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

The prognostic value of mean apparent diffusion coefficient measured with diffusion-weighted magnetic resonance image in patients with prostate cancer treated with definitive radiotherapy

PURPOSE

To assess the correlation between initial tumor apparent diffusion coefficient (ADC) values and clinicopathological parameters in prostate cancer (PCa) patients treated with definitive radiotherapy (RT). Additionally, the prognostic factors for freedom from biochemical failure (FFBF) and progression-free survival (PFS) in this patient cohort were analyzed.

MATERIALS AND METHODS

The clinical data of 503 patients with biopsy-confirmed PCa were evaluated retrospectively. All patients had clearly evident tumors on diffusion-weighted magnetic resonance imaging (DW-MRI) for ADC values. Univariable and multivariable analyses were used to determine prognostic factors for FFBF and PFS.

RESULTS

The median follow-up was 72.9 months. The 5-year FFBF and PFS rates were 93.2% and 86.2%, respectively. Significantly lower ADC values were found in patients with a high PSA level; advanced clinical stage; higher ISUP score, and higher risk group than their counterparts. Receiver operating characteristic (ROC) curve analysis revealed an ADC cut-off value of 0.737 × 10^-3 mm²/sec for tumor recurrence. Patients who progressed had a lower mean ADC value than those who did not (0.712±0.158 vs. 1.365±0.227 × 10^-3 mm²/sec; p<0.001). There was a significant difference in 5-year FFBF (96.3% vs. 90%; p<0.001) and PFSrates (83.8% vs. 73.5%; p=0.002) between patients with higher and lower mean ADC values. The FFBF and PFS were found to be correlated with tumor ADC value and ISUP grades in multivariable analysis. Additionally, older age was found to be a significant predictor of worse PFS.

CONCLUSIONS

Lower ADC values were found in patients with high-risk characteristics such as a high serum PSA level, stage or grade of tumor, or high-risk disease, implying that ADC values could be used to predict prognosis. Lower ADC values and higher ISUP grades were associated with an increased risk of BF and progression, implying that treatment intensification may be required in these patients.

Active Surveillance Strategies for Low-Grade Prostate Cancer: Comparative Benefits and Cost-effectiveness

Background Active surveillance (AS) is the recommended treatment option for low-risk prostate cancer (PC). Surveillance varies in MRI, frequency of follow-up, and the Prostate Imaging Reporting and Data System (PI-RADS) score that would repeat biopsy. Purpose To compare the effectiveness and cost-effectiveness of AS strategies for low-risk PC with versus without MRI. Materials and Methods This study developed a mathematical model to evaluate the cost-effectiveness of surveillance strategies in a simulation of men with a diagnosis of low-risk PC. The following strategies were compared: watchful waiting, prostate-specific antigen (PSA) and annual biopsy without MRI, and PSA testing and MRI with varied PI-RADS thresholds for biopsy. MRI strategies differed regarding scheduling and use of PI-RADS score of at least 3, or a PI-RADS score of at least 4 to indicate the need for biopsy. Life-years, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios were calculated by using microsimulation. Sensitivity analysis was used to assess the impact of varying parameter values on results. Results For the base case of 60-year-old men, all strategies incorporating prostate MRI extended QALYs and life-years compared with watchful waiting and non-MRI strategies. Annual MRI strategies yielded 16.19 QALYs, annual biopsy with no MRI yielded 16.14 QALYs, and watchful waiting yielded 15.94 QALYs. Annual MRI with PI-RADS score of at least 3 or of at least 4 as the biopsy threshold and annual MRI with biopsy even after MRI with negative findings offered similar QALYs and the same unadjusted life expectancy: 23.05 life-years. However, a PI-RADS score of at least 4 yielded 42% fewer lifetime biopsies. With a cost-effectiveness threshold of $100 000 per QALY, annual MRI with biopsy for lesions with PI-RADS scores of 4 or greater was most cost-effective (incremental cost-effectiveness ratio, $67 221 per QALY). Age, treatment type, risk of initial grade misclassification, and quality-of-life impact of procedural complications affected results. Conclusion The use of active surveillance (AS) with biopsy decisions guided by findings from annual MRI reduces the number of biopsies while preserving life expectancy and quality of life. Biopsy in lesions with PI-RADS scores of 4 or greater is likely the most cost-effective AS strategy for men with low-risk prostate cancer who are younger than 70 years. © RSNA, 2021 Online supplemental material is available for this article. An earlier incorrect version appeared online. This article was corrected on July 13, 2021.

Phase I dose escalation trial of stereotactic radiotherapy prior to robotic prostatectomy in high risk prostate cancer

Background

The aim of the study was to investigate the safety of combining preoperative stereotactic body radiotherapy (SBRT) with robotic radical prostatectomy (RP) for high risk prostate cancer (HRCaP). Many patients with HRCaP will require adjuvant or salvage radiotherapy after RP. The addition of preoperative SBRT before RP may spare patients from subsequent prolonged courses of RT.

Materials and methods

Eligible patients had NCC N HRCaP and received a total of 25 Gy or 30 Gy in five daily fractions of SBRT to the prostate and seminal vesicles followed by robotic RP with pelvic lymphadenectomy 31-45 days later. The primary endpoint was prevalence of acute genitourinary (GU) and gastrointestinal (GI) toxicity. Secondary endpoints were patient-reported quality of life (QOL) and biochemical recurrence (BcR).

Results

Three patients received preoperative SBRT to 25 Gy and four received 30 Gy. Median follow-up was 18 months. Highest toxicity was grade 2 and 3 in six (85.7%) and one (14.3%) patients, respectively. All patients developed grade 2 erectile dysfunction and 4 of 7 (57%) developed grade 2 urinary incontinence (UI) within a month after surgery. One patient developed acute grade 3 UI, but there was no grade ≥ 4 toxicity. One patient experienced acute grade 2 hemorrhoidal bleeding. On QOL, acute GU complaints were common and peaked within 3 months. Bowel symptoms were mild. Two patients with pN+ experienced BcR.

Conclusions

Preoperative SBRT before robotic RP in HRCaP is feasible and safe. The severity of acute GU toxicity with preoperative SBRT may be worse than RP alone, while bowel toxicity was mild.

Suboptimal Prediction of Clinically Significant Prostate Cancer in Radical Prostatectomy Specimens by mpMRI-Targeted Biopsy

OBJECTIVE

To investigate the correlation of multiparametric magnetic resonance imaging targeted (TBx) and/or systematic prostate biopsy (SBx) in predicting the presence of clinically significant (cs) prostate cancer (PCa) in radical prostatectomy (RP) specimens. Concordance of mpMRI and RP specimen lesions was also investigated in terms of tumor localization and histopathological features.

METHODS

A total of 70 male patients with PCa and treated with robot-assisted RP were included in this study between January 2016 and December 2019. All patients underwent mpMRI-TBx and concomitant SBx. Suspicious lesions on mpMRI were scored according to Prostate Imaging-Reporting and Data System version 2 (PI-RADS) criteria. TBx was performed for all suspicious lesions with a PI-RADS score ≥3.

RESULTS

The median age was 67 (43-77) years. Presence of csPCa in prostatectomy specimens was missed by TBx and SBx specimens in 25.4% and 19.4% of the cases, respectively (P<.001, for each). Combination of both biopsy (CBx) results improved detection by missing only 4.5% of csPCa (P = .250). International Society of Urologic Pathology grade group concordance with RP specimens were 50%, 54.3% and 67.1% for SBx, TBx, and CBx, respectively. There was a statistically significant correlation in terms of tumor localization and histopathological features between prostatectomy specimens and the first 3 lesions, particularly for the index lesions.

CONCLUSIONS

CBx improved detection rate of csPCa. We propose TBx of 3 lesions with highest PI-RADS score(s) and a combination with SBx for the highest correlation with prostatectomy histopathology.

Race, tumor location, and disease progression among low-risk prostate cancer patients

Background

The relationship between race, prostate tumor location, and BCR‐free survival is inconclusive. This study examined the independent and joint roles of patient race and tumor location on biochemical recurrence‐free (BCR) survival.

Methods

A retrospective cohort study was conducted among men with newly diagnosed, biopsy‐confirmed, NCCN‐defined low risk CaP who underwent radical prostatectomy (RP) at the Walter Reed National Military Medical Center from 1996 to 2008. BCR‐free survival was modeled using Kaplan‐Meier estimation curves and multivariable Cox proportional hazards (PH) analyses.

Results

There were 539 eligible patients with low‐risk CaP (25% African American, AA; 75% Caucasian American, CA). Median age at CaP diagnosis and post‐RP follow‐up time was 59.2 and 8.1 years, respectively. Kaplan‐Meier analyses showed no significant association between race (P = .52) or predominant tumor location (P = .98) on BCR‐free survival. In Cox PH multivariable analysis, neither race (HR = 1.18; 95% CI = 0.68‐2.02; P = .56) nor predominant tumor location (HR = 1.13; 95% CI = 0.59‐2.15; P = .71) was an independent predictor of BCR‐free survival.

Conclusions

Neither race nor predominant tumor location was associated with adverse oncologic outcome.

Use of MRI-Guided Biopsy for Selection and Follow-up of Men Undergoing Hemi-gland Cryoablation of Prostate Cancer

OBJECTIVE

To investigate safety, efficacy, and quality of life impact of hemi-gland cryotherapy for clinically-significant prostate cancer (CaP), when patient selection and follow-up includes MRI-guided biopsy.

METHODS

Twenty-nine men with unilateral CaP (all clinically significant with prostate volume <60 cc) were enrolled in a prospective observational trial of hemi-gland cryotherapy. Mean patient age was 68.7 years. Median prostate-specific antigen (PSA) was 6.6 ng/mL. MRI-guided biopsy (3T-MRI, Artemis US fusion) was used for diagnosis and repeated at 6-month follow-up in all men. Treatment was under general anesthesia using the BTG/Galil system. Validated questionnaires were used to determine effects of treatment on urinary and sexual function and quality of life.

RESULTS

Cryotherapy was completed satisfactorily in all 29 cases in <60 minutes with no intraoperative complications. Significant decreases in PSA (median decrease 5.6 ng/mL) and PSA density (median decrease 0.14 ng/mL/cc) were observed (P < .01). At 6 months, 23 patients (79%) demonstrated no residual cancer on follow-up MRI-guided biopsy of the treated side. Three patients (10%) revealed micro-residual disease. Three patients (10%) had residual cancer and underwent further treatment. Ipsilateral MRI lesions were present before treatment in 26 patients and after treatment in only 2, reflecting the gross ablative effect; however, MRI showed disappearance of lesions in 4 patients with residual tumor on biopsy. The single complication was 1 case of transient urinary retention; 85% of men who were sexually active continued without change after treatment. Voiding function was unchanged.

CONCLUSION

Hemi-gland cryoablation for clinically-significant CaP is well-tolerated, and when patients are selected and followed by MRI/US fusion biopsy, cancer control appears promising at 6 months.

Diagnostic performance of 68Gallium-PSMA-11 PET/CT to detect significant prostate cancer and comparison with 18FEC PET/CT

Background

Radiolabeled prostate-specific membrane antigen (PSMA) has proven to be a highly accurate method to detect recurrence and metastases of prostate cancer, but only sparse data is available about its performance in the diagnosis of clinically significant primary prostate cancer.

Methods

We compared ⁶⁸Ga-PSMA-11 PET/CT in 25 patients with ¹⁸FEC PET/CT in 40 patients with suspected prostate carcinoma based on an increased PSA level.The PET/CT results were compared with the histopathologic Gleason Score (GS) of biopsies.

Results

The ⁶⁸Ga-PSMA-11 PET/CT revealed highly suspect prostatic lesions (maximum standardized uptake value/SUV_max >2.5) in 21/25 patients (84%), associated with GS≥6 (low-grade/high-grade carcinoma). Two histopathologic non-malignancy-relevant cases (GS<6) had PSMA-SUV_max ≤2.5; all histopathologic high-grade cases (GS≥7b) showed PSMA-SUV_max >12.0 which further increased with rising GS. There were 2 false positives and no false negative findings for high-grade prostate cancer using a cut off-level for SUV_max of 2.5.In contrast, the ¹⁸FEC PET/CT showed suspected malignant lesions in 38/40 patients (95%), which included 3 lesions with GS<6. The mean SUV_max values did not differ with different GS. There were 11 false positives and 1 false negative for detection of high-grade prostate cancer (cut off 2.5).By means of ROC analysis a SUV_max of 5.4 was found to be an optimal cut off-level to distinguish between low- and high-grade carcinoma in ⁶⁸Ga-PSMA-11 PET/CT (AUC=0.9692; 95% CI 0.9086;1.0000;SD(AUC)=0.0309)). Choosing a cut off-level of SUV_max5.4, ⁶⁸Ga-PSMA-11 PET/CT was able to distinguish between GS ≤7a/≥7b with a sensitivity of 84%, a specificity of 100%, a negative predictive value (NPV) of 67%, and an efficiency of 88% (p<0.001).The ROC analysis revealed a SUV_max 6.5 as an optimal cut off-level to distinguish between low- and high-grade carcinoma in ¹⁸FEC PET/CT (AUC=0.7470; 95% CI 0.5919;0.9020;SD(AUC)=0.0791) with a sensitivity of 61% and a specificity of 92%; but the efficiency was only 70% and the NPV 50% (p=0.01).

Conclusion

⁶⁸Ga-PSMA-11 PET/CT guided biopsy of the prostate increases diagnostic precision and is likely to help to reduce overtreatment of low-grade malignant disease as well as detect the foci of the highest Gleason pattern. Both methods (⁶⁸Ga-PSMA-11,¹⁸FEC) were suitable to detect primary prostate cancer, but the excellent image quality, the higher specificity and the good correlation of positive scans with GS are advantages of ⁶⁸Ga-PSMA-11.

Low serum total testosterone level as a predictor of upstaging and upgrading in low-risk prostate cancer patients meeting the inclusion criteria for active surveillance

Active surveillance (AS) is currently a widely accepted treatment option for men with clinically localized prostate cancer (PCa). Several reports have highlighted the association of low serum testosterone levels with high-grade, high-stage PCa. However, the impact of serum testosterone as a predictor of progression in men with low-risk PCa has been little assessed.

In this study, we evaluated the association of circulating testosterone concentrations with a staging/grading reclassification in a cohort of low-risk PCa patients meeting the inclusion criteria for the AS protocol but opting for radical prostatectomy.

Radical prostatectomy (RP) was performed in 338 patients, eligible for AS according to the following criteria: clinical stage T2a or less, PSA<10ng/ml, two or fewer cancer cores, Gleason score (GS)=6 and PSA density<0.2 ng/mL/cc. Reclassification was defined as upstaging (stage>pT2) and upgrading (GS=7; primary Gleason pattern 4) disease. Unfavorable disease was defined as the occurrence of pathological stage>pT2 and predominant Gleason score 4. Total testosterone was measured before surgery.

Low serum testosterone levels (<300 ng/dL) were significantly associated with upgrading, upstaging, unfavorable disease and positive surgical margins. The addition of testosterone to a base model, including age, PSA, PSA density, clinical stage and positive cancer involvement in cores, showed a significant independent influence of this variable on upstaging, upgrading and unfavorable disease.

In conclusion, our results support the idea that total testosterone should be a selection criterion for inclusion of low-risk PCa patients in AS programs and suggest that testosterone level less than 300 ng/dL should be considered a discouraging factor when a close AS program is considered as treatment option

Active Surveillance Versus Watchful Waiting for Localized Prostate Cancer: A Model to Inform Decisions

BACKGROUND

An increasing proportion of prostate cancer is being managed conservatively. However, there are no randomized trials or consensus regarding the optimal follow-up strategy.

OBJECTIVE

To compare life expectancy and quality of life between watchful waiting (WW) versus different strategies of active surveillance (AS).

DESIGN, SETTING, AND PARTICIPANTS

A Markov model was created for US men starting at age 50, diagnosed with localized prostate cancer who chose conservative management by WW or AS using different testing protocols (prostate-specific antigen every 3-6 mo, biopsy every 1-5 yr, or magnetic resonance imaging based). Transition probabilities and utilities were obtained from the literature.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Primary outcomes were life years and quality-adjusted life years (QALYs). Secondary outcomes include radical treatment, metastasis, and prostate cancer death.

RESULTS AND LIMITATIONS

All AS strategies yielded more life years compared with WW. Lifetime risks of prostate cancer death and metastasis were, respectively, 5.42% and 6.40% with AS versus 8.72% and 10.30% with WW. AS yielded more QALYs than WW except in cohorts age >65 yr at diagnosis, or when treatment-related complications were long term. The preferred follow-up strategy was also sensitive to whether people value short-term over long-term benefits (time preference). Depending on the AS protocol, 30-41% underwent radical treatment within 10 yr. Extending the surveillance biopsy interval from 1 to 5 yr reduced life years slightly, with a 0.26 difference in QALYs.

CONCLUSIONS

AS extends life more than WW, particularly for men with higher-risk features, but this is partly offset by the decrement in quality of life since many men eventually receive treatment.

PATIENT SUMMARY

More intensive active surveillance protocols extend life more than watchful waiting, but this is partly offset by decrements in quality of life from subsequent treatment.

[Diagnostic significance of multiparametric MRI combined with US-fusion guided biopsy of the prostate in patients with increased PSA levels and negative standard biopsy results to detect significant prostate cancer - Correlation with the Gleason score. Korrelation mit dem Gleason Score]

AIMS

To increase diagnostic precision and to reduce overtreatment of low-risk malignant disease, multiparametric MRI (mpMRI) combined with ultrasound (US) fusion guided biopsy of the prostate were performed.

METHODS

In 99 male patients with increased PSA plasma levels and previous negative standard biopsy procedures, mpMRI was carried out followed by US fusion guided perineal biopsy. PI-RADS-Data (PS) of mpMRI and histopathological Gleason score (GS) were categorized and statistically compared.

RESULTS

Lesions in 72/99 (73 %) of patients were determined to be suspect of malignancy, based on a PS 4 or 5. In 33/99 (33 %) of patients, malignancy could not be confirmed by histopathology. With regard to the remaining 66 patients with previous negative biopsy results, 42 (64 %) were diagnosed with a low-grade carcinoma (GS 6, 7a) and 24 (36 %) with a high-grade carcinoma (GS ≥ 7b). The proportion of corresponding results in mpMRI (PS 4-5) when a high-grade carcinoma had been detected, was 21/24 (88 %), which related to a sensitivity of 88 % and a negative predictive value (NPV) of 85 % (p = 0,002). In addition, 35 of 42 patients (83%), graded PS 4-5 in mpMRI, were diagnosed with low-grade carcinoma-positive (p < 0,001). Sensitivity to differentiation between low- and high-grade carcinomas (GS ≤ 7a vs. ≥ 7b) by means of PS was 88 % with a NPV of 70 % (p = 0,74).

CONCLUSION

Our results suggest that mpMRI combined with US-fusion guided biopsy is able to detect considerably higher rates of clinically relevant prostate malignancies compared to conventional diagnostic procedures. However, no statistical significance could be shown regarding the differentiation between high- and low-grade carcinomas. It is hoped that the hybrid methods PSMA-PET/CT or PSMA-PET/MRI will lead to the next optimization step in the differentiation between high- and low-grade carcinomas which so far has been unsatisfactory.

Relationship between Gleason score and apparent diffusion coefficients of diffusion-weighted magnetic resonance imaging in prostate cancer patients

INTRODUCTION

We assessed the correlation between the apparent diffusion coefficient (ADC) and pathological Gleason score (GS) of prostate cancer patients.

METHODS

A total of 125 patients who underwent multiparametric magnetic resonance imaging before radical prostatectomy for prostate cancer were included in this study. ADC values were compared with different GS. We used receiver operating characteristic analysis and determined the ADC cutoff value to differentiate tumours with a GS of 6 from those with a GS ≥7.

RESULTS

We identified 34 patients (27.2%) with a GS of 6; 33 patients (26.4%) with a GS of 7; 22 patients (17.6%) with a GS of 8; and 36 patients (28.8%) with a GS of ≥9. The mean ADC value for disease with a GS of 6 was 0.914 ± 0.161 ×10^-3 mm²/s; GS of 7: 0.741 ± 0.164 ×10^-3 mm²/s; GS of 8: 0.679 ± 0.130 ×10^-3 mm²/s; and GS of ≥9: 0.593 ± 0.089 ×10^-3 mm²/s. An ADC value of 0.830 ×10^-3mm²/s was the best cutoff value to identify prostate cancer with a GS of 6.

CONCLUSIONS

We observed an inverse relationship between GS and ADC value. Moreover, a cutoff ADC value may help differentiate disease with a GS of 6 from disease with a GS ≥7.

Timing of Adverse Prostate Cancer Reclassification on First Surveillance Biopsy: Results from the Canary Prostate Cancer Active Surveillance Study

PURPOSE

During active surveillance for localized prostate cancer, the timing of the first surveillance biopsy varies. We analyzed the Canary PASS (Prostate Cancer Active Surveillance Study) to determine biopsy timing influence on rates of prostate cancer adverse reclassification at the first active surveillance biopsy.

MATERIALS AND METHODS

Of 1,085 participants in PASS, 421 had fewer than 34% of cores involved with cancer and Gleason sum 6 or less, and thereafter underwent on-study active surveillance biopsy. Reclassification was defined as an increase in Gleason sum and/or 34% or more of cores with prostate cancer. First active surveillance biopsy reclassification rates were categorized as less than 8, 8 to 13 and greater than 13 months after diagnosis. Multivariable logistic regression determined association between reclassification and first biopsy timing.

RESULTS

Of 421 men, 89 (21.1%) experienced reclassification at the first active surveillance biopsy. Median time from prostate cancer diagnosis to first active surveillance biopsy was 11 months (IQR 7.8-13.8). Reclassification rates at less than 8, 8 to 13 and greater than 13 months were 24%, 19% and 22% (p = 0.65). On multivariable analysis, compared to men biopsied at less than 8 months the OR of reclassification at 8 to 13 and greater than 13 months were 0.88 (95% CI 0.5,1.6) and 0.95 (95% CI 0.5,1.9), respectively. Prostate specific antigen density 0.15 or greater (referent less than 0.15, OR 1.9, 95% CI 1.1, 4.1) and body mass index 35 kg/m² or greater (referent less than 25 kg/m², OR 2.4, 95% CI 1.1,5.7) were associated with increased odds of reclassification.

CONCLUSIONS

Timing of the first active surveillance biopsy was not associated with increased adverse reclassification but prostate specific antigen density and body mass index were. In low risk patients on active surveillance, it may be reasonable to perform the first active surveillance biopsy at a later time, reducing the overall cost and morbidity of active surveillance.

Management of prostate cancer patients with locally adverse pathologic features after radical prostatectomy: feasibility of active surveillance for cases with Gleason grade 3 + 4 = 7

PURPOSE

To evaluate the ability of the new Gleason grade groups (GGGs) to stratify risk in prostate cancer patients with locally adverse pathologic features after radical prostatectomy (RP) thereby allowing more accurate assessment for planning eventual adjuvant therapy.

PATIENTS AND METHODS

Data on 172 patients with locally adverse pathologic features (including seminal vesicle invasion, extracapsular extension, or positive surgical margins) who had been treated with wait and see policy after RP were retrospectively analyzed for biochemical recurrence (BCR)-free survival. Kaplan-Meier survival analysis and Cox proportional hazard regression models were used to test the association between the GGGs and BCR. Finally, concordance indices of different grading classifications were calculated to evaluate the predictive accuracy for biochemical failure after RP.

RESULTS

The five-year BCR-free survival rates were 71.2, 66.9, 25.7, 17.4, and 8.3 % for GGG 1-5 assessed on surgical specimens (p < 0.001, log-rank test). In the two-way log-rank test, men with prostatectomy GGG 2 had a lower progression risk relative to GGG 3 (p = 0.001), though similar risk as GGG 1 (p = 0.105). In multivariate Cox regression analysis, specimen GGG ≥3 and early postoperative PSA ≥0.1 ng/ml were independent risk factors for biochemical failure (p < 0.001). In addition, GGGs had higher predictive accuracy compared with the alternate classification system (improvement in concordance index by 0.036-0.141).

CONCLUSIONS

For the appropriate patient, depending on age, physical condition, early postoperative PSA, patient desire, etc., could be a candidate for wait and see policy with specimen GGG 2 disease, so to distinguish this from GGG 3 may facilitate discussions at the point of treatment decision making.

Outcome of radical prostatectomy in primary circulating prostate cell negative prostate cancer

INTRODUCTION

Around 90% of prostate cancers detected using the serum prostate specific antigen (PSA) as a screening test are considered to be localised. However, 20-30% of men treated by radical prostatectomy experience biochemical failure within two years of treatment. The presence of primary circulating prostate cells (CPCs) in the blood of these men implies a dissemination of the tumour and could indicate a greater risk of treatment failure.

OBJECTIVE

To evaluate the use of the number of primary CPCs detected before surgery in the prediction of biochemical failure at ten years.

HYPOTHESIS

The dissemination of cancer cells to distant sites will determine the patient's prognosis. The absence of primary CPCs in men undergoing radical prostatectomy for prostate cancer may imply a less aggressive disease and therefore could be utilised as a prognostic factor to predict biochemical failure after surgery.

METHODS AND PATIENTS

A single-centre observational study of a cohort of 285 men who underwent radical prostatectomy as monotherapy for prostate cancer, in whom the number of CPCs prior to treatment was determined, and who were followed up for ten years to determine biochemical failure. A Cox proportional risks with polynomial fractions analysis was used to predict biochemical failure based on the number of primary CPCs detected. A decision curve analysis was performed for the model obtained.

RESULTS

Kaplan-Meier curves for biochemical free survival at ten years was 47.34% (95% CI 38.71-55.48%). It is important to note that in CPC negative men, the ten years Kaplan-Meier biochemical-free survival was 90.35% (95% CI 75.0-96.27) whereas in men who were primary CPC positive, the biochemical free survival rate was 30.00% (95% CI 20.34-40.60%). The Coxs´model to predict biochemical failure using transformed data with a power of minus one for the number of primary CPCs detected, showed a Harrell´s C concordance index of 0.74 and a decision analysis curve showing a net benefit of CPC detection over other risk factors to predict biochemical failure.

CONCLUSIONS

The number of primary CPCs detected before surgery permits a good prediction of subsequent biochemical failure in men undergoing radical prostatectomy as monotherapy for prostate cancer. Men negative for primary CPCs have a biochemical-free survival of over 90% at ten years and should be considered for curative surgery.

Oncological and functional outcomes 1 year after radical prostatectomy for very-low-risk prostate cancer: results from the prospective LAPPRO trial

OBJECTIVES

To analyse oncological and functional outcomes 12 months after treatment of very-low-risk prostate cancer with radical prostatectomy in men who could have been candidates for active surveillance.

PATIENTS AND METHODS

We conducted a prospective study of all men with very-low-risk prostate cancer who underwent radical prostatectomy at one of 14 participating centres. Validated patient questionnaires were collected at baseline and after 12 months by independent healthcare researchers. Biochemical recurrence (BCR) was defined as prostate-specific antigen (PSA) ≥0.25 ng/mL or treatment with salvage radiotherapy or with hormones. Urinary continence was defined as <1 pad changed per 24 h. Erectile function was defined as ability to achieve erection hard enough for penetration more than half of the time after sexual stimulation. Changes in tumour grade and stage were obtained from pathology reports. We report descriptive frequencies and proportions of men who had each outcome in various subgroups. Fisher's exact test was used to assess differences between the age groups.

RESULTS

Of the 4003 men in the LAPPRO cohort, 338 men fulfilled the preoperative national criteria for very-low-risk prostate cancer. Adverse pathology outcomes included upgrading, defined as pT3 or postoperative Gleason sum ≥7, which was present in 35% of the men (115/333) and positive surgical margins, which were present in 16% of the men (54/329). Only 2.1% of the men (7/329) had a PSA concentration >0.1 ng/mL 6-12 weeks postoperatively. Erectile function and urinary continence were observed in 44% (98/222) and 84% of the men (264/315), respectively, 12 months postoperatively. The proportion of men achieving the trifecta, defined as preoperative potent and continent men who remained potent and continent with no BCR, was 38% (84/221 men) at 12 months.

CONCLUSIONS

Our prospective study of men with very-low-risk prostate cancer undergoing open or robot-assisted radical prostatectomy showed that there were favourable oncological outcomes in approximately two-thirds. Approximately 40% did not have surgically induced urinary incontinence or erectile dysfunction 12 months postoperatively. These results provide additional support for the use of active surveillance in men with very-low-risk prostate cancer; however, the number of men with risk of upgrading and upstaging is not negligible. Improved stratification is still urgently needed.

The value of ADC, T2 signal intensity, and a combination of both parameters to assess Gleason score and primary Gleason grades in patients with known prostate cancer

BACKGROUND

The ability to non-invasively analyze tumor aggressiveness is an important predictor for individual treatment stratification and patient outcome in prostate cancer (PCA).

PURPOSE

To evaluate: (i) whether apparent diffusion coefficient (ADC), the T2 signal intensity (SI), and a combination of both parameters allow for an improved discrimination of Gleason Score (GS) ≥7 (intermediate and high risk) and GS <7 (low risk) in PCA; and (ii) whether ADC may distinguish between 3 + 4 and 4 + 3 PCA (primary Gleason grades [pGG]).

MATERIAL AND METHODS

Prostatectomy specimens of 66 patients (mean age, 63 ± 5.6 years; 104 PCA foci) with a preceding multiparametric 1.5 T endorectal coil magnetic resonance imaging (MRI) were included. ADC (b values = 0, 100, 400, 800 s/mm(2)), standardized T2 (T2s), and the ADC/T2s ratio were tested for correlation with GS applying multivariate analysis. ADC cutoff values were calculated for prediction of GS and pGG, and logarithm of the odds (LOGIT) was used to express the probability for GS and pGG. Diagnostic accuracy was assessed by ROC analysis.

RESULTS

We found an almost linear negative relationship of ADC for GS ≥7 (P = 0.002). The effect of ADC for GS ≥7 (adjusted odds ratio = 0.995) was almost identical for peripheral and transition zone PCA (P = 0.013 and P < 0.001, respectively). ADC showed an AUC of 78.9% for discrimination between GS <7 and GS ≥7. An ADC cutoff of <1.005 × 10(-3 )mm(2)/s indicated a GS ≥7 (90.5% sensitivity, 62.5% specificity). Within the group of GS = 7 PCA, an ADC > 0.762 × 10(-3 )mm(2)/s indicated a pGG of 3 (AUC = 69.6%).

CONCLUSION

T2s and the ADC/T2s ratio do not provide additional information regarding prediction of GS. ADC values have a good discriminatory power to distinguish tumors with GS ≥7 from GS <7 and to predict pGG in GS = 7 PCA.

Evaluation of the 2015 Gleason Grade Groups in a Nationwide Population-based Cohort

BACKGROUND

New five-tiered Gleason grade groups (GGGs) were recently proposed, in which Gleason 6 is GGG 1, Gleason 3+4 is GGG 2, Gleason 4+3 is GGG 3, Gleason 8 is GGG 4, and Gleason 9-10 is GGG 5.

OBJECTIVE

To examine the performance of the new GGGs in men with prostate cancer from a nationwide population-based cohort.

DESIGN, SETTING, AND PARTICIPANTS

From the National Prostate Cancer Register of Sweden, we identified 5880 men diagnosed with prostate cancer from 2005 to 2007, including 4325 who had radical prostatectomy and 1555 treated with radiation therapy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Kaplan-Meier survival analysis, Cox proportional hazards models, and concordance indices were used to examine the relationship between the GGGs and biochemical recurrence after radical prostatectomy and radiation therapy.

RESULTS AND LIMITATIONS

Among men treated with surgery, the 4-yr biochemical recurrence-free survival rates were 89%, 82%, 74%, 77%, and 49% for GGG 1-5 on biopsy, and 92%, 85%, 73%, 63%, and 51% based on prostatectomy GGG, respectively. For men treated by radiation therapy, men with biopsy GGG of 1-5 had 4-yr biochemical recurrence-free survival rates of 95%, 91%, 85%, 78%, and 70%. Adjusting for preoperative serum prostate-specific antigen and clinical stage, biopsy GGGs were significant independent predictors of biochemical recurrence after radical prostatectomy and radiation therapy. The new 5-tier system resulted in virtually no change in predictive accuracy compared with the current 3- and 4-tier classifications. Limitations include a median follow-up of 4.6 yr, precluding the ability to examine long-term oncologic outcomes.

CONCLUSIONS

The newly proposed GGGs offer a simplified, user-friendly nomenclature to aid in patient counseling, with similar predictive accuracy in a population-based setting to previous classifications.

PATIENT SUMMARY

The new Gleason grade groups, ranging from 1-5, provide a simplified, user-friendly classification system to predict the risk of recurrence after prostatectomy and radiation therapy.

The Significance of Accurate Determination of Gleason Score for Therapeutic Options and Prognosis of Prostate Cancer

The Gleason score (GS) to date remains one of the most reliable prognostic predictors in prostate cancer (PCa). However, the majority of studies supporting its prognostic relevance were performed prior to its modification by the International Society of Urological Pathology (ISUP) in 2005. Furthermore, the combination of Gleason grading and nuclear/nucleolar subgrading (Helpap score) has been shown to essentially improve grading concordance between biopsy and radical prostatectomy (RP) specimens. This prompted us to investigate the modified GS and combigrading (Gleason/Helpap score) in association with clinicopathological features, biochemical recurrence (BCR), and survival. Core needle biopsies and corresponding RP specimens from 580 patients diagnosed with PCa between 2005 and 2010 were evaluated. According to the modified GS, the comparison between biopsy and RP samples resulted in an upgrading from GS 6 to GS 7a and GS 7b in 65% and 19%, respectively. Combigrading further resulted in an upgrading from low grade (GS 6/2a) to intermediate grade PCa (GS 6/2b) in 11.1% and from intermediate grade (GS 6/2b) to high grade PCa (GS 7b/2b) in 22.6%. Overall, well-differentiated PCa (GS 6/2a) was detected in 2.8% of RP specimens, while intermediate grade (GS 6/2b and GS 7a/2b) and high grade cancers (≥ GS 7b) accounted for 39.5% and 57.4% of cases, respectively. At a mean follow-up of 3.9 years, BCR was observed in 17.6% of patients with intermediate (9.8%) or high grade PCa (30.2%), while PSA relapse did not occur in GS 6/2a PCa. In conclusion, adding nuclear/nucleolar subgrading to the modified GS allowed for a more accurate distinction between low and intermediate grade PCa, therefore offering a valuable tool for the identification of patients eligible for active surveillance (AS).

Targeted Prostate Biopsy: Lessons Learned Midst the Evolution of a Disruptive Technology

Lessons learned during a 6-year experience with more than 1200 patients undergoing targeted prostate biopsy via MRI/ultrasound fusion are reported: (1) the procedure is safe and efficient, requiring some 15-20 minutes in an office setting; (2) MRI is best performed by a radiologist with specialized training, using a transabdominal multiparametric approach and preferably a 3T magnet; (3) grade of MRI suspicion is the most powerful predictor of biopsy results, eg, Grade 5 usually represents cancer; (4) some potentially important cancers (15%-30%) are MRI-invisible; (5) Targeted biopsies provide >80% concordance with whole-organ pathology. Early enthusiasm notwithstanding, cost-effectiveness is yet to be resolved, and the technologies remain in evolution.

Disease reclassification risk with stringent criteria and frequent monitoring in men with favourable-risk prostate cancer undergoing active surveillance

OBJECTIVES

To determine the frequency of disease reclassification and to identify clinicopathological variables associated with it in patients with favourable-risk prostate cancer undergoing active surveillance (AS).

PATIENTS AND METHODS

We assessed 191 men, selected by what may be the most stringent criteria used in AS studies yet conducted, who were enrolled in a prospective cohort AS trial. Clinicopathological characteristics were analysed in a multivariate Cox proportional hazards regression model. Key features were an extended biopsy with a single core positive for Gleason score (GS) 3 + 3 (<3 mm) or 3 + 4 (<2 mm) and a prostate-specific antigen (PSA) level <4 ng/mL (adjusted for prostate volume). Biopsies were repeated every 1-2 years and clinical evaluations every 6 months. Disease was reclassified when PSA level increased by 30% from baseline, or when biopsy tumour length increased beyond the enrolment criteria, more than one positive core was detected or any grade increased to a dominant 4 pattern or any 5 pattern.

RESULTS

Disease was reclassified in 32 patients (16.8%) including upgrading to GS 4 + 3 in five patients (2.6%). The median (interquartile range) follow-up time among survivors was 3 (1.9-4.6) years. Overall, 13 of the 32 (40.6%) had incremental increases in GS. Tumour length (hazard ratio 2.95, 95% confidence interval [CI] 1.34-6.46; P = 0.007) and older age (hazard ratio 1.05, 95% CI 1.00-1.09; P = 0.05) were identified as significant and marginally significant predictors of disease reclassification, respectively. Disease remained stable in 83.2% of patients.

CONCLUSION

The need persists for improvements in risk stratification and predictive indicators of cancer progression.

Identifying in vivo DCE MRI markers associated with microvessel architecture and gleason grades of prostate cancer

BACKGROUND

To identify computer extracted in vivo dynamic contrast enhanced (DCE) MRI markers associated with quantitative histomorphometric (QH) characteristics of microvessels and Gleason scores (GS) in prostate cancer.

METHODS

This study considered retrospective data from 23 biopsy confirmed prostate cancer patients who underwent 3 Tesla multiparametric MRI before radical prostatectomy (RP). Representative slices from RP specimens were stained with vascular marker CD31. Tumor extent was mapped from RP sections onto DCE MRI using nonlinear registration methods. Seventy-seven microvessel QH features and 18 DCE MRI kinetic features were extracted and evaluated for their ability to distinguish low from intermediate and high GS. The effect of temporal sampling on kinetic features was assessed and correlations between those robust to temporal resolution and microvessel features discriminative of GS were examined.

RESULTS

A total of 12 microvessel architectural features were discriminative of low and intermediate/high grade tumors with area under the receiver operating characteristic curve (AUC) > 0.7. These features were most highly correlated with mean washout gradient (WG) (max rho = -0.62). Independent analysis revealed WG to be moderately robust to temporal resolution (intraclass correlation coefficient [ICC] = 0.63) and WG variance, which was poorly correlated with microvessel features, to be predictive of low grade tumors (AUC = 0.77). Enhancement ratio was the most robust (ICC = 0.96) and discriminative (AUC = 0.78) kinetic feature but was moderately correlated with microvessel features (max rho = -0.52).

CONCLUSION

Computer extracted features of prostate DCE MRI appear to be correlated with microvessel architecture and may be discriminative of low versus intermediate and high GS.

Transperineal Template Guided Prostate Biopsy Selects Candidates for Active Surveillance--How Many Cores are Enough?

PURPOSE

Most prostate cancer active surveillance protocols recommend a confirmatory biopsy within 3 to 6 months of diagnosis. Transperineal template guided biopsy is an approach to improve the detection of high grade prostate cancer. However, to our knowledge the optimal technique is unknown. We evaluated the relative performance of 2 transperineal template guided biopsy approaches.

MATERIALS AND METHODS

Institutional review board approved prospective databases at Virginia Mason and University of Michigan were used. Men eligible for active surveillance based on initial 12-core biopsy demonstrating NCCN® guideline low risk prostate cancer were included in study. All men underwent confirmatory transperineal template guided biopsy between 2005 and 2014, and within 6 months of diagnosis. The biopsy technique was based on a 24-core template with 12 anterior and 12 posterior cores or a template based on gland volume with an average of 1 core per cc. Outcome comparisons were made by the chi-square and Fisher exact tests, the Welch t-test and linear regression.

RESULTS

Of the 135 men 46 underwent 24-core biopsy and 89 underwent volume based biopsy (median 62 cores). No statistically significant difference was noted in the prevalence of upgrading (35% vs 29%, p = 0.64) or complications (9% vs 16%, p = 0.38) between the 24-core and volume based groups. The difference in the probability of upgrading by volume based biopsy adjusted for age, prostate specific antigen, prostate volume, clinical stage and number of prior biopsies was -4% (95% CI -24 to 14%, p = 0.63).

CONCLUSIONS

A significant difference was not detected in upgrading or morbidity between a 24-core template and a more exhaustive volume based template. A less invasive 24-core transperineal template guided biopsy strategy may suffice to accurately identify men who are appropriate for active surveillance.

Future-proofing Gleason Grading: What to Call Gleason 6 Prostate Cancer?

At the 2014 International Society of Urological Pathology meeting, changes to prostate cancer grading were discussed including new prognostic Gleason grade groups 1-5 representing Gleason scores of 3+3, 3+4, 4+3, 8, and 9-10, respectively.

Advantages of evaluating mean nuclear volume as an adjunct parameter in prostate cancer

BACKGROUND

Efforts to improve the diagnosis, prognosis and surveillance of prostate cancer (PCa) are relevant. Gleason score (GSc) overestimation may subject individuals to unnecessary aggressive treatment. We aimed to use stereology in PCa evaluations and investigate whether mean nuclear volume (MNV) correlates with the Gleason primary pattern (Gpp) and to improve the subjective GSc to obtain an objective and reliable method without inter-observer dissension.

METHODS

We identified 74 radical prostatectomy specimens that were divided into six groups based on Gpp, from 3 to 5. Controls (C) were designed in paired non-tumor regions of the same specimens. MNV was estimated using the "point-sampled intercepts" method. Differences in MNV among the C groups and the Gpp groups were tested with the Kruskall-Wallis test and Dunn post-hoc test. Differences between each Gpp group and its control counterpart were tested with the Wilcoxon test. Correlations were evaluated with the Spearman rank correlation (R[Spearman]).

RESULTS

The correlations between prostate-specific antigen (PSA) and GSc (R[Spearman] of 0.76) and between PSA and MNV (R[Spearman] of 0.78) were moderately strong and highly significant, and the correlation between MNV and Gpp (R[Spearman] of 0.53) was moderate and highly significant. MNV was significantly greater in cancerous regions than in paired-control regions. Limitations included sample size.

CONCLUSIONS

Proper planning of a study, as well as the availability of equipment and software for morphological quantification, can provide incentive to quickly and accurately estimate MNV as an adjunct parameter in the assessment of PCa. Current data are in favor of the use of MNV associated with GSc and PSA in the assessment of PCa.

Low free testosterone levels predict disease reclassification in men with prostate cancer undergoing active surveillance

OBJECTIVE

To determine whether total testosterone and free testosterone levels predict disease reclassification in a cohort of men with prostate cancer (PCa) on active surveillance (AS).

PATIENTS AND METHODS

Total testosterone and free testosterone concentrations were determined at the time the men began the AS protocol. Statistical analysis was performed using Student's t-test and a chi-squared test to compare groups. Odds ratios (ORs) with 95% confidence intervals (CIs) were obtained using univariate logistic regression. Receiver-operator characteristic curves were generated to determine the investigated testosterone thresholds. Kaplan-Meier curves were used to estimate time to disease reclassification. A Cox proportional hazard regression model was used for multivariate analysis.

RESULTS

A total of 154 men were included in the AS cohort, of whom 54 (35%) progressed to active treatment. Men who had disease reclassification had significantly lower free testosterone levels than those who were not reclassified (0.75 vs 1.02 ng/dL, P = 0.03). Men with free testosterone levels <0.45 ng/dL had a higher rate of disease reclassification than patients with free testosterone levels ≥0.45 (P = 0.032). Free testosterone levels <0.45 ng/dL were associated with a several-fold increase in the risk of disease reclassification (OR 4.3, 95% CI 1.25-14.73). Multivariate analysis showed that free testosterone and family history of PCa were independent predictors of disease reclassification.

CONCLUSIONS

Free testosterone levels were lower in men with PCa who had reclassification during AS. Men with moderately severe reductions in free testosterone level are at increased risk of disease reclassification.