Association of Gleason Grade With Androgen Deprivation Therapy Duration and Survival Outcomes: A Systematic Review and Patient-Level Meta-analysis

Prostate-Specific Antigen Response to Androgen Deprivation Therapy in the Neoadjuvant Setting for High-Risk Prostate Adenocarcinoma (PIRANHA): Pooled Analysis of Two Randomized Clinical Trials

PURPOSE

A suboptimal prostate-specific antigen (PSA) response to neoadjuvant androgen deprivation therapy (ADT) among men who go on to receive definitive radiation therapy for prostate cancer might suggest the existence of castration-resistant disease or altered androgen receptor signaling. This in turn may portend worse long-term clinical outcomes, especially in men with high-risk disease. We set out to evaluate the prognostic impact of poor PSA response to neoadjuvant ADT in men with high-risk prostate cancer.

METHODS AND MATERIALS

This was a post hoc analysis of the multicenter TROG 03.04 RADAR and PCS IV randomized clinical trials. Inclusion criteria for this analysis were patients with high-risk prostate cancer (defined as Gleason score ≥8, initial PSA ≥20 ng/mL, or cT3a disease or higher) who received definitive radiation therapy, at least 18 months of ADT, and had a preradiation therapy PSA level drawn after at least 3 months of neoadjuvant ADT. Poor PSA response was defined as PSA >0.5 ng/mL. Cox regression and Fine-Gray models were used to test whether poor PSA response was associated with metastasis-free survival, biochemical recurrence, prostate-cancer specific mortality, and overall survival.

RESULTS

Nine hundred thirty men met inclusion criteria for this analysis. Median follow-up was 130 months (interquartile range [IQR], 89-154 months). After a median of 3 months (IQR, 3-4.2 months) of neoadjuvant ADT, the median PSA was 0.60 ng/mL (IQR, 0.29-1.59). Overall, 535 men (57%) had a PSA >0.5 ng/mL. Poor PSA response was associated with significantly worse metastasis-free survival (hazard ratio [HR], 3.93; P = .02), worse biochemical recurrence (subdistribution HR, 2.39; P = .003), worse prostate-cancer specific mortality (subdistribution HR, 1.50; P = .005), and worse overall survival (HR, 4.51; P = .05).

CONCLUSIONS

Patients with PSA >0.5 mg/mL after at least 3 months of neoadjuvant ADT had worse long-term clinical outcomes and should be considered for treatment intensification.

The Current Therapeutic Landscape for Metastatic Prostate Cancer

In 2024, there will be an estimated 1,466,718 cases of prostate cancer (PC) diagnosed globally, of which 299,010 cases are estimated to be from the US. The typical clinical approach for PC involves routine screening, diagnosis, and standard lines of treatment. However, not all patients respond to therapy and are subsequently diagnosed with treatment emergent neuroendocrine prostate cancer (NEPC). There are currently no approved treatments for this form of aggressive PC. In this review, a compilation of the clinical trials regimen to treat late-stage NEPC using novel targets and/or a combination approach is presented. The novel targets assessed include DLL3, EZH2, B7-H3, Aurora-kinase-A (AURKA), receptor tyrosine kinases, PD-L1, and PD-1. Among these, the trials administering drugs Alisertib or Cabozantinib, which target AURKA or receptor tyrosine kinases, respectively, appear to have promising results. The least effective trials appear to be ones that target the immune checkpoint pathways PD-1/PD-L1. Many promising clinical trials are currently in progress. Consequently, the landscape of successful treatment regimens for NEPC is extremely limited. These trial results and the literature on the topic emphasize the need for new preventative measures, diagnostics, disease specific biomarkers, and a thorough clinical understanding of NEPC.

Small Cell/Neuroendocrine Prostate Cancer: A Rare Treatment-Resistant Variant Presenting as Acute Onset Severe Back Pain

Adenocarcinoma of the prostate is the most frequent subtype of prostate cancer. Being an androgen-driven disease, androgen deprivation therapy (ADT) is one of the mainstay treatments for prostatic adenocarcinoma. ADT however can induce androgen resistance and can cause neuroendocrine differentiation of the cells and subsequently can lead to the emergence of neuroendocrine prostate cancer (NEPC). NEPC, despite being rare, is very aggressive with a very low survival period. The majority of the NEPC cases are treatment-emergent. There is no definite guideline on screening for the development of NEPC for patients who are on ADT. Our case highlights the lethality and aggressiveness of NEPC and the relationship between ADT and NEPC. More research is needed to compare different imaging techniques for early detection and identification of NEPC and to establish screening protocols for patients at risk of developing NEPC while on ADT.

Multi-Institutional Clinical Outcomes of Biopsy Gleason Grade Group 5 Prostate Cancers Treated With Contemporary High-Dose Radiation and Long-Term Androgen Deprivation Therapy

AIMS

This multicentric retrospective study reports long-term clinical outcomes of non-metastatic grade group 5 prostate cancers treated with external beam radiotherapy (EBRT) alone with long-term androgen deprivation therapy (ADT).

MATERIALS AND METHODS

Patients treated across 19 institutions were studied. The key endpoints that were evaluated were 5-year biochemical recurrence-free survival (bRFS), metastases-free survival (MFS), overall survival, together with EBRT-related acute and late toxicities. The impact of various prognostic factors on the studied endpoints was analysed using univariate and multivariate analyses.

RESULTS

Among the 462 patients, 88% (405) had Gleason 9 disease and 31% (142) had primary Gleason pattern 5. A prostate-specific membrane antigen positron emission tomography-computed tomography scan was used for staging in 33% (153), 80% (371) were staged as T3/T4 and 30% (142) with pelvic nodal disease. The median ADT duration was 24 months; 66% received hypofractionated EBRT and 71.4% (330) received pelvic nodal irradiation. With a median follow-up of 56 months, the 5-year bRFS, MFS and overall survival were 73.1%, 77.4% and 90.5%, respectively. Primary Gleason pattern 5 was associated with worse bRFS, MFS and overall survival with hazard ratios of 0.51 (95% confidence interval 0.35 to 0.73, P < 0.001), 0.64 (95% confidence interval 0.43 to 0.96, P = 0.031) and 0.52 (95% confidence interval 0.28 to 0.97, P = 0.040), respectively, whereas pelvic nodal disease was associated with worse bRFS (hazard ratio 0.67, 95% confidence interval 0.46 to 0.98, P = 0.039) and MFS (hazard ratio 0.56, 95% confidence interval 0.37 to 0.85, P = 0.006). The acute and late radiation-related toxicities were low overall and pelvic nodal irradiation was associated with higher toxicities.

CONCLUSION

Contemporary EBRT and long-term ADT led to excellent 5-year clinical outcomes and low rates of toxicity in this cohort of non-metastatic grade group 5 prostate cancers. Primary Gleason pattern 5 and pelvic node disease portends inferior clinical outcomes.

Duration of androgen deprivation with radio-therapy for high-risk or locally advanced prostate cancer: A network meta-analysis

OBJECTIVE

To evaluate various outcomes of different lengths of androgen deprivation therapy in high- and very-high-risk prostate cancer, we conducted a network meta-analysis of randomized trials. The treatment of high-risk PC comprises the use of radical radiotherapy associated with various durations of androgen deprivation therapy, with luteinizing hormone releasing hormone analogues initiated during or immediately before the beginning of radiation.

METHODS AND MATERIALS

This study followed the PRISMA extension statement to report network meta-analyses. We systematically searched online databases, including MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials, for all randomized trials published up to April 2022. The primary outcomes were overall survival, prostate cancer-specific mortality, and metastasis-free survival. Network meta-analyses were performed under a Bayesian framework using the "gemtc" package (https://gemtc.drugis.org).

RESULTS

The network meta-analysis included 12 studies (10 treatments) on overall survival outcomes. None of the arms showed superiority to radiotherapy alone with respect to overall deaths. Nine studies and 10 treatment arms had prostate cancer-specific mortality data. Overall, 36 months of adjuvant androgen deprivation therapy resulted in a better outcome than radiotherapy alone, three months of neoadjuvant androgen deprivation therapy, or 12 or 24 months of adjuvant androgen reprivation therapy, and it was the better treatment (73%) in terms of cancer mortality. Treatment involving luteinizing hormone releasing hormone analogues for 6 months before and during radiotherapy ranked the highest in reducing distant metastases (42%).

CONCLUSIONS

We found that 36 months of adjuvant androgen deprivation therapy after radiotherapy was the optimal duration of endocrine treatment with regard to cancer mortality for high-risk and locally advanced prostate cancer.

Molecular Mechanisms of Noncoding RNA in the Occurrence of Castration-Resistant Prostate Cancer

Although several therapeutic options have been shown to improve survival of most patients with prostate cancer, progression to castration-refractory state continues to present challenges in clinics and scientific research. As a highly heterogeneous disease entity, the mechanisms of castration-resistant prostate cancer (CRPC) are complicated and arise from multiple factors. Among them, noncoding RNAs (ncRNAs), the untranslated part of the human transcriptome, are closely related to almost all biological regulation, including tumor metabolisms, epigenetic modifications and immune escape, which has encouraged scientists to investigate their role in CRPC. In clinical practice, ncRNAs, especially miRNAs and lncRNAs, may function as potential biomarkers for diagnosis and prognosis of CRPC. Therefore, understanding the molecular biology of CRPC will help boost a shift in the treatment of CRPC patients. In this review, we summarize the recent findings of miRNAs and lncRNAs, discuss their potential functional mechanisms and highlight their clinical application prospects in CRPC.

Adjusting the duration of androgen deprivation therapy (ADT) based on nadir PSA for high risk localized prostate cancer patients treated with definitive external beam radiation therapy and ADT

BACKGROUND

A nadir Prostate-Specific Antigen (nPSA) of 0.06 ng/mL has been shown to be a strong independent predictor of biochemical recurrence-free survival (bRFS) in patients with intermediate or high-risk (HR) prostate cancer treated with definitive external beam radiation therapy (RT) and androgen deprivation therapy (ADT). We aimed to examine the association between the duration of ADT and bRFS in HR localized prostate cancer, based on nPSA.

METHODS

Between 1998 and 2015, 204 patients with HR localized prostate cancer were identified. Of them, 157 patients (77.0%) reached the desired nPSA of < 0.06 ng/mL (favorable group), while 47 (23.0%) did not (unfavorable group). Duration of ADT varied among patients depending on physician preference, patient tolerance, and/or compliance. Survival outcomes were calculated using Kaplan-Meier methods and predictors of outcomes using multi-variable cox regression model.

RESULTS

In the favorable group, ADT for at least 12 months lead to superior bRFS compared to ≤ 9 months of ADT (P = 0.036). However, no significant difference was seen when examining the value of receiving ADT beyond 12, 18, or 24 months, respectively. On univariate analysis for bRFS, the use of ADT for at least 12 months was significant (P = 0.012) as well as time to nadir PSA (tnPSA), (≤ 6 vs > 6 months); (P = 0.043). The presenting T stage was borderline significant (HR 3.074; 95% CI 0.972-9.719; P = 0.056), while PSA at presentation, Gleason Score and age were not. On multivariate analysis, the use of ADT for 12 months (P = 0.012) and tnPSA (P = 0.037) remained significant. In the unfavorable group, receiving ADT beyond 9 and 12 months was associated with improved bRFS (P = 0.044 and 0.019, respectively). However, beyond 18 months, there was no significant difference.

CONCLUSION

In HR localized prostate cancer patients treated with definitive RT and ADT, the total duration of ADT may be adjusted according to treatment response using nPSA. In patients reaching a nPSA below 0.06 ng/mL, a total of 12 months of ADT may be sufficient, while in those not reaching a nPSA below 0.06 ng/mL, a total duration of 18 months is required.

Grade group system and plasma androgen receptor status in the first line treatment for metastatic castration resistant prostate cancer

In localized prostate cancer (PCa), Grade Group (GG) and Gleason Score (GS) have a well-established prognostic role. In metastatic castration resistant prostate cancer (mCRPC), the prognostic role of GS and GG is less defined. In first-line treatment of mCRPC, androgen receptor (AR)-directed drugs (abiraterone acetate, enzalutamide) and docetaxel represent the referring options. There is no evidence that the GS/GG systems can add information to guide the choice between AR-directed drugs and docetaxel in the first-line setting of mCRPC. Nowadays there are no validated biomarkers, which define patients who may benefit or not from hormonal treatments or chemotherapy. Androgen receptor (AR) copy number variations (CNV) are predictive factors of poor response to abiraterone and enzalutamide. There are no available data about the association between AR CNV and GG. In this retrospective study, we analysed the association of the highest GG score with AR CNV and their impact on the clinical outcome of AR-directed drugs and docetaxel as first-line therapy for mCRPC patients. Patients benefit from docetaxel, abiraterone or enzalutamide regardless the GG. However, the presence of GG5 and AR CNV gain identifies a subgroup of patients with poor prognosis, which could benefit from front-line docetaxel instead of AR-directed drugs.

Conventional dose versus dose escalated radiotherapy including high-dose-rate brachytherapy boost for patients with Gleason score 9-10 clinical localized prostate cancer

As several recent researches focus on the importance of Gleason 9-10, we examine the role of radiotherapy dose escalation in those patients. We analyzed 476 patients with Gleason score 9-10 prostate cancer treated with radiotherapy. Of them, 127 patients were treated with conventional-dose external beam radiotherapy (Conv RT) and 349 patients were treated with high-dose radiotherapy (HDRT; 249 patients received high-dose-rate brachytherapy boost + external beam radiotherapy [HDR boost] and 100 patients received intensity-modulated radiotherapy [IMRT]). We compared these treatment groups using multi-institutional retrospective data. The patients had a median follow-up period of 66.3 months. HDRT showed superior biochemical disease-free survival (bDFS) rate (85.2%; HDR boost 84.7% and IMRT 86.6%) to Conv RT (71.1%, p < 0.0001) at 5 years, with a hazard ratio of 0.448. There were borderline difference in prostate cancer-specific mortality (PCSM; 4.3% and 2.75%, p = 0.0581), and distant metastasis-free survival (DMFS; 94.4% and 89.6%, p = 0.0916) rates at 5-years between Conv RT and HDRT group. Dose escalated radiotherapy showed better bDFS, borderline improvement in PCSM, and equivocal outcome in DMFS in with clinically localized Gleason 9-10 prostate cancer.

Performance of a Prostate-Specific Membrane Antigen Positron Emission Tomography/Computed Tomography-Derived Risk-Stratification Tool for High-risk and Very High-risk Prostate Cancer

IMPORTANCE

Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) can detect low-volume, nonlocalized (ie, regional or metastatic) prostate cancer that was occult on conventional imaging. However, the long-term clinical implications of PSMA PET/CT upstaging remain unclear.

OBJECTIVES

To evaluate the prognostic significance of a nomogram that models an individual's risk of nonlocalized upstaging on PSMA PET/CT and to compare its performance with existing risk-stratification tools.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included patients diagnosed with high-risk or very high-risk prostate cancer (ie, prostate-specific antigen [PSA] level >20 ng/mL, Gleason score 8-10, and/or clinical stage T3-T4, without evidence of nodal or metastatic disease by conventional workup) from April 1995 to August 2018. This multinational study was conducted at 15 centers. Data were analyzed from December 2020 to March 2021.

EXPOSURES

Curative-intent radical prostatectomy (RP), external beam radiotherapy (EBRT), or EBRT plus brachytherapy (BT), with or without androgen deprivation therapy.

MAIN OUTCOMES AND MEASURES

PSMA upstage probability was calculated from a nomogram using the biopsy Gleason score, percentage positive systematic biopsy cores, clinical T category, and PSA level. Biochemical recurrence (BCR), distant metastasis (DM), prostate cancer-specific mortality (PCSM), and overall survival (OS) were analyzed using Fine-Gray and Cox regressions. Model performance was quantified with the concordance (C) index.

RESULTS

Of 5275 patients, the median (IQR) age was 66 (60-72) years; 2883 (55%) were treated with RP, 1669 (32%) with EBRT, and 723 (14%) with EBRT plus BT; median (IQR) PSA level was 10.5 (5.9-23.2) ng/mL; 3987 (76%) had Gleason grade 8 to 10 disease; and 750 (14%) had stage T3 to T4 disease. Median (IQR) follow-up was 5.1 (3.1-7.9) years; 1221 (23%) were followed up for at least 8 years. Overall, 1895 (36%) had BCR, 851 (16%) developed DM, and 242 (5%) died of prostate cancer. PSMA upstage probability was significantly prognostic of all clinical end points, with 8-year C indices of 0.63 (95% CI, 0.61-0.65) for BCR, 0.69 (95% CI, 0.66-0.71) for DM, 0.71 (95% CI, 0.67-0.75) for PCSM, and 0.60 (95% CI, 0.57-0.62) for PCSM (P < .001). The PSMA nomogram outperformed existing risk-stratification tools, except for similar performance to Staging Collaboration for Cancer of the Prostate (STAR-CAP) for PCSM (eg, DM: PSMA, 0.69 [95% CI, 0.66-0.71] vs STAR-CAP, 0.65 [95% CI, 0.62-0.68]; P < .001; Memorial Sloan Kettering Cancer Center nomogram, 0.57 [95% CI, 0.54-0.60]; P < .001; Cancer of the Prostate Risk Assessment groups, 0.53 [95% CI, 0.51-0.56]; P < .001). Results were validated in secondary cohorts from the Surveillance, Epidemiology, and End Results database and the National Cancer Database.

CONCLUSIONS AND RELEVANCE

These findings suggest that PSMA upstage probability is associated with long-term, clinically meaningful end points. Furthermore, PSMA upstaging had superior risk discrimination compared with existing tools. Formerly occult, PSMA PET/CT-detectable nonlocalized disease may be the main driver of outcomes in high-risk patients.

Moderately Hypofractionated Radiotherapy and Androgen Deprivation Therapy for High-risk Localised Prostate Cancer: Predictors of Long-term Biochemical Control and Toxicity

AIMS

There is a paucity of long-term data on outcomes of high-risk prostatic adenocarcinoma after moderately hypofractionated radiotherapy with elective nodal treatment and long-term androgen deprivation therapy (ADT). We report long-term control and toxicity outcomes and analyse the predictors of failure and toxicity.

MATERIALS AND METHODS

The records of 120 consecutive high-risk prostate cancer patients treated in a single institution between February 2012 and December 2016 were retrospectively analysed. A moderately hypofractionted radiotherapy (HypoRT) regimen of 60 Gy in 20 fractions over 4 weeks with simultaneous elective pelvic irradiation to 44 Gy in 20 fractions with intensity-modulated radiotherapy was used, together with long-term ADT with either orchiectomy or medical castration for a total duration of 2-3 years. We analysed biochemical control, metastasis-free survival and late toxicities and their predictive factors using survival analysis.

RESULTS

Patients had locally advanced cancers (cT3 77.5%, median pretreatment prostate-specific antigen 30 ng/ml, Gleason score 8-10 in 45.8%). The median follow-up time was 70 months. The 3- and 5-year probability of freedom from biochemical progression was 93% and 80%, respectively. The 5-year probability of freedom from local relapse/intra-pelvic nodal relapse/distant metastases as the site of first failure was 96%/97%/86%, respectively. Gleason score 8-10 and medical ADT for 2-3 years (as opposed to orchidectomy) were independent risk factors for distant metastases. A total of 18 grade 2 and above late gastrointestinal toxicity events and a total of 23 grade 2 and above late genitourinary toxicity events were documented. Patients who underwent a transurethral resection of prostate prior to radiotherapy had worse urological toxicity.

CONCLUSIONS

HypoRT with elective nodal treatment results in excellent pelvic control. Distant metastases are the primary mode of failure. Risk of metastases is associated with Gleason score and the duration of ADT. Late urinary toxicities are more common in those with prior transurethral resection of prostate.

Favorable prognosis of patients who received adjuvant androgen deprivation therapy after radiotherapy achieving undetectable levels of prostate-specific antigen in high- or very high-risk prostate cancer

Introduction

To determine the prognostic significance of long-term adjuvant androgen deprivation therapy (A-ADT) over 1 year in achieving undetectable levels of prostate-specific antigen (PSA) less than 0.001 ng/mL in prostate cancer patients with high- or very high-risk prostate cancer who underwent radiotherapy (RT).

Materials and methods

A total of 197 patients with prostate cancer received RT, with a follow-up of ≥12 months. Biochemical failure was defined as PSA ≥nadir + 2 ng/mL after RT. We analyzed clinical outcomes, including survival, failure patterns, and prognostic factors affecting outcomes.

Results

Biochemical failure-free survival (BCFFS), clinical failure-free survival, distant metastasis-free survival, cancer-specific survival, and overall survival (OS) rates at 5 years were 91.1%, 95.4%, 96.9%, 99.5%, and 89.1%, respectively. Administration of long-term A-ADT significantly predicted favorable BCFFS (p = 0.027) and OS (p < 0.001) in multivariate analysis. Nadir PSA ≤0.001 ng/mL was an independent prognostic factor for BCFFS (p = 0.006) and OS (p = 0.021). The use of long-term A-ADT significantly affected nadir PSA ≤0.001 ng/mL (p < 0.001). The patients with A-ADT for 1 year or longer had better BCFFS or OS than those for less than 1 year or those without A-ADT (p < 0.001). The best prognosis was demonstrated in patients treated with long-term A-ADT and nadir PSA ≤0.001 ng/mL in BCFFS (p < 0.001).

Conclusion

The addition of long-term A-ADT over 1 year to RT demonstrated good treatment outcomes in patients with locally advanced prostate cancer. Achieving a nadir PSA value ≤0.001 ng/mL using combination therapy with RT and A-ADT is a powerful clinical predictor of treatment outcomes.

Utilization of multimodality therapy with primary radical prostatectomy versus radiation therapy for Gleason 8-10 prostate cancer

PURPOSE

The role of multimodality therapy (MMT) in the treatment of Gleason 8-10 prostate cancer remains controversial. We sought to evaluate factors associated with MMT utilization for primary radical prostatectomy (RP) and primary radiation therapy (RT).

METHODS AND MATERIALS

From the National Cancer Database, we conducted a retrospective review of 81,528 men with National Cancer Center Network Gleason 8-10 prostate cancer diagnosed between 2004 and 2015, who underwent (1) primary RP with or without early postoperative external beam RT (EBRT) or (2) primary RT (androgen deprivation therapy + EBRT) with or without brachytherapy (BT) boost. Using multivariable logistic regression models, we evaluated factors associated with the utilization of MMT, defined as early postoperative EBRT for primary RP or BT boost for primary RT.

RESULTS

For primary RP, the percentages of men who underwent MMT for Gleason 8 and 9-10 disease were 12.2% and 24.1%, respectively. On multivariable logistic regression, men with Gleason 9-10 were more likely to undergo MMT (odds ratio 1.03 [1.02, 1.04]), although adverse pathologic features such as T3b-4 (1.24 [1.23, 1.25]) disease demonstrated the strongest associations. For primary RT, the percentages of men who underwent BT boost for Gleason 8 and 9-10 disease were 11.8% and 9.8%, respectively. On multivariable logistic regression, men with Gleason 9-10 disease were less likely to receive BT boost (0.99 [0.98, 0.99]).

CONCLUSIONS

Men with more aggressive Gleason 9 disease were more likely to undergo MMT if they underwent primary RP but not primary RT. Further blood-based or imaging biomarkers may aid in identifying optimal candidates for MMT, especially for primary RT.

Inhibition of the Lysophosphatidylinositol Transporter ABCC1 Reduces Prostate Cancer Cell Growth and Sensitizes to Chemotherapy

Expression of ATP-binding cassette (ABC) transporters has long been implicated in cancer chemotherapy resistance. Increased expression of the ABCC subfamily transporters has been reported in prostate cancer, especially in androgen-resistant cases. ABCC transporters are known to efflux drugs but, recently, we have demonstrated that they can also have a more direct role in cancer progression. The pharmacological potential of targeting ABCC1, however, remained to be assessed. In this study, we investigated whether the blockade of ABCC1 affects prostate cancer cell proliferation using both in vitro and in vivo models. Our data demonstrate that pharmacological inhibition of ABCC1 reduced prostate cancer cell growth in vitro and potentiated the effects of Docetaxel in vitro and in mouse models of prostate cancer in vivo. Collectively, these data identify ABCC1 as a novel and promising target in prostate cancer therapy.

Transcriptomic Heterogeneity of Gleason Grade Group 5 Prostate Cancer

Gleason grade group (GG) 5 prostate cancer has been associated with an aggressive natural history, and retrospective data support a role for treatment intensification. However, clinical outcomes remain heterogeneous in this cohort, and intensified treatments carry an increased risk of adverse events. We sought to explore the transcriptomic heterogeneity of GG 5 tumors by querying transcriptomic data from the tumors of 2138 patients with GG 5 disease who underwent prostatectomy. Four distinct consensus clusters were identified with respect to differential transcriptional activation of hallmark pathways, with distinct molecular subtyping profiles and different average genomic risks (AGRs). One cluster, accounting for 325 tumors (15.2% of the population), was enriched for genes related to the cell cycle/proliferation, metabolic pathways, androgen response pathways, and DNA repair, and had a higher AGR than the other clusters (p < 0.001). This clustering, with an identification of a high genomic risk cluster, was subsequently validated in a separate cohort of 1921 patients as well as a third cohort of 201 patients. The latter cohort had outcomes available, and it was found that patients in the high genomic risk cluster had significantly worse distant metastasis-free survival than the other clusters. Tumors in this high genomic risk cluster of GG 5 disease may be particularly likely to benefit from treatment intensification. PATIENT SUMMARY: In this report, we examined differences in gene expression in tumors from men with Gleason grade group 5 prostate cancer. We identified significant diversity, with one specific subgroup of tumors associated with expression profiles that suggest a worse prognosis.

Association Between New Unconfirmed Bone Lesions and Outcomes in Men With Metastatic Castration-Resistant Prostate Cancer Treated With Enzalutamide: Secondary Analysis of the PREVAIL and AFFIRM Randomized Clinical Trials

Importance

For men with metastatic castration-resistant prostate cancer (mCRPC) whose condition is responding to enzalutamide, new unconfirmed bone lesions detected at posttreatment scinitigraphy may reflect an osteoblastic reaction that represents healing, known as pseudoprogression, which can lead to premature discontinuation of therapy.

Objective

To determine the association between new unconfirmed lesions detected on a follow-up bone scintigram (bone scan) and outcomes in enzalutamide-treated men with mCRPC.

Design, Setting, and Participants

This post hoc, retrospective secondary analysis of 1672 enzalutamide-treated men from 2 phase 3, randomized mCRPC studies (PREVAIL and AFFIRM) before or after treatment with docetaxel was conducted from April 12, 2018, to July 25, 2019. Participants were men from the enzalutamide groups of the 2 studies with a decrease in prostate-specific antigen level at any time or with stable disease or soft-tissue disease responding to treatment based onradiologic findings.

Intervention

Enzalutamide, 160 mg once daily.

Main Outcomes and Measures

The clinical significance of new lesions detected on the first (early) or second (late) posttreatment bone scan, without an unfavorable change in prostate-specific antigen level or soft-tissue progression, was investigated. Associations of new unconfirmed lesions with radiographic progression-free survival, overall survival, decrease in prostate-specific antigen level, objective response in soft tissue, and quality of life were evaluated.

Results

Among the 643 men (median age, 72 years [range, 43-93 years]) in PREVAIL, early and late unconfirmed lesions were observed in 177 men (27.5%) with stable disease or disease responding to enzalutamide. Among the 404 men (median age, 70 years [range, 41-88 years]) in AFFIRM, early and late unconfirmed lesions were observed in 73 men (18.1%) with stable disease or disease responding to enzalutamide. In PREVAIL, men with new unconfirmed lesions had median radiographic progression-free survival (hazard ratio [HR], 1.37 [95% CI, 0.81-2.30]; P = .23) and median overall survival (HR, 1.25 [95% CI, 0.85-1.83]) in the chemotherapy-naive setting similar to men those of men without such new lesions. In AFFIRM, the median overall survival (HR, 1.94 [95% CI, 1.10-3.44]) was reduced among men with unconfirmed bone lesions, but the median radiographic progression-free survival was not reduced (HR, 1.21 [95% CI, 0.83-1.75]; P = .32). Quality of life over time was similar regardless of the presence of new unconfirmed lesions detected on a follow-up bone scan in either setting.

Conclusions and Relevance

These results suggest that new unconfirmed lesions detected on follow-up bone scans may represent pseudoprogression in men with mCRPC and are indicative of a favorable treatment response to enzalutamide. The detection of new unconfirmed bone lesions in men with mCRPC that responded to treatment with enzalutamide after docetaxel appears to be associated with worse overall survival and may represent true progression, thus highlighting the need for improved functional bone metastasis imaging.

Trial Registration

ClinicalTrials.gov Identifiers: NCT01212991 and NCT00974311.

Local Failure and Survival After Definitive Radiotherapy for Aggressive Prostate Cancer: An Individual Patient-level Meta-analysis of Six Randomized Trials

BACKGROUND

The importance of local failure (LF) after treatment of high-grade prostate cancer (PCa) with definitive radiotherapy (RT) remains unknown.

OBJECTIVE

To evaluate the clinical implications of LF after definitive RT.

DESIGN, SETTING, AND PARTICIPANTS

Individual patient data meta-analysis of 992 patients (593 Gleason grade group [GG] 4 and 399 GG 5) enrolled in six randomized clinical trials.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Multivariable Cox proportional hazard models were developed to evaluate the relationship between overall survival (OS), PCa-specific survival (PCSS), and distant metastasis (DM)-free survival (DMFS) and LF as a time-dependent covariate. Markov proportional hazard models were developed to evaluate the impact of specific transitions between disease states on these endpoints.

RESULTS AND LIMITATIONS

Median follow-up was 6.4 yr overall and 7.2 yr for surviving patients. LF was significantly associated with OS (hazard ratio [HR] 1.70 [95% confidence interval {CI} 1.37-2.10]), PCSS (3.10 [95% CI 2.33-4.12]), and DMFS (HR 1.92 [95% CI 1.54-2.39]), p < 0.001 for all). Patients who had not transitioned to the LF state had a significantly lower hazard of transitioning to a PCa-specific death state than those who transitioned to the LF state (HR 0.13 [95% CI 0.04-0.41], p < 0.001). Additionally, patients who transitioned to the LF state had a greater hazard of DM or death (HR 2.46 [95% CI 1.22-4.93], p = 0.01) than those who did not.

CONCLUSIONS

LF is an independent prognosticator of OS, PCSS, and DMFS in high-grade localized PCa and a subset of DM events that are anteceded by LF events. LF events warrant consideration for intervention, potentially suggesting a rationale for upfront treatment intensification. However, whether these findings apply to all men or just those without significant comorbidity remains to be determined.

PATIENT SUMMARY

Men who experience a local recurrence of high-grade prostate cancer after receiving upfront radiation therapy are at significantly increased risks of developing metastases and dying of prostate cancer.

Gleason pattern 5 is associated with an increased risk for metastasis following androgen deprivation therapy and radiation: An analysis of RTOG 9202 and 9902

BACKGROUND/PURPOSE

Stratification of Gleason score (GS) into three categories (2-6, 7, and 8-10) may not fully utilize its prognostic discrimination, with Gleason pattern 5 (GP5) previously identified as an independent adverse factor.

MATERIALS/METHODS

Patients treated on RTOG 9202 (n = 1292) or RTOG 9902 (n = 378) were pooled and assessed for association of GS and GP5 on biochemical failure (BF), local failure (LF), distant metastasis (DM), and overall survival (OS). Fine and Gray's regression and cumulative incidence methods were used for univariate and multivariate analyses.

RESULTS

With median follow-up of 9.4 years, patients with GS 8-10 with GP5 had worse outcome than GS 4 + 4 for DM on both RTOG9202 (p = 0.038) and RTOG9902 (p < 0.001) with a trend toward worse OS (p = 0.059 and p = 0.089, respectively), but without differences in BF or LF. At 10-years DM was higher by 11% (RTOG 9202) and 18% (RTOG 9902) with GP5 compared to GS 4 + 4. On multivariate analysis restricted to long-term androgen deprivation therapy the presence of GP5 substantially increased distant metastasis (HR = 0.43, 95%CI: 0.24-0.76, p = 0.0039) with a trend toward worse OS (HR:0.74, 95% CI:0.54-1.0, p = 0.052) without association with LF (HR:0.55, 95%CI:0.28-1.09, p = 0.085) or BF (HR:1.15, 95%CI:0.84-1.59, p = 0.39). We did not observed substantial differences between Gleason 3 + 5, 5 + 3, or Gleason 9-10.

CONCLUSIONS

These results validate GP5 as an independent prognostic factor which is strongest for DM. As a result GP5 should be considered when stratifying patients with GS 8 and may be a patient population in which to evaluate newly approved systemic therapies or additional local treatments.

Application of a Prognostic Stratification System for High-risk Prostate Cancer to Patients Treated With Radiotherapy: Implications for Treatment Optimization

OBJECTIVES

We applied an established prognostic model to high-risk prostate cancer (HRPC) patients treated with radiotherapy (RT) and evaluated the influence of clinical and treatment variables on treatment outcomes.

METHODS

In total, 1075 HRPC patients undergoing definitive radiotherapy (RT) between 1995 and 2010 were retrospectively reviewed. Median follow-up was 62.3 months. Patients received either dose-escalated external beam radiotherapy (n=628, EBRT) or combined-modality radiotherapy (n=447, pelvic RT and low-dose rate brachytherapy boost, CMRT). 82.9% received androgen-deprivation therapy (ADT). A prognostic model stratified patients into predefined groups (good, intermediate, and poor). Kaplan-Meier methods and Cox proportional hazards regressions assessed biochemical failure (BF), distant metastasis (DM), prostate cancer-specific mortality (PCSM) and overall mortality (OM). C-indices analyzed predictive value.

RESULTS

The model was prognostic; C-indices for BF, DM, PCSM and OM were: 0.62, 0.64, 0.61, and 0.57. On multivariate analysis, CMRT and longer ADT (≥24 mo) were associated with improved BF, DM, and PCSM. Gleason score (GS) 9-10 was the strongest predictor of PCSM. C-indices for BF, DM, PCSM, and OM using a 4-compartment model incorporating GS 9-10 were: 0.62, 0.65, 0.68, and 0.56. In poor-prognosis patients (GS 8-10+additional risk factors), CMRT+LTADT (>12 mo) had 10-year PCSM (3.7%±3.6%), comparing favorably to 25.8%±9.2% with EBRT+LTADT.

CONCLUSIONS

The model applies to high-risk RT patients; GS 9-10 remains a powerful predictor of PCSM. Comparing similar prognosis patients, CMRT is associated with improved disease-specific outcomes relative to EBRT. In poor-prognosis patients, CMRT+LTADT yields superior 10-year PCSM, potentially improving RT treatment personalization for those with HRPC.