Pathologic Outcomes of Candidates for Active Surveillance Undergoing Radical Prostatectomy

Oncological outcomes in patients potentially eligible for active surveillance who underwent radical prostatectomy

OBJECTIVE

To determine whether there are differences in the oncological outcomes after radical prostatectomy (adverse pathology and biochemical recurrence) based on clinical selection criteria used in two active surveillance (AS) protocols.

MATERIAL AND METHODS

442 patients diagnosed with localized prostate cancer (CP) underwent radical prostatectomy at our institution between August 2003 and December 2009. We selected patients with low-risk CP, which could have been included in an AS program. Patients were divided into two groups: group i, those who met the most strict surveillance criteria described by Epstein (PSAD<.15; T1/T2a;<2 positive core, Gleason≤6,<50% involvement of the core) and group ii, those meeting the more open criteria described by Klotz (PSA≤10 or<15 at age 70, Gleason≤6 or<7 [3+4] in over 70 years). We compared both groups to determine differences in pathological stage, positive surgical margins and biochemical recurrence after radical prostatectomy.

RESULTS

Of the 442 patients 48% (213 patients) had low-risk PC, and become potential candidates for an AS program. Of the patients operated on 17% (76 patients) met the criteria for AS as of Epstein's and 48% (213 patients) according to Klotz. Comparing patients in both groups there were no statistically significant differences in the presence of pT3 (7.9% vs 10.8%) P=.55, positive margins (22.4% vs. 28.3%) P=.41, nor in biochemical recurrence at 3 years (5.3% vs 5.6%) P=.86.

CONCLUSIONS

In our series of patients theoretically candidates for inclusion in a program of active surveillance, we found no differences in the percentage of patients with pathological stage pT3, positive margins and biochemical recurrence according to clinical inclusion criteria currently used.

Circulating MicroRNAs as Biomarkers of Prostate Cancer: The State of Play

MicroRNAs are key regulators of gene expression and play critical roles in both normal physiology and pathology. Recent research has demonstrated that these molecules are present in body fluids, such as serum, plasma, and urine, and can be readily measured using a variety of techniques. More importantly, emerging evidence suggests that circulating or urine miRNAs are useful indicators of disease. Here, we consider the potential utility of such miRNAs as noninvasive biomarkers of prostate cancer, a disease that would benefit substantially from novel diagnostic and prognostic tools. The studies aimed at identifying diagnostic, prognostic, and/or predictive miRNAs for prostate cancer are summarised and reviewed. Finally, practical considerations that will influence the translation of this recent research into clinical implementation are discussed.

Increased incidence of pathologically nonorgan confined prostate cancer in African-American men eligible for active surveillance

OBJECTIVE

To compare the clinicopathologic findings of African-American (AA) and White-American (WA) men with prostate cancer (PCa) who were candidates for active surveillance (AS) and underwent radical prostatectomy (RP).

METHODS

Prospectively maintained database of men who underwent RP from 2 academic centers were analyzed retrospectively. Postoperative pathologic characteristics of patients who met the AS inclusion criteria of the University of California, San Francisco (UCSF) and National Comprehensive Cancer Network (NCCN) were evaluated. After RP, the rate of pathological upstaging and Gleason upgrading were compared between AA and WA men.

RESULTS

In the AA cohort, 196 and 124 men met the UCSF and NCCN criteria for AS, respectively. With respect to WA patients, 191 and 148 fulfilled the AS criteria for UCSF and NCCN, respectively. AA men had a higher percentage of maximum biopsy core than WA men (15.3%-20.4% vs 11.5%-15.0%, P <.05, respectively) in both cohorts. In addition, a greater proportion of AA men had multiple positive biopsy cores compared to WA men (45.2% vs 33.1%, P = .046) under the NCCN criteria. A higher proportion of AA men were upstaged (≥pT3) compared to WA men (19.4% vs 10.1%, P = .037). A multivariate regression test revealed that age, preoperative PSA, and number of positive cores were independent predictors of more advanced disease (upstaging and/or upgrading) in AA men.

CONCLUSION

AA men who were candidates for AS criteria had worse clinicopathological features on final surgical pathology than WA men. These results suggest that a more stringent AS criteria should be considered in AA men with prostate cancer.

The role of free to total PSA ratio in prediction of extracapsular tumor extension and biochemical recurrence after radical prostatectomy in patients with PSA between 4 and 10 ng/ml

OBJECTIVES

The prognostic value of free to total PSA ratio (F/T PSA) in patients eligible for radical prostatectomy (RP) is controversial. The aim of the present study was to evaluate correlation of F/T PSA with tumor extracapsular extension (ECE) and biochemical recurrence (BR) at long-term follow-up.

PATIENT AND METHODS

Clinical and pathological data were prospectively gathered from 200 patients treated with RP for clinically localized prostate cancer (PCa) and PSA between 4 and 10 ng/mL. Correlations of preoperative variables including F/T PSA with ECE and BR were evaluated with uni- and multivariate analysis. Adjunctive analyses evaluated the association of PSA F/T with other pathological results. The relationship between preoperative F/T PSA and BR was also assessed with Kaplan–Meier survival analysis.

RESULTS

Lower F/T PSA was significantly correlated with ECE (p = 0.0063), higher GS (p = 0.0054), and seminal vesicles involvement (p = 0.0047). The F/T PSA value of 14% provided the greatest discrimination in predicting ECE. At multivariate analysis, F/T PSA did not achieve the statistical significance for predicting ECE independently. At a mean (median, range) follow-up of 52 (48, 14–116) months, preoperative F/T PSA resulted significantly correlated with BR (p = 0.001). At the Kaplan–Meier survival analysis, the 5-year BR free survival rate resulted 89.3 and 68.9% in the group with F/T PSA >14 and ≤14 ng/mL, respectively (log rank p = 0.0022). At Cox proportional hazard model, only ECE resulted an independent predictor of BR (R = 2.646, p = 0.037).

CONCLUSION

In patients with clinically localized PCa and PSA 4–10 ng/ml, lower F/T PSA was significantly associated with ECE, other adverse pathologic features, and with BR at the long-term follow-up, but only ECE resulted an independent predictor of BR in our series.

Prostate cancer: multiparametric MRI for index lesion localization--a multiple-reader study

OBJECTIVE

The purpose of this study was to evaluate the utility of multiparametric MRI in localization of the index lesion of prostate cancer.

MATERIALS AND METHODS

Fifty-one patients who underwent 3-T MRI of the prostate with a pelvic phased-array coil that included T2-weighted, diffusion-weighted, and dynamic contrast-enhanced sequences before prostatectomy were included. Six radiologists assessed all images to identify the lesion most suspicious of being the index lesion, which was localized to one of 18 regions. A uropathologist using the same 18-region scheme reviewed the prostatectomy slides to localize the index lesion. MRI performance was assessed by requiring either an exact match or an approximate match (discrepancy of up to one region) between the MRI and pathologic findings in terms of assigned region.

RESULTS

The pathologist identified an index lesion in 49 of 51 patients. In exact-match analysis, the average sensitivity was 60.2% (range, 51.0-63.3%), and the average positive predictive value (PPV) was 65.3% (range, 61.2-69.4%). In approximate-match analysis, the average sensitivity was 75.9% (range, 65.3-69.6%), and the average PPV was 82.6% (range, 79.2-91.4%). The sensitivity was higher for index lesions with a Gleason score greater than 6 in exact-match (74.8% vs 15.3%, p<0.001) and approximate-match (88.7% vs 36.1%, p=<0.001) analyses and for index lesions measuring at least 1 cm in approximate-match analysis (80.3% vs 58.3%, p=0.016). In exact-match analysis, 30.0%, 44.9%, and 79.1% of abnormalities found with one, two, and three MRI parameters represented the index lesion (p<0.001).

CONCLUSION

The sensitivity and PPV of multiparametric MRI for index lesion localization were moderate, although they improved in the setting of more aggressive pathologic features and a greater number of abnormal MRI parameters, respectively.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

International multicentre study examining selection criteria for active surveillance in men undergoing radical prostatectomy

Background:

The controversies concerning possible overtreatment of prostate cancer, highlighted by debate over PSA screening, have highlighted active surveillance (AS) as an alternative management option for appropriate men. Regional differences in the underlying prevalence of PSA testing may alter the pre-test probability for high-risk disease, which can potentially interfere with the performance of selection criteria for AS. In a multicentre study from three different countries, we examine men who were initially suitable for AS according to the Toronto and Prostate Cancer Research International: Active Surveillance (PRIAS) criteria, that underwent radical prostatectomy (RP) in regards to:1.the proportion of pathological reclassification(Gleason score ⩾7, ⩾pT3 disease),2.predictors of high-risk disease,3.create a predictive model to assist with selection of men suitable for AS.

Methods:

From three centres in the United Kingdom, Canada and Australia, data on men who underwent RP were retrospectively reviewed (n=2329). Multivariable logistic regression was performed to identify predictors of high-risk disease. A nomogram was generated by logistic regression analysis, and performance characterised by receiver operating characteristic curves.

Results:

For men suitable for AS according to the Toronto (n=800) and PRIAS (410) criteria, the rates for upgrading were 50.6, 42.7%, and upstaging 17.6, 12.4%, respectively. Significant predictors of high-risk disease were:•Toronto criteria: increasing age, cT2 disease, centre of diagnosis and number of positive cores.•PRIAS criteria: increasing PSA and cT2 disease.Cambridge had a high pT3a rate (26 vs 12%). To assist selection of men in the United Kingdom for AS, from the Cambridge data, we generated a nomogram predicting high-risk features in patients who meet the Toronto criteria (AUC of 0.72).

Conclusion:

The proportion of pathological reclassification in our cohort was higher than previously reported. Care must be used when applying the AS criteria generated from one population to another. With more stringent selection criteria, there is less reclassification but also fewer men who may benefit from AS.

Active surveillance for favorable-risk prostate cancer: background, patient selection, triggers for intervention, and outcomes

With the advent of increasingly sensitive and widely used diagnostic testing, cancer overdiagnosis in particular has emerged as a problem in multiple organ sites. This has the greatest ramifications in the case of prostate cancer because of the very high incidence of latent prostate cancer in aging men, the availability of the prostate-specific antigen (PSA) test, and the long-term effects of definitive therapy. The condition of most men with favorable-risk prostate cancer is far removed from the consequences of a rampaging, aggressive disease. Most of these men are not destined to die of their disease, even in the absence of treatment. Unfortunately, most of these patients are treated radically and are exposed to the risk of significant side effects. Therefore, a selective approach to treatment is appealing. The concept is to identify the subset that harbor more aggressive disease early enough that curative therapy is still a possibility, thereby allowing the others to enjoy improved quality of life, free from the side effects of treatment. This review article summarizes the evidence supporting active surveillance, and the current approach to this management strategy, including the roles of serial biopsy, PSA kinetics, and MR imaging.

Molecular profiling of indolent human prostate cancer: tackling technical challenges to achieve high-fidelity genome-wide data

The contemporary problem of prostate cancer overtreatment can be partially attributed to the diagnosis of potentially indolent prostate cancers that pose low risk to aged men, and lack of sufficiently accurate risk stratification methods to reliably seek out men with indolent diseases. Since progressive acquisition and accumulation of genomic alterations, both genetic and epigenetic, is a defining feature of all human cancers at different stages of disease progression, it is hypothesized that RNA and DNA alterations characteristic of indolent prostate tumors may be different from those previously characterized in the setting of clinically significant prostate cancer. Approaches capable of detecting such alterations on a genome-wide level are the most promising. Such analysis may uncover molecular events defining early initiating stages along the natural history of prostate cancer progression, and ultimately lead to rational development of risk stratification methods for identification of men who can safely forego treatment. However, defining and characterizing indolent prostate cancer in a clinically relevant context remains a challenge, particularly when genome-wide approaches are employed to profile formalin-fixed paraffin-embedded (FFPE) tissue specimens. Here, we provide the conceptual basis underlying the importance of understanding indolent prostate cancer from molecular profiling studies, identify the key hurdles in sample acquisition and variables that affect molecular data derived from FFPE tissues, and highlight recent progresses in efforts to address these technical challenges.

Prostate cancer: feasibility and preliminary experience of a diffusional kurtosis model for detection and assessment of aggressiveness of peripheral zone cancer

PURPOSE

To assess the feasibility of diffusional kurtosis (DK) imaging for distinguishing benign from malignant regions, as well as low- from high-grade malignant regions, within the peripheral zone (PZ) of the prostate in comparison with standard diffusion-weighted (DW) imaging.

MATERIALS AND METHODS

The institutional review board approved this retrospective HIPAA-compliant study and waived informed consent. Forty-seven patients with prostate cancer underwent 3-T magnetic resonance imaging by using a pelvic phased-array coil and DW imaging (maximum b value, 2000 sec/mm2). Parametric maps were obtained for apparent diffusion coefficient (ADC); the metric DK (K), which represents non-Gaussian diffusion behavior; and corrected diffusion (D) that accounts for this non-Gaussianity. Two radiologists reviewed these maps and measured ADC, D, and K in sextants positive for cancer at biopsy. Data were analyzed by using mixed-model analysis of variance and receiver operating characteristic curves.

RESULTS

Seventy sextants exhibited a Gleason score of 6; 51 exhibited a Gleason score of 7 or 8. K was significantly greater in cancerous sextants than in benign PZ (0.96±0.24 vs 0.57±0.07, P<.001), as well as in cancerous sextants with higher rather than lower Gleason score (1.05±0.26 vs 0.89±0.20, P<.001). K showed significantly greater sensitivity for differentiating cancerous sextants from benign PZ than ADC or D (93.3% vs 78.5% and 83.5%, respectively; P<.001), with equal specificity (95.7%, P>.99). K exhibited significantly greater sensitivity for differentiating sextants with low- and high-grade cancer than ADC or D (68.6% vs 51.0% and 49.0%, respectively; P≤.004) but with decreased specificity (70.0% vs 81.4% and 82.9%, respectively; P≤.023). K had significantly greater area under the curve for differentiating sextants with low- and high-grade cancer than ADC (0.70 vs 0.62, P=.010). Relative contrast between cancerous sextants and benign PZ was significantly greater for D or K than ADC (0.25±0.14 and 0.24±0.13, respectively, vs 0.18±0.10; P<.001).

CONCLUSION

Preliminary findings suggest increased value for DK imaging compared with standard DW imaging in prostate cancer assessment.

Comprehensive report on prostate cancer misclassification by 16 currently used low-risk and active surveillance criteria

What's known on the subject? and What does the study add? Prostate cancer characterisation, based on laboratory findings, clinical examination and histopathological cancer features that are used to define selection criteria for AS, is not ideal. Consequently, a panel of strict or more lenient criteria to select patients for AS have been published. Studies investigating the relationship between pretreatment variables and final pathology have been done in the past showing the risk of cancer misclassification for some criteria. No study has presented an overview of cancer selection using a panel of 16 currently used AS criteria that is presented in the present study. In an exactly defined cohort after radical prostatectomy, each set of criteria was used as a diagnostic test to separate between patients with more favourable (pT2, no Gleason upgrade between biopsy grading and final pathology) and unfavourable cancer features (pT3, pN+, Gleason upgrade). To the best of our knowledge a comparison of test quality criteria for AS criteria given by sensitivity, specificity, positive and negative predictive value and likelihood ratio has not yet been reported. Moreover, we showed that tumour characterisation, by a formally sufficient 12-core biopsy, in the present dataset harboured a risk of ≈20% that unfavourable cancer features were missed regardless of whether strict or more lenient selection criteria for AS were chosen.

OBJECTIVE

To evaluate final histopathological features among men diagnosed with prostate cancer eligible for low-risk (LR) or active surveillance (AS) criteria.

PATIENTS AND METHODS

Retrospective application of 16 definitions for AS or LR prostate cancer to a contemporary (January 2008 to March 2011) open retropubic radical prostatectomy (RRP) series of 1745 patients.

EXCLUSION CRITERIA

neoadjuvant hormones, radiotherapy, inadequate histopathological reports, <10 biopsy cores. Report on the number of men with insignificant tumours (defined as: ≤pT2, Gleason score ≤6, tumour volume <0.5 mL) and men who had unfavourable tumour characteristics on final pathology (defined as: extracapsular extension or seminal vesicle invasion or lymph node metastasis or Gleason upgrading). Sensitivity, specificity, positive predictive value (PPV) and negative predictive values (NPV) were calculated.

RESULTS

Eligibility of patients in the final study cohort (n = 1070) varied from 5.1% to 92.7% depending on the AS or LR criteria used. Final pathology revealed 77 insignificant cancers and 578 patients who had unfavourable histopathological criteria. The detection rate for insignificant cancers on final pathology was variable ranging from 7.8% to 28.3% depending on the AS- or LR-prediction tool used; unfavourable tumour characteristics were found in up to 33.5% on final pathology. The sensitivity, specificity, PPV and NPV were 8.5-97.9%, 24.7-97.8%, 67.7-89.1% and 45.3-78.2%, respectively. The likelihood ratio to correctly identify a patient with LR disease on final pathology ranged from 1.3 to 8.

CONCLUSIONS

AS or LR criteria have a significant risk of cancer misclassification. Better prediction tools are needed to improve these criteria. Re-biopsy might improve safety and should be considered more frequently in patients who opt for AS.

Pathological outcomes of men eligible for active surveillance after undergoing radical prostatectomy: are results predictable?

INTRODUCTION

To analyze pathological results in patients with prostate cancer eligible for active surveillance (AS) after radical prostatectomy and available prediction systems.

METHODS

A retrospective analysis was performed of 612 patients who underwent radical prostatectomy during a 14-year period. Subsequently, we selected those patients who would have been eligible for AS according to 2 different published criteria. Group AS-A matched the following criteria: ≤T2a; Gleason Score ≤6; and prostate-specific antigen <10 ng/mL, while group AS-B applied to different criteria: ≤T2a; Gleason Score <7; and prostate-specific antigen ≤15 ng/mL. Pathological outcomes were compared with results of the 2001 Partin tables.

RESULTS

Altogether, 125 (20.4%) patients were included in group AS-A and 159 (25.9%) in group AS-B. We detected 32 cases of >pT2c (25.6%) for group AS-A and 47 cases (29.6%) for AS-B, respectively. Gleason score upgrading was recorded in 34.4% (AS-A) and 38.3% (AS-B). Results of the Partin tables showed good discrimination among patients at risk for positive lymph nodes but limited discrimination for organ-confined disease, seminal vesicle.

CONCLUSIONS

Overall >25% of patients eligible for AS showed either upstaging or Gleason score upgrading, which could not be measured with the examined predictive tools. Patients should be informed about the risks of inaccurate preoperative diagnostic.

Association of prostate cancer risk alleles with unfavourable pathological characteristics in potential candidates for active surveillance

OBJECTIVE

• To assess whether the carrier status of 35 risk alleles for prostate cancer (CaP) is associated with having unfavourable pathological features in the radical prostatectomy specimen in men with clinically low risk CaP who fulfil commonly accepted criteria as candidates for active surveillance.

PATIENTS AND METHODS

• We studied men of European ancestry with CaP who fulfilled the commonly accepted clinical criteria for active surveillance (T1c, prostate-specific antigen <10 ng/mL, biopsy Gleason ≤6, three or fewer positive cores, ≤50% tumour involvement/core) but instead underwent early radical prostatectomy. • We genotyped these men for 35 CaP risk alleles. We defined 'unfavourable' pathological characteristics to be Gleason ≥7 and/or ≥ pT2b in their radical prostatectomy specimen.

RESULTS

• In all, 263 men (median age 60 [46-72] years) fulfilled our selection criteria for active surveillance, and 58 of 263 (22.1%) were found to have 'unfavourable' pathological characteristics. • The frequencies of three CaP risk alleles (rs1447295 [8q24], P= 0.004; rs1571801 [9q33.2], P= 0.03; rs11228565 [11q13], P= 0.02) were significantly higher in men with 'unfavourable' pathological characteristics. • Two other risk alleles were proportionately more frequent (rs10934853 [3q21], P= 0.06; rs1859962 [17q24], P= 0.07) but did not achieve nominal statistical significance. • Carriers of any one of the significantly over-represented risk alleles had twice the likelihood of unfavourable tumour features (P= 0.03), and carriers of any two had a sevenfold increased likelihood (P= 0.001). • Receiver-operator curve analysis demonstrated an area under the curve of 0.66, suggesting that the number of single nucleotide polymorphisms carried provided discrimination between men with 'favourable' and 'unfavourable' tumour features in their prostatectomy specimen.

CONCLUSION

• In potential candidates for active surveillance, certain CaP risk alleles are more prevalent in patients with 'unfavourable' pathological characteristics in their radical prostatectomy specimen.

Minimally invasive ablative therapies for definitive treatment of localized prostate cancer in the primary setting

Traditionally, the patient with a new diagnosis of localized prostate cancer faces either radical therapy, in the form of surgery or radiation, or active surveillance. A growing subset of these men may not be willing to accept the psychological burden of active surveillance nor the side effects of extirpative or radiation therapy. Local ablative therapies including cryotherapy, high-intensity focused ultrasound, and vascular-targeted photodynamic therapy have emerged as a means for minimally invasive definitive treatment. These treatments are well tolerated with decreased morbidity in association with improvements in technology; however, long-term oncologic efficacy remains to be determined.