostates have been linked to unfavorable clinical characteristics and poor short-term outcomes following radical prostatectomy (RP). We examined the relation between prostate weight at RP and prostate cancer (PC) outcomes post-RP.

METHODS

Men in the SEARCH cohort undergoing RP between 1988 and 2017 (N = 6242) were studied for PC-specific mortality (PCSM) as the primary outcome, and for biochemical recurrence (BCR), castration-resistant PC (CRPC) and metastasis as secondary outcomes. Hazard ratios (HR) and 95% confidence intervals (CI) were determined for associations between prostate weight and outcomes using Fine-Gray competing risk regression multivariable analyses. Sensitivity analyses were also carried out following exclusion of: (i) men with extreme prostate weights (<20 g and ≥100 g); and (ii) men with elevated prostate specific antigen (PSA) levels.

RESULTS

Median values for age, pre-RP PSA and prostate weight were 63 years, 6.6 ng/ml, and 42.0 g, respectively. During a median follow-up of 7.9 years, 153 (3%) died from PC, 2103 (34%) had BCR, 203 (3%) developed CRPC, and 289 (5%) developed metastases. Prostate weight was not associated with PCSM in the main analyses (multivariable HR = 1.43; 95% CI: 0.87-2.34) or in sensitivity analyses. Prostate weight was inversely associated with BCR in the main analyses (multivariable HR = 0.70; 95%CI: 0.61-0.79) which was unchanged in sensitivity analyses. HRs for prostate weight and CRPC and metastasis were elevated but statistical significance was not attained. Similar results were observed in sensitivity analyses.

CONCLUSIONS

Inconsistent results for prostate weight and short-term vs longer-term outcomes highlight the need to better understand the complex biology leading to prostate size and the relevance of prostate size as a predictor of PC outcomes.

The efficiency of prostate-specific antigen density measurement using three different methods on the prediction of biochemical recurrence

BACKGROUND

The aim of this study was to evaluate the efficiency of prostate-specific antigen (PSA) density (PSAD) calculated through prostate volume (PV) obtained via transrectal ultrasound (TRUS) and magnetic resonance imaging (MRI) and actual prostate weight (PW) methods obtained via pathological evaluation on the prediction of biochemical recurrence (BCR) in the follow-ups of patients who had undergone radical prostatectomy (RP).

METHODS

A total of 335 clinically localized prostate cancer (PCa) patients who had received open RP between January 2015 and December 2018 were enrolled in the study. Pre and postoperative demographic data, clinical and pathological findings and BCR conditions were recorded. The PSAD was calculated using information obtained through preoperative TRUS examinations, MRI, and collected pathological specimens after RP by dividing the maximum preoperative PSA value and PV/PW.

RESULTS

In a mean follow-up duration of 20.2 ± 8.5 months, recurrence was observed in 52 patients (24.4%) and progression was observed in 8 (3.8%) patients. The TRUS-PSAD, MRI-PSAD, and PW-PSAD values were statistically significantly higher in BCR patients compared to non-BCR patients. The International Society of Urologic Pathologists (ISUP) grade 5 and pT3b as a pathological stage were detected as independent variables in the prediction of BCR formation. Actual PW had a high prediction value compared to other PSAD measurements at <40 g prostate weights, but it had a low prediction value in prostates with an actual PW >60 g.

CONCLUSIONS

In this study, it was stated that PSAD acquired through different imaging methods does not affect the usability of PSAD in BCR prediction in clinical practice. The ISUP grade 5 and pT3b stage PCa were detected as independent markers in BCR prediction after RP.

Addition of Prostate Volume and Prostate-specific Antigen Density to Memorial Sloan Kettering Cancer Center Prostate Cancer Nomograms

Prostate-specific antigen (PSA) density is an established prognostic marker for prostate cancer. We investigated whether the inclusion of PSA density or prostate volume in the Memorial Sloan Kettering Cancer Center nomograms improves the prediction of biochemical recurrence (BCR) after radical prostatectomy (RP). Among the 11 725 men included, 2140 developed BCR. Neither PSA density nor prostate volume was associated with BCR when added to either the pre-RP or post-RP model (all p values ≥0.10) and changes in the C index were very small (largest change, 0.002). The results were robust to exclusion of outlying prostate volumes and restriction to patients treated after 2005. There is no justification for adding prostate volume or PSA density to BCR nomograms.

Patient summary

Addition of prostate volume or prostate-specific antigen density to Memorial Sloan Kettering Cancer Center prediction schemes did not improve the prediction of recurrence of prostate cancer after removal of the prostate.

Measurement of Prostate Volume with MRI (A Guide for the Perplexed): Biproximate Method with Analysis of Precision and Accuracy

To review the anatomic basis of prostate boundary selection on T2-weighted magnetic resonance imaging (MRI). To introduce an alternative 3D ellipsoid measuring technique that maximizes precision, report the intra- and inter-observer reliability, and to advocate it's use for research involving multiple observers. We demonstrate prostate boundary anatomy using gross pathology and MRI examples. This provides background for selecting key boundary marks when measuring prostate volume. An alternative ellipsoid volume method is then proposed using these boundaries in an attempt to improve inter-observer precision. An IRB approved retrospective study of 140 patients with elevated serum prostate specific antigen levels and/or abnormal digital rectal examinations was done with T2-weighted MRI applying a new (Biproximate) technique. Measurements were made by 2 examiners, correlated with each other for inter-observer precision and correlated with an expert observer for accuracy. Correlation statistics, linear regression analysis, and tests of means were applied using p ≤ 0.05 as the threshold for significance. Inter-observer correlation (precision) was 0.95 between observers. Correlation between these observers and the expert (accuracy) was 0.94 and 0.97 respectively. Intra-observer correlation for the expert was 0.98. Means for inter-rater reliability and accuracy were all the same (p = 0.001). We conclude that using more precise reproducible landmarks with biproximate technique, precision and accuracy of total prostate volume is found to be demonstrated.

Multicenter Evaluation of Biochemical Relapse-Free Survival Outcomes for Intraoperatively Planned Prostate Brachytherapy Using an Automated Delivery System

PURPOSE

To report biochemical recurrence in prostate cancer treated with intraoperatively planned low-dose-rate prostate brachytherapy using an automated delivery system (IO-LDRB).

METHODS AND MATERIALS

Between 2003 and 2013, 2608 patients from 3 centers were treated with IO-LDRB as single-modality treatment for low or low-tier intermediate-risk prostate cancer. Databases from the 3 centers have been analyzed. These independent databases were collected prospectively. Patient, tumor, and treatment characteristics were then compared, Kaplan-Meier survival estimates of biochemical relapse-free survival (bRFS) were generated, and the Cox proportional hazards model was used to determine factors predicting for relapse.

RESULTS

A total of 2608 patients with a median follow-up of 4.7 (interquartile range, 3.1-6.9) years were analyzed. Median age was 64 (range, 42-84) years. In these patients, median initial prostate-specific antigen was 5.5 ng/mL, 74% were T1, and 26% were T2; 73% were Gleason 6, and 25% Gleason 7. Median percentage of biopsy cores positive was 33%, and median gland volume was 34.2 cm³. Eleven percent of patients received hormones for a median of 3.0 months before implantation. Median seed activity was 0.437 mCi, D90 (dose covering 90% of the prostate volume) was 186.7 Gy, and V100 was 99.37%. Biochemical relapse was observed in 124 patients (4.8%), and median time to failure was 4.0 years. Predicted bRFS was 93% at 7 years. On Cox regression bRFS was dependent only on D90 at the time of implantation and prostate-specific antigen density.

CONCLUSIONS

This study demonstrates that IO-LDRB is an effective treatment option for patients with low and low-tier intermediate-risk prostate cancer. Rates of biochemical relapse remain low several years after treatment. These results compared favorably to published manual preplan technique results.

ERG rearrangement as a novel marker for predicting the extra-prostatic extension of clinically localised prostate cancer

Currently, there are no well-established preoperative clinicopathological parameters for predicting extra-prostatic extension (EPE) in patients with clinically localised prostate cancer (PCa). The transmembrane protease serine 2 (TMPRSS2)-ETS-related gene (ERG) fusion gene is a specific biomarker of PCa and is considered a prognostic predictor. The aim of the present study was to assess the value of this marker for predicting EPE in patients with clinically localised PCa. In total, 306 PCa patients with clinically localised disease, including 220 patients (71.9%) with organ-confined disease and 86 EPE cases (28.1%), were included in the study. Receiver operating characteristic curves and logistic regression were employed to establish the optimal cut-off value and to investigate whether ERG rearrangement was an independent predictor for the EPE of clinically localised PCa. A leave-one-out cross-validation (LOOCV) model was implemented to validate the predictive power of ERG rearrangement. An increase in ERG rearrangements was identified to be associate'd with EPE, and the optimal cut-off for predicting EPE was determined to be 2.25%, with a sensitivity of 70.24% [95% confidence interval (CI), 62.6-78.9%], a specificity of 80.43% (95% CI, 75.4-85.1%), and an area under the curve (AUC) of 0.781 (95% CI, 0.730-0.826). In the LOOCV model, ERG rearrangement also demonstrated good performance for predicting EPE (sensitivity, 76.923%; specificity, 71.429%; 95% CI for AUC, 0.724-0.958). In addition, a high Gleason score (≥7) and a cT2c classification upon biopsy were independent factors for EPE.

Overexpression of cofilin 1 in prostate cancer and the corresponding clinical implications

Cofilin 1 (CFL1) is a cytoskeletal protein and overexpression of the protein has been associated with aggressiveness in certain types of malignancies. The aim of the present study was to investigate the clinical implications of CFL1 expression in prostate cancer (PCa). Immunohistochemical analysis was performed using formalin-fixed paraffin-embedded tissue sections obtained from 111 patients with PCa and 47 patients with benign prostatic hyperplasia (BPH). In total, 78 (70.3%) out of 111 PCa tissues were found to express the CFL1 protein, while no expression was detected in BPH tissues. In addition, CFL1 was also observed to be significantly associated with the Gleason score (GS; <7 vs. ≥7; P<0.0001) and presence of lymph node metastasis (presence vs. absence; P<0.0001). However, there was no association between the expression of CFL1 and other clinicopathological variables, such as age (<69 years vs. ≥69 years; P=0.54), pre-operative prostate specific antigen level (<20 ng/ml vs. ≥20 ng/ml; P=0.45) and pathological stage (T2 vs. ≥T3a; P=0.055). In addition, 35 tissues (31.5%) were observed to possess a CFL1-positive mesenchyme. CFL1 expression was revealed to be an independent predictive factor for a high GS. The status of CFL1 expression in the mesenchyme also found to individually predict extraprostatic extension in PCa patients, based on multivariate analysis. The results of the present study indicated that CFL1 may specifically predict the development of PCa, and that the expression of CFL1 in the mesenchyme may be closely associated with the development of lymph node metastasis.

Importance of prostate volume in the stratification of patients with intermediate-risk prostate cancer

OBJECTIVES

To evaluate the role of prostate volume assessed at final pathology in the risk of biochemical recurrence in patients with clinically localized prostate cancer treated with radical prostatectomy.

METHODS

Overall, 5637 patients treated with radical prostatectomy between January 1993 and August 2013 were identified. Multivariable Cox regression analyses tested the association between prostate volume and biochemical recurrence in the overall population and after stratifying patients according to the D'Amico risk groups.

RESULTS

Mean (median) prostate volume was 50.61 mL (46 mL). When patients were stratified according to D'Amico risk groups, mean (median) prostate volume was 51.7 mL (48 mL), 49.8 mL (45 mL) and 50.6 mL (46 mL) in low-, intermediate-, and high-risk prostate cancer, respectively (P = 0.04). Overall, the 5-year biochemical recurrence-free survival rate was 87.9%. In multivariable Cox regression analyses, prostate volume was associated with a lower risk of biochemical recurrence (hazard ratio 0.99, 95% confidence interval 0.99-1.00), after accounting for disease characteristics. However, when patients were stratified according to D'Amico risk groups, prostate volume represented an independent predictor of biochemical recurrence only in individuals with intermediate-risk disease (hazard ratio 0.99, 95% confidence interval 0.99-1.00). Conversely, prostate volume was not associated with the risk of experiencing biochemical recurrence in patients with low- and high-risk disease.

CONCLUSIONS

Smaller prostates are associated with increased risk of biochemical recurrence after surgery only in men with intermediate-risk disease. In this category, the preoperative assessment of prostate volume might be helpful in order to identify patients at higher risk of biochemical recurrence after surgery. Additionally, prostate volume might be used to individualize follow-up schedules after radical prostatectomy.

Prediction of extraprostatic extension in patients with clinically organ-confined prostate cancer

INTRODUCTION

Preoperative parameters for predicting extraprostatic extension (ECE) in clinically organ-confined prostate cancer patients are not well defined. Our aim was to evaluate the roles of the biopsy Gleason score, prostate-specific antigen (PSA)-based parameters, volume, and clinical T classification in prediction of ECE.

MATERIALS AND METHODS

A total of 188 patients with clinically organ-confined prostate cancer who underwent radical prostatectomy from January 1998 to December 2007 were included in the study. Age, prostate volume, preoperative total serum PSA (tPSA), free PSA, PSA density (PSAD), biopsy Gleason score, and clinical T classification were analyzed by univariate and multivariate analyses to predict ECE.

RESULTS

Pathologic examination revealed 130 patients had organ-confined disease and 58 patients were positive for ECE. Multivariate logistic regression analyses showed that tPSA was an independent predictor of ECE. Gleason score ≥8 had a trend for predicting ECE. Receiver operating characteristic (ROC) curves suggested that tPSA and PSAD had a similar diagnosis performance in the whole cohort. For patients with Gleason score of 7, PSAD was found to be statistically better than tPSA for predicting ECE.

CONCLUSIONS

tPSA remains one of the most important factors for predicting ECE in prostate cancer patients. PSAD may be more helpful than tPSA for predicting ECE in the patients with Gleason score of 7.

Evaluating PSA Density as a Predictor of Biochemical Failure after Radical Prostatectomy: Results of a Prospective Study after a Median Follow-Up of 36 Months

Purpose. To evaluate the predictive ability of PSA density for biochemical relapse after radical prostatectomy in patients operated for clinically localized disease and to compare its predictive strength with preoperative PSA and Gleason score. Patients and Methods. The study evaluated 244 patients with localized disease who underwent an open retropubic radical prostatectomy between February 2007 and April 2011. PSA was measured every 3 months after surgery with a mean follow-up period of 36 months. Two consecutive rises >0.2 ng/mL were considered as biochemical relapse. Results. Biochemical recurrence was observed in 71 (29.1%). A great correlation was found between relapse and PSA (P = 0.005), PSA density (P = 0.002), Gleason score (P = 0.015), pathological stage (P = 0.001), positive surgical margins (P = 0.021), and invasion of seminal vesicles (P < 0.001) and lymph nodes (P < 0.001). We also found that PSA density was associated with adverse pathological findings. In univariate and multivariate analysis both PSA (P = 0.006) and PSA density (P = 0.009) were found to be significant predictors for relapse in contrast to tumor grade. Conclusion. PSA density is a valuable parameter in estimating the danger of biochemical failure and it may increase predictive potential through the incorporation in preoperative nomograms.