Predicting Gleason Group Progression for Men on Prostate Cancer Active Surveillance: Role of a Negative Confirmatory Magnetic Resonance Imaging-Ultrasound Fusion Biopsy

Is Active Surveillance Too Active?

PURPOSE OF REVIEW

Many prostate cancer active surveillance protocols mandate serial monitoring at defined intervals, including but certainly not limited to serum PSA (often every 6 months), clinic visits, prostate multiparametric MRI, and repeat prostate biopsies. The purpose of this article is to evaluate whether current protocols result in excessive testing of patients on active surveillance.

RECENT FINDINGS

Multiple studies have been published in the past several years evaluating the utility of multiparametric MRI, serum biomarkers, and serial prostate biopsy for men on active surveillance. While MRI and serum biomarkers have promise with risk stratification, no studies have demonstrated that periodic prostate biopsy can be safely omitted in active surveillance. Active surveillance for prostate cancer is too active for some men with seemingly low-risk cancer. The use of multiple prostate MRIs or additional biomarkers do not always add to the prediction of higher-grade disease on surveillance biopsy.

Impact of a negative confirmatory biopsy on risk of disease progression among men on active surveillance for prostate cancer

OBJECTIVE

Most prostate cancer active surveillance (AS) protocols suggest a confirmatory biopsy within 12 to 18 months of diagnosis to mitigate the risk of unsampled high-grade disease. We investigate whether the results of confirmatory biopsy impact AS outcomes and could be used to tailor surveillance intensity.

METHODS

We retrospectively reviewed our institutional database of prostate cancer patients managed by AS from 1997 to 2019 who underwent confirmatory biopsy and ≥3 biopsies overall. Biopsy progression was defined as either an increase in grade group or an increase in the proportion of positive biopsy cores to >34% and was compared between patients with a negative vs positive confirmatory biopsy using the Kaplan-Meier method and Cox proportional hazards regression.

RESULTS

We identified 452 patients meeting inclusion criteria for this analysis, of whom 169 (37%) had a negative confirmatory biopsy. With a median follow-up of 6.8 years, 37% of patients progressed to treatment, most commonly due to biopsy progression. A negative confirmatory biopsy was significantly associated with biopsy progression-free survival in multivariable analysis (HR 0.54, 95% CI 0.34-0.88, P = 0.013), adjusting for known clinical and pathologic factors, including use of mpMRI prior to confirmatory biopsy. Negative confirmatory biopsy was also associated with an increased risk of adverse pathologic features at prostatectomy but not with biochemical recurrence among men who ultimately underwent definitive treatment.

CONCLUSIONS

A negative confirmatory biopsy is associated with a lower risk of biopsy progression. While the increased risk of adverse pathology at time of definitive treatment sounds a small cautionary note regarding decreasing surveillance intensity, the majority of such patients have a favorable outcome on AS.

Beyond blood biomarkers: the role of SelectMDX in clinically significant prostate cancer identification

INTRODUCTION

New potential biomarkers to pre-intervention identification of a clinically significant prostate cancer (csPCa) will prevent overdiagnosis and overtreatment and limit quality of life impairment of PCa patients.

AREAS COVERED

We have developed a comprehensive review focusing our research on the increasing knowledge of the role of SelectMDX® in csPCa detection. Areas identified as clinically relevant are the ability of SelectMDX® to predict csPCa in active surveillance setting, its predictive ability when combined with multiparametric MRI and the role of SelectMDX® in the landscape of urinary biomarkers.

EXPERT OPINION

Several PCa biomarkers have been developed either alone or in combination with clinical variables to improve csPCa detection. SelectMDX® score includes genomic markers, age, PSA, prostate volume, and digital rectal examination. Several studies have shown consistency in the ability to improve detection of csPCa, avoidance of unnecessary prostate biopsies, helpful in decision-making for clinical benefit of PCa patients with future well designed, and impactful studies.

Association between previous negative biopsies and lower rates of progression during active surveillance for prostate cancer

Purpose

To test any-cause discontinuation and ISUP GG upgrading rates during Active Surveillance (AS) in patients that underwent previous negative biopsies (PNBs) before prostate cancer (PCa) diagnosis vs. biopsy naive patients.

Methods

Retrospective analysis of 961 AS patients (2008–2020). Three definitions of PNBs were used: (1) PNBs status (biopsy naïve vs. PNBs); (2) number of PNBs (0 vs. 1 vs. ≥ 2); (3) histology at last PNB (no vs. negative vs. HGPIN/ASAP). Kaplan–Meier plots and multivariable Cox models tested any-cause and ISUP GG upgrading discontinuation rates.

Results

Overall, 760 (79.1%) vs. 201 (20.9%) patients were biopsy naïve vs. PNBs. Specifically, 760 (79.1%) vs. 138 (14.4%) vs. 63 (6.5%) patients had 0 vs. 1 vs. ≥ 2 PNBs. Last, 760 (79.1%) vs. 134 (13.9%) vs. 67 (7%) patients had no vs. negative PNB vs. HGPIN/ASAP. PNBs were not associated with any-cause discontinuation rates. Conversely, PNBs were associated with lower rates of ISUP GG upgrading: (1) PNBs vs. biopsy naïve (HR:0.6, p = 0.04); (2) 1 vs. 0 PNBs (HR:0.6, p = 0.1) and 2 vs. 0 PNBs, (HR:0.5, p = 0.1); (3) negative PNB vs. biopsy naïve (HR:0.7, p = 0.3) and HGPIN/ASAP vs. biopsy naïve (HR:0.4, p = 0.04). However, last PNB ≤ 18 months (HR:0.4, p = 0.02), but not last PNB > 18 months (HR:0.8, p = 0.5) were associated with lower rates of ISUP GG upgrading.

Conclusion

PNBs status is associated with lower rates of ISUP GG upgrading during AS for PCa. The number of PNBs and time from last PNB to PCa diagnosis (≤ 18 months) appear also to be critical for patient selection.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00345-022-03983-8.

Role of multi-parametric magnetic resonance imaging fusion biopsy in active surveillance of prostate cancer: a systematic review

Background:

Our goal is to review current literature regarding the role of multi-parametric magnetic resonance imaging (mpMRI) in the active surveillance (AS) of prostate cancer (PCa) and identify trends in rate of reclassification of risk category, performance of fusion biopsy (FB) versus systematic biopsy (SB), and progression-free survival.

Methods:

We performed a comprehensive literature search in PubMed and identified 121 articles. A narrative summary was performed.

Results:

Thirty-two articles were chosen to be featured in this review. SB and FB are complementary in detecting higher-grade disease in follow-up. While FB was more likely than SB to detect clinically significant disease, FB missed 6.4–11% of clinically significant disease. Imaging factors that predicted upgrading include number of lesions on magnetic resonance imaging (MRI), lesion density, and MRI suspicion level.

Conclusion:

Incorporating mpMRI FB in conjunction with SB should be part of contemporary AS protocols. mpMRI should additionally be used routinely for follow-up; however, mpMRI is not currently sensitive enough in detecting disease progression to replace biopsy in the surveillance protocol.

Considering Predictive Factors in the Diagnosis of Clinically Significant Prostate Cancer in Patients with PI-RADS 3 Lesions

The use of multi-parametric magnetic resonance imaging (mpMRI) in conjunction with the Prostate Imaging Reporting and Data System (PI-RADS) is standard practice in the diagnosis, surveillance, and staging of prostate cancer. The risk associated with lesions graded at a PI-RADS score of 3 is ambiguous. Further characterization of the risk associated with PI-RADS 3 lesions would be useful in guiding further work-up and intervention. This study aims to better characterize the utility of PI-RADS 3 and associated risk factors in detecting clinically significant prostate cancer. From a prospectively maintained IRB-approved dataset of all veterans undergoing mpMRI fusion biopsy at the Southeastern Louisiana Veterans Healthcare System, we identified a cohort of 230 PI-RADS 3 lesions from a dataset of 283 consecutive UroNav-guided biopsies in 263 patients from October 2017 to July 2020. Clinically significant prostate cancer (Gleason Grade ≥ 2) was detected in 18 of the biopsied PI-RADS 3 lesions, representing 7.8% of the overall sample. Based on binomial analysis, PSA densities of 0.15 or greater were predictive of clinically significant disease, as was PSA. The location of the lesion within the prostate was not shown to be a statistically significant predictor of prostate cancer overall (p = 0.87), or of clinically significant disease (p = 0.16). The majority of PI-RADS 3 lesions do not represent clinically significant disease; therefore, it is possible to reduce morbidity through biopsy. PSA density is a potential adjunctive factor in deciding which patients with PI-RADS 3 lesions require biopsy. Furthermore, while the risk of prostate cancer for African-American men has been debated in the literature, our findings indicate that race is not predictive of identifying prostate cancer, with comparable Gleason grade distributions on histology between races.

The 2019 Genitourinary Pathology Society (GUPS) White Paper on Contemporary Grading of Prostate Cancer

CONTEXT.—

Controversies and uncertainty persist in prostate cancer grading.

OBJECTIVE.—

To update grading recommendations.

DATA SOURCES.—

Critical review of the literature along with pathology and clinician surveys.

CONCLUSIONS.—

Percent Gleason pattern 4 (%GP4) is as follows: (1) report %GP4 in needle biopsy with Grade Groups (GrGp) 2 and 3, and in needle biopsy on other parts (jars) of lower grade in cases with at least 1 part showing Gleason score (GS) 4 + 4 = 8; and (2) report %GP4: less than 5% or less than 10% and 10% increments thereafter. Tertiary grade patterns are as follows: (1) replace "tertiary grade pattern" in radical prostatectomy (RP) with "minor tertiary pattern 5 (TP5)," and only use in RP with GrGp 2 or 3 with less than 5% Gleason pattern 5; and (2) minor TP5 is noted along with the GS, with the GrGp based on the GS. Global score and magnetic resonance imaging (MRI)-targeted biopsies are as follows: (1) when multiple undesignated cores are taken from a single MRI-targeted lesion, an overall grade for that lesion is given as if all the involved cores were one long core; and (2) if providing a global score, when different scores are found in the standard and the MRI-targeted biopsy, give a single global score (factoring both the systematic standard and the MRI-targeted positive cores). Grade Groups are as follows: (1) Grade Groups (GrGp) is the terminology adopted by major world organizations; and (2) retain GS 3 + 5 = 8 in GrGp 4. Cribriform carcinoma is as follows: (1) report the presence or absence of cribriform glands in biopsy and RP with Gleason pattern 4 carcinoma. Intraductal carcinoma (IDC-P) is as follows: (1) report IDC-P in biopsy and RP; (2) use criteria based on dense cribriform glands (>50% of the gland is composed of epithelium relative to luminal spaces) and/or solid nests and/or marked pleomorphism/necrosis; (3) it is not necessary to perform basal cell immunostains on biopsy and RP to identify IDC-P if the results would not change the overall (highest) GS/GrGp part per case; (4) do not include IDC-P in determining the final GS/GrGp on biopsy and/or RP; and (5) "atypical intraductal proliferation (AIP)" is preferred for an intraductal proliferation of prostatic secretory cells which shows a greater degree of architectural complexity and/or cytological atypia than typical high-grade prostatic intraepithelial neoplasia, yet falling short of the strict diagnostic threshold for IDC-P. Molecular testing is as follows: (1) Ki67 is not ready for routine clinical use; (2) additional studies of active surveillance cohorts are needed to establish the utility of PTEN in this setting; and (3) dedicated studies of RNA-based assays in active surveillance populations are needed to substantiate the utility of these expensive tests in this setting. Artificial intelligence and novel grading schema are as follows: (1) incorporating reactive stromal grade, percent GP4, minor tertiary GP5, and cribriform/intraductal carcinoma are not ready for adoption in current practice.

Changes in Magnetic Resonance Imaging Using the Prostate Cancer Radiologic Estimation of Change in Sequential Evaluation Criteria to Detect Prostate Cancer Progression for Men on Active Surveillance

BACKGROUND

The ability of serial magnetic resonance imaging (MRI) to capture pathologic progression during active surveillance (AS) remains in question.

OBJECTIVE

To determine whether changes in MRI are associated with pathologic progression for patients on AS.

DESIGN, SETTING, AND PARTICIPANTS

From July 2007 through January 2020, we identified all patients evaluated for AS at our institution. Following confirmatory biopsy, a total of 391 patients who underwent surveillance MRI and biopsy at least once were identified (median follow-up of 35.6 mo, interquartile range 19.7-60.6).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

All MRI intervals were scored using the "Prostate Cancer Radiologic Estimation of Change in Sequential Evaluation" (PRECISE) criteria, with PRECISE scores =4 considered a positive change in MRI. A generalized estimating equation-based logistic regression analysis was conducted for all intervals with a PRECISE score of <4 to determine the predictors of Gleason grade group (GG) progression despite stable MRI.

RESULTS AND LIMITATIONS

A total of 621 MRI intervals were scored by PRECISE and validated by biopsy. The negative predictive value of stable MRI (PRECISE score <4) was greatest for detecting GG1 to?=?GG3 disease (0.94 [0.91-0.97]). If 2-yr surveillance biopsy were performed exclusively for a positive change in MRI, 3.7% (4/109) of avoided biopsies would have resulted in missed progression from GG1 to?=?GG3 disease. Prostate-specific antigen (PSA) density (odds ratio 1.95 [1.17-3.25], p?=? 0.01) was a risk factor for progression from GG1 to =GG3 disease despite stable MRI.

CONCLUSIONS

In patients with GG1 disease and stable MRI (PRECISE score <4) on surveillance, grade progression to?=?GG3 disease is not common. In patients with grade progression detected on biopsy despite stable MRI, elevated PSA density appeared to be a risk factor for progression to?=?GG3 disease.

PATIENT SUMMARY

For patients with low-risk prostate cancer on active surveillance, the risk of progressing to grade group 3 disease is low with a stable magnetic resonance image (MRI) after 2?yr. Having higher prostate-specific antigen density increases the risk of progression, despite having a stable MRI.

Risk of adverse pathology at prostatectomy in the era of MRI and targeted biopsies; rethinking active surveillance for intermediate risk prostate cancer patients

PURPOSE

Men with intermediate risk (IR) prostate cancer (CaP) are often excluded from active surveillance (AS) due to higher rates of adverse pathology (AP). We determined our rate of AP in men who underwent multiparametric MRI (MpMRI) with combined biopsy (CB) consisting of targeted biopsy (TB) and systematic biopsy (SB) prior to radical prostatectomy (RP).

METHODS

A retrospective review was conducted of men with Gleason Grade Group (GG) 2 disease who underwent RP after SB alone or after preoperative MRI with CB. AP was defined as either pathologic stage T3a (AP ≥ T3a) or pathologic stage T3b (AP ≥ T3b) and/or GG upgrading. Rates of AP were determined for both groups and those who fit the National Comprehensive Cancer Network (NCCN) definition of favorable IR (FIR) or the low volume IR (LVIR) criteria. Multivariable logistic regression was used to determine predictive factors.

RESULTS

The overall rate of AP ≥ T3b was 21.2% in the SB group vs. 8.6% in the MRI with CB group, P = 0.006. This rate was lowered to 6.8% and 5.6% when men met the definition of NCCN FIR or LVIR, respectively. Suspicion for extraprostatic extension (EPE) (OR 7.65, 95% CI 1.77-33.09, P = 0.006) and positive cores of GG 2 on SB (OR 1.43, 95% CI 1.05-1.96, P = 0.023) were significant for predicting AP ≥ T3b.

CONCLUSIONS

Rates of AP at RP after MRI with CB are lower than studies prior to the adoption of this technology, suggesting that more men with IR disease may be considered for AS. However, increasing cores positive on SB and MRI findings suggestive of EPE remain unsafe.

Probability of Prostate Cancer Diagnosis following Negative Systematic and Targeted MRI: Transrectal Ultrasound Fusion Biopsy: A Real-Life Observational Study

INTRODUCTION

The risk of occult prostate carcinoma (PCa) after negative multiparametric MRI (mpMRI)-transrectal fusion biopsy (F-Bx) is unknown. To determine the false-negative predictive value, we examined PCa detection after prior negative F-Bx.

METHODS

Between December 2012 and November 2016, 491 patients with suspected PCa and suspicious mpMRI findings underwent transrectal F-Bx. Patients with benign pathology (n = 191) were eligible for our follow-up (FU) survey. Patient characteristics and clinical parameters were correlated to subsequent findings of newly detected PCa.

RESULTS

Complete FU with a median of 31 (interquartile range: 17-39) months was available for 176/191 (92.2%) patients. Of those, 54 men had either surgical interventions on the prostate or re-Bxs. Newly detected PCa was evident in 14/176 (7.95%) patients stratified to ISUP ≤2 in 10 and ≥3 in 4 cases. The comparison of patients with newly detected PCa to those without cancerous findings in FU showed significant differences in prostate-specific antigen (PSA) density (0.16 vs. 0.13 ng/mL2) and prostate volume (45 vs. 67 mL, both p < 0.05). Both factors are significant predictors for newly detected cancer after initial negative F-Bx.

CONCLUSION

Only PSA density (>0.13 ng/mL2) and small prostate volume are significant predictors for newly detected PCa after initial negative F-Bx. Despite negative mpMRI/TRUS F-Bx results, patients should be further monitored due to a risk of developing PCa over time. Notwithstanding the limitation of our study that not all patients underwent another Bx, we assume that the false-negative rate is low but existing. Our data represent a real-world scenario.

Negative first follow-up prostate biopsy on active surveillance is associated with decreased risk of upgrading, suspicion of progression and converting to active treatment

OBJECTIVE

To determine the risk of disease progression and conversion to active treatment following a negative biopsy while on active surveillance (AS) for prostate cancer (PCa).

PATIENTS AND METHODS

Men on an AS programme at a single tertiary hospital (London, UK) between 2003 and 2018 with confirmed low-intermediate-risk PCa, Gleason Grade Group <3, clinical stage <T3 and a diagnostic prostate-specific antigen (PSA) level of <20 ng/mL. This cohort included men diagnosed by transrectal ultrasonography guided (12-14 cores) or transperineal (median 32 cores) biopsy. Multivariate Cox hazards regression analysis was undertaken to determine (i) risk of upgrading, (ii) clinical or radiological suspicion of disease progression, and (iii) transitioning to active treatment. Suspicion of disease progression was defined as any biopsy upgrading, >30% positive cores, magnetic resonance imaging (MRI) Likert score >3/T3 or PSA level of >20 ng/mL. Conversion to treatment included radical or hormonal treatment.

RESULTS

Among the 460 eligible patients, 23% had negative follow-up biopsy findings. The median follow-up was 62 months, with one to two repeat biopsies and two MRIs per patient during that period. Negative biopsy findings at first repeat biopsy were associated with decreased risk of converting to active treatment (hazard ration [HR] 0.18, 95% confidence interval [CI] 0.09-0.37; P < 0.001), suspicion of disease progression (HR 0.56, 95% CI: 0.34-0.94; P = 0.029), and upgrading (HR 0.48, 95% CI 0.23-0.99; P = 0.047). Data are limited by fewer men with multiple follow-up biopsies.

CONCLUSION

A negative biopsy finding at the first scheduled follow-up biopsy among men on AS for PCa was strongly associated with decreased risk of subsequent upgrading, clinical or radiological suspicion of disease progression, and conversion to active treatment. A less intense surveillance protocol should be considered for this cohort of patients.

Combined MRI-targeted Plus Systematic Confirmatory Biopsy Improves Risk Stratification for Patients Enrolling on Active Surveillance for Prostate Cancer

OBJECTIVE

To evaluate the efficacy of combined MRI-targeted plus systematic 12-core biopsy (Cbx) to aid in the selection of patients for active surveillance (AS).

METHODS

From July 2007 to January 2020, patients with Gleason Grade Group (GG) 1 or GG 2 prostate cancer were referred to our center for AS consideration. All patients underwent an MRI and confirmatory combined MRI-targeted plus systematic biopsy (Cbx), and AS outcomes based on Cbx results were compared. Cox regression was used to identify predictors of AS failure, defined as progression to ≥ GG3 disease on follow-up biopsies.

RESULTS

Of 579 patients referred for AS, 79.3% (459/579) and 20.7% (120/579) had an initial diagnosis of GG1 and GG2 disease, respectively. Overall, 43.2% of patients (250/579) were upgraded on confirmatory Cbx, with 19.2% (111/579) upgraded to ≥ GG3. For the 226 patients followed on AS, 32.7% (74/226) had benign, 45.6% (103/226) had GG1, and 21.7% (49/226) had GG2 results on confirmatory Cbx. In total, 28.8% (65/226) of patients eventually progressed to ≥ GG3, with a median time to AS failure of 89 months. The median time from confirmatory Cbx to AS failure for the negative, GG1, and GG2 groups were 97, 97, and 32 months, respectively (p < .001). On multivariable regression, only age (hazard ratio 1.06 [1.02-1.11], p < .005) and GG on confirmatory Cbx (hazard ratio 2.75 [1.78-4.26], p < .005) remained as positive predictors of AS failure.

CONCLUSION

The confirmatory combined MRI-targeted plus systematic biopsy provides useful information for the risk stratification of patients at the time of AS enrollment.

Role of multiparametric prostate MRI in the management of prostate cancer

INTRODUCTION

Prostate cancer has traditionally been diagnosed by an elevation in PSA or abnormal exam leading to a systematic transrectal ultrasound (TRUS)-guided biopsy. This diagnostic pathway underdiagnoses clinically significant disease while over diagnosing clinically insignificant disease. In this review, we aim to provide an overview of the recent literature regarding the role of multiparametric MRI (mpMRI) in the management of prostate cancer.

MATERIALS AND METHODS

A thorough literature review was performed using PubMed to identify articles discussing use of mpMRI of the prostate in management of prostate cancer.

CONCLUSION

The incorporation of mpMRI of the prostate addresses the shortcomings of the prostate biopsy while providing several other advantages. mpMRI allows some men to avoid an immediate biopsy and permits visualization of areas likely to harbor clinically significant cancer prior to biopsy to facilitate use of MR-targeted prostate biopsies. This allows for reduction in diagnosis of clinically insignificant disease as well as improved detection and better characterization of higher risk cancers, as well as the improved selection of patients for active surveillance. In addition, mpMRI can be used for selection and monitoring of patients for active surveillance and treatment planning during surgery and focal therapy.

Advanced ultrasound in the diagnosis of prostate cancer

The diagnosis of prostate cancer (PCa) can be challenging due to the limited performance of current diagnostic tests, including PSA, digital rectal examination and transrectal conventional US. Multiparametric MRI has improved PCa diagnosis and is recommended prior to biopsy; however, mp-MRI does miss a substantial number of PCa. Advanced US modalities include transrectal prostate elastography and contrast-enhanced US, as well as improved B-mode, micro-US and micro-Doppler techniques. These techniques can be combined to define a novel US approach, multiparametric US (mp-US). Mp-US improves PCa diagnosis but is not sufficiently accurate to obviate the utility of mp-MRI. Mp-US using advanced techniques and mp-MRI provide complementary information which will become even more important in the era of focal therapy, where precise identification of PCa location is needed.

Evolution of prostate cancer diagnosis: retrospective analysis of magnetic resonance imaging/ultrasound fusion guided biopsies protocol in routine practice and patients management

Background

Magnetic resonance imaging (MRI) is today strongly recommended in prostate cancer (PCa) diagnosis. Therefore, MRI/ultrasound (MRI/US) fusion-guided biopsy is becoming the new standard patients management.

Methods

We report our experience during the last 4 years using this technique, with a protocol of 6 random cores (instead of the most used 12 cores protocol) associated to the target cores (2 to 3 per lesion). Our study involved 236 patients including real life routine practice: biopsy naïve patients (n=107), patients with previous negative standard prostate biopsies (n=67) and patients in PCa active surveillance (n=62). Finally, 76 patients have a robotic radical prostatectomy.

Results

Mean age of the population was 66 years. Median PSA was 8.5 ng/mL. Overall and significant cancer detection were respectively 66.6% and 38.5%, with a large difference considering biopsy history: 63.5% in biopsy naïve patient, 53.7% in patient with previous negative biopsies and 82.3% in patients under active surveillance. Targeted biopsies missed 28 cancers among 8 were significant and standard biopsies missed 33 cancers among 14 were significant. Moreover, concordance between biopsy samples and radical prostatectomy specimens was evaluated at 80%.

Conclusions

Comparing to literature data, similar results were observed in our retrospective study, even with reduced random cores, suggesting a real change in patients management in particular in active surveillance group with a reclassification rate of 56.4% using the Epstein criteria.

Confirmatory multiparametric magnetic resonance imaging at recruitment confers prolonged stay in active surveillance and decreases the rate of upgrading at follow-up

BACKGROUND

To understand the value of multiparametric magnetic resonance imaging (mpMRI) and targeted biopsies at recruitment on active surveillance (AS) outcomes.

MATERIALS AND METHODS

This retrospective single-center study enrolled two cohorts of 206 and 310 patients in AS. The latter group was submitted to mpMRI and targeted biopsies at recruitment. Kaplan-meier curves quantified progression-free survival (PFS) and Bioptic-PFS (B-PFS: no upgrading or >3 positive cores) in the two cohorts. Cox-regression analyses tested independent predictors of PFS and B-PFS. In patients submitted to radical prostatectomy (RP) after AS, significant cancer (csPCa) was defined as: GS ≥ 4 + 3 and/or pT ≥ 3a and/or pN+ . Logistic-regression analyses predicted csPCa at RP.

RESULTS AND LIMITATIONS

Median time follow-up and median time of persistence in AS were 46 (24-70) and 36 (23-58) months, respectively. Patients submitted to mpMRI at AS begin, showed greater PFS at 1- (98% vs. 91%), 3- (80% vs. 57%), and 5-years (70% vs. 35%) follow-up, respectively (all p < 0.01). At Cox-regression analysis only confirmatory mpMRI± targeted biopsy (HR: 0.3; 95% CI 0.2-0.5; p < 0.01) at AS begin was an independent predictor of PFS. Globally, 50 (16%) vs. 128 (62%) and 26 (8.5%) vs. 64 (31%) [all p < 0.01] men in the two groups experienced any-cause and bioptic AS discontinuation, respectively. Patients submitted to confirmatory mpMRI experienced greater 1-(98% vs. 93%), 3-(90% vs. 75%), and 5-years (83% vs. 56%) B-PFS, respectively (all p < 0.01). At Cox-regression analysis, mpMRI±-targeted biopsy at AS begin was associated with B-PFS (HR: 0.3; 95% CI 0.2-0.6; p < 0.01). No differences were recorded in csPCa rates between the two groups (22% vs. 28%; p = 0.47). Limitations of the study are the single-center retrospective nature and the absence of long-term follow-up.

CONCLUSIONS

Confirmatory mpMRI±-targeted biopsies are associated with higher PFS and B-PFS during AS. However, a non-negligible percentage of patients experience csPCa after switching to active treatment.

Magnetic Resonance Imaging-Guided Confirmatory Biopsy for Initiating Active Surveillance of Prostate Cancer

IMPORTANCE

Transrectal, ultrasonography-guided prostate biopsy often fails to disclose the severity of underlying pathologic findings for prostate cancer. Magnetic resonance imaging (MRI)-guided biopsy may improve the characterization of prostate pathologic results, but few studies have examined its use for the decision to enter active surveillance.

OBJECTIVE

To evaluate whether confirmatory biopsy findings by MRI guidance are associated with the risk of pathologic disease upgrading among patients with prostate cancer during active surveillance.

DESIGN, SETTINGS, AND PARTICIPANTS

This retrospective cohort study used prospectively obtained registry data from 332 men with prostate cancer of Gleason grade group (GG) 2 or lower who were referred for active surveillance at a large academic medical center from January 1, 2009, through December 31, 2017.

EXPOSURES

All confirmatory and follow-up biopsies were performed using MRI guidance with an MRI-ultrasonography fusion device. Patients underwent repeated MRI-guided biopsies every 12 to 24 months. At follow-up sessions, in addition to obtaining systematic samples, lesions seen on MRI were targeted and foci of low-grade prostate cancer were obtained again using tracking technology. Active surveillance was terminated with detection of at least GG3 disease or receipt of treatment.

MAIN OUTCOMES AND MEASURES

The primary outcome was upgrading to at least GG3 disease during active surveillance. Secondary outcomes were the associations of MRI lesion grade, prostate-specific antigen (PSA) level, PSA density, and biopsy method (targeted, systematic, or tracked) with the primary outcome.

RESULTS

Of 332 patients (mean [SD] age, 62.8 [7.6] years), 39 (11.7%) upgraded to at least GG3 disease during follow-up. The incidence of upgrading was 7.9% (9 of 114) when the confirmatory biopsy finding was normal, 11.4% (20 of 175) when the finding showed GG1 disease, and 23.3% (10 of 43) when the finding was GG2 disease (P = .03). Men with GG2 disease were almost 8 times more likely to upgrade during surveillance compared with those with normal findings but only among those with low PSA density (hazard ratio [HR], 7.82; 95% CI, 2.29-26.68). A PSA density of at least 0.15 ng/mL/mL was associated with increased risk of upgrading among patients with normal findings (HR, 7.21; 95% CI, 1.98-26.24) or GG1 disease (HR, 2.86; 95% CI, 1.16 to 7.03) on confirmatory biopsy. A total of 46% of pathologic disease upgrades would have been missed if only the targeted biopsy was performed and 65% of disease upgrades were detected only with tracked biopsy.

CONCLUSIONS AND RELEVANCE

The findings suggest that confirmatory biopsy with MRI guidance is significantly associated with future disease upgrading of prostate cancer, especially when combined with PSA density, and should be considered as an appropriate entry point for active surveillance. Systematic and targeted biopsies were additive in detection of clinically significant cancers. Repeated biopsy at sites at which findings were previously abnormal (tracking biopsy) facilitated detection of cancers not suitable for continued active surveillance.

A novel predictor of clinical progression in patients on active surveillance for prostate cancer

INTRODUCTION

Active surveillance (AS) is standard of care in low-risk prostate cancer (PCa). This study describes a novel total cancer location (TCLo) density metric and aims to determine its performance in predicting clinical progression (CP) and grade progression (GP).

METHODS

This was a retrospective study of patients on AS after confirmatory biopsy (CBx). We excluded patients with Gleason ≥7 at CBx and <2 years followup. TCLo was the number of locations with positive cores at diagnosis (DBx) and CBx. TCLo density was TCLo/prostate volume (PV). CP was progression to any active treatment while GP occurred if Gleason ≥7 was identified on repeat biopsy or surgical pathology. Independent predictors of time to CP or GP were estimated with Cox regression. Kaplan-Meier analysis compared progression-free survival (PFS) curves between TCLo density groups. Test characteristics of TCLo density were explored with receiver operating characteristic (ROC) curves.

RESULTS

We included 181 patients who had CBx from 2012-2015 and met inclusion criteria. The mean age of patients was 62.58 years (standard deviation [SD] 7.13) and median followup was 60.9 months (interquartile range [IQR] 23.4). A high TCLo density score (>0.05) was independently associated with time to CP (hazard ratio [HR] 4.70; 95% confidence interval [CI] 2.62-8.42; p<0.001) and GP (HR 3.85; 95% CI 1.91-7.73; p<0.001). ROC curves showed TCLo density has greater area under the curve than number of positive cores at CBx in predicting progression.

CONCLUSIONS

TCLo density is able to stratify patients on AS for risk of CP and GP. With further validation, it could be added to the decision-making algorithm in AS for low-risk localized PCa.

Using prognosis to guide inclusion criteria, define standardised endpoints and stratify follow-up in active surveillance for prostate cancer

OBJECTIVES

To test whether using disease prognosis can inform a rational approach to active surveillance (AS) for early prostate cancer.

PATIENTS AND METHODS

We previously developed the Cambridge Prognostics Groups (CPG) classification, a five-tiered model that uses prostate-specific antigen (PSA), Grade Group and Stage to predict cancer survival outcomes. We applied the CPG model to a UK and a Swedish prostate cancer cohort to test differences in prostate cancer mortality (PCM) in men managed conservatively or by upfront treatment in CPG2 and 3 (which subdivides the intermediate-risk classification) vs CPG1 (low-risk). We then applied the CPG model to a contemporary UK AS cohort, which was optimally characterised at baseline for disease burden, to identify predictors of true prognostic progression. Results were re-tested in an external AS cohort from Spain.

RESULTS

In a UK cohort (n = 3659) the 10-year PCM was 2.3% in CPG1, 1.5%/3.5% in treated/untreated CPG2, and 1.9%/8.6% in treated/untreated CPG3. In the Swedish cohort (n = 27 942) the10-year PCM was 1.0% in CPG1, 2.2%/2.7% in treated/untreated CPG2, and 6.1%/12.5% in treated/untreated CPG3. We then tested using progression to CPG3 as a hard endpoint in a modern AS cohort (n = 133). During follow-up (median 3.5 years) only 6% (eight of 133) progressed to CPG3. Predictors of progression were a PSA density ≥0.15 ng/mL/mL and CPG2 at diagnosis. Progression occurred in 1%, 8% and 21% of men with neither factor, only one, or both, respectively. In an independent Spanish AS cohort (n = 143) the corresponding rates were 3%, 10% and 14%, respectively.

CONCLUSION

Using disease prognosis allows a rational approach to inclusion criteria, discontinuation triggers and risk-stratified management in AS.

[Active surveillance in prostate cancer]

Prostate cancer remains among the most commonly diagnosed malignancies worldwide in men. In patients with low-risk prostate cancer, the risk of metastasis and mortality is very low; therefore, a tumor surveillance strategy can be used. In patients undergoing active surveillance, curative active therapy is postponed without compromising opportunities for cure until there is evidence of progression or the patient desires active therapy. The aim of active surveillance in prostate cancer patients is to minimize treatment-related toxicity without impairing patient survival. To maintain patients under active surveillance, the following criteria should be met: prostate-specific antigen (PSA) ≤10 ng/ml, Gleason score ≤6, cT1 or cT2a, ≤2 biopsy cores with <50% cancer involvement of every positive core. Follow-up in active surveillance patients is based on repeat biopsy, serial PSA measurements, and digital rectal examination.

Standardized Magnetic Resonance Imaging Reporting Using the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation Criteria and Magnetic Resonance Imaging/Transrectal Ultrasound Fusion with Transperineal Saturation Biopsy to Select Men on Active Surveillance

BACKGROUND

Contemporary selection criteria for men with prostate cancer (PC) suitable for active surveillance (AS) are unsatisfactory, leading to high disqualification rates based on tumor misclassification. Conventional biopsy protocols are based on standard 12-core transrectal ultrasound (TRUS) biopsy.

OBJECTIVE

To assess the value of magnetic resonance imaging (MRI)/TRUS fusion biopsy over 4-yr follow-up in men on AS for low-risk PC.

DESIGN, SETTING, AND PARTICIPANTS

Between 2010 and 2018, a total of 273 men were included. Of them, 157 men with initial 12-core TRUS biopsy and 116 with initial MRI/TRUS fusion biopsy were followed by systematic and targeted transperineal MRI/TRUS fusion biopsies based on Prostate Cancer Research International Active Surveillance criteria. MRI from follow-up MRI/TRUS fusion biopsy was assessed using the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) scoring system.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

AS-disqualification rates for patients on AS initially diagnosed by either 12-core TRUS biopsy or by MRI/TRUS fusion biopsy were compared using Kaplan-Meier estimates, log-rank tests, and regression analyses. We also analyzed the influence of negative primary MRI and PRECISE scoring to predict AS disqualification using Kaplan-Meier estimates, log-rank tests, and receiver operating characteristic (ROC) curve analysis.

RESULTS AND LIMITATIONS

Of men diagnosed by 12-core TRUS biopsy, 59% were disqualified from AS based on the results of subsequent MRI/TRUS fusion biopsy. In the initial MRI fusion biopsy cohort, upgrading occurred significantly less frequently (19%, p<0.001). ROC curve analyses demonstrated good discrimination for the PRECISE score with an area under the curve of 0.83. No men with a PRECISE score of 1 or 2 (demonstrating absence or downgrading of lesions in follow-up MRI) were disqualified from AS. In our cohort, a negative baseline MRI scan was not a predictor of nondisqualification from AS. Limitations include transperineal approach and extended systematic biopsies used with MRI/TRUS fusion biopsy, which may not be representative of other centers.

CONCLUSIONS

MRI/TRUS fusion biopsies allow a reliable risk classification for patients who are candidates for AS. The application of the PRECISE scoring system demonstrated good discrimination.

PATIENT SUMMARY

In this study, we investigated the value of multiparametric magnetic resonance imaging (MRI) and MRI/transrectal ultrasound (TRUS) fusion biopsies for the assessment of active surveillance (AS) reliability using the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation criteria. Standard TRUS biopsies lead to significant underestimation of prostate cancer. In contrast, MRI/TRUS fusion biopsies allowed for a more reliable risk classification. For appropriate inclusion into AS, men should receive either an initial or a confirmatory MRI/TRUS fusion biopsy.