Relationship between initial PSA density with future PSA kinetics and repeat biopsies in men with prostate cancer on active surveillance

The association between patient and disease characteristics, and the risk of disease progression in patients with prostate cancer on active surveillance

PURPOSE

The objective of this study was to identify and assess patient and disease characteristics associated with an increased risk of disease progression in men with prostate cancer on active surveillance.

METHODS

We studied patients with low-risk (ISUP GG1) or favorable intermediate-risk (ISUP GG2) PCa. All patients had at least one repeat biopsy. Disease progression was the primary outcome of this study, based on pathological upgrading. Univariate and multivariate Cox proportional hazard analyses were used to evaluate the association between covariates and disease progression.

RESULTS

In total, 240 men were included, of whom 198 (82.5%) were diagnosed with low-risk PCa and 42 (17.5%) with favorable intermediate-risk PCa. Disease progression was observed in 42.9% (103/240) of men. Index lesion > 10 mm (HR = 2.85; 95% CI 1.74-4.68; p < 0.001), MRI (m)T-stage 2b/2c (HR = 2.52; 95% CI 1.16-5.50; p = 0.02), highest PI-RADS score of 5 (HR 3.05; 95% CI 1.48-6.28; p = 0.002) and a higher PSA level (HR 1.06; 95% CI 1.01-1.11; p = 0.014) at baseline were associated with disease progression on univariate analysis. Multivariate analysis showed no significant baseline predictors of disease progression.

CONCLUSION

In AS patients with low-risk or favorable intermediate-risk PCa, diameter of index lesion, MRI (m)T-stage, height of the PI-RADS score and the PSA level at baseline are significant predictors of disease progression to first repeat biopsy.

Clinical and histological predictive factors of reclassification of prostate cancer patients on active surveillance

INTRODUCTION AND OBJECTIVE

Active surveillance (AS) has been established as a therapeutic strategy in patients with low-risk prostate cancer. Demographic and anatomopathological factors that increase the probability of reclassifying patients have been identified.

MATERIALS AND METHODS

Laboratory and histopathological data were collected from 116 patients included on AS since 2014. Univariate analysis was performed with Chi-square, t-student and Kendall's Tau, multivariate analysis according to logistic regression and Kaplan-Meier curves were calculated.

RESULTS

Of the 116 patients in AS, the median age at diagnosis was 66 years and the median follow-up was 13 months (2-72). Of these, 61 (52.6%) are still on surveillance, while 55 (47.4%) have left the program, mostly due to histological progression (52 patients (45.2%)); radical prostatectomy was performed in 27 (49.1%). Prostate volume (PV)≤60cc and the number of positive cylinders >1 in diagnostic biopsy (P=.05) were associated with higher reclassification rate in univariate analysis (P<.05). Multivariate analysis showed that these two variables significantly correlated with higher reclassification rate (PV 60 cc: OR 4.39, P=.04; >1 positive cylinder at diagnostic biopsy: OR 2.48, P=.03).

CONCLUSIONS

It has been shown that initial ultrasound volume and the number of positive cylinders in the diagnostic biopsy are independent risk factors for reclassification. Initial PSA, laterality of the affected cylinders and PSA density were not predictive factors of progression in our series.

Intermediate-risk Prostate Cancer-A Sheep in Wolf's Clothing?

This case-based discussion describes a 65-year-old man newly diagnosed with International Society of Urological Pathology (ISUP) grade 2 prostate cancer (PCa). According to the European Association of Urology classification system, the patient harbors an intermediate-risk cancer. In step-by step discussion, we elaborate guideline-based treatment modalities for intermediate-risk PCa focused on debating active surveillance versus active treatment. Thereby, we discuss the importance of patient characteristics, including age, hereditary factors, life expectancy and comorbidity status, findings of multiparametric magnetic resonance imaging, as well as prostate-specific antigen (PSA) density and PSA kinetics, in predicting the clinical course of the disease. In addition, we focus on cribriform pathology as a predictor of adverse outcomes and critically discuss its relevance in patient management. Lastly, we outline genomic stratification in ISUP 2 cancer as a future tool to predict PCa aggressiveness. PATIENT SUMMARY: Based on current guidelines, patients with intermediate-risk prostate cancer are treated actively or can alternatively undergo an active surveillance approach when favorable risk factors are present. One major issue is to discriminate between patients who benefit from an active therapy approach and those who benefit from a deferred treatment. Therefore, reliable biomarkers and early predictors of disease progression are needed urgently.

Association of Prostate-Specific Antigen Velocity With Clinical Progression Among African American and Non-Hispanic White Men Treated for Low-Risk Prostate Cancer With Active Surveillance

IMPORTANCE

The association of prostate-specific antigen velocity (PSAV) with clinical progression in patients with localized prostate cancer managed with active surveillance remains unclear and, to our knowledge, has not been studied in African American patients.

OBJECTIVES

To test the hypothesis that PSAV is associated with clinical progression in patients with low-risk prostate cancer treated with active surveillance and to identify differences between African American and non-Hispanic White patients.

DESIGN, SETTING, AND PARTICIPANTS

This was a retrospective population-based cohort study using patient records from the Veterans Heath Administration Informatics and Computing Infrastructure on 5296 patients with a diagnosis of localized prostate cancer from January 1, 2001, to December 31, 2015, who were managed with active surveillance. Follow-up extended through March 31, 2020. Low-risk prostate cancer was defined as International Society of Urologic Pathology grade group (GG) 1 clinical tumor stage 2A or lower, PSA level of 10 ng/dL or lower, active surveillance, and no definitive treatment within the first year after diagnosis with at least 1 additional staging biopsy after diagnostic biopsy.

EXPOSURES

Prostate-specific antigen testing.

MAIN OUTCOMES AND MEASURES

The primary outcome was GG progression detected after repeated biopsy or prostatectomy, defined as GG2 or higher or GG3 or higher. The secondary outcome was incident metastases. Cumulative incidence functions and multivariable Cox proportional hazards regression models were used to test associations between PSAV and outcomes.

RESULTS

The final cohort (n = 5296) included 3919 non-Hispanic White men (74.0%; mean [SD] age, 65.7 [5.8] years) and 1377 African American men (26.0%; mean [SD] age, 62.8 [6.6] years). Compared with African American patients, non-Hispanic White patients were older (mean [SD] age, 65.7 [5.8] years vs 62.8 [6.6] years; P < .001), presented with higher cT stage (stage T2, 608 [15.5%] vs 111 [8.1%]; P < .001), had a higher Charlson Comorbidity Index score (1 and ≥2, 912 [23.3%] vs 273 [19.8%]; P = .002), had higher median income ($60 000 to ≥$100 000, 1223 [31.2%] vs 282 [20.5%]; P < .001), and had a higher median level of education (20% to ≥30% with college degree, 1192 [30.4%] vs 333 [24.2%]; P < .001). Progression to GG2 or higher occurred in 2062 patients (38.9%), with a cumulative incidence of 43.2%, and progression to GG3 or higher occurred in 728 patients (13.7%). Fifty-four patients (1.0%) developed metastases. On multivariable analysis, PSAV was significantly associated with progression to GG2 (hazard ratio, 1.32 [95% CI, 1.26-1.39]), GG3 (hazard ratio, 1.51 [95% CI, 1.41-1.62]), and metastases (hazard ratio, 1.38 [95% CI, 1.10-1.74]). Optimal PSAV thresholds that were associated with progression were significantly lower for African American patients (0.44 ng/mL/y) compared with non-Hispanic White patients (1.18 ng/mL/y).

CONCLUSIONS AND RELEVANCE

This study suggests that PSAV is significantly associated with grade progression among patients with low-risk prostate cancer managed with active surveillance, but at lower values for African American patients compared with non-Hispanic White patients. These data suggest that serial PSA measures may potentially substitute for multiple prostate biopsies and that African American patients may merit increased frequency of PSA testing.

Decision Tree Analysis for Prostate Cancer Prediction in Patients with Serum PSA 10 ng/ml or Less

Serum prostate-specific antigen (PSA) testing increases the number of persons who undergo prostate biopsy. However, the best possible strategy for selecting patients for prostate biopsy has not yet been defined. The aim of this study was to develop a classification and regression tree (CART) decision model that can be used to predict significant prostate cancer (PCa) in the course of prostate biopsy for patients with serum PSA levels of 10 ng/ml or less.

The following clinicopathological characteristics of patients who had undergone ultrasound-guided transrectal prostate biopsy were collected: age, PSA, digital rectal examination, volume of the prostate, and PSA density (PSAD). CART analysis was carried out by using all predictors. Different aspects of the predictive performances of the prediction model were assessed.

In this retrospective study, significant PCa values were detected in 26 (26.8%) of a total of 97 patients. The CART model had three branching levels based on PSAD as the most decisive variable and age. The model sensitivity was 73.1%, the specificity was 80.3% and the accuracy was 78.3%. Our model showed an area under the receiver operating characteristic curve of 82.6%. The model was well calibrated.

In conclusion, CART analysis determined that PSAD was the key parameter for the identification of patients with a minimal risk for positive biopsies. The model showed a good discrimination capacity that surpassed individual predictors. However, before recommending its use in clinical practice, an evaluation of a larger and more complete database is necessary for the prediction of significant PCa.

Prostate-specific antigen velocity in diagnosis and prognosis of prostate cancer - a systematic review

Prostate-specific antigen velocity (PSAV) is widely used to detect PC and predict its progression. In this study, we qualitatively synthesized the currently available evidence from published studies regarding the PSAV role in PC. Electronic databases were searched to find relevant articles published until January 2019. Inclusion and exclusion criteria were applied to identify related papers. Eventually, data extraction followed by evidence synthesis was conducted. Full-text screening resulted in 42 included studies. Multiple definitions and intervals were used for PSAV calculation across studies. Results from the included studies were conflicting regarding the role of PSAV in detecting PC and predicting progression in active surveillance cases. However, there is evidence that PSAV may have a predictive role in post-treated men. There is no clear-cut evidence from the published literature to support the use of PSAV in clinical practice.

Previous, Current, and Future Pharmacotherapy and Diagnosis of Prostate Cancer-A Comprehensive Review

Prostate cancer (PCa) is one of the most common cancers in men that usually develops slowly. Since diagnostic methods improved in the last decade and are highly precise, more cancers are diagnosed at an early stage. Active surveillance or watchful waiting are appealing approaches for men diagnosed with low-risk prostate cancer, and they are an antidote to the overtreatment problem and unnecessary biopsies. However, treatment depends on individual circumstances of a patient. Older hormonal therapies based on first generation antiandrogens and steroids were widely used in metastatic castration-resistant prostate cancer (mCRPC) patients prior to the implementation of docetaxel. Nowadays, accordingly to randomized clinical trials, abiraterone, enzalutamide, apalutamide. and docetaxel became first line agents administrated in the treatment of mCRPC. Furthermore, radium-223 is an optional therapy for bone-only metastasis patients. Sipuleucel-T demonstrated an overall survival benefit. However, other novel immunotherapeutics showed limitations in monotherapy. Possible combinations of new vaccines or immune checkpoint blockers with enzalutamide, abiraterone, radium-223, or docetaxel are the subject of ongoing rivalry regarding optimal therapy of prostate cancer.

The role of mpMRI and PSA density in patients with an initial negative prostatic biopsy

INTRODUCTION

While an elevated PSA significantly increases the risk of men harboring prostate cancer, many men with a persistently elevated PSA have negative prostate biopsies. More recently, multiparametric MRI (mpMRI) has had promising implications for the diagnosis of prostate cancer. We aim to investigate the diagnostic role of mpMRI in predicting the future diagnosis of prostate cancer in patients with an initial negative biopsy.

METHODS

This study included all men with negative biopsies, elevated PSA and mpMRI. All patients had their age, PSA, and PSAd recorded. mpMRI lesions were classified using the PI-RADS 2 scoring system.

RESULTS

mpMRI imaging was performed in 336 men with an initial negative biopsy, of whom 108, 111, 76 and 41 men underwent single, two, three and four biopsies, respectively. Of the 228 men with more than one biopsy, 115 patients were diagnosed with prostate cancer on further biopsies. Older patients and men with higher PSA, PSAd and PIRADS score had a significant risk to progress to cancer but only higher PSAd and higher PI-RADS score were significantly associated with clinically significant cancers. For clinically significant cancer; sensitivity and specificity of PI-RADS scoring was 86 and 45%, respectively, and a NPV of 87.6%. When combined with PSAd, NPV was 93%.

CONCLUSION

Men with benign prostatic biopsy and both PSAd < 0.15 and low PI-RADS score may avoid second biopsy. PI-RADS scoring system has a high sensitivity to diagnose clinically significant prostate cancer and repeat biopsy should be recommended in men with benign biopsy and high score.

Clinical and pathologic factors predicting reclassification in active surveillance cohorts

The incidence of small, lower risk well-differentiated prostate cancer is increasing and almost half of the patients with this diagnosis are candidates for initial conservative management in an attempt to avoid overtreatment and morbidity associated with surgery or radiation. A proportion of patients labeled as low risk, candidates for Active Surveillance (AS), harbor aggressive disease and would benefit from definitive treatment. The focus of this review is to identify clinicopathologic features that may help identify these less optimal AS candidates. A systematic Medline/PubMed Review was performed in January 2017 according to PRISMA guidelines; 83 articles were selected for full text review according to their relevance and after applying limits described. For patients meeting AS criteria including Gleason Score 6, several factors can assist in predicting those patients that are at higher risk for reclassification including higher PSA density, bilateral cancer, African American race, small prostate volume and low testosterone. Nomograms combining these features improve risk stratification. Clinical and pathologic features provide a significant amount of information for risk stratification (>70%) for patients considering active surveillance. Higher risk patient subgroups can benefit from further evaluation or consideration of treatment. Recommendations will continue to evolve as data from longer term AS cohorts matures.

Reduction of MRI-targeted biopsies in men with low-risk prostate cancer on active surveillance by stratifying to PI-RADS and PSA-density, with different thresholds for significant disease

Background

The fear of undergrading prostate cancer (PCa) in men on active surveillance (AS) have led to strict criteria for monitoring, which have resulted in good long-term cancer-specific survival, proving the safety of this approach. Reducing undergrading, MRI-targeted biopsies are increasingly used in men with low-risk disease despite their undefined role yet. The objective of this study is to investigate the rate of upgrading using MRI-targeted biopsies in men with low-risk disease on AS, stratified on the basis of PI-RADS and PSA-density, with the aim to reduce potential unnecessary repeat biopsy procedures.

Methods

A total of 331 men were prospectively enrolled following the MRI-PRIAS protocol. MR imaging was according to Prostate Imaging Reporting and Data System (PI-RADSv2) guidelines. Suspicious MRI lesions (PI-RADS 3–5) were additionally targeted by MRI-TRUS fusion biopsies. Outcome measure was upgrading to Gleason score (GS) ≥3+4 with MRI-targeted biopsies, stratified for PI-RADS and PSA-density.

Results

In total, 25% (82/331) of men on AS showed upgrading from GS 3+3. Only 3% (11/331) was upgraded to GS ≥8. In 60% (198/331) a suspicious MRI lesion was identified, but in only 41% (82/198) of men upgrading was confirmed. PI-RADS 3, 4 and 5 categorized index lesions, showed upgrading in 30%, 34% and 66% of men, respectively. Stratification to PI-RADS 4–5, instead of PI-RADS 3–5, would have missed a small number of high volume Gleason 4 PCa in PI-RADS 3 category. However, further stratification into PI-RADS 3 lesions and PSA-density <0.15 ng/mL² could result in a safe targeted biopsy reduction of 36% in this category, without missing any upgrades.

Conclusions

Stratification with the combination of PI-RADS and PSA-density may reduce unnecessary additional MRI biopsy testing. Overall, the high rate of detected upgrading in men on AS may result in an unintended tightening of continuing in AS. Since patients, included under current AS criteria showed extremely favorable outcome, there might be no need to further restrict continuing on AS with MRI and targeted biopsies.

Prostate-specific antigen density is predictive of outcome in suboptimal prostate seed brachytherapy

PURPOSE

In prostate seed brachytherapy, a D₉₀ of <130 Gy is an accepted predictive factor for biochemical failure (BF). We studied whether there is a subpopulation that does not need additional treatment after a suboptimal permanent seed brachytherapy implantation.

METHODS AND MATERIALS

A total of 486 patients who had either BF or a minimum followup of 48 months without BF were identified. BF was defined according to the Phoenix definition (nadir prostate-specific antigen + 2). Univariate and multivariate analyses were performed, adjusting for known prognostic factors such as D₉₀ and prostate-specific antigen density (PSAD) of ≥0.15 ng/mL/cm³, to evaluate their ability to predict BF.

RESULTS

Median followup for patients without BF was 72 months (interquartile range 56-96). BF-free recurrence rate at 5 years was 95% and at 8 years 88%. In univariate analysis, PSAD and cancer of the prostate risk assessment score were predictive of BF. On multivariate analysis, none of the factors remained significant. The best prognosis had patients with a low PSAD (<0.15 ng/mL/cm³) and an optimal implant at 30 days after implantation (as defined by D₉₀ ≥ 130 Gy) compared to patients with both factors unfavorable (p = 0.006). A favorable PSAD was associate with a good prognosis, independently of the D₉₀ (<130 Gy vs. ≥130 Gy, p = 0.7).

CONCLUSIONS

Patients with a PSAD of <0.15 ng/mL/cm³ have little risk of BF, even in the case of a suboptimal implant. These results need to be validated in other patients' cohorts.

Evaluation of predictors of unfavorable pathological features in men eligible for active surveillance using radical prostatectomy specimens: a multi-institutional study

OBJECTIVE

Active surveillance has emerged as an alternative to immediate treatment in men with favorable-risk prostate cancer; however, consensus about defining the appropriate candidates is still lacking. To examine the factors predicting unfavorable pathology among active surveillance candidates, we assessed low-risk radical prostatectomy specimens.

METHODS

This retrospective study included 1753 men who had undergone radical prostatectomy at six independent institutions in Japan from 2005 to 2011. Patients who met the active surveillance criteria were categorized depending on the pathological features of the radical prostatectomy specimens. 'Reclassification' was defined as upstaging (≥pT3) or upgrading (radical prostatectomy Gleason score ≥7), and 'adverse pathology' was defined as pathological stage ≥pT3 or radical prostatectomy Gleason score ≥4 + 3. Multivariate analysis was used to analyze the preoperative factors for reclassification and adverse pathology. The rates of reclassification and adverse pathology were evaluated by classifying patients according to biopsy core numbers.

RESULTS

The active surveillance criteria were met by 284 cases. Reclassification was identified in 154 (54.2%) cases, while adverse pathology in 60 (21.1%) cases. Prostate-specific antigen density and percentage of positive cores were independently associated with reclassification and adverse pathology. The rates of reclassification and adverse pathology were significantly higher among patients with <10 biopsy cores than among others. Thus, focusing on 149 patients with ≥10 biopsy cores, prostate-specific antigen density was the only independent predictor of unfavorable pathological features. The receiver operating characteristic curve analysis determines an optimal cut-off value of prostate-specific antigen density as 0.15 ng/ml².

CONCLUSIONS

Prostate-specific antigen density is the most important predictor of unfavorable pathological features in active surveillance candidates.

Combination of prostate imaging reporting and data system (PI-RADS) score and prostate-specific antigen (PSA) density predicts biopsy outcome in prostate biopsy naïve patients

OBJECTIVE

To assess the value of the Prostate Imaging Reporting and Data System (PI-RADS) scoring system, for prostate multi-parametric magnetic resonance imaging (mpMRI) to detect prostate cancer, and classical parameters, such as prostate-specific antigen (PSA) level, prostate volume and PSA density, for predicting biopsy outcome in biopsy naïve patients who have suspected prostate cancer.

PATIENTS AND METHODS

Patients who underwent mpMRI at our hospital, and who had their first prostate biopsy between July 2010 and April 2014, were analysed retrospectively. The prostate biopsies were taken transperineally under transrectal ultrasonography guidance. In all, 14 cores were biopsied as a systematic biopsy in all patients. Two cognitive fusion-targeted biopsy cores were added for each lesion in patients who had suspicious or equivocal lesions on mpMRI. The PI-RADS scoring system version 2.0 (PI-RADS v2) was used to describe the MRI findings. Univariate and multivariate analyses were performed to determine significant predictors of prostate cancer and clinically significant prostate cancer.

RESULTS

In all, 288 patients were analysed. The median patient age, PSA level, prostate volume and PSA density were 69 years, 7.5 ng/mL, 28.7 mL, and 0.26 ng/mL/mL, respectively. The biopsy results were benign, clinically insignificant, and clinically significant prostate cancer in 129 (45%), 18 (6%) and 141 (49%) patients, respectively. The multivariate analysis revealed that PI-RADS v2 score and PSA density were independent predictors for prostate cancer and clinically significant prostate cancer. When PI-RADS v2 score and PSA density were combined, a PI-RADS v2 score of ≥4 and PSA density ≥0.15 ng/mL/mL, or PI-RADS v2 score of 3 and PSA density of ≥0.30 ng/mL/mL, was associated with the highest clinically significant prostate cancer detection rates (76-97%) on the first biopsy. Of the patients in this group with negative biopsy results, 22% were subsequently diagnosed as prostate cancer. In contrast, a PI-RADS v2 score of ≤3 and PSA density of <0.15 ng/mL/mL yielded no clinically significant prostate cancer and no additional detection of prostate cancer on further biopsies.

CONCLUSIONS

A combination of PI-RADS v2 score and PSA density can help in the decision-making process before prostate biopsy and in the follow-up strategy in biopsy naïve patients. Patients with a PI-RADS v2 score of ≤3 and PSA density of <0.15 ng/mL/mL may avoid unnecessary biopsies.

Can Confirmatory Biopsy be Omitted in Patients with Prostate Cancer Favorable Diagnostic Features on Active Surveillance?

PURPOSE

We evaluated whether initial diagnostic parameters could predict the confirmatory biopsy result in patients initiating active surveillance for prostate cancer, to determine whether some men at low risk for disease reclassification could be spared unnecessary biopsy.

MATERIALS AND METHODS

The cohort included 392 men with Gleason 6 prostate cancer on initial biopsy undergoing confirmatory biopsy. We used univariate and multivariable logistic regression to assess if high grade cancer (Gleason 7 or greater) on confirmatory biopsy could be predicted from initial diagnostic parameters (prostate specific antigen density, magnetic resonance imaging result, percent positive cores, percent cancer in positive cores and total tumor length).

RESULTS

Median patient age was 62 years (IQR 56-66) and 47% of patients had a dominant or focal lesion on magnetic resonance imaging. Of the 392 patients 44 (11%) had high grade cancer on confirmatory biopsy, of whom 39 had Gleason 3+4, 1 had 4+3, 3 had Gleason 8 and 1 had Gleason 9 disease. All predictors were significantly associated with high grade cancer at confirmatory biopsy on univariate analysis. However, in the multivariable model only prostate specific antigen density and total tumor length were significantly associated (AUC 0.85). Using this model to select patients for confirmatory biopsy would generally provide a higher net benefit than performing confirmatory biopsy in all patients, across a wide range of threshold probabilities.

CONCLUSIONS

If externally validated, a model based on initial diagnostic criteria could be used to avoid confirmatory biopsy in many patients initiating active surveillance.

Active surveillance for prostate cancer: when to recommend delayed intervention

There are no agreed upon guidelines for placing patients on active surveillance (AS). Therefore, there are no absolute criteria for taking patients off AS and when to recommend treatment. The criteria used to define progression are currently based on prostate specific antigen (PSA) kinetics, biopsy reclassification, and change in clinical stage. Multiple studies have evaluated predictors of progression such as PSA, PSA density (PSAD), prostate volume, core positivity, and visible lesion on multiparametric magnetic resonance imaging (mpMRI). Furthermore, published nomograms designed to predict indolent prostate cancer do not perform well when used to predict progression. Newer biomarkers have also not performed well to predict progression. These findings highlight that clinical and pathologic variables are not enough to identify patients that will progress while on AS. In the future, with the use of imaging, biomarkers, and gene expression assays, we should be better equipped to diagnose/stage prostate cancer and to distinguish between insignificant and significant disease.

Predictive role of free prostate-specific antigen in a prospective active surveillance program (PRIAS)

PURPOSE

To evaluate the utility of percentage of free serum PSA (%fPSA) as a predictor of adverse rebiopsy findings, treatment change and radical prostatectomy (RP) findings in a prospective active surveillance (AS) trial.

METHODS

Patients enrolled in the global PRIAS study with baseline %fPSA available were included. Putative baseline predictors (e.g. PSA, %fPSA) of adverse rebiopsy findings were explored using logistic regression analysis. Association of variables with treatment change and RP findings over time were evaluated with Cox regression analysis. Active treatment-free survival was assessed with a Kaplan-Meier method.

RESULTS

Of 3701 patients recruited to PRIAS, 939 had %fPSA measured at study entry. Four hundred and thirty-eight of them had %fPSA available after 1 year. Median follow-up was 17.2 months. First rebiopsy results were available for 595 patients and of those, 144 (24.2 %) had adverse findings. A total of 283 (30.1 %) patients discontinued surveillance, of those 181 (64.0 %) due to protocol-based reasons. Although median %fPSA values were significantly lower in patients who changed treatment, according to the multivariate regression analysis, initial %fPSA value was not predictive for treatment change or adverse rebiopsy findings. However, the probability of discontinuing AS was significantly lower in patients with "favourable" initial %fPSA characteristics and %fPSA during follow-up (initial %fPSA ≥15 and positive %fPSA velocity) compared to those with "adverse" %fPSA characteristics (initial %fPSA <15 and negative %fPSA velocity).

CONCLUSIONS

Diagnostic %fPSA provides no additional prognostic value when compared to other predictors already in use in AS protocols. However, %fPSA velocity during surveillance may aid in predicting the probability for future treatment change.

FDG-PET/CT for pre-operative staging and prognostic stratification of patients with high-grade prostate cancer at biopsy

Background

The role of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in prostate cancer (PCa) has not been well defined yet. Because high-grade PCa tends to exhibit increased glycolytic rate, FDG-PET/CT could be useful in this setting. The aim of this study was to assess the value of FDG-PET/CT for pre-operative staging and prognostic stratification of patients with high-grade PCa at biopsy.

Methods

Fifty-four patients with a Gleason sum ≥8 PCa at biopsy underwent FDG-PET/CT as part of the staging workup. Thirty-nine patients underwent radical prostatectomy (RP) and pelvic lymph node (LN) dissection, 2 underwent LN dissection only, and 13 underwent non-surgical treatments. FDG-PET/CT findings from clinical reports, blinded reading and quantitative analysis were correlated with clinico-pathological characteristics at RP.

Results

Suspicious foci of increased FDG uptake were found in the prostate, LNs and bones in 44, 13 and 6% of patients, respectively. Higher clinical stage, post-RP Gleason sum and pattern, and percentage of cancer involvement within the prostate were significantly associated with the presence of intraprostatic FDG uptake (IPFU) (P < 0.05 in all cases). Patients without IPFU who underwent RP were downgraded to Gleason ≤7 in 84.6% of cases, as compared to 30.8% when IPFU was reported (P = 0.003). Qualitative and quantitative IPFU were significantly positively correlated with post-RP Gleason pattern and sum, and pathological T stage. Absence and presence of IPFU were associated with a median 5-year cancer-free survival probability of 70.2 and 26.9% (P = 0.0097), respectively, using the CAPRA-S prognostic tool.

Conclusion

These results suggest that, among patients with a high-grade PCa at biopsy, FDG-PET/CT could improve pre-treatment prognostic stratification by predicting primary PCa pathological grade and survival probability following RP.

Circulating biomarkers for discriminating indolent from aggressive disease in prostate cancer active surveillance

PURPOSE OF REVIEW

To review research on the use of circulating biomarkers to predict unfavorable tumor pathology in the setting of active surveillance, or in clinical contexts that are informative for active surveillance, such as men with low-risk prostate cancer evaluated for upgrading or upstaging at surgery.

RECENT FINDINGS

Biomarkers have been evaluated in serum, plasma, urine, and expressed prostatic secretions. Only a small number of biomarkers have been evaluated in multiple studies: %free prostate-specific antigen (PSA), PSA velocity, PSA doubling time, proPSA, PCA3, TMPRSS2-ERG. Single studies with relevance to active surveillance have evaluated microRNAs, circulating tumor cells, and exosomes. The most consistent significant associations with unfavorable tumor pathology have been with %free PSA. Associations with [-2]proPSA and Prostate Health Index have also been consistent; however, three of four studies come from the same active surveillance patient cohort.

SUMMARY

Circulating biomarkers represent a promising approach to identify men with apparently low-risk biopsy pathology, but who harbor potentially aggressive tumors unsuitable for active surveillance. Research is still at an early stage; existing biomarkers need rigorous validation with consistent methodology, and additional biomarkers need to be evaluated. Successful clinical translation would reduce the frequency of surveillance biopsies, and may enhance acceptance of active surveillance.

Targeted prostate biopsy in select men for active surveillance: do the Epstein criteria still apply?

PURPOSE

Established in 1994, the Epstein histological criteria (Gleason score 6 or less, 2 or fewer cores positive and 50% or less of any core) have been widely used to select men for active surveillance. However, with the advent of targeted biopsy, which may be more accurate than conventional biopsy, we reevaluated the likelihood of reclassification upon confirmatory rebiopsy using multiparametric magnetic resonance imaging-ultrasound fusion.

MATERIALS AND METHODS

We identified 113 men enrolled in active surveillance at our institution who met Epstein criteria and subsequently underwent confirmatory targeted biopsy via multiparametric magnetic resonance imaging-ultrasound fusion. Median patient age was 64 years, median prostate specific antigen was 4.2 ng/ml and median prostate volume was 46.8 cc. Targets or regions of interest on multiparametric magnetic resonance imaging-ultrasound fusion were graded by suspicion level and biopsied at 3 mm intervals along the longest axis (median 10.5 mm). Also, 12 systematic cores were obtained during confirmatory rebiopsy. Our reporting is consistent with START (Standards of Reporting for MRI-targeted Biopsy Studies) criteria.

RESULTS

Confirmatory fusion biopsy resulted in reclassification in 41 men (36%), including 26 (23%) due to Gleason grade 6 or greater and 15 (13%) due to high volume Gleason 6 disease. When stratified by suspicion on multiparametric magnetic resonance imaging-ultrasound fusion, the likelihood of reclassification was 24% to 29% for target grade 0 to 3, 45% for grade 4 and 100% for grade 5 (p=0.001). Men with grade 4 and 5 vs lower grade targets were greater than 3 times more likely to be reclassified (OR 3.2, 95% CI 1.4-7.1, p=0.006).

CONCLUSIONS

Upon confirmatory rebiopsy using multiparametric magnetic resonance imaging-ultrasound fusion men with high suspicion targets on imaging were reclassified 45% to 100% of the time. Criteria for active surveillance should be reevaluated when multiparametric magnetic resonance imaging-ultrasound fusion guided prostate biopsy is used.

Pathological outcomes of Japanese men eligible for active surveillance after radical prostatectomy

BACKGROUND

The aim of this study was to analyze the pathological features of prostatectomy specimens from patients with low-risk prostate cancer eligible for active surveillance (AS) and evaluate preoperative data suitable for predicting upstaged (≥pT3) or upgraded disease (Gleason score of ≥7), defined as 'reclassification'.

METHODS

A retrospective analysis of 521 consecutive radical prostatectomy procedures (January 2005 through to December 2011) performed at our institution without neoadjuvant hormonal therapy was performed. Eighty-four patients fulfilled the following criteria-clinical T1 or T2 disease, prostate-specific antigen (PSA) level of ≤10 ng/ml, one or two positive biopsies, and Gleason score of <7. Clinicopathological features at diagnosis were compared between patients with and without reclassification after radical prostatectomy.

RESULTS

Forty of 84 patients (47.6 %) had a Gleason score of ≥7, and 8 (9.5 %) had upstaged disease (≥pT3). Seven patients with upstaged disease also showed upgraded reclassification. Two patients with reclassification showed biochemical recurrence at 59 and 89 months after surgery, respectively. Preoperative parameters evaluated included age, PSA level, PSA density (PSAD), clinical T stage, and number and percentage of positive prostate cores. Among 82 patients with complete data, univariate analysis showed that PSAD (ng/ml(2)) was a significant parameter to discriminate patients with reclassified disease and those without reclassified disease (p < 0.001). Multivariate analysis revealed that PSAD was the only independent variable to predict disease with reclassification (p = 0.006).

CONCLUSIONS

Preoperative PSAD may be a good indicator for selecting patients eligible for AS in the Japanese population.

Active surveillance for low-risk prostate cancer worldwide: the PRIAS study

BACKGROUND

Overdiagnosis and subsequent overtreatment are important side effects of screening for, and early detection of, prostate cancer (PCa). Active surveillance (AS) is of growing interest as an alternative to radical treatment of low-risk PCa.

OBJECTIVE

To update our experience in the largest worldwide prospective AS cohort.

DESIGN, SETTING, AND PARTICIPANTS

Eligible patients had clinical stage T1/T2 PCa, prostate-specific antigen (PSA) ≤ 10 ng/ml, PSA density <0.2 ng/ml per milliliter, one or two positive biopsy cores, and Gleason score ≤ 6. PSA was measured every 3-6 mo, and volume-based repeat biopsies were scheduled after 1, 4, and 7 yr. Reclassification was defined as more than two positive cores or Gleason >6 at repeat biopsy. Recommendation for treatment was triggered in case of PSA doubling time <3 yr or reclassification.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Multivariate regression analysis was used to evaluate predictors for reclassification at repeat biopsy. Active therapy-free survival (ATFS) was assessed with a Kaplan-Meier analysis, and Cox regression was used to evaluate the association of clinical characteristics with active therapy over time.

RESULTS AND LIMITATIONS

In total, 2494 patients were included and followed for a median of 1.6 yr. One or more repeat biopsies were performed in 1480 men, of whom 415 men (28%) showed reclassification. Compliance with the first repeat biopsy was estimated to be 81%. During follow-up, 527 patients (21.1%) underwent active therapy. ATFS at 2 yr was 77.3%. The strongest predictors for reclassification and switching to deferred treatment were the number of positive cores (two cores compared with one core) and PSA density. The disease-specific survival rate was 100%. Follow-up was too short to draw definitive conclusions about the safety of AS.

CONCLUSIONS

Our short-term data support AS as a feasible strategy to reduce overtreatment. Clinical characteristics and PSA kinetics during follow-up can be used for risk stratification. Strict monitoring is even more essential in men with high-risk features to enable timely recognition of potentially aggressive disease and offer curative intervention. Limitations of using surrogate end points and markers in AS should be recognized.

TRIAL REGISTRATION

The current program is registered at the Dutch Trial Register with ID NTR1718 (http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=1718).

Active surveillance in prostate cancer: patient selection and triggers for intervention

PURPOSE OF REVIEW

The long-term safety and effectiveness of active surveillance depends on our ability to select appropriate patients and trigger delayed treatment in those who need it, whereas avoiding intervention in those who do not. In this review, we will consider how recent advances have influenced patient selection for active surveillance and review the range of different intervention triggers that have been proposed.

RECENT FINDINGS

Several large surveillance cohort studies have been reported recently showing excellent medium-term outcomes in well selected patients, with approximately a third of patients going on to have deferred treatment. Debate continues on the most appropriate eligibility criteria for active surveillance and what triggers for intervention should be used. There is growing interest in the role of transperineal template biopsies and multiparametric MRI, both for patient selection and in identifying triggers for intervention.

SUMMARY

Active surveillance is a well tolerated treatment option in well selected groups of patients. There is no 'one size fits all' set of criteria for patient selection or triggers for intervention but decisions can be guided by information from histology, prostate-specific antigen kinetics and imaging.