Active Surveillance Versus Treatment of Prostate Cancer: Should Metastasis Be the Primary End Point?

Fifteen-Year Outcomes after Monitoring, Surgery, or Radiotherapy for Prostate Cancer

BACKGROUND

Between 1999 and 2009 in the United Kingdom, 82,429 men between 50 and 69 years of age received a prostate-specific antigen (PSA) test. Localized prostate cancer was diagnosed in 2664 men. Of these men, 1643 were enrolled in a trial to evaluate the effectiveness of treatments, with 545 randomly assigned to receive active monitoring, 553 to undergo prostatectomy, and 545 to undergo radiotherapy.

METHODS

At a median follow-up of 15 years (range, 11 to 21), we compared the results in this population with respect to death from prostate cancer (the primary outcome) and death from any cause, metastases, disease progression, and initiation of long-term androgen-deprivation therapy (secondary outcomes).

RESULTS

Follow-up was complete for 1610 patients (98%). A risk-stratification analysis showed that more than one third of the men had intermediate or high-risk disease at diagnosis. Death from prostate cancer occurred in 45 men (2.7%): 17 (3.1%) in the active-monitoring group, 12 (2.2%) in the prostatectomy group, and 16 (2.9%) in the radiotherapy group (P = 0.53 for the overall comparison). Death from any cause occurred in 356 men (21.7%), with similar numbers in all three groups. Metastases developed in 51 men (9.4%) in the active-monitoring group, in 26 (4.7%) in the prostatectomy group, and in 27 (5.0%) in the radiotherapy group. Long-term androgen-deprivation therapy was initiated in 69 men (12.7%), 40 (7.2%), and 42 (7.7%), respectively; clinical progression occurred in 141 men (25.9%), 58 (10.5%), and 60 (11.0%), respectively. In the active-monitoring group, 133 men (24.4%) were alive without any prostate cancer treatment at the end of follow-up. No differential effects on cancer-specific mortality were noted in relation to the baseline PSA level, tumor stage or grade, or risk-stratification score. No treatment complications were reported after the 10-year analysis.

CONCLUSIONS

After 15 years of follow-up, prostate cancer-specific mortality was low regardless of the treatment assigned. Thus, the choice of therapy involves weighing trade-offs between benefits and harms associated with treatments for localized prostate cancer. (Funded by the National Institute for Health and Care Research; ProtecT Current Controlled Trials number, ISRCTN20141297; ClinicalTrials.gov number, NCT02044172.).

Prognostic Value of the Intermediate-risk Feature in Men with Favorable Intermediate-risk Prostate Cancer: Implications for Active Surveillance

Background

Guidelines suggest that active surveillance (AS) may be considered for select patients with favorable intermediate-risk (fIR) prostate cancer.

Objective

To compare the outcomes between fIR prostate cancer patients included by Gleason score (GS) or prostate-specific antigen (PSA). Most patients are classified with fIR disease due to either a 3 + 4 = 7 GS (fIR-GS) or a PSA level of 10-20 ng/ml (fIR-PSA). Previous research suggests that inclusion by GS 7 may be associated with worse outcomes.

Design setting and participants

We conducted a retrospective cohort study of US veterans diagnosed with fIR prostate cancer from 2001 to 2015.

Outcome measurements and statistical analysis

We compared the incidence of metastatic disease, prostate cancer-specific mortality (PCSM), all-cause mortality (ACM), and receipt of definitive treatment between fIR-PSA and fIR-GS patients managed with AS. Outcomes were compared with those of a previously published cohort of patients with unfavorable intermediate-risk disease using cumulative incidence function and Gray's test for statistical significance.

Results and limitations

The cohort included 663 men; 404 had fIR-GS (61%) and 249 fIR-PSA (39%). There was no evidence of difference in the incidence of metastatic disease (8.6% vs 5.8%, p = 0.77), receipt of definitive treatment (77.6% vs 81.5%, p = 0.43), PCSM (5.7% vs 2.5%, p = 0.274), and ACM (16.8% vs 19.1%, p = 0.14) between the fIR-PSA and fIR-GS groups at 10 yr. On multivariate regression, unfavorable intermediate-risk disease was associated with higher rates of metastatic disease, PCSM, and ACM. Limitations included varying surveillance protocols.

Conclusions

There is no evidence of difference in oncological and survival outcomes between men with fIR-PSA and fIR-GS prostate cancer undergoing AS. Thus, presence of GS 7 disease alone should not exclude patients from consideration of AS. Shared decision-making should be utilized to optimize management for each patient.

Patient summary

In this report, we compared the outcomes of men with favorable intermediate-risk prostate cancer in the Veterans Health Administration. We found no significant difference between survival and oncological outcomes.

The ReIMAGINE prostate cancer risk study protocol: A prospective cohort study in men with a suspicion of prostate cancer who are referred onto an MRI-based diagnostic pathway with donation of tissue, blood and urine for biomarker analyses

INTRODUCTION

The ReIMAGINE Consortium was conceived to develop risk-stratification models that might incorporate the full range of novel prostate cancer (PCa) diagnostics (both commercial and academic).

METHODS

ReIMAGINE Risk is an ethics approved (19/LO/1128) multicentre, prospective, observational cohort study which will recruit 1000 treatment-naive men undergoing a multi-parametric MRI (mpMRI) due to an elevated PSA (≤20ng/ml) or abnormal prostate examination who subsequently had a suspicious mpMRI (score≥3, stage ≤T3bN0M0). Primary outcomes include the detection of ≥Gleason 7 PCa at baseline and time to clinical progression, metastasis and death. Baseline blood, urine, and biopsy cores for fresh prostate tissue samples (2 targeted and 1 non-targeted) will be biobanked for future analysis. High-resolution scanning of pathology whole-slide imaging and MRI-DICOM images will be collected. Consortium partners will be granted access to data and biobanks to develop and validate biomarkers using correlation to mpMRI, biopsy-based disease status and long-term clinical outcomes.

RESULTS

Recruitment began in September 2019(n = 533). A first site opened in September 2019 (n = 296), a second in November 2019 (n = 210) and a third in December 2020 (n = 27). Acceptance to the study has been 65% and a mean of 36.5ml(SD+/-10.0), 12.9ml(SD+/-3.7) and 2.8ml(SD+/-0.7) urine, plasma and serum donated for research, respectively. There are currently 4 academic and 15 commercial partners spanning imaging (~9 radiomics, artificial intelligence/machine learning), fluidic (~3 blood-based and ~2urine-based) and tissue-based (~1) biomarkers.

CONCLUSION

The consortium will develop, or adjust, risk models for PCa, and provide a platform for evaluating the role of novel diagnostics in the era of pre-biopsy MRI and targeted biopsy.

Description of Surgical Technique and Oncologic and Functional Outcomes of the Precision Prostatectomy Procedure (IDEAL Stage 1-2b Study)

BACKGROUND

The existing treatment options for men with intermediate- or high-volume low-risk prostate cancer (PCa) are associated with a substantial risk of over- or undertreatment. The development of risk-adjusted therapies is an unmet need for these patients.

OBJECTIVE

To describe our novel technique of precision prostatectomy, a form of surgical focal therapy that allows radical excision of the index PCa lesion along with >90% prostatic tissue extirpation while preserving the prostatic capsule and seminal vesicle/vas deferens complex on the side contralateral to the dominant cancer lesion, and to report on medium-term functional and oncologic outcomes in the first 88 consecutive men who underwent this procedure between December 2016 and January 2020.

DESIGN, SETTING, AND PARTICIPANTS

Men with (1) prostate-specific antigen (PSA) ≤20 ng/ml, (2) clinical T stage ≤cT2, (3) a dominant unilateral lesion with Gleason ≤ 4 + 3 disease with any number or percentage of cores involved ipsilaterally on prostate biopsy, (4) no primary Gleason ≥4 lesion contralaterally, and (5) a preoperative Sexual Health Inventory of Men (SHIM) score of ≥17 (out of 25) with/without phosphodiesterase type-5 inhibitor use who consented to undergo precision prostatectomy were included in this single-arm, single-center, IDEAL stage 2b prospective development study.

INTERVENTION

Robotic precision prostatectomy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The safety and urinary, sexual, and oncologic outcomes of the precision prostatectomy technique were studied. Descriptive statistics and Kaplan-Meier analyses were used to assess 12-mo urinary continence (0-1 pad), 12-mo sexual potency (SHIM score ≥17), 36-mo freedom from clinically significant PCa (grade group ≥2), secondary treatments, metastatic disease, and mortality.

RESULTS AND LIMITATIONS

At study entry, the median age, PSA, and SHIM score were 60.0 yr (interquartile range [IQR] 54.2-65.9), 5.7 ng/ml (IQR 4.2-7.1), and 22 points (IQR 19-24), respectively. The median follow-up was 25 mo (IQR 14-38). At 12 mo, all patients were continent (0-1 pads), with 90.9% of patients using 0 pads. The median time to urinary continence was 1 mo (IQR 1-4). At 12 mo, 85% of all-comers and 90.2% of the preoperatively potent men were potent. The median time to sexual potency was 4 mo (IQR 4-12). From an oncologic standpoint, at 36 mo an estimated 93.4% of the patients were free from clinically significant residual PCa and 91.7% had not undergone any additional treatment. All patients were alive and free of metastatic disease at 36 mo.

CONCLUSIONS

Precision prostatectomy is technically safe and reproducible and offers excellent postoperative functional results. At 36-mo follow-up, the oncologic outcomes and secondary treatment rates appear to be superior to existing ablative focal therapy results. Pending long-term data, a risk-stratified surgical approach to PCa may avoid whole-gland therapy and preserve functional quality of life in men with localized PCa.

PATIENT SUMMARY

Precision prostatectomy is a new form of focal therapy for intermediate-risk prostate cancer in which a 5-10-mm rim of prostate capsule is left on the opposite side of the gland to where the dominant cancer is located. The technique appears to be safe and efficacious and adds to the growing armamentarium of risk-adapted therapies for treatment of localized prostate cancer that avoid the adverse effects on urinary and erectile function of whole-gland treatments.

United States trends in active surveillance or watchful waiting across patient socioeconomic status from 2010 to 2015

BACKGROUND

Prospective evidence supports active surveillance/watchful waiting (AS/WW) as an efficacious management option for low-risk prostate cancer that avoids potential treatment toxicity. AS/WW schedules require regular follow-up and adherence, and it is unknown to what extent patient socioeconomic status (SES) may impact management decisions for AS/WW. We sought to determine whether AS/WW use in the United States differs according to patient SES.

DESIGN

Using the Surveillance, Epidemiology, and End Results Prostate with AS/WW Database, all adult men diagnosed with localized low-risk prostate cancer (clinical T1-T2a, Gleason 6, and prostate-specific antigen <10 ng/mL) and managed with either AS/WW, radical prostatectomy, or radiotherapy were identified between 2010 and 2015. SES tertile was measured by the validated Yost Index (low: 0-10,901; middle: 10,904-11,469; high: 11,470-11,827). AS/WW trends were defined across SES tertiles from 2010 to 2015. Logistic multivariable regression defined adjusted odds ratios (aOR) for receipt of AS/WW by SES tertile.

RESULTS

In 50,302 men, AS/WW use was higher with increasing SES tertile (24.6, 25.3, and 30.5% for low, middle, and high SES tertiles, respectively; P_{Trend (SES)} <0.001). From 2010 to 2015, AS/WW use in the low, middle, and high SES tertiles increased from 11.2 to 37.3%, 14.1 to 45.8%, and 17.6 to 46.4%, respectively (P_Trends <0.001). By 2015, likelihood of AS/WW became comparable among the middle vs. high SES tertiles (aOR 0.96, 95% confidence interval (CI): 0.83-1.11, P = 0.55), but remained lower among the low vs. high SES tertile (aOR 0.73, 95% CI: 0.64-0.83, P < 0.001).

CONCLUSIONS

AS/WW use for low-risk prostate cancer in the US differs by SES. Despite increases in AS/WW across SES from 2010 to 2015, patients from low SES received significantly lower rates of AS/WW compared with higher SES groups. SES may therefore influence management decisions, where factors associated with low SES might act as a barrier to AS/WW, and may need to be addressed to reduce any disproportionate risk of unnecessary treatment to lower SES patients.

Conservative management of low-risk prostate cancer among young versus older men in the United States: Trends and outcomes from a novel national database

BACKGROUND

Management for men aged ≤55 years with low-risk prostate cancer (LRPC) is debated given quality-of-life implications with definitive treatment versus the potential missed opportunity for cure with conservative management. The objective of this study was to define rates of conservative management for LRPC and associated short-term outcomes in young versus older men in the United States.

METHODS

The nonpublic Surveillance, Epidemiology, and End Results Prostate with Active Surveillance/Watchful Waiting (AS/WW) Database identified 50,302 men who were diagnosed with LRPC from 2010 through 2015. AS/WW rates in the United States were stratified by age (≤55 vs ≥56 years). Prostate cancer-specific mortality and overall mortality were defined by initial management type (AS/WW vs definitive treatment [referent]) and age.

RESULTS

AS/WW utilization increased from 8.61% (2010) to 34.56% (2015) among men aged ≤55 years (P for trend <0.001) and from 15.99% to 43.81% among men aged ≥56 years (P for trend <.001). Among patients who had ≤2 positive biopsy cores, AS/WW rates increased from 12.90% to 48.78% for men aged ≤55 years and from 21.85% to 58.01% for men aged ≥56 years. Among patients who had ≥3 positive biopsy cores, AS/WW rates increased from 3.89% to 22.45% for men aged ≤55 years and from 10.05% to 28.49% for men aged ≥56 years (all P for trend <.001). Five-year prostate cancer-specific mortality rates were <0.30% across age and initial management type subgroups.

CONCLUSIONS

AS/WW rates quadrupled for patients aged ≤55 years from 2010 to 2015, with favorable short-term outcomes. These findings demonstrate the short-term safety and increasing acceptance of AS/WW for both younger and older patients. However, there are still higher absolute rates of AS/WW in older patients (P < .001), suggesting some national ambivalence toward AS/WW in younger patients.

Prostate cancer heterogeneity: texture analysis score based on multiple magnetic resonance imaging sequences for detection, stratification and selection of lesions at time of biopsy

OBJECTIVE

To undertake an early proof-of-concept study on a novel, semi-automated texture-based scoring system in order to enhance the association between magnetic resonance imaging (MRI) lesions and clinically significant prostate cancer (SPCa).

PATIENTS AND METHODS

With ethics approval, 536 imaging volumes were generated from 20 consecutive patients who underwent multiparametric MRI (mpMRI) at time of biopsy. Volumes of interest (VOIs) included zonal anatomy segmentation and suspicious MRI lesions for cancer (Likert Scale score >2). Entropy (E), measuring heterogeneity, was computed from VOIs and plotted as a multiparametric score defined as the entropy score (ES) = E ADC + E K^trans + E Ve + E T2WI. The reference test that was used to define the ground truth comprised systematic saturation biopsies coupled with MRI-targeted sampling. This generated 422 cores in all that were individually labelled and oriented in three-dimensions. Diagnostic accuracy for detection of SPCa, defined as Gleason score ≥3 + 4 or >3 mm of any grade of cancer on a single core, was assessed using receiver operating characteristics, correlation, and descriptive statistics. The proportion of cancerous lesions detected by ES and visual scoring (VS) were statistically compared using the paired McNemar test.

RESULTS

Any cancer (Gleason score 6-8) was found in 12 of the 20 (60%) patients, with a median PSA level of 8.22 ng/mL. SPCa (mean [95% confidence interval, CI] ES = 17.96 [0.72] NATural information unit [NAT]) had a significantly higher ES than non-SPCa (mean [95% CI] ES = 15.33 [0.76] NAT). The ES correlated with Gleason score (r_s = 0.568, P = 0.033) and maximum cancer core length (ρ = 0.781; P < 0.001). The area under the curve for the ES (0.89) and VS (0.91) were not significantly different (P = 0.75) for the detection of SPCa amongst MRI lesions. Best ES estimated numerical threshold of 16.61 NAT led to a sensitivity of 100% and negative predictive value of 100%. The proportion of MRI lesions that were found to be positive for SPCa using this ES threshold (54%) was significantly higher (P < 0.001) than using the VS (24% of score 3, 4, 5) in a paired analysis using the McNemar test. In all, 53% of MRI lesions would have avoided biopsy sampling without missing significant disease.

CONCLUSION

Capturing heterogeneity of prostate cancer across multiple MRI sequences with the ES yielded high performances for the detection and stratification of SPCa. The ES outperformed the VS in predicting positivity of lesions, holding promise in the selection of targets for biopsy and calling for further understanding of this association.

Inosine monophosphate dehydrogenase 2 as a marker of aggressive and advanced prostate cancer

Introduction

There is a need for a new biochemical marker of aggressive prostate cancer (PCa). Inosine monophosphate dehydrogenase 2 (IMPDH2) is a candidate for such a marker – its activity is increased in certain tumors and neoplastic cell lines, including PCa, and may correlate with cancer aggressiveness.

Material and methods

IMPDH2 levels were measured in blood samples from 34 PCa patients. The results were analyzed and correlated with prostate-specific antigen (PSA), digital rectal examination (DRE), Gleason score, risk groups according to d'Amico and metastatic disease. Twenty healthy (non-PCa) patients served as the control group.

Results

There was no significant difference in IMPDH2 level between the PCa and control group, and no significant correlation between PSA and IMPDH2. IMPDH2 levels were significantly higher in the DRE (+) patients (148.5 ±174.8 vs. 33.4 ±46.4, p <0.05), in patients with metastatic disease (100.1 ±139.0 vs. 25.3 ±25.9, p <0.05) and in the high-risk group according to d'Amico (93.4 ±129.2 vs. 18.8 ±10.4, p <0.05). There was a significant correlation between the Gleason score and IMPDH2.

Conclusions

These results suggest that IMPDH2 is a promising candidate as a biomarker for those with advanced PCa and those at high risk of progression towards advanced PCa.

Long-term outcomes of partial prostate treatment with magnetic resonance imaging-guided brachytherapy for patients with favorable-risk prostate cancer

BACKGROUND

Partial prostate treatment has emerged as a potential method for treating patients with favorable-risk prostate cancer while minimizing toxicity. The authors previously demonstrated poor rates of biochemical disease control for patients with National Comprehensive Cancer Network (NCCN) intermediate-risk disease using partial gland treatment with brachytherapy. The objective of the current study was to estimate the rates of distant metastasis and prostate cancer-specific mortality (PCSM) for this cohort.

METHODS

Between 1997 and 2007, a total of 354 men with clinical T1c disease, a prostate-specific antigen (PSA) level < 15 ng/mL, and Gleason grade ≤3 + 4 prostate cancer underwent partial prostate treatment with brachytherapy to the peripheral zone under 0.5-Tesla magnetic resonance guidance. The cumulative incidences of metastasis and PCSM for the NCCN very low-risk, low-risk, and intermediate-risk groups were estimated. Fine and Gray competing risk regression was used to evaluate clinical factors associated with time to metastasis.

RESULTS

A total of 22 patients developed metastases at a median of 11.0 years (interquartile range, 6.9-13.9 years). The 12-year metastasis rates for patients with very low-risk, low-risk, and intermediate-risk disease were 0.8% (95% confidence interval [95% CI], 0.1%-4.4%), 8.7% (95% CI, 3.4%-17.2%), and 15.7% (95% CI, 5.7%-30.2%), respectively, and the 12-year PCSM estimates were 1.6% (95% CI, 0.1%-7.6%), 1.4% (95% CI, 0.1%-6.8%), and 8.2% (95% CI, 1.9%-20.7%), respectively. On multivariate analysis, NCCN risk category (low risk: hazard ratio, 6.34 [95% CI, 1.18-34.06; P = .03] and intermediate risk: hazard ratio, 6.98 [95% CI, 1.23-39.73; P = .03]) was found to be significantly associated with the time to metastasis.

CONCLUSIONS

Partial prostate treatment with brachytherapy may be associated with higher rates of distant metastasis and PCSM for patients with intermediate-risk disease after long-term follow-up. Treatment of less than the full gland may not be appropriate for this cohort.

Contemporary Incidence and Outcomes of Prostate Cancer Lymph Node Metastases

PURPOSE

The incidence of localized prostate cancer has decreased with shifts in prostate cancer screening. While recent population based studies demonstrated a stable incidence of locoregional prostate cancer, they categorized organ confined, extraprostatic and lymph node positive disease together. However, to our knowledge the contemporary incidence of prostate cancer with pelvic lymph node metastases remains unknown.

MATERIALS AND METHODS

We used SEER (Surveillance, Epidemiology and End Results) data from 2004 to 2014 to identify men diagnosed with prostate cancer. We analyzed trends in the age standardized prostate cancer incidence by stage. The impact of disease extent on mortality was assessed by adjusted Cox proportional hazard analysis.

RESULTS

During the study period the annual incidence of nonmetastatic prostate cancer decreased from 5,119.1 to 2,931.9 per million men (IR 0.57, 95% CI 0.56-0.58, p <0.01) while the incidence of pelvic lymph node metastases increased from 54.1 to 79.5 per million men (IR 1.47, 95% CI 1.33-1.62, p <0.01). The incidence of distant metastases in men 75 years old or older reached a nadir in 2011 compared to 2004 (IR 0.81, 95% CI 0.74-0.90, p <0.01) and it increased in 2012 compared to 2011 (IR 1.13, 95% CI 1.02-1.24, p <0.05). The risk of cancer specific mortality significantly increased in men diagnosed with pelvic lymph node metastases (HR 4.5, 95% CI 4.2-4.9, p <0.01) and distant metastases (HR 21.9, 95% CI 21.2-22.7, p <0.01) compared to men with nonmetastatic disease.

CONCLUSIONS

The incidence of pelvic lymph node metastases is increasing coincident with a decline in the detection of localized disease. Whether this portends an increase in the burden of advanced disease or simply reflects decreased lead time remains unclear. However, this should be monitored closely as the increase in N1 disease reflects an increase in incurable prostate cancer at diagnosis.

Conventional Versus Hypofractionated Radiation Therapy for Localized Prostate Cancer: A Meta-analysis of Randomized Noninferiority Trials

CONTEXT

Whether hypofractionated radiation therapy (RT) compared with conventionally fractionated RT provides comparable or possibly improved cancer control without increased toxicity in localized prostate cancer (PC) remains unknown.

OBJECTIVE

Realizing from the CHHiP trial that outcomes are highly sensitive to the dose fractionation schedule and number of treatments, we conducted a systematic review and meta-analysis selecting only the randomized noninferiority trials, because the randomized arms closely approximated one another in terms of the dose fractionation schedule, and compared cancer control and toxicity of hypofractionated RT with conventionally fractionated RT for localized PC.

EVIDENCE ACQUISITION

Randomized noninferiority trials evaluating hypofractionated (2.4-4Gy daily fractions for 15-30 treatments) versus conventionally fractionated RT (1.8-2Gy daily fractions for 40-45 treatments) in men with localized PC were selected. Studies that were not noninferiority trials, used extreme hypofractionation, or treated metastatic disease were excluded. Three studies were retained for analysis. Data were pooled using a random-effects model to determine hazard ratio (HR) and risk ratio (RR). Heterogeneity was assessed via chi-square test, I² statistics, and metaregression. The primary outcome was disease-free survival (DFS), defined as death from any cause or biochemical, local, regional, or distant progression.

EVIDENCE SYNTHESIS

Of the 5484 men, 3553 (64.8%) had intermediate-risk PC. Hypofractionated RT as compared with conventionally fractionated RT was associated with significantly improved DFS (HR 0.869; 95% confidence interval [CI], 0.757, 0.998; p=0.047), whereas overall survival was not (HR 0.84; 95% CI, 0.66, 1.07; p=0.16). Acute grade 2 or higher gastrointestinal toxicity was significantly increased with hypofractionation (RR 1.42; 95% CI 1.15, 1.77; p=0.002); however, this did not translate into late grade 2 or higher gastrointestinal toxicity. An increase in late grade 2 or higher genitourinary complications was observed (RR 1.18; 95% CI 0.98, 1.43; p=0.08).

CONCLUSIONS

Hypofractionated RT as compared with conventionally fractionated RT could improve DFS in men with intermediate-risk PC and, therefore, would be reasonable to consider in men who do not have risk factors for late genitourinary complications.

PATIENT SUMMARY

Treatment with a shorter course of radiation, using higher doses per treatment over fewer days, may be the preferred approach in appropriately selected patients with localized prostate cancer.