Management of Biochemically Recurrent Prostate Cancer: Ensuring the Right Treatment of the Right Patient at the Right Time

Biochemical recurrence in patients with prostate cancer after primary definitive therapy: treatment based on risk stratification

BACKGROUND

Nearly one-third of patients with prostate cancer (PCa) experience biochemical recurrence (BCR) after primary definitive treatment. BCR increases the risk of distant metastasis and mortality in patients with prognostically unfavorable features. These patients are best managed with a tailored treatment strategy incorporating risk stratification using clinicopathological factors, next-generation imaging, and genomic testing.

OBJECTIVE

This narrative review examines the utility of risk stratification for the management of patients with BCR in the context of clinical trial data, referencing the latest recommendations by European and US medical societies.

METHODS

PubMed was searched for relevant studies published through May 21 2023 on treatment of patients with BCR after radical prostatectomy (RP) or external beam radiotherapy (EBRT).

RESULTS

European and US guidelines support the risk-stratified management of BCR. Post-RP, salvage EBRT (with or without androgen deprivation therapy [ADT]) is an accepted treatment option for patients with BCR. Post-EBRT, local salvage therapies (RP, cryotherapy, high-intensity focused ultrasound, stereotactic body radiotherapy, and low-dose-rate and high-dose-rate brachytherapy) have demonstrated comparable relapse-free survival rates but differing adverse event profiles, short and long term. Local salvage therapies should be used for local-only relapses while ADT should be considered for regional or distant relapses. In practice, patients often receive ADT, with varying guidance for intermittent ADT vs. continuous ADT, due to consideration of quality-of-life effects.

CONCLUSIONS

Despite a lack of consensus for BCR treatment among guideline associations and medical societies, risk stratification of patients is essential for personalized treatment approaches, as it allows for an informed selection of therapeutic strategies and estimation of adverse events. In lower-risk disease, observation is recommended while in higher-risk disease, after failed repeat local therapy, ADT and/or clinical trial enrollment may be appropriate. Results from ongoing clinical studies of patients with BCR should provide consensus for management.

Updates on Management of Biochemical Recurrent Prostate Cancer

OPINION STATEMENT

Patients with biochemical recurrent prostate cancer (BCR) are a heterogeneous group, whereby a personalized approach to management is critical. Patients with high-risk features such as PSA doubling time (PSADT) ≤ 9-12 months warrant earlier imaging for metastasis detection and consideration for intensified therapy (beyond intermittent androgen deprivation alone) during this phase of BCR-only disease. The BCR phase represents a unique opportunity to impact disease survival and delay metastasis progression. There is compelling evidence from the EMBARK trial that ADT monotherapy is no longer the optimal consideration for high-risk BCR patients.

Novel hormone therapy and coordination of care in high-risk biochemically recurrent prostate cancer

Biochemical recurrence (BCR) occurs in 20-50% of patients with prostate cancer (PCa) undergoing primary definitive treatment. Patients with high-risk BCR have an increased risk of metastatic progression and subsequent PCa-specific mortality, and thus could benefit from treatment intensification. Given the increasing complexity of diagnostic and therapeutic modalities, multidisciplinary care (MDC) can play a crucial role in the individualized management of this patient population. This review explores the role for MDC when evaluating the clinical evidence for the evolving definition of high-risk BCR and the emerging therapeutic strategies, especially with novel hormone therapies (NHTs), for patients with either high-risk BCR or oligometastatic PCa. Clinical studies have used different characteristics to define high-risk BCR and there is no consensus regarding the definition of high-risk BCR nor for management strategies. Next-generation imaging and multigene panels offer potential enhanced patient identification and precision-based decision-making, respectively. Treatment intensification with NHTs, either alone or combined with radiotherapy or metastasis-directed therapy, has been promising in clinical trials in patients with high-risk BCR or oligometastases. As novel risk-stratification and treatment options as well as evidence-based literature evolve, it is important to involve a multidisciplinary team to identify patients with high-risk features at an earlier stage, and make informed decisions on the treatments that could optimize their care and long-term outcomes. Nevertheless, MDC data are scarce in the BCR or oligometastatic setting. Efforts to integrate MDC into the standard management of this patient population are needed, and will likely improve outcomes across this heterogeneous PCa patient population.

Can 68 Ga-PSMA positron emission tomography and multiparametric MRI guide treatment for biochemical recurrence after radical prostatectomy?

OBJECTIVE

To evaluate the role of multiparametric magnetic resonance imaging (mpMRI) and Gallium-68 (68 Ga)-prostate-specific membrane antigen (PSMA) positron emission tomography (PET)/computed tomography (CT) in guiding salvage therapy for patients with biochemical recurrence (BCR) post-radical prostatectomy.

PATIENTS AND METHODS

Patients were evaluated with paired mpMRI and 68 Ga-PSMA PET/CT scans for BCR (prostate-specific antigen [PSA] >0.2 ng/mL). Patient, tumour, PSA and imaging characteristics were analysed with descriptive statistics.

RESULTS

A total of 117 patients underwent paired scans to investigate BCR, of whom 53.0% (62/117) had detectable lesions on initial scans and 47.0% (55/117) did not. Of those without detectable lesions, 8/55 patients proceeded to immediate salvage radiotherapy (sRT) and 47/55 were observed. Of patients with negative imaging who were initially observed, 46.8% (22/47) did not reach threshold for repeat imaging, while 53.2% were rescanned due to rising PSA levels. Of these rescanned patients, 31.9% (15/47) were spared sRT due to proven distant disease, or due to absence of disease on repeat imaging. Of the original 117 patients, 53 (45.3%) were spared early sRT due to absence of disease on imaging or presence of distant disease, while those undergoing delayed sRT still maintained good PSA responses. Of note, patients with high-risk features who underwent sRT despite negative imaging demonstrated satisfactory PSA responses to sRT. Study limitations include the observational design and absence of cause-specific or overall survival data.

CONCLUSION

Our findings support the use of mpMRI and 68 Ga-PSMA PET/CT in guiding timing and necessity of salvage therapy tailored to detected lesions, with potential to reduce unnecessary sRT-related morbidity. Larger or randomized trials are warranted to validate this.

Management of high-risk and post-operative non-metastatic prostate cancer in Catalonia: an expert Delphi consensus

BACKGROUND

To reach a consensus on recommendations for the management of high-risk and post-operative non-metastatic prostate cancer by a group of Radiation Oncologists in Catalonia dedicated to prostate cancer.

METHODS

A modified Delphi approach was employed to reach consensus on controversial topics in Radiation Oncology on high-risk non-metastatic (eight questions) and post-operative (eight questions) prostate cancer. An agreement of at least 75% was considered as consensus. The survey was electronically sent 6 weeks before an expert meeting where topics were reviewed and discussed. A second-round survey for the controversial questions only was sent and answered by participants after the meeting.

RESULTS

After the first round of the survey, 19 experienced Radiation Oncologists attended the meeting and 74% fulfilled the second-round online questionnaire. An agreement of 9 of the 16 questions was accounted for the first round. After the meeting, an additional agreement was reached in 3 questions leading to a final consensus on 12 of the 16 questions. There are still controversial topics like the use of PET for staging of high-risk and post-operative non-metastatic prostate cancer and the optimal dose to the prostate bed in the salvage setting.

CONCLUSION

This consensus contributes to establish recommendations and a framework to help in prostate cancer radiation therapy and pharmacological management in daily clinical practice of high-risk and post-operative non-metastatic prostate cancer.

Comparing the clinical performance and cost efficacy of [68Ga]Ga-PSMA-11 and [18F]PSMA-1007 in the diagnosis of recurrent prostate cancer: a Markov chain decision analysis

PURPOSE

Amongst others, [68Ga]Ga-PSMA-11 and [18F]PSMA-1007 are available for the detection of recurrent prostate cancer (rPC). There are currently limited data comparing the performance of these two radioligands with respect to clinical outcomes or their cost efficacy, which this study aims to address.

METHODS

Two hundred and forty-four patients undergoing PSMA PET/CT for rPC were retrospectively analysed for this study (one hundred and twenty two with each radiopharmaceutical) to generate rates of PET positivity, negativity and unclear findings. Patients underwent follow-up to determine the rate of additional examinations and to confirm PET findings. A Markov chain decision analysis was implemented to model clinical decision-making processes and to analyse clinical performance of the two tracers. We determine their clinical cost efficacies using cost data from several countries where both radiotracers are in routine use.

RESULTS

The PET positivity rate was non-significantly higher for [18F]PSMA-1007 compared to [68Ga]Ga-PSMA-11 (91.8% vs. 86.9%, p = 0.68), whereas the rate of uncertain findings was significantly greater (17.2% vs. 8.25%, p = 0.02). The probability of a true positive finding was higher for [68Ga]Ga-PSMA-11 (0.90, 95% CI 0.70-0.98) vs. [18F]PSMA-1007 (0.81, 95% CI 0.66-0.91). A significantly (p < 0.0001) higher PPV for [68Ga]Ga-PSMA-11 (0.99, 95% CI 0.99-1.0 vs. 0.86) was found compared to [18F]PSMA-1007 (0.86, 95% CI 0.82-1.00). Intervention efficacy analysis favoured [68Ga]Ga-PSMA-11, where the number needed to image (to achieve a true positive finding) was 10.58 and the number needed to image to harm (to achieve a false positive finding) was - 8.08. A cost efficacy analysis favours [68Ga]Ga-PSMA-11 in three of the four jurisdictions analysed where health economic data was available (Switzerland, Israel, Australia) and [18F]PSMA-1007 in one jurisdiction (Denmark).

CONCLUSION

The analysis reveals a non-significantly higher PET positivity rate for [18F]PSMA-1007, but finds significantly greater rates of uncertain findings and false positive findings when compared to [68Ga]Ga-PSMA-11. We find differences in the two tracers in terms of clinical performance and cost efficacy. The method presented herein is generalisable and can be used with clinical or cost data for other countries or tracers.

Impact of Circulating Tumor DNA-Based Detection of Molecular Residual Disease on the Conduct and Design of Clinical Trials for Solid Tumors

Earlier detection of cancer recurrence using circulating tumor DNA (ctDNA) to detect molecular residual disease (MRD) has the potential to dramatically affect cancer management. We review evidence supporting the use of ctDNA as a biomarker for detection of MRD and highlight the potential impact that ctDNA testing could have on the conduct of clinical trials.

Biomarkers for prostate cancer detection and risk stratification

Although prostate cancer (PCa) is the most commonly diagnosed cancer in men, most patients do not die from the disease. Prostate specific antigen (PSA), the most widely used oncologic biomarker, has revolutionized screening and early detection, resulting in reduced proportion of patients presenting with advanced disease. However, given the inherent limitations of PSA, additional diagnostic and prognostic tools are needed to facilitate early detection and accurate risk stratification of disease. Serum, urine, and tissue-based biomarkers are increasingly being incorporated into the clinical care paradigm, but there is still a limited understanding of how to use them most effectively. In the current article, we review test characteristics and clinical performance data for both serum [4 K score, prostate health index (phi)] and urine [SelectMDx, ExoDx Prostate Intelliscore, MyProstateScore (MPS), and PCa antigen 3 (PCA3)] biomarkers to aid decisions regarding initial or repeat biopsies as well as tissue-based biomarkers (Confirm MDx, Decipher, Oncotype Dx, and Polaris) aimed at risk stratifying patients and identifying those patients most likely to benefit from treatment versus surveillance or monotherapy versus multi-modal therapy.

Prospects of Treating Prostate Cancer through Apalutamide: A Mini-Review

BACKGROUND

Prostate cancer is considered the second most diagnosed cancer, and one of the most common causes of death from cancer in men. Apalutamide is an effective, safe, and well-tolerated agent used for the treatment of men with non-metastatic castration-resistant prostate cancer (nmCRPC) and metastatic hormone-naive prostate cancer (mHNPC). Androgen receptor signaling is a leading factor that drives these prostate tumors. USFDA has approved apalutamide on 14 February 2018 as an agent that targets androgen receptor signaling through inhibition causing significant improvement in metastasis-free survival in patients with prostate cancer. <P> Objective: In this review, various aspects related to apalutamide have been summarized which involve the mechanism of action, chemistry, synthesis, pharmacokinetics, pharmacodynamics, adverse reactions, and safety parameters. <P> Methods: The literature was thoroughly searched in the relevant databases to identify studies published in this field during recent years. Special attention has been given to apalutamide clinical trials phases and its promising future as one of the first-line agents for the treatment of patients with advanced prostate cancer. <P> Results: Ongoing trials are progressing for apalutamide monotherapy and also for its combinations in other disease settings. The expected results of such trials will shape the future scenario of prostate cancer therapy. <P> Conclusion: This review article has highlighted different aspects of Apalutamide like its mechanism of action, adverse effects, pharmacokinetics, pharmacodynamics, clinical trials among others. The contents of this article should make an excellent read for prospective researchers in this field.

Management of late events after conventional radical prostate radiotherapy: against the odds of secondary tumours and recurrence of prostate cancer

We present two 85-year-old men, with a similar history of prostate cancer treated more than 10 years ago with radiotherapy, who were in remission, but sought medical care at a time, due to alarm sign and symptoms. Case 2 resulted in a locally advanced secondary radiation-induced sarcoma of the penile base. Case 1 suffered from a round, 2 cm soft-tissue lesion with spiculated borders at the ureterovesical junction responsible for ipsilateral iliac vein compression and urinary obstruction without proven biochemical prostate cancer relapse, raising concerns about recurrence or secondary tumour. Both patients followed an oncological geriatric assessment and were 'vulnerable' at their presentation. Hence, we describe the effort to perform medical care adequacy regarding patient's frailty and the anatomic locations within the prior radiation field. In case 2, we got a pathological diagnose and followed sequential multimodal treatments without success. But in case 1, minimal intervention resulted in improvement.

Progress in gene therapy treatments for prostate cancer

Prostate cancer is one of the predominant cancers affecting men and has been widely reported. In the past, various therapies and drugs have been proposed to treat prostate cancer. Among these treatments, gene therapy has been considered to be an optimal and widely applicable treatment. Furthermore, due to the increased specificity of gene sequence complementation, the targeted delivery of complementary gene sequences may represent a useful treatment in certain instances. Various gene therapies, including tumor-suppressor gene therapy, suicide gene therapy, immunomodulation gene therapy and anti-oncogene therapies, have been established to treat a wide range of diseases, such as cardiac disease, cystic fibrosis, HIV/AIDS, diabetes, hemophilia, and cancers. To this end, several gene therapy clinical trials at various phases are underway. This overview describes the developments and progress in gene therapy, with a special focus being placed on prostate cancer.

Patterns of Clinical Progression in Radiorecurrent High-risk Prostate Cancer

The natural history of radiorecurrent high-risk prostate cancer (HRPCa) is not well-described. To better understand its clinical course, we evaluated rates of distant metastases (DM) and prostate cancer-specific mortality (PCSM) in a cohort of 978 men with radiorecurrent HRPCa who previously received either external beam radiation therapy (EBRT, n = 654, 67%) or EBRT + brachytherapy (EBRT + BT, n = 324, 33%) across 15 institutions from 1997 to 2015. In men who did not die, median follow-up after treatment was 8.9 yr and median follow-up after biochemical recurrence (BCR) was 3.7 yr. Local and systemic therapy salvage, respectively, were delivered to 21 and 390 men after EBRT, and eight and 103 men after EBRT + BT. Overall, 435 men developed DM, and 248 were detected within 1 yr of BCR. Measured from time of recurrence, 5-yr DM rates were 50% and 34% after EBRT and EBRT + BT, respectively. Measured from BCR, 5-yr PCSM rates were 27% and 29%, respectively. Interval to BCR was independently associated with DM (p < 0.001) and PCSM (p < 0.001). These data suggest that radiorecurrent HRPCa has an aggressive natural history and that DM is clinically evident early after BCR. These findings underscore the importance of further investigations into upfront risk assessment and prompt systemic evaluation upon recurrence in HRPCa. PATIENT SUMMARY: High-risk prostate cancer that recurs after radiation therapy is an aggressive disease entity and spreads to other parts of the body (metastases). Some 60% of metastases occur within 1 yr. Approximately 30% of these patients die from their prostate cancer.

Performance of 18F-DCFPyL PET/CT Imaging in Early Detection of Biochemically Recurrent Prostate Cancer: A Systematic Review and Meta-Analysis

Background: Prostate-specific membrane antigen (PSMA)-targeted 2-(3-{1-carboxy-5-[(6-[18F] fluoro-pyridine-3-carbonyl)-amino]-pentyl}-ureido)-pentanedioic acid (18F-DCFPyL) positron emission tomography/computed tomography (PET/CT) has shown advantages in primary staging, restaging, and metastasis detection of prostate cancer (PCa). However, little is known about the role of 18F-DCFPyL PET/CT in biochemically recurrent prostate cancer (BRPCa). Hence, we performed a systematic review and meta-analysis to evaluate 18F-DCFPyL PET/CT as first-line imaging modality in early detection of BRPCa. Methods: A comprehensive literature search of PubMed, Web of Science, Embase, and Cochrane Library was conducted until December 2020. The pooled detection rate on a per-person basis and together with 95% confidence interval (CI) was calculated. Furthermore, a prostate-specific antigen (PSA)-stratified performance of detection positivity was obtained to assess the sensitivity of 18F-DCFPyL PET/CT in BRPCa with different PSA levels. Results: A total of nine eligible studies (844 patients) were included in this meta-analysis. The pooled detection rate (DR) of 18F-DCFPyL PET/CT in BRPCa was 81% (95% CI: 76.9-85.1%). The pooled DR was 88.8% for PSA ≥ 0.5 ng/ml (95% CI: 86.2-91.3%) and 47.2% for PSA < 0.5 ng/ml (95% CI: 32.6-61.8%). We also noticed that the regional lymph node was the most common site with local recurrence compared with other sites (45.8%, 95% CI: 42.1-49.6%). Statistical heterogeneity and publication bias were found. Conclusion: The results suggest that 18F-DCFPyL PET/CT has a relatively high detection rate in BRPCa. The results also indicate that imaging with 18F-DCFPyL may exhibit improved sensitivity in BRPCa with increased PSA levels. Considering the publication bias, further large-scale multicenter studies are warranted for validation.

Seek and Find: Current Prospective Evidence for Prostate-specific Membrane Antigen Imaging to Detect Recurrent Prostate Cancer

CONTEXT

Men with biochemically relapsed prostate cancer face a clinical conundrum. Depending on the detected distribution of disease, treatment goals may range from cure with focal therapy to palliative with systemic therapy to expectant observation. Retrospective studies of prostate-specific membrane antigen (PSMA)-based imaging demonstrate higher disease detection rates than conventional imaging.

OBJECTIVE

This review focuses on available prospective evidence for diagnostic use of PSMA-based imaging to accurately restage recurrent prostate cancer and explores the potential clinical impact, near future uses, and challenges for PSMA-based imaging in this setting.

EVIDENCE ACQUISITION

PubMed and EMBASE databases were searched for prospective studies with primary, secondary, or exploratory endpoints evaluating PSMA-based imaging for patients with recurrent prostate cancer published in English in the past 10 yrs.

EVIDENCE SYNTHESIS

We reviewed 48 prospective studies evaluating the role of PSMA positron emission tomography (PET) in recurrent prostate cancer. These studies establish the diagnostic accuracy and safety of PSMA PET using the 68Ga-PSMA-11 and 18F-DCFPyL radiotracers even at lower prostate-specific antigen (PSA) levels (0.5 ≤ PSA < 1.0 ng/m: disease detection rate 51-78%). The use of PSMA PET has been shown to result in changes in management in up to two-thirds of patients.

CONCLUSIONS

There is now higher-level regulatory-quality prospective evidence for PSMA-based imaging for the detection of recurrent prostate cancer. There is prospective evidence of superiority over cross-sectional imaging and bone scintigraphy, as well as for the alterations in disease management as a result of PSMA-based imaging.

PATIENT SUMMARY

When the prostate-specific antigen (PSA) level is rising after primary therapy, prostate-specific membrane antigen (PSMA) positron emission tomography (PET) is excellent at detecting and localizing prostate cancer, even at low PSA levels. Those who benefit best from treatment modifications based on PSMA PET findings are yet to be defined.

Clinical and immunologic impact of short-course enzalutamide alone and with immunotherapy in non-metastatic castration sensitive prostate cancer

BACKGROUND

The standard treatment for non-metastatic castration sensitive prostate cancer (nmCSPC) is androgen deprivation therapy (ADT) or surveillance. This study evaluated the potential synergy of immunotherapy and enzalutamide (without ADT) in nmCSPC. In addition, the immunologic impact of enzalutamide was also evaluated in men with normal testosterone.

METHODS

Patients with rising prostate-specific antigen (PSA) after definitive therapy, normal testosterone and no radiographic metastasis were randomized to enzalutamide for 3 months with/without PROSTVAC for 6 months. Thereafter, patients could be retreated with another 3 month course of enzalutamide when PSA returned to baseline. Immune profiles were evaluated in these patients.

RESULTS

Thirty-eight patients were randomized with a median PSA=4.38 ng/dL and PSA doubling time=4.1 months. No difference was observed between the two groups for PSA growth kinetics, but PSA responses to enzalutamide were noteworthy regardless of PROSTVAC. The median PSA decline after short-course enzalutamide without ADT/testosterone lowering therapy was 99% in both courses. The median time to PSA recovery to baseline after each 84-day course of enzalutamide was also noteworthy because of the duration of response after enzalutamide was discontinued. After the first and second 3 month cycle of enzalutamide, PSA recovery to baseline took a median 224 (range 84-1246) and 189 days (78-400), respectively. The most common adverse events related to the enzalutamide were grade 1 fatigue (71%) and grade 1 breast pain/nipple tenderness (81%). The only grade 3 toxicity was aspartate aminotransferase (AST)/alanine aminotransferase (ALT) elevation in two patients. Enzalutamide was independently associated with immune changes, increasing natural killer cells, naïve-T cells, and decreasing myeloid-derived suppressor cells.

CONCLUSIONS

Three months of enzalutamide without ADT induced substantial PSA control beyond the treatment period and was repeatable, perhaps representing an alternative to intermittent ADT in nmCSPC. In addition, enzalutamide was associated with immune changes that could be relevant as future immune combinations are developed. TRAIL REGISTRATION NUMBER: clinicaltrials.gov (NCT01875250).

Toward the Discovery and Development of PSMA Targeted Inhibitors for Nuclear Medicine Applications

BACKGROUND

The rising incidence rate of prostate cancer (PCa) has promoted the development of new diagnostic and therapeutic radiopharmaceuticals during the last decades. Promising improvements have been achieved in clinical practice using prostate specific membrane antigen (PSMA) labeled agents, including specific antibodies and small molecular weight inhibitors. Focusing on molecular docking studies, this review aims to highlight the progress in the design of PSMA targeted agents for a potential use in nuclear medicine.

RESULTS

Although the first development of radiopharmaceuticals able to specifically recognize PSMA was exclusively oriented to macromolecule protein structure such as radiolabeled monoclonal antibodies and derivatives, the isolation of the crystal structure of PSMA served as the trigger for the synthesis and the further evaluation of a variety of low molecular weight inhibitors. Among the nuclear imaging probes and radiotherapeutics that have been developed and tested till today, labeled Glutamate-ureido inhibitors are the most prevalent PSMA-targeting agents for nuclear medicine applications.

CONCLUSION

PSMA represents for researchers the most attractive target for the detection and treatment of patients affected by PCa using nuclear medicine modalities. [99mTc]MIP-1404 is considered the tracer of choice for SPECT imaging and [68Ga]PSMA-11 is the leading diagnostic for PET imaging by general consensus. [18F]DCFPyL and [18F]PSMA-1007 are clearly the emerging PET PSMA candidates for their great potential for a widespread commercial distribution. After paving the way with new imaging tools, academic and industrial R&Ds are now focusing on the development of PSMA inhibitors labeled with alpha or beta minus emitters for a theragnostic application.

Diagnostic performance of F-18 fluciclovine PET/CT in post-radical prostatectomy prostate cancer patients with rising prostate-specific antigen level ≤0.5 ng/mL

PURPOSE

The aim of the study was to assess the diagnostic performance of fluciclovine positron emission tomography (PET)/computerized tomography (CT) in post-radical prostatectomy prostate cancer patients with rising prostate-specific antigen (PSA) ≤0.5 ng/mL, and identify the associated predictive factors of positive studies.

PATIENTS AND METHODS

From 30 June 2017 to 9 August 2019, patients with post-radical prostatectomy prostate cancer who underwent F-18 fluciclovine PET/CT and had PSA level within 2-week interval (PSAPET) ≤0.5 ng/mL were enrolled into this single-institution retrospective study. Data on tumor characteristics, including Gleason scores, extra-prostatic extension, seminal vesicle invasion, surgical margin and nodal metastasis, PSA after radical prostatectomy, previous hormonal therapy, PSA doubling time (PSADT), scanner type, PSAPET and site of recurrence were collected. Comparison of these factors between groups of positive and negative fluciclovine PET/CT was done by using Mann-Whitney U-test and Fisher's exact test.

RESULTS

Of 94 eligible patients with post-radical prostatectomy prostate cancer, 10 patients had positive studies (10.6%). Detection rate at PSAPET 0.1, 0.2, 0.3, 0.4 and 0.5 ng/mL were 0% (0/11), 0% (0/15), 20% (6/30), 4% (1/25) and 23.1% (3/13), respectively. Upon multivariate analysis of clinical factors, only a PSADT <3 months (P = 0.023) was shown to have a statistically significant correlation with a positive study.

CONCLUSION

In post-radical prostatectomy prostate cancer patients with rising PSA 0.1-0.5 ng/mL, the sensitivity of F-18 fluciclovine PET/CT for identifying tumor recurrence/metastases is poor with an overall detection rate of 10.6%. Larger prospective studies are required to validate these findings.

Cost-consequence analysis of 18F-fluciclovine for the staging of recurrent prostate cancer

Background: Current detection methodologies are often unable to identify the location and extent of recurrent prostate cancer (PCa) leading potentially to 'futile' local therapies in the presence of metastatic disease. The use of ¹⁸ F-fluciclovine PET/CT may lead to better patient management. Objective: The aim of this study was to quantify the economic impact and cost-consequence of using ¹⁸ F-fluciclovine PET/CT in PCa recurrence. Study design: A decision analytic model based on recurrent PCa imaging guidelines. Setting: US hospital. Participants: PCa patients experiencing biochemical recurrence. Intervention: ¹⁸ F-fluciclovine PET/CT was compared to conventional imaging. Main outcome measure: Budget impact, correct diagnoses, futile treatments, and cost-consequence (cost per correct diagnosis) Results: For a hypothetical hospital serving 500,000 individuals, the model showed the use of ¹⁸ F-fluciclovine reduced 'futile' therapies by 19.2%. Re-imaging costs were reduced by 40.2% ($8.2 million); however, when assuming diagnostic and staging costs only, the total costs increased from $31.2 to $34.6 million (10.9%), driven by ¹⁸ F-fluciclovine imaging agent and procedure costs. The cost per 'correct' diagnosis declined $30,673 (46.8%). When including subsequent 5-year patient management, the cost per 'correct' diagnosis declined $410,206 (49.2%). Conclusion: ¹⁸ F-fluciclovine PET/CT imaging may improve the clinical management of men with recurrent PCa with minimal increase in healthcare spending.

Methylation Markers in Prostate Biopsies Are Prognosticators for Late Biochemical Recurrence and Therapy after Surgery in Prostate Cancer Patients

After diagnosis of prostate cancer is confirmed by a positive biopsy, the tumor may be surgically removed via radical prostatectomy (RP). However, many prostate cancer patients experience biochemical recurrence after surgery and/or undergo salvage radiotherapy or hormone therapy. Timely treatment is required to prevent the spread of disease in these cases, and biopsy tissue may hold potential for disease prognostication before surgery is ever performed. We previously developed a prognostic multigene methylation panel in RP specimens, including APC, CRIP3, HOXD3, and TGFB2. In the current study, this panel was applied to a cohort of biopsy specimens (n = 86), which were assessed for DNA methylation using the real-time quantitative PCR-based multiplex MethyLight. The biopsy-based methylation panel is significantly associated with biochemical recurrence when combined with the current clinical parameter of prostate-specific antigen (PSA) levels at diagnosis and is able to prognosticate the initiation of salvage radiotherapy, where it outperforms PSA, and/or hormone therapy after RP. In addition, this methylation panel is significantly associated with late recurrence occurring within 5 and 7 years after surgery, when combined with PSA at diagnosis. Combining DNA methylation and clinicopathologic markers at the biopsy stage will not only increase their prognostic ability but will also ensure effective patient management.

Assessment of biochemical recurrence of prostate cancer (Review)

The assessment of the risk of biochemical recurrence (BCR) is critical in the management of males with prostate cancer (PC). Over the past decades, a comprehensive effort has been focusing on improving risk stratification; a variety of models have been constructed using PC-associated pathological features and molecular alterations occurring at the genome, protein and RNA level. Alterations in RNA expression (lncRNA, miRNA and mRNA) constitute the largest proportion of the biomarkers of BCR. In this article, we systemically review RNA-based BCR biomarkers reported in PubMed according to the PRISMA guidelines. Individual miRNAs, mRNAs, lncRNAs and multi-gene panels, including the commercially available signatures, Oncotype DX and Prolaris, will be discussed; details related to cohort size, hazard ratio and 95% confidence intervals will be provided. Mechanistically, these individual biomarkers affect multiple pathways critical to tumorigenesis and progression, including epithelial-mesenchymal transition (EMT), phosphatase and tensin homolog (PTEN), Wnt, growth factor receptor, cell proliferation, immune checkpoints and others. This variety in the mechanisms involved not only validates their associations with BCR, but also highlights the need for the coverage of multiple pathways in order to effectively stratify the risk of BCR. Updates of novel biomarkers and their mechanistic insights are considered, which suggests new avenues to pursue in the prediction of BCR. Additionally, the management of patients with BCR and the potential utility of the stratification of the risk of BCR in salvage treatment decision making for these patients are briefly covered. Limitations will also be discussed.

An integrative DNA methylation model for improved prognostication of postsurgery recurrence and therapy in prostate cancer patients

PURPOSE

Patients with clinically localized, high-risk prostate cancer are often treated with surgery, but exhibit variable prognosis requiring long-term monitoring. An ongoing challenge for such patients is developing optimal strategies and biomarkers capable of differentiating between men at risk of early recurrence (<3 years) that will benefit from adjuvant therapies and men at risk of late recurrence (>5 years) who will benefit from long-term monitoring and/or salvage therapies.

PATIENTS AND METHODS

DNA methylation changes for 12 genes associated with disease progression were analyzed in 453 prostate tumors. A 4-gene prognostic model (4-G model) for biochemical recurrence (BCR) was derived utilizing LASSO from Cohort 1 (n = 254) and validated in Cohort 2 (n = 199). Subsequently, the 4-G model was evaluated for its association with salvage radiotherapy (RT) and/or hormone therapy, and the additive potential to CAPRA-S to develop an integrative gene model was assessed.

RESULTS

The 4-G model was significantly associated with BCR in both cohorts (chi-squared analysis P≤ 0.004) and specifically, with late recurrence at 5+ years (P < 0.001, Cohort 1; P= 0.028, Cohort 2). Multivariable Cox proportional regression analysis identified the 4-G model as significantly associated with salvage RT or hormone therapy in Cohort 1 (hazard ratio (HR) 1.64, 95% confidence interval (CI) 1.29-2.10, P< 0.001) and further validated in Cohort 2 (HR 1.63, 95% CI 1.18-2.25, P< 0.001). The integrative model outperformed prostate-specific antigen and the 4-G model alone for predicting BCR and was associated with patients who received hormone therapy 3+ years postsurgery.

CONCLUSIONS

We have identified and validated a novel integrative gene model as an independent prognosticator of BCR and demonstrated its association with late BCR. These patients require more long-term postsurgical monitoring and could be spared the comorbidities of adjuvant therapies.

Oligometastatic Prostate Cancer: A Shrinking Subset or an Opportunity for Cure?

Oligometastatic prostate cancer (OMPC), generally defined by presence of five or fewer metastatic sites on imaging, represents a transitional state between localized and widespread metastatic disease and encompasses a wide spectrum of disease biologies and clinical behaviors. A collaborative effort is ongoing to determine the genomics of OMPC. The prevalence of OMPC varies significantly in the literature and is likely to change further as substantial improvements in imaging improve our ability to reclassify a subset of patients with biochemical recurrence by conventional imaging as OMPC and another subset from OMPC to polymetastatic disease. The mainstay of OMPC treatment remains systemic therapy, either with androgen-deprivation therapy (ADT) alone or in combination with other agents (docetaxel, abiraterone, etc.). Focal therapies, including resection or radiotherapy (RT), to the primary tumor have demonstrated an improvement in outcomes, including failure-free survival in several retrospective studies. RT to the prostate has specifically demonstrated an overall survival (OS) advantage in patients with low-volume disease in a clinical trial. Improvement in outcomes has been observed with focal therapies for retroperitoneal and more distant metastatic sites in retrospective studies. Advancements in our understanding of the biology, imaging modalities, and treatments may allow for aggressive multimodality therapies in an effort to obtain deeper responses and, potentially, cures for selected patients with OMPC with favorable clinicopathologic characteristics. Participation in clinical trials or institutional registries is strongly encouraged for patients with OMPC who opt for an aggressive multimodality approach.