Smaller Prostate Size Predicts High Grade Prostate Cancer at Final Pathology

The Impact of Prostate Volume in Open Radical Prostatectomy: A Single Centre Experience

BACKGROUND

Even the most experienced surgeons experience technical difficulties and challenges when operating on very large prostates, regardless of surgical technique. Our goal was to determine whether preoperative prostate volume has an impact on functional and oncological outcomes after open radical prostatectomy.

MATERIALS AND METHODS

We reviewed the records of 909 patients who underwent open radical prostatectomy by a single surgeon at our institution. Variables were compared across quartile distributions of prostate volume as defined by preoperative transrectal ultrasound examination, including group A with prostate volume < 30ccm 3, group B with prostate volume ≥ 30ccm 3 and < 50ccm 3, group C with prostate volume ≥ 50ccm 3 and < 70ccm 3 and group D with prostate volume ≥ 70ccm3. Factors assessed in this analysis were patient age, preoperative prostate specific antigen (p-PSA), Gleason score, pathological stage, margin status, operative time, cystography leakage, early continence, biochemical recurrence (BCR)-free, and overall-survival (OS). The complication rates were classified using Clavien Dindo classification.

RESULTS

There were no statistically relevant differences between the groups considering preoperative factors such as age, p-PSA, Gleason score, and tumor stadium. Patients with a very large prostate had slightly higher percentage of anastomosis leakage, severe Clavien Dindo complication rates (≥ 3), longer operation time and severe early incontinence (IV°) rates, simultaneously having lower positive margin rates. Nevertheless, the early continence rates, BCR-free and OS were similar regardless of the prostate size.

CONCLUSIONS

open radical prostatectomy for patients with very large prostate is a viable therapy option with slightly higher urinary leakage-, early incontinence- and complication-rates that takes slightly more operation time. However, the functional and oncological outcomes are similar when compared to smaller prostates.

The prognosis of patients with prostate cancer receiving permanent seed implantation stratified by prostate volume: Should we be reluctant to treat with brachytherapy because of a very small prostate (<15 cc)?

PURPOSE

We evaluated the treatment outcomes of different prostate volumes (PVs), <15 cc, 15-20 cc, and > 20 cc, in patients with prostate cancer who underwent permanent seed implantation (PI) ± external beam radiation therapy ± hormone therapy in a national Japanese prospective cohort study (J-POPS).

METHODS AND MATERIALS

Of the 6721 patients in J-POPS from 2005 to 2011, 6652 were included in the analysis population. We categorized the patients into the following three PV groups: <15 cc, 15-20 cc, and > 20 cc. We evaluated the effect of PV on biochemical freedom from failure (bFFF), prostate cancer-specific mortality (PCSM), and all-cause mortality (ACM) using the Phoenix definition and Cox proportional hazard models.

RESULTS

The median follow-up period was 60.0 months. Patients in each PV group was 491 (7.4%), 1118 (16.8%), and 5043 (75.8%), respectively. No difference was observed in bFFF (94.7%, 96.2%, and 95.7%, p = 0.407), PCSM (99.8%, 99.7%, and 99.8%, p = 0.682), and ACM (98.2%, 96.7%, and 97.2%, p = 0.119) at 5 years for each PV group. In univariate and multivariate analyses, PV was not associated with bFFF, PCSM, ACM, or grade 2 toxicity. The percentage of positive biopsies was the single most significant predictor for all treatment outcomes.

CONCLUSIONS

Our results obtained by analyzing a very large Japanese prospective database showed no difference in treatment outcomes according to PV (<15 cc, 15-20 cc, and ˃20 cc). Our study confirmed that PI in small prostates (even < 15 cc) remains an effective treatment option.

Genetic risk assessment of lethal prostate cancer using polygenic risk score and hereditary cancer susceptibility genes

BACKGROUND

The genetic risk of aggressive prostate cancer (PCa) is hard to be assessed due to the lack of aggressiveness-related single-nucleotide polymorphisms (SNPs). Prostate volume (PV) is a potential well-established risk factor for aggressive PCa, we hypothesize that polygenic risk score (PRS) based on benign prostate hyperplasia (BPH) or PV-related SNPs may also predict the risk of aggressive PCa or PCa death.

METHODS

We evaluated a PRS using 21 BPH/PV-associated SNPs, two established PCa risk-related PRS and 10 guideline-recommended hereditary cancer risk genes in the population-based UK Biobank cohort (N = 209,502).

RESULTS

The BPH/PV PRS was significantly inversely associated with the incidence of lethal PCa as well as the natural progress in PCa patients (hazard ratio, HR = 0.92, 95% confidence interval [CI]: 0.87-0.98, P = 0.02; HR = 0.92, 95% CI 0.86-0.98, P = 0.01). Compared with men at the top 25th PRS, PCa patients with bottom 25th PRS would have a 1.41-fold (HR, 95% CI 1.16-1.69, P = 0.001) increased PCa fatal risk and shorter survival time at 0.37 yr (95% CI 0.14-0.61, P = 0.002). In addition, patients with BRCA2 or PALB2 pathogenic mutations would also have a high risk of PCa death (HR = 3.90, 95% CI 2.34-6.51, P = 1.79 × 10-7; HR = 4.29, 95% CI 1.36-13.50, P = 0.01, respectively). However, no interactive but independent effects were detected between this PRS and pathogenic mutations.

CONCLUSIONS

Our findings provide a new measurement of PCa patients' natural disease outcomes via genetic risk ways.

Association of prostate size with capsule thickness and glandular epithelial cell density: The possible clinical implications on prostate cancer development

Objective:

Benign prostatic hyperplasia (BPH) and prostate cancer (PCa) are the two most common urologic diseases in aging males. The negative association between prostate/BPH size and incidence of PCa is well documented in the literature. However, the exact mechanism is not well understood. This study aims to further investigate the possible effect of prostate volume on prostate capsule thickness and glandular cell density in the prostatic peripheral zone (PZ).

Materials and Methods:

A total of 100 patients were selected that had undergone radical prostatectomy with prostate sizes ranging from 20 to 160 mL. Quantitative measurements of capsule thickness and density of epithelial glands within the peripheral zone not affected by cancer were analysed and calculated on histo-anatomical slides using computer-based imaging software. Associations between the different variables were calculated using Spearman correlation with 95% confidence intervals (CIs).

Results:

In the non-cancerous areas of the PZ, prostate volume and average capsule thickness are positively associated ( rs = +0.6526, 95% CI +0.5233 to +0.7526, p < 0.0001), while prostate volume and average glandular epithelial cell density of the PZ are negatively associated ( rs = −0.6011, 95% CI −0.7133 to −0.4589, p < 0.0001). These associations remain consistent on subgroup analysis.

Conclusion:

The findings of this study support the hypothesis that transition zone (TZ) growth in large BPH prostates may cause pressure on the outer PZ, leading to fibrosis and atrophy of the glandular tissue. This may provide a protective effect against PCa, as most PCa originates in the PZ of the prostate.

Level of evidence:

Not applicable

Association of prostate zonal volume with location and aggressiveness of clinically significant prostate cancer: A multiparametric MRI study according to PI-RADS version 2.1

BACKGROUND

The relationship between prostate cancer (PCa) and benign prostatic hyperplasia (BPH) remains unclear. This study aimed to determine whether prostate zonal volume was associated with the location and aggressiveness of PCa.

METHODS

412 PCa patients were retrospectively enrolled. The volumes of the whole prostate (V) and transition zone (Vtz) were calculated by the prolate ellipsoid formula, and volume of the peripheral zone (Vpz) was calculated by their subtraction. Locations of PCa were divided into three categories, including peripheral zone (PZ), transition zone (Vtz) and mixed zone group. The mixed zone group was further divided into PZ-dominated, TZ-dominated and equally distributed subgroups.

RESULTS

The Vtz of Gleason score (GS) 3 + 4 group was the largest, while the Vpz of GS 9 group was the largest. Tumor diameters of the PZ and TZ groups were weakly correlated with their corresponding zonal volume (r = 0.261, p < 0.001; r = 0.311, p = 0.009, respectively). There was no significant difference in the zonal volumes and GS distribution among the location groups. The proportion of tumors with high-grade GS of 8 and 9 was higher in the PZ than that in the TZ group (38.5 vs 24.3%, p = 0.041). For tumors located in the TZ, the V and Vpz of tumors with high-grade GS were larger than those in the low-grade GS of 7 group (p = 0.033 and 0.039, respectively). Among the subgroups of mixed zone group, the Vtz of the TZ-dominated group was larger than those of PZ-dominated and equally distributed groups (p = 0.016 and 0.001, respectively).

CONCLUSION

PCa with high-grade GS is more likely to have a relatively larger Vpz and involve PZ, while PCa with a larger Vtz is more likely to be with low-grade GS, which support the theoretical model that pressure exerted by increasing prostate size/mechanical deformation may inhibit PCa growth from the clinical point. However, the increase in zonal volume might not be the direct cause of tumorigenesis and aggressiveness.

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.

Any Correlation Between Prostate Volume and Incidence of Prostate Cancer: A Review of Reported Data for the Last Thirty Years

PURPOSE

Prostate cancer (PCa) is the most common non-skin cancer in men worldwide and more than 80% of men with PCa also have histo-anatomical findings of benign prostate hyperplasia (BPH). It is well documented that BPH develops in the transition zone (TZ), whereas 80-85% of PCa originates in the peripheral zone (PZ) of the prostate. Possible causal links between both disease entities are controversially discussed in the current literature. Some studies have reported that larger prostates have a decreased incidence of PCa compared to smaller prostates. The purpose of this systematic review is to comprehensively summarize studies analyzing any association between prostate gland volume and incidence of PCa.

METHODS

A thorough literature review was performed between 01.01.1990 through 02.28.2020 using PubMed and applying the "PRISMA" guidelines. Inclusion and exclusion criteria were defined.

RESULTS

Our systematic review found 41 articles reporting an inverse (negative) relationship between prostate gland volume and incidence of prostate cancer. Sample sizes ranged from 114 to 6692 patients in these single institutional and multi-institutional studies. Thirty-nine (95%) of the 41 articles showed a statistically significant inverse relationship. In our search, no study was found showing a positive correlation between BPH size and the incidence of PCa.

CONCLUSION

To our knowledge, this is the first systematic review on the important clinical question of interaction between prostate size and the incidence of PCa. The results are demonstrating an inverse relationship, and therefore reveal strong evidence that large prostates may be protective of PCa when compared to smaller prostates.

Benign prostate hyperplasia as a potential protective factor against prostate cancer: Insights from a magnetic resonance imaging study of compositional characteristics

PURPOSE

The structural relationship between benign prostate hyperplasia (BPH) and prostate cancer (Pca) is controversial. The purpose of our study was to examine the association between quantitative prostate compositional metrics by magnetic resonance imaging (MRI) and Pca.

METHODS

We identified 405 patients who underwent prostate MRI and biopsy and/or prostatectomy from January 2019 to January 2021 at our institution. Segmentation volumetric methods were used to assess central gland (CG) and peripheral zone (PZ) volume. PZ mean thickness and mean apparent diffusion coefficient (ADC), marker of underlying histologic components, were measured. Multivariable logistic regression was performed with outcomes of ≥Grade Group (GG) 2 Pca and for multifocal disease.

RESULTS

On multivariable analysis, higher CG volumes were at lower odds of ≥GG2 disease (n = 227) (OR: 0.97, 95% CI 0.96-0.98, p < 0.0001), taking into account PZ volume (p = 0.18) and thickness (p = 0.70). For every one cc increase in CG volume, there was an approximately 3% decrease in odds of ≥GG2 disease. Similar findings were noted for multifocal disease (n = 180) (OR: 0.97, 95% CI 0.96-0.98, p < 0.0001). Notably, ADC of the normal PZ was not significantly associated with CG volume (p = 0.21) nor a predictor of disease (p = 0.49).

CONCLUSIONS

Increasing central gland volume, driven by BPH, is associated with lower odds of significant Pca, including multifocal disease, while PZ anatomic and histologic surrogate changes were noncontributory. Findings support BPH impediment of global tumor growth predicted by theoretical mechanobiological model. This potential stabilizing factor should be further studied for risk stratification and in consideration for BPH therapy.

Quantitative measurements of prostatic zones by MRI and their dependence on prostate size: possible clinical implications in prostate cancer

AIM

Many studies support an inverse relationship between benign prostate hypertrophy (BPH) size and incidence of prostate cancer (PCa), but the causal link between these conditions is poorly understood. Recent studies suggest that a growing transition zone (TZ) in the prostate may induce pressure on the outer peripheral zone (PZ), leading to atrophy of the glandular tissue where PCa often originates, providing a possible explanation for this interaction. To further investigate this phenomenon, our pilot study uses magnetic resonance imaging (MRI) to examine quantitative zonal changes in a consecutive cohort of prostates.

METHODS

MRI scans of male patients [n = 204, 61.57 ± 13.90 years, average body mass index (BMI) 29.05 kg/m2] with various prostate sizes were analyzed statistically to identify possible associations between prostate parameters, such as total prostate volume (TPV) and peripheral zone thickness (PZT).

RESULTS

TPV and PZT demonstrated a weak, inverse correlation (r = -0.21, p = 0.002). However, when examining the plotted data, the relationship between TPV and PZT was significantly different when the cohort was divided into two groups; lower TPV: ⩽87.5 ml (n = 188, TPV x- = 36.01 ± 18.18 ml), and higher TPV: >87.5 ml (n = 17, TPV x- = 125.69 ± 41.13 ml). Average PZT differed significantly between these groups (z = -3.5554, p = 0.0004).

CONCLUSIONS

PZT was significantly different for patients with lower versus higher TPVs, suggesting that, above a certain point of BPH growth, the PZ is unable to withstand pressure from an expanding TZ, supporting the notion that growing BPH causes compression of the PZ glandular tissue, and, therefore, BPH may be protective against PCa.

Comparison of Transabdominal and Transrectal Ultrasound for Sizing of the Prostate

OBJECTIVE

To compare the accuracy of prostate sizing between pelvic abdominal (PUS) and transrectal (TRUS) ultrasound in a large, diverse cohort of men at our institution. Prostate volume plays a vital role in all types of prostate disease. American Urological Association guidelines (2018) for surgical management of benign prostatic hyperplasia now include consideration of prostate volume measurement prior to surgical intervention. Ultrasound is a quick and radiation-free imaging modality.

METHODS

We performed a single-center, retrospective study of 299 patients with prostate sizing between January 1, 2012 and August 31, 2017. Prostate volume was derived from ellipsoid volume calculation using dimensions measured on ultrasound. PUS and TRUS were compared by calculating the Pearson correlation coefficient and intraclass correlation coefficient, and agreement between modalities assessed using the Bland Altman analysis. This analysis was done for the whole sample population as well as for specific groupings according to body mass index, prostate size, and time between exams.

RESULTS

A total of 236 patients had PUS followed by TRUS and met study inclusion criteria. Median age was 63, median prostate specific antigen value prior to PUS was 7.6 ng/mL, and only 20% were white. Mean volume differences between the two modalities for the data (vol_PUS - vol_TRUS) were (-0.3 ± 1.1) cm³. Bland-Altman analysis showed agreement between PUS and TRUS only for prostates ≤ 30 cm³.

CONCLUSION

For prostates less than 30 cc, we found that PUS is interchangeable with TRUS in estimating prostate volume. However, for larger prostates where size may alter surgical management, we would recommend TRUS or cross-sectional imaging.

Performance evaluation of Cerenkov luminescence imaging: a comparison of 68Ga with 18F

BACKGROUND

Cerenkov Luminescence Imaging (CLI) is an emerging technology for intraoperative margin assessment. Previous research only evaluated radionuclide 18-Fluorine (¹⁸F); however, for future applications in prostate cancer, 68-Gallium (⁶⁸Ga) seems more suitable, given its higher positron energy. Theoretical calculations predict that ⁶⁸Ga should offer a higher signal-to-noise ratio than ¹⁸F; this is the first experimental confirmation. The aim of this study is to investigate the technical performance of CLI by comparing ⁶⁸Ga to ¹⁸F.

RESULTS

The linearity of the system, detection limit, spatial resolution, and uniformity were determined with the LightPath imaging system. All experiments were conducted with clinically relevant activity levels in vitro, using dedicated phantoms. For both radionuclides, a linear relationship between the activity concentration and detected light yield was observed (R² = 0.99). ⁶⁸Ga showed approximately 22 times more detectable Cerenkov signal compared to ¹⁸F. The detectable activity concentration after a 120 s exposure time and 2 × 2 binning of ¹⁸F was 23.7 kBq/mL and 1.2 kBq/mL for ⁶⁸Ga. The spatial resolution was 1.31 mm for ¹⁸F and 1.40 mm for ⁶⁸Ga. The coefficient of variance of the uniformity phantom was 0.07 for the central field of view.

CONCLUSION

⁶⁸Ga was superior over ¹⁸F in terms of light yield and minimal detection limit. However, as could be expected, the resolution was 0.1 mm less for ⁶⁸Ga. Given the clinical constraints of an acquisition time less than 120 s and a spatial resolution < 2 mm, CLI for intraoperative margin assessment using ⁶⁸Ga could be feasible.

Computer simulations suggest that prostate enlargement due to benign prostatic hyperplasia mechanically impedes prostate cancer growth

Prostate cancer and benign prostatic hyperplasia are common genitourinary diseases in aging men. Both pathologies may coexist and share numerous similarities, which have suggested several connections or some interplay between them. However, solid evidence confirming their existence is lacking. Recent studies on extensive series of prostatectomy specimens have shown that tumors originating in larger prostates present favorable pathological features. Hence, large prostates may exert a protective effect against prostate cancer. In this work, we propose a mechanical explanation for this phenomenon. The mechanical stress fields that originate as tumors enlarge have been shown to slow down their dynamics. Benign prostatic hyperplasia contributes to these mechanical stress fields, hence further restraining prostate cancer growth. We derived a tissue-scale, patient-specific mechanically coupled mathematical model to qualitatively investigate the mechanical interaction of prostate cancer and benign prostatic hyperplasia. This model was calibrated by studying the deformation caused by each disease independently. Our simulations show that a history of benign prostatic hyperplasia creates mechanical stress fields in the prostate that impede prostatic tumor growth and limit its invasiveness. The technology presented herein may assist physicians in the clinical management of benign prostate hyperplasia and prostate cancer by predicting pathological outcomes on a tissue-scale, patient-specific basis.

Evaluating the size criterion for PI-RADSv2 category 5 upgrade: is 15 mm the best threshold?

PURPOSE

The purpose of the study was to determine if the ≥ 15 mm threshold currently used to define PIRADS 5 lesions is the optimal size threshold for predicting high likelihood of clinically significant (CS) cancers.

MATERIALS

Three hundred and fifty-eight lesions that may be changed from category 4 to 5 or vice versa on the basis of the size criterion (category 4: n = 288, category 5: n = 70) from 255 patients were evaluated. Kendall's tau-b statistic accounting for inter-lesion correlation, generalized estimation equation logistic regression, and receiver operating curve analysis evaluated two lesion size-metrics (lesion diameter and relative lesion diameter-defined as lesion diameter/prostate volume) for ability to identify CS (Gleason grade ≥ 3 + 4) cancer at targeted biopsy. Optimal cut-points were identified using the Youden index. Analyses were performed for the whole prostate (WP) and zone-specific sub-cohorts of lesions in the peripheral and transition zones (PZ and TZ).

RESULTS

Lesion diameter showed a modest correlation with Gleason grade (WP: τB = 0.21, p < 0.0001; PZ: τB = 0.13, p = 0.02; TZ: τB = 0.32, p = 0.001), and association with CS cancer detection (WP: AUC = 0.63, PZ: AUC = 0.59, TZ: AUC = 0.74). Empirically derived thresholds (WP: 14 mm, PZ: 13 mm, TZ: 16 mm) performed similarly to the current ≥ 15 mm standard. Lesion relative lesion diameter improved identification of CS cancers compared to lesion diameter alone (WP: τB = 0.30, PZ: τB = 0.24, TZ: τB = 0.42, all p < 0.0001). AUC also improved for WP and PZ lesions (WP: AUC = 0.70, PZ: AUC = 0.68, and TZ: AUC = 0.74).

CONCLUSIONS

The current ≥ 15 mm diameter threshold is a reasonable delineator of PI-RADS category 4 and category 5 lesions in the absence of extraprostatic extension to predict CS cancers. Additionally, relative lesion diameter can improve identification of CS cancers and may serve as another option for distinguishing category 4 and 5 lesions.

Perineural invasion status, Gleason score and number of positive cores in biopsy pathology are predictors of positive surgical margin following laparoscopic radical prostatectomy

This study was designed to define possible preoperative predictors of positive surgical margin after laparoscopic radical prostatectomy. We retrospectively analyzed the records of 296 patients with prostate cancer diagnosed by prostate biopsy, and eventually treated with laparoscopic radical prostatectomy. The prognostic impact of age, prostate volume, preoperative prostate-specific antigen, biopsy Gleason score, maximum percentage tumor per core, number of positive cores, biopsy perineural invasion, capsule invasion on imaging, and tumor laterality on surgical margin was assessed. The overall positive surgical margin rate was 29.1%. Gleason score, number of positive cores, perineural invasion, tumor laterality in the biopsy specimen, and prostate volume significantly correlated with risk of positive surgical margin by univariate analysis (P < 0.05). Gleason score (odds ratio [OR] = 2.286, 95% confidence interval [95% CI] = 1.431–3.653, P = 0.001), perineural invasion (OR = 4.961, 95% CI = 2.656–9.270, P < 0.001), and number of positive cores (OR = 4.403, 95% CI = 1.878–10.325, P = 0.001) were independent predictors of positive surgical margin at the multivariable logistic regression analysis. Patients with perineural invasion, higher biopsy Gleason scores and/or a large number of positive cores in biopsy pathology had more possibility of capsule invasion. The positive surgical margin rate in patients with capsule invasion (49.5%) was much higher than that with localized disease (17.8%). In contrast, prostate volume showed a protective effect against positive surgical margin (OR = 0.572, 95% CI = 0.346–0.945, P = 0.029). Gleason score, perineural invasion, and number of positive cores in the biopsy specimen were preoperative independent predictors of positive surgical margin after laparoscopic radical prostatectomy while prostate volume was a protective factor against positive surgical margin.

Sex steroids in the tumor microenvironment and prostate cancer progression

Prostate cancer is uniquely dependent on androgens. Despite years of research on the relationship between androgens and prostate cancer, many questions remain as to the biological effects of androgens and other sex steroids during prostate cancer progression. This article reviews the clinical and basic research on the influence of sex steroids such as androgens, estrogens and progesterone within the prostate tumor microenvironment on the progression of prostate cancer. We review clinical studies to date evaluating serum sex steroids as prognostic biomarkers and discuss their respective biological effects within the prostate tumor microenvironment. We also review the link between genomic alterations and sex steroid levels within prostate tumors. Finally, we highlight the links between sex steroid levels and the function of the immune system within the tumor microenvironment. As the context of treatment of lethal prostate cancer evolves over time, an understanding of this underlying biology remains central to developing optimal treatment approaches.

Mechanism underlying the negative effect of prostate volume on the outcome of extensive transperineal ultrasound-guided template prostate biopsy

Previous studies have indicated a possible relationship between increased prostate volume (PV) and decreased biopsy yield, although the mechanism involved is unclear. We evaluated 1650 patients who underwent template biopsy. The distribution of 993 cancer lesions in 302 prostatectomy specimens was compared with the biopsy data to determine whether each lesion was detected. A receiver operating characteristic (ROC) model was used to determine the diagnostic accuracy of prostate-specific antigen (PSA) and related markers. A medical record number (MRN) was used as a negative control. The cancer positive rate did not change as PSA increased in patients with PV ≥50 mL (P = 0.466), although it increased as PSA increased in patients with PV<50 mL (P = 0.001). The detection rate of cancer lesions decreased as the diameter of the lesions decreased (P = 0.018), but remained unchanged with respect to PV. The diameters of the maximum lesions in patients with PV ≥ 50 mL were significantly smaller than those in patients with PV<50 mL (P = 0.003). In patients with PV ≥ 50 mL, the areas under the ROC curves for PSA-related markers did not differ significantly from that for MRN, although they were significantly greater than that for MRN in patients with PV<50 mL (P < 0.001). These results suggest that an increase in PV is associated with a decrease in size and detectability of cancer lesions resulting in a decrease in biopsy yield. Loss of diagnostic accuracy of markers in patients with PV ≥ 50 mL indicates a decrease in serum levels of PSA produced by prostate cancer, which suggests growth inhibition of the cancer.

The predictive efficacy of hypoechoic lesion in ultrasound for prostate cancer in Chinese people: five-year experience in a moderated 10-core transperineal prostate biopsy procedure

We aim to investigate the predictive efficacy of hypoechoic lesion for prostate cancer at different levels of serum PSA in the procedure of transrectal ultrasound guided 10-core trans-perineal prostate biopsy (TP-PBx). In this study, we collected clinical parameters involving age, digital rectal examination (DRE), PSA, prostate volume, pathological diagnosis, Gleason score, novel Gleason group, and numbers of positive cores from 856 patients who had elevated level of PSA above 4 ng/ml or susceptible nodule of prostate gland in DRE received the moderated 10-core TP-PBx procedure. There were 481 cases (56.2%) with no visible lesion of hypoechoic nodule in transrectal ultrasound (TRUS) and 375 cases (43.8%) with the hypoechoic lesion. The total cancer detection rate is 45.56%. The predictive efficacy of hypoechoic lesion for prostate cancer varies among different PSA intervals. For PSA groups of 0-4, 4-10, 10-20, 20-100, > 100 ng/ml, the Youden's indexes are 0.3483, 0.3506, 0.3941, 0.2795 and 0.8667, respectively. Besides, the visible lesions are inclined to be detected in patients with higher Gleason score. We concluded that the hypoechoic lesions in TRUS could improve the predictive accuracy for diagnosing prostate cancer and present different predictive efficacy in the respective PSA intervals. Besides, it was probably associated with more aggressive clinical significance.

Integration of MRI to clinical nomogram for predicting pathological stage before radical prostatectomy

BACKGROUND

Debate persists regarding whether MRI should be used routinely for preoperative evaluation of prostate cancer.

OBJECTIVE

The aim is to assess the role of prostatic magnetic resonance imaging (MRI) and other preoperative data in extra-prostatic extension (EPE) evaluation.

PATIENTS AND METHODS

From 2000 to 2013, 1743 patients operated for radical prostatectomy had a preoperative MRI. Age, clinical stage with digital rectal exam (DRE), PSA, prostate weight, biopsy, MRI and pathological findings of the surgical specimen were noticed. A multiparametric score of the variables independently associated with EPE was built with or without MRI on a random sample test population and internally validated.

RESULTS

With mean age of 62.9 years and mean PSA of 9.6 ng/ml, the population was distributed as follows: 1424 DRE T1, 254 T2, 32 T3; on biopsy 990 Gleason score = 6 and 717 ≥ 7; on MRI 1322 iT2, 290 iT3A and 131 iT3B; on prostatectomy 15 pT0, 998 pT2, 548 pT3A, 181 pT3B and 1 pT4A. In multivariate analysis, DRE, PSA, Gleason score, prostate weight and MRI were independently associated with EPE and integrated in a score with an area under curve (AUC) of 0.74 [95% CI 0.71-0.77] (0.72 without MRI, p < 0.01) a positive predictive value of 61% and a negative predictive value of 74%, internally validated. The Hosmer-Lemeshow goodness-of-fit test showed good accuracy (p = 0.77).

CONCLUSIONS

Integration of MRI with clinical data for predicting pathological stage before radical prostatectomy permits to exclude accurately EPE in 74% of cases.

Number of positive preoperative biopsy cores is a predictor of positive surgical margins (PSM) in small prostates after robot-assisted radical prostatectomy (RARP)

OBJECTIVE

To determine the impact of prostate size on positive surgical margin (PSM) rates after robot-assisted radical prostatectomy (RARP) and the preoperative factors associated with PSM.

PATIENTS AND METHODS

In all, 1229 men underwent RARP by a single surgeon, from 2005 to August of 2013. Excluded were patients who had transurethral resection of the prostate, neoadjuvant therapy, clinically advanced cancer, and the first 200 performed cases (to reduce the effect of learning curve). Included were 815 patients who were then divided into three prostate size groups: <31 g (group 1), 31-45 g (group 2), >45 g (group 3). Multivariate analysis determined predictors of PSM and biochemical recurrence (BCR).

RESULTS

Console time and blood loss increased with increasing prostate size. There were more high-grade tumours in group 1 (group 1 vs group 2 and group 3, 33.9% vs 25.1% and 25.6%, P = 0.003 and P = 0.005). PSM rates were higher in prostates of <45 g with preoperative PSA levels of >20 ng/dL, Gleason score ≥7, T3 tumour, and ≥3 positive biopsy cores. In group 1, preoperative stage T3 [odds ratio (OR) 3.94, P = 0.020] and ≥3 positive biopsy cores (OR 2.52, P = 0.043) were predictive of PSM, while a PSA level of >20 ng/dL predicted the occurrence of BCR (OR 5.34, P = 0.021). No preoperative factors predicted PSM or BCR for groups 2 and 3.

CONCLUSION

A preoperative biopsy with ≥3 positive cores in men with small prostates predicts PSM after RARP. In small prostates with PSM, a PSA level of >20 ng/dL is a predictor of BCR. These factors should guide the choice of therapy and indicate the need for closer postoperative follow-up.

Prostate size and adverse pathologic features in men undergoing radical prostatectomy

OBJECTIVE

To investigate the relationship between prostate volume measured from preoperative imaging and adverse pathologic features at the time of radical prostatectomy and evaluate the potential effect of clinical stage on such relationship.

METHODS

In 1756 men who underwent preoperative magnetic resonance imaging and radical prostatectomy from 2000 to 2010, we examined associations of magnetic resonance imaging-measured prostate volume with pathologic outcomes using univariate logistic regression and with postoperative biochemical recurrence using Cox proportional hazards models. We also analyzed the effects of clinical stage on the relationship between prostate volume and adverse pathologic features via interaction analyses.

RESULTS

In univariate analyses, smaller prostate volume was significantly associated with high pathologic Gleason score (P<.0001), extracapsular extension (P<.0001), and positive surgical margins (P=.032). No significant interaction between clinical stage and prostate volume was observed in predicting adverse pathologic features (all P>.05). The association between prostate volume and recurrence was significant in a multivariable analysis adjusting for postoperative variables (P=.031) but missed statistical significance in the preoperative model (P=.053). Addition of prostate volume did not change C-Indices (0.78 and 0.83) of either model.

CONCLUSION

Although prostate size did not enhance the prediction of recurrence, it is associated with aggressiveness of prostate cancer. There is no evidence that this association differs depending on clinical stage. Prospective studies are warranted assessing the effect of initial method of detection on the relationship between volume and outcome.

Are hypoechoic lesions on transrectal ultrasonography a marker for clinically significant prostate cancer?

Purpose

To investigate the relationship of transrectal ultrasound (TRUS) findings with the pathological characteristics of prostate cancer (PCa).

Materials and Methods

The study was conducted retrospectively by analyzing the data for 970 patients who underwent prostate biopsies. Gleason scores and other clinical variables were compared between PCa patients with and without hypoechoic lesions on TRUS.

Results

Of the 970 patients, PCa was diagnosed in 291 (30%). Of these, high-grade PCa (Gleason score of 7 or more) was diagnosed in 190 (65%). The cancer detection rate was higher in patients with hypoechoic lesions (43.9%) than in those without hypoechoic lesions (21.4%, p<0.001). High-grade PCa was detected more often in patients with hypoechoic lesions than in those without hypoechoic lesions (p<0.001). Independent predictors for high-grade PCa by logistic regression analysis included hypoechoic lesions on TRUS and abnormal digital rectal examination findings.

Conclusions

Patients with PCa who had hypoechoic lesions on TRUS had more aggressive pathological disease than did those without lesions. Therefore, hypoechoic lesions on TRUS could be a marker for clinically significant PCa.

The influence of prostate volume on outcome after high-dose-rate brachytherapy alone for localized prostate cancer

OBJECTIVE

To determine whether late genitourinary toxicity, biochemical control of prostate cancer, and dosimetric parameters in patients with large prostate glands is different from those variables in men with smaller glands after treatment with high-dose-rate brachytherapy alone (HDR-BT).

METHODS

From November 2003 to July 2009, 164 patients with locally advanced prostate carcinoma were sequentially enrolled and treated with 34 or 36 Gy in 4 fractions and 31.5 Gy in 3 fractions of (192)Ir HDR-BT alone. The median follow-up time was 71 months. Gland size was not considered in the selection criteria for this study. Estimates of freedom from biochemical relapse (FFbR) and late morbidity, stratified by median clinical target volume (CTV), were obtained, and differences were compared.

RESULTS

The median CTV volume was 60 cc (range, 15-208 cc). Dose-volume parameters D90 and V100 (ie, minimum dose to 90% of the prostate volume and volume receiving 100% of the prescribed isodose) achieved in patients with glands ≥60 cc were not significantly different from those with glands <60 cc (P≥.2). Nonetheless, biochemical control in patients with larger CTV was significantly higher (91% vs 78% at 6 years; P=.004). In univariate and multivariate analysis, CTV was a significant predictor for risk of biochemical relapse. This was not at the expense of an increase in either moderate (P=.6) or severe (P=.3) late genitourinary toxicity. The use of hormonal therapy was 17% lower in the large gland group (P=.01).

CONCLUSIONS

Prostate gland size does not affect dosimetric parameters in HDR-BT assessed by D90 and V100. In patients with larger glands, a significantly higher biochemical control of disease was observed, with no difference in late toxicity. This improvement cannot be attributed to differences in dosimetry. Gland size should not be considered in the selection of patients for HDR-BT.

Risk of Gleason grade inaccuracies in prostate cancer patients eligible for active surveillance

OBJECTIVE

To evaluate increases in Gleason grade because of sample bias after immediate rebiopsy or prostatectomy for patients considered active surveillance candidates by institutional protocol.

METHODS

A contemporary medical literature search was performed using PubMed. Series were included if the patients had no more than Gleason 6 prostate cancer score on initial biopsy and underwent a prostatectomy or rebiopsy within 6 months. Patient sets using neoadjuvant hormonal therapy or focal prostate treatment were excluded.

RESULTS

In patients who would have fallen into the D'Amico low-risk prostate cancer group, 42% were found to have an increase in the Gleason score: 32% resulting in grade ≥ 7 disease and 3% grade ≥ 8. For series that limited patients to the Epstein criteria, Gleason upgrades were 34%, 29%, and 2%, respectively. Of the 139 patients whose second tissue specimens were from a rebiopsy, 17% were found to have grade ≥ 7 disease, whereas only 1 patient had grade ≥ 8. There were no consistent multivariate analysis variables among the series to predict for an increase in Gleason score.

CONCLUSION

More than one third of the patients were found to have been undergraded based on their initial prostate biopsy. Therefore, 1 biopsy alone may not be sufficient to offer active surveillance as an option. Further exploration is necessary to better ensure low-risk disease before active surveillance.

Androgen deprivation therapy in combination with radiotherapy for high-risk clinically localized prostate cancer

Androgen deprivation therapy (ADT) has remained the main therapeutic option for patients with advanced prostate cancer (PCa) for about 70 years. Several reports and our findings revealed that aggressive PCa can occur under a low dihydrotestosterone (DHT) level environment where the PCa of a low malignancy with high DHT dependency cannot easily occur. Low DHT levels in the prostate with aggressive PCa are probably sufficient to propagate the growth of the tumor, and the prostate with aggressive PCa can produce androgens from the adrenal precursors more autonomously than that with non-aggressive PCa does under the low testosterone environment with testicular suppression. In patients treated with ADT the pituitary-adrenal axis mediated by adrenocorticotropic hormone has a central role in the regulation of androgen synthesis. Several experimental studies have confirmed the potential benefits from the combination of ADT with radiotherapy (RT). A combination of external RT with short-term ADT is recommended based on the results of phase III randomized trials. In contrast, the combination of RT plus 6 months of ADT provides inferior survival as compared with RT plus 3 years of ADT in the treatment of locally advanced PCa. Notably, randomized trials included patients with diverse risk groups treated with older RT modalities, a variety of ADT scheduling and duration and, importantly, suboptimal RT doses. The use of ADT with higher doses of RT or newer RT modalities has to be properly assessed.

[Relation between prostate gland volume and some histological markers of malignancy]

OBJECTIVES

The relationship between the total volume of the prostate gland or its weight after radical prostatectomy and the histological markers of malignancy in cases of prostate cancer is a controversial subject. We have analyzed 100 consecutive radical prostatectomy specimens in order to determine the relationship between volume or weight of the prostate gland and the biological aggressiveness of the tumor process by different histological markers.

MATERIAL AND METHODS

One hundred consecutive radical prostatectomy specimens in patients who had not received pre-operative hormone treatment were retrospectively reviewed. These surgical samples were processed according to a standardized protocol. In a subsequent evaluation, the following were studied with greater detail: Gleason grade, tumor volume, multimodality, neural or vascular invasion, put stage, and presence of PIN foci. The histological findings were compared with the prostate gland weight using Windows SPAS, 13.0 statistical package with a significance value of p<0.05. According to the prostate gland weight, three groups were established: <40 g (33%), 40 - 90 g (61%), and >90 g (6%).

RESULTS

A statistically significant association (p=0.001) was found between the prostate gland weight and tumor volume since 15 of the 33 glands with weight under 40 g accounted for more than 50% of the glands affected by tumor compared to none of the 6 patients with total weight over 90 g. A significant relationship was also found between the multimodality and weight. (P=0.03), so that 24 of the 33 glands under 40 g had bilateral multimodality compared to only 1 out of the 6 glands over 90 g. The neural invasion, number of PIN foci and the highest combined Gleason grade were frequent in low volume prostates, but the difference did not reach statistical significance.

CONCLUSIONS

Our study indicates that large volume prostate glands have tumors with lower malignancy (tumor volume, bilateralism). This finding justifies the adequacy of using total volume of the prostate gland for diagnostic decision (indication of prostatic biopsy and their repetition) and the prognostic determination.

Prostate size as a predictor of Gleason score upgrading in patients with low risk prostate cancer

PURPOSE

Gleason score upgrading between biopsy and surgical pathological specimens occurs in 30% to 50% of cases. Predicting upgrading in men with low risk prostate cancer may be particularly important since high grade disease influences management decisions and impacts prognosis. We determined whether prostate size predicts Gleason score upgrading in patients with low risk prostate cancer.

MATERIALS AND METHODS

A total of 1,251 consecutive patients with D'Amico low risk disease and complete data available underwent radical prostatectomy at our institution between January 2000 and June 2008. Patients were divided into 3 groups by pathological Gleason score, including no, minor (3 + 4 = 7) and major (4 + 3 = 7 or greater) Gleason score upgrading. We developed bivariate and multivariate models to determine whether prostate size was an important predictor of upgrading while controlling for clinical and biopsy characteristics.

RESULTS

Of 1,251 cases 387 (31.0%) were upgraded, including 324 (26%) and 63 (5%) with minor and major upgrading, respectively. As expected, Gleason score upgrading was associated with worse pathological and cancer control outcomes. On multivariate analysis smaller prostate size was an independent predictor of any and major upgrading (OR 0.58, 95% CI 0.48-0.69, p <0.01 and OR 0.67, 95% CI 0.49-0.96, p = 0.03, respectively). Men with prostate volume at the 25th percentile (36 cm(3)) were 50% more likely to experience upgrading than men with prostate volume at the 75th percentile (58 cm(3)).

CONCLUSIONS

Of low risk cases 31% were upgraded at final pathology. Smaller prostate size predicts Gleason score upgrading in men with clinically low risk prostate cancer. This is important information when counseling patients on management and prognosis.

[Prostate cancer: Gleason scores correlation between biopsies and surgical gross specimen]

The Gleason score is a histopronostic criterion which gives an appraisal of prostate cancer aggressiveness and outcomes.

OBJECTIVE

The goal of this retrospective study was to assess the relationship between Gleason scores appreciated on biopsies and later on surgical gross specimen.

RESULTS

During the period of the study, 123 patients benefit of a histological diagnosis of prostate cancer recording Gleason score on biopsies and postsurgical intervention on gross specimen. After analysis of biopsies and for gross specimen the reported Gleason scores vary from 3 to 9 and the mean was 5.9 and 6.1 respectively. There was a good concordance between the Gleason scores for biopsies and gross specimen in about 32.5% of cases. We noted a difference of score of one point in 37.3% of patients and a difference of two points and more in 30% of cases. In 28.4% the Gleason scores were overestimated while in 39% they were underestimated. More than half of the patients' cohort was classified in the group of histologically moderately differentiated cancer. When grouping the patients according to the histological types well, moderately or less differentiated cancers, the Gleason scores concordance for biopsies and for gross specimen change from 32.5% up to 74.8%. The correlation can be considered good for the less differentiated cancers.

CONCLUSION

Gleason score showed some limits in the appreciation of the prediction. The grouping of patients according to the three distinct histological differentiation groups increases the concordance between the score of Gleason on biopsy specimen and gross specimen but it seems less powerful for cancers well and moderately differentiated cancers.