Definitive Pathology at Radical Prostatectomy Is Commonly Favorable in Men Following Initial Active Surveillance

Does active surveillance avoid overtreatment in prostate cancer? Lessons learned from salvage radical prostatectomies

OBJECTIVE

Determine whether our institution´s active surveillance (AS) protocol is a suitable strategy to minimise prostate cancer overtreatment.

MATERIAL AND METHODS

Retrospective analysis of 516 patients on AS after prostate cancer diagnosis. Population divided into "per-protocol" vs "induced" AS depending on fulfilment of protocol´s inclusion criteria. Radical prostatectomies after AS were selected and stratified based on: reclassification, progression or patient anxiety. Clinicopathological features and biochemical relapse-free survival were studied. Primary endpoint was overtreatment ratio based on the presence of insignificant prostate cancer and adverse pathological features in the surgical specimen. Kaplan-Meier curves were used to estimate the biochemical relapse-free survival and compared with log-rank test.

RESULTS

304 patients fulfilled inclusion criteria; 100 proceeded to radical prostatectomy (31% "induced", 69% "per-protocol" AS). Surgery indications were reclassification, progression and anxiety in 66%, 18% and 16% of patients respectively. Rate of positive lymph nodes was higher in the progression group (11%) compared to reclassification and anxiety (5% and 0% respectively, P = .002). Positive surgical margins were more frequently reported in the progression cohort compared to reclassification (28% vs 20%). Median follow-up from diagnosis until last radical prostatectomy was 48.3 months (32.4-70). 3 year biochemical relapse-free survival in the salvage radical prostatectomy was 85.4% (95 CI 78.3-93.2). Insignificant cancer was noticed in 7% of patients (Epstein´s vs 24% Wolters´ criteria). Rate of patients with adverse pathological features was 36%.

CONCLUSIONS

The majority of patients who underwent salvage surgery after AS were not overtreated. Radical prostatectomy should be considered a safe rescue treatment.

Does active surveillance avoid overtreatment in prostate cancer? Lessons learned from salvage radical prostatectomies

OBJECTIVE

Determine whether our institution's active surveillance (AS) protocol is a suitable strategy to minimise prostate cancer overtreatment.

MATERIAL AND METHODS

Retrospective analysis of 516 patients on AS after prostate cancer diagnosis. Population divided into «per-protocol» vs «induced» AS depending on fulfilment of protocol's inclusion criteria. Radical prostatectomies after AS were selected and stratified based on reclassification, progression or patient anxiety. Clinicopathological features and biochemical relapse-free survival were studied. Primary endpoint was overtreatment ratio based on the presence of insignificant prostate cancer and adverse pathological features in the surgical specimen. Kaplan-Meier curves were used to estimate the biochemical relapse-free survival and compared with log-rank test.

RESULTS

304 patients fulfilled inclusion criteria; 100 proceeded to radical prostatectomy (31% «induced», 69% «per-protocol» AS). Surgery indications were reclassification, progression and anxiety in 66%, 18% and 16% of patients, respectively. Rate of positive lymph nodes was higher in the progression group (11%) compared to reclassification and anxiety (5% and 0%, respectively; P=.002). Positive surgical margins were more frequently reported in the progression cohort compared to reclassification (28% vs 20%). Median follow-up from diagnosis until last radical prostatectomy was 48.3months (32.4-70). Three year biochemical relapse-free survival in the salvage radical prostatectomy was 85.4% (95%CI: 78.3-93.2). Insignificant cancer was noticed in 7% of patients (Epstein's vs 24% Wolters' criteria). Rate of patients with adverse pathological features was 36%.

CONCLUSIONS

The majority of patients who underwent salvage surgery after AS were not overtreated. Radical prostatectomy should be considered a safe rescue treatment.

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

OBJECTIVES

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Identification of candidates for observation

PURPOSE OF REVIEW

The clinical value of active surveillance may still be limited due to acceptance and considerable misclassification rates, and inadequate follow-up criteria. This review focuses on the most recent developments in the use of active surveillance and patient-specific factors that may be used to identify patients suitable for this strategy.

RECENT FINDINGS

The number of patients diagnosed with low-risk prostate cancer has risen. Active surveillance acceptance rates are increasing, but still limited and varying importantly (2-49%). Misclassification is inevitable in all currently used protocols, although most of these patients still have relatively favorable-risk prostate cancer. African-American race, obese, and older-aged patients show more unfavorable intermediate results in an active surveillance situation. These are unlikely to be explained by the small differences in preoperative characteristics only. Psychological profiling may also be added to the selection process. Most studies report intermediate endpoints only.

SUMMARY

Patient-specific factors may be incorporated when identifying patients for active surveillance. This does not imply that active surveillance is not justified in specific groups, but may suggest the need for an intensified and personalized selection, instead of a one-size-fits-all approach.

An Increase in Gleason 6 Tumor Volume While on Active Surveillance Portends a Greater Risk of Grade Reclassification with Further Followup

PURPOSE

We evaluated the relative risk of later grade reclassification and outcomes of patients in whom high volume Gleason 6 prostate cancer develops while on active surveillance.

MATERIALS AND METHODS

A prospectively maintained database was used to identify patients on active surveillance between 1998 and 2013. Tumor volume was assessed based on the number of positive cores and proportion of core involvement. The chi-square and Fisher exact tests were used for analysis as appropriate. The primary end point was the development of grade reclassification, defined as grade only and/or grade and volume at the event biopsy.

RESULTS

A total of 555 men met the study inclusion criteria. Mean followup was 46 months. Overall 70 patients demonstrated an increase in tumor volume at or after biopsy 2. Compared to those men never experiencing volume or grade reclassification, prostate specific antigen at diagnosis was not significantly different (p=0.95), but median prostate volume was smaller in patients who demonstrated volume reclassification (p <0.001). The incidence of pure volume reclassification was 6.8%, 6.1% and 7.8% at biopsy 2, 3 and 4, respectively. Men with volume reclassification were more likely to experience later grade reclassification than those without at 33.3% vs 9.3%, respectively (p <0.0001).

CONCLUSIONS

While Gleason 6 prostate cancer has a favorable natural history, it appears that patients on active surveillance who experience volume reclassification are at substantially higher risk for grade reclassification. Thus, urologists should pay close attention to tumor core involvement, and monitoring should be adjusted accordingly for early volume reclassification in younger men and those in good health.

Active surveillance in localized prostate cancer: comparison of incidental tumours (T1a/b) and tumours diagnosed by core needle biopsy (T1c/T2a): results from the HAROW study

OBJECTIVE

To conduct a comparative prospective analysis of patients with incidental T1a/T1b prostate cancer (IPCa) and those with prostate cancer (PCa) diagnosed by core needle biopsy, treated by active surveillance (AS), with regard to inclusion criteria, progression and switch to deferred treatment.

PATIENTS AND METHODS

The HAROW study is an observational outcomes research study on the management of localized PCa. Treating urologists reported clinical variables and information on therapy and clinical course of disease at 6-month intervals. With respect to therapy, only recommendations were made; the final decision on the therapeutic method rested with the treating physician.

RESULTS

Out of 2 957 patients included in the HAROW study, 447 chose AS. The median follow-up was 28.3 months. T1a, T1b, T1c and T2a disease were diagnosed in 81, 18, 292 and 56 patients, respectively. Patients in the IPCa group had lower prostate-specific antigen (PSA) levels (4.2 vs 6.1 ng/mL) and more comorbidities than those diagnosed by core needle biospy. The IPCa group also had fewer re-biopsies (25.3 vs 43.2%) and fewer changes to invasive treatment (12.1 vs 25.9%). No significant differences were found with respect to the criteria for discontinuation, subsequent therapies and histological findings after radical prostatectomy.

CONCLUSION

Urologists are highly inclined to use AS as a therapeutic option in IPCa. More patients with IPCa than those diagnosed after core needle biopsy continued on AS, which was also associated with the indication for a re-biopsy being less stringently observed.

Active surveillance for low-risk prostate cancer

Overtreatment of prostate cancer has become evident as studies comparing radical prostatectomy vs watchful waiting have shown that radical treatment benefits only a proportion of patients. Active surveillance was introduced as a management option for prostate cancer at low-risk of progression with the aim to closely observe for disease progression or change of tumour characteristics and offer active treatment if and when necessary. Active surveillance has been reserved for patients with Gleason 6 localised disease and low PSA; however, selection criteria may be widened as intermediate-term outcomes demonstrate excellent safety, efficacy and patient acceptance.

What is the optimal definition of misclassification in patients with very low-risk prostate cancer eligible for active surveillance? Results from a multi-institutional series

BACKGROUND

The risk of unfavorable prostate cancer in active surveillance (AS) candidates is nonnegligible. However, what represents an adverse pathologic outcome in this setting is unknown. We aimed at assessing the optimal definition of misclassification and its effect on recurrence in AS candidates treated with radical prostatectomy (RP).

MATERIALS AND METHODS

Overall, 1,710 patients eligible for AS according to Prostate Cancer Research International: Active Surveillance criteria treated with RP between 2000 and 2013 at 3 centers were evaluated. Patients were stratified according to pathology results at RP: organ-confined disease and pathologic Gleason score ≤ 6 (group 1); organ-confined disease and Gleason score 3+4 (group 2); and non-organ-confined disease, Gleason score ≥ 4+3, and nodal invasion (group 3). Biochemical recurrence (BCR) was defined as 2 consecutive prostate-specific antigen (PSA) ≥ 0.2 ng/ml. Kaplan-Meier curves assessed time to BCR. Multivariable Cox regression analyses tested the association between pathologic features and BCR. Multivariable logistic regression analyses identified the predictors of adverse pathologic characteristics.

RESULTS

Overall, 926 (54.2%), 653 (33.0%), and 220 (12.9%) patients were categorized in groups 1, 2, and 3, respectively. Median follow-up was 32.2 months. The 5-year BCR-free survival rate was 94.2%. Patients in group 3 had lower BCR-free survival rates compared with those in group 1 (79.1% vs. 97.0%, P<0.001). No differences were observed between patients included in group 1 vs. group 2 (97.0% vs. 94.7%, P = 0.1). These results were confirmed at multivariable analyses and after stratification according to margin status. Older age and PSA density ≥ 10 ng/ml/ml were associated with higher risk of unfavorable pathologic characteristics (i.e., inclusion in group 3; all P<0.001).

CONCLUSIONS

Among patients eligible for AS treated with RP, only men with Gleason score ≥ 4+3 or non-organ-confined disease at final pathology were at increased risk of BCR. These individuals represent the real misclassified AS patients, who can be predicted based on older age and higher PSA density.

The role of 3-tesla diffusion-weighted magnetic resonance imaging in selecting prostate cancer patients for active surveillance

Purpose

Differentiating significant cancer from insignificant cancer is a major challenge in active surveillance (AS) for prostate cancer. We evaluated whether the apparent diffusion coefficient (ADC) grade from 3-T diffusion-weighted magnetic resonance imaging (DW-MRI) is useful to exclude men with unfavorable pathological features from men meeting current AS eligibility criteria.

Methods

Among patients who underwent radical prostatectomy, 117 potential AS candidates defined according to 2013 European Association of Urology guidelines who had undergone preoperative 3-T DW-MRI were included. A blinded uro-radiologist graded the level of suspicion from the ADC map using the Likert scale from 1 to 5. The rate of unfavorable pathological features was evaluated according to ADC grade. Unfavorable pathological features were defined as non–organ-confined disease or pathological Gleason score≥7 (4+3). The associations between unfavorable pathological features and clinical variables including ADC grade (>3 vs. ≤3) were evaluated using logistic regression analysis.

Results

The rates of unfavorable pathological features were 0.0% (0/14), 2.9% (1/34), 5.4% (2/37), 25.0% (6/24), and 37.5% (3/8) from grades 1 to 5 (P=0.002). The predictive accuracy was as high as 0.804. The rates were significantly different between low (≤3, 3.5%) and high (>3, 28.1%, P<0.001) grades. The sensitivity, specificity, and positive and negative predictive values were 75.0%, 78.1%, 28.1%, and 96.5%. ADC grade (odds ratio [OR], 10.696; 95% confidence interval [CI], 2.675–42.773) was significantly associated with unfavorable pathological features, even after adjusting for other variables (OR, 11.274; 95% CI, 2.622–48.471).

Conclusions

ADC grade from 3-T DW-MRI is useful to predict men with unfavorable pathologic features from AS candidates.

Can we expand active surveillance criteria to include biopsy Gleason 3+4 prostate cancer? A multi-institutional study of 2,323 patients

OBJECTIVE

To test the expandability of active surveillance (AS) to Gleason score 3+4 cancers by assessing the unfavorable disease risk in a large multi-institutional cohort.

MATERIALS AND METHODS

We performed a retrospective analysis including 2,323 patients with localized Gleason score 3+4 prostate cancer who underwent a radical prostatectomy between 2005 and 2013 from 6 academic centers. We analyzed the rates of biopsy downgrading/upgrading and advanced stage in the overall cohort by employing standardized AS criteria (using biopsy Gleason score 3+4).

RESULTS

The final pathologic Gleason score was 3+3 = 6 in 8%, 3+4 = 7 in 67%, 4+3 = 7 in 20%, and 8 to 10 in 5% cases. The overall rate of unfavorable disease (upgrading or advanced stage or both) was 46%. In multivariable analysis, prostate-specific antigen (PSA) level>10 ng/ml, PSA density (PSAD) >0.15 ng/ml/g, clinical stage >T1, and>2 positive cores were predictors of unfavorable disease. According to the AS criteria used, the risk of unfavorable disease ranged from 30% to 42%. In patients without any risk factor (PSA level≤ 10 ng/ml, PSAD ≤ 0.15 ng/ml/g, T1c, and ≤ 2 positive cores), the unfavorable disease rate was 19%. The main limitations of this study are the retrospective design and nonstandardization of pathologic assessment between centers.

CONCLUSIONS

Approximately half of patients with biopsy Gleason score 3+4 cancer have unfavorable disease at final pathology. Nevertheless, expanding AS eligibility to these patients may be acceptable provided adherence to strict selection criteria leading to a<20% risk of unfavorable disease. Future tools for selection such as magnetic resonance imaging, early rebiopsy, and serum markers may be especially beneficial in this group of patients.

A 17-gene assay to predict prostate cancer aggressiveness in the context of Gleason grade heterogeneity, tumor multifocality, and biopsy undersampling

BACKGROUND

Prostate tumor heterogeneity and biopsy undersampling pose challenges to accurate, individualized risk assessment for men with localized disease.

OBJECTIVE

To identify and validate a biopsy-based gene expression signature that predicts clinical recurrence, prostate cancer (PCa) death, and adverse pathology.

DESIGN, SETTING, AND PARTICIPANTS

Gene expression was quantified by reverse transcription-polymerase chain reaction for three studies-a discovery prostatectomy study (n=441), a biopsy study (n=167), and a prospectively designed, independent clinical validation study (n=395)-testing retrospectively collected needle biopsies from contemporary (1997-2011) patients with low to intermediate clinical risk who were candidates for active surveillance (AS).

OUTCOME MEASURES AND STATISTICAL ANALYSIS

The main outcome measures defining aggressive PCa were clinical recurrence, PCa death, and adverse pathology at prostatectomy. Cox proportional hazards regression models were used to evaluate the association between gene expression and time to event end points. Results from the prostatectomy and biopsy studies were used to develop and lock a multigene-expression-based signature, called the Genomic Prostate Score (GPS); in the validation study, logistic regression was used to test the association between the GPS and pathologic stage and grade at prostatectomy. Decision-curve analysis and risk profiles were used together with clinical and pathologic characteristics to evaluate clinical utility.

RESULTS AND LIMITATIONS

Of the 732 candidate genes analyzed, 288 (39%) were found to predict clinical recurrence despite heterogeneity and multifocality, and 198 (27%) were predictive of aggressive disease after adjustment for prostate-specific antigen, Gleason score, and clinical stage. Further analysis identified 17 genes representing multiple biological pathways that were combined into the GPS algorithm. In the validation study, GPS predicted high-grade (odds ratio [OR] per 20 GPS units: 2.3; 95% confidence interval [CI], 1.5-3.7; p<0.001) and high-stage (OR per 20 GPS units: 1.9; 95% CI, 1.3-3.0; p=0.003) at surgical pathology. GPS predicted high-grade and/or high-stage disease after controlling for established clinical factors (p<0.005) such as an OR of 2.1 (95% CI, 1.4-3.2) when adjusting for Cancer of the Prostate Risk Assessment score. A limitation of the validation study was the inclusion of men with low-volume intermediate-risk PCa (Gleason score 3+4), for whom some providers would not consider AS.

CONCLUSIONS

Genes representing multiple biological pathways discriminate PCa aggressiveness in biopsy tissue despite tumor heterogeneity, multifocality, and limited sampling at time of biopsy. The biopsy-based 17-gene GPS improves prediction of the presence or absence of adverse pathology and may help men with PCa make more informed decisions between AS and immediate treatment.

PATIENT SUMMARY

Prostate cancer (PCa) is often present in multiple locations within the prostate and has variable characteristics. We identified genes with expression associated with aggressive PCa to develop a biopsy-based, multigene signature, the Genomic Prostate Score (GPS). GPS was validated for its ability to predict men who have high-grade or high-stage PCa at diagnosis and may help men diagnosed with PCa decide between active surveillance and immediate definitive treatment.