Predictors of metastatic disease in men with biochemical failure following radical prostatectomy

European Association of Urology biochemical recurrence risk groups after radical prostatectomy: External validation and identification of independent risk factors for progression and death

BACKGROUND

The EAU proposed a progression and death risk classification in patients with biochemical recurrence after radical prostatectomy (PR).

OBJECTIVE

To validate the EAU BCR-risk classification in our setting and to find factors related to progression and death.

MATERIAL AND METHODS

Multicenter, retrospective, observational study including 2140 patients underwent RP between 2011 and 2015. Patients with BCR were identified and stratified in low risk (PSA-DT >1yr and pGS <8) or high-risk (PSA-DT ≤1yr or pGS ≥8) grouping. PSA and metastatic free survival (PSA-PFS, MFS), cancer specific survival (CSS) and overall survival (OS) were calculated (Kaplan Meier curves and log-rank test). Independent risk factors were identified (Cox regression).

RESULTS

427 patients experienced BCR (32.3% low-risk and 67.7% high-risk). Median PSA-PFS was 135,0 mo (95% CI 129,63-140,94) and 115,0 mo (95% CI 104,02-125,98) (p<0,001), for low and high-risk groups, respectively. There were also significant differences in MFS and OS. The EAU BCR risk grouping was independent factor for PSA-progression (HR 2.55, p 0.009). Time from PR to BCR, was an independent factor for metastasis onset (HR 0.43, 95% CI 0.18-0.99; p 0.044) and death (HR 0.17, 95% CI 0.26.0.96; 23 p 0.048). Differences in MFS (p 0.001) and CSS (p 0.004) were found for <12, ≥12-<36 and ≥36 months from PR to BCR. Others independent factors were early salvage radiotherapy and PSA at BCR.

CONCLUSIONS

High-risk group is a prognostic factor for biochemical progression, but it has a limited accuracy on MP and death in our setting. The inclusion of other factors could increase its predictive power.

How can we best manage biochemical failure after radical prostatectomy?

Biochemical recurrence (BCR) is common after radical prostatectomy, but effective treatment options for men with BCR after curative treatment remain controversial. Although prostate-specific antigen is widely used as a surrogate marker for prostate cancer survival, it cannot fully differentiate between prostate-cancer-specific survival and overall survival. Thus, it is challenging for physicians to determine the timing of treatment to halt or slow the clinical progression of disease in patients with BCR while avoiding overtreatment for patients whose disease may not progress beyond BCR. Adjuvant therapy for radical prostatectomy or radiotherapy in intermediate- or high-risk localized prostate cancer has a benefit in terms of disease progression and survival but is not recommended in low-risk prostate cancer because of the significant adverse effects related to radiotherapy and androgen-deprivation therapy (ADT). Salvage radiotherapy (SRT) is also recommended for patients with BCR after radical prostatectomy. Several options for management of BCR after radical prostatectomy include SRT to the prostatic bed and/or pelvis, continuous or intermittent ADT, or observation. Patients' comorbidity, preferences, and cancer-related factors must be considered when deciding the best management strategy. Modern imaging technology such as positron emission tomography imaging of prostate-specific membrane antigen-positive regions enables earlier detection of disease progression, thus enhancing decision making for future disease management.

Adjuvant or Salvage Radiation Therapy for Prostate Cancer after Prostatectomy: Current Status, Controversies and Perspectives

Simple Summary

The management of patients with biochemical recurrence after prostatectomy has undergone significant changes in recent years. Currently, close monitoring of prostate-specific antigen (PSA) with early salvage radiotherapy (RT) in case of recurrence is the standard of care based on several randomized trials and a meta-analysis that has demonstrated its non-inferiority to adjuvant RT. Uncertainties remain regarding the management of patients at very high risk of recurrence, including appropriate selection criteria for adjuvant hormone therapy, and the role of imaging in refining the treatment strategy. This review explains this paradigm shift, raises points of controversy, and suggests ways to think about the future.

Abstract

Nearly one-third of the patients who undergo prostatectomy for prostate cancer have a biochemical recurrence (BCR) during follow-up. While several randomized trials have shown that adjuvant radiation therapy (aRT) improves biochemical control, this strategy has not been widely used because of the risk of toxicity and the fear of overtreating patients who would not have relapsed. In addition, the possibility of close PSA monitoring in the era of ultrasensitive assays enables to anticipate early salvage strategies (sRT). Three recent randomized trials and their meta-analysis have confirmed that aRT does not improve event-free survival compared to sRT, imposing the latter as the new standard of treatment. The addition of androgen deprivation therapy (ADT) to RT has been shown to improve biochemical control and metastasis-free survival, but the precise definition of to whom it should be proposed is still a matter of debate. The development of genomic tests or the use of artificial intelligence will allow more individualized treatment in the future. Therapeutic intensification with the combination of new-generation hormone therapy and RT is under study. Finally, the growing importance of metabolic imaging (PET/CT) due to its performance especially for low PSA levels will help in further personalizing management strategies.

Comparing 99mTc-PSMA to 99mTc-MDP in Prostate Cancer Staging of the Skeletal System

PURPOSE

This prospective study was aimed at assessing the ability of 99mTc-PSMA scan to detect bone metastases in prostate cancer (PCa) against 99mTc-MDP scan as a standard and assess the correlation of these modalities in PCa staging of bone involvement.

PATIENTS AND METHODS

Forty-one patients (41) with histologically confirmed PCa were scanned using both methods. Planar imaging was performed with additional regional SPECT/CT 3 to 4 hours posttracer injection. Scans were reported as positive, negative, or equivocal. In the case of positive scans, lesions were quantified by each of the 3 reporters separately. Planar and SPECT/CT images were reported together to obtain the final report on each scan.

RESULTS

Our preliminary results showed no significant difference in the detection of bone metastases between the 2 scans. 99mTc-PSMA detected 52 of the 55 bone lesions detected on 99mTc-MDP. However, 99mTc-PSMA provided extra information by reporting lymph nodal metastases in 7 patients and residual disease in the prostate in 2 patients with biochemical progression after radical therapy. In 1 patient, the PSMA scan resulted in change in management with patient now on 177Lu-PSMA radioligand therapy. Equivocal findings were reported in 4 patients on 99mTc-MDP and none on 99mTc-PSMA.

CONCLUSIONS

99mTc-PSMA was comparable to 99mTc-MDP in detection of bone metastases and demonstrated an additional benefit of providing information on visceral disease. 99mTc-PSMA may be a better alternative to 99mTc-MDP in staging, restaging, and assessment of patients with biochemical progression after radical therapy of PCa in a resource-limited setup like ours while also assisting to detect patients eligible for PSMA-labeled radioligand therapy.

The Clinical Utility of 18F-Fluciclovine PET/CT in Biochemically Recurrent Prostate Cancer: an Academic Center Experience Post FDA Approval

PURPOSE

To evaluate the diagnostic performance and clinical utility of ¹⁸F-fluciclovine PET/CT in patients with biochemical recurrence (BCR) of prostate cancer (PC).

METHODS

¹⁸F-Fluciclovine scans of 165 consecutive men with BCR after primary definitive treatment with prostatectomy (n = 102) or radiotherapy (n = 63) were retrospectively evaluated. Seventy patients had concurrent imaging with at least one other conventional modality (CT (n = 31), MRI (n = 31), or bone scan (n = 26)). Findings from ¹⁸F-fluciclovine PET were compared with those from conventional imaging modalities. The positivity rate and impact of ¹⁸F-fluciclovine PET on patient management were recorded. In 33 patients who underwent at least one other PET imaging (¹⁸F-NaF PET/CT (n = 12), ⁶⁸Ga-PSMA11 PET/CT (n = 5), ¹⁸F-DCFPyL PET/CT (n = 20), and ⁶⁸Ga-RM2 PET/MRI (n = 5)), additional findings were evaluated.

RESULTS

The overall positivity rate of ¹⁸F-fluciclovine PET was 67 %, which, as expected, increased with higher prostate-specific antigen (PSA) levels (ng/ml): 15 % (PSA < 0.5), 50 % (0.5 ≤ PSA < 1), 56 % (1 ≤ PSA < 2), 68 % (2 ≤ PSA < 5), and 94 % (PSA ≥ 5), respectively. One hundred and two patients (62 %) had changes in clinical management based on ¹⁸F-fluciclovine PET findings. Twelve of these patients (12 %) had lesion localization on ¹⁸F-fluciclovine PET, despite negative conventional imaging. Treatment plans of 14 patients with negative ¹⁸F-fluciclovine PET were changed based on additional PET imaging with a different radiopharmaceutical.

CONCLUSION

¹⁸F-Fluciclovine PET/CT remains a useful diagnostic tool in the workup of patients with BCR PC, changing clinical management in 62 % of participants in our cohort.

Does whole-body bone SPECT/CT provide additional diagnostic information over [18F]-FCH PET/CT for the detection of bone metastases in the setting of prostate cancer biochemical recurrence?

BACKGROUND

To assess whether whole-body (WB) bone SPECT/CT provides additional diagnostic information over [18F]-FCH PET/CT for the detection of bone metastases in the setting of prostate cancer biochemical recurrence (PC-BR).

METHODS

Patients referred for a PC-BR and whom benefited from a WB bone SPECT/CT and FCH PET/CT were retrospectively included. Tests were classified as positive, equivocal, or negative for bone metastases. A best valuable comparator (BVC) strategy including imaging and follow-up data was used to determine the metastatic status in the absence of systematic histological evaluation.

RESULTS

Between January 2011 and November 2017, 115 consecutive patients with a PC-BR were evaluated. According to the BVC, 30 patients had bone metastases and 85 patients did not present with bone lesions. The sensitivity, specificity, positive and negative predictive values were respectively 86.7% [69.3-96.2], 98.8% [93.6-100.0], 96.3% [78.7-99.5], and 95.5% [89.4-98.1] for WB bone SPECT/CT and 93.3% [77.9-99.2], 100.0% [95.8-100.0], 100.0 and 97.7% [91.8-99.4] for FCH PET/CT. There was no significant difference in diagnostic accuracy of bone metastases between WB Bone SPECT/CT (AUC 0.824 [0.74-0.90]) and FCH PET/CT (AUC 0.829 [0.75-0.90], p = 0.41).

CONCLUSION

Despite good performances for the diagnosis of bone metastases in PC-BR, WB bone SPECT/CT does not provide additive diagnostic information over concomitant FCH PET/CT.

Obesity, race, and long-term prostate cancer outcomes

BACKGROUND

The authors previously found that obesity was linked with prostate cancer (PC)-specific mortality (PCSM) among men who underwent radical prostatectomy (RP). Herein, in a larger RP cohort, the authors investigated whether the association between obesity and long-term PC outcomes, including PCSM, differed by race.

METHODS

Data from 5929 patients who underwent RP and were in the Shared Equal Access Regional Cancer Hospital (SEARCH) database were analyzed. Prior to RP, body mass index (BMI) was measured and recorded in the medical records. BMI was categorized as normal weight (<25 kg/m² ), overweight (25-29.9 kg/m² ), and obese (≥30 kg/m² ). The authors assessed the association between BMI and biochemical disease recurrence (BCR), castration-resistant prostate cancer (CRPC), metastasis, and PCSM, accounting for confounders.

RESULTS

Of the 5929 patients, 1983 (33%) were black, 1321 (22%) were of normal weight, 2605 (44%) were overweight, and 2003 (34%) were obese. Compared with white men, black men were younger; had higher prostate-specific antigen levels; and were more likely to have a BMI ≥30 kg/m² , seminal vesicle invasion, and positive surgical margins (all P ≤ .032). During a median follow-up of 7.4 years, a total of 1891 patients (32%) developed BCR, 181 patients (3%) developed CRPC, 259 patients (4%) had metastasis, and 135 patients (2%) had died of PC. On multivariable analysis, obesity was found to be associated with an increased risk of PCSM (hazard ratio, 1.78; 95% confidence interval, 1.04-3.04 [P = .035]). No interaction was found between BMI and race in predicting PCSM (P ≥ .88), BCR (P ≥ .81), CRPC (P ≥ .88), or metastasis (P ≥ .60). Neither overweight nor obesity was associated with risk of BCR, CRPC, or metastasis (all P ≥ .18).

CONCLUSIONS

Obese men undergoing RP at several Veterans Affairs hospitals were found to be at an increased risk of PCSM, regardless of race.

Imaging Biochemical Recurrence After Prostatectomy: Where Are We Headed?

OBJECTIVE. In this article, we discuss the evolving roles of imaging modalities in patients presenting with biochemical recurrence after prostatectomy. CONCLUSION. Multiple imaging modalities are currently available to evaluate patients with prostate cancer presenting with biochemical recurrence after prostatectomy. Multiparametric MRI (mpMRI) focuses on the postsurgical bed as well as regional lymph nodes and bones. PET/CT studies using ¹⁸F-fluciclovine, ¹¹C-choline, and prostate-specific membrane antigen (PSMA) ligands are useful in detecting locoregional and distant metastasis. Multiparametric MRI is preferred for patients with low risk of metastasis for localizing recurrence in prostate bed as well as pelvic lymph node and bone recurrence. Moreover, mpMRI aids in guiding biopsy and additional salvage treatments. For patients with high risk of metastatic disease, both mpMRI and whole-body PET/CT may be performed. PET/MRI using ⁶⁸Ga-PSMA has potential to enable a one-stop shop for local recurrence and metastatic disease evaluation, and clinical trials of PET/MRI are ongoing.

Contribution of Radiology to Staging of Prostate Cancer

Accurate tumor detection and establishment of disease extent are important for optimal management of prostate cancer. Disease stage, beginning with identification of the index prostate lesion, followed by primary tumor, lymph node, and distant metastasis evaluation, provide crucial clinical information that not only have prognostic and predictive value, but guide patient management. A wide array of radiological imaging modalities including ultrasound, computed tomography, and magnetic resonance imaging have been used for the purpose of prostate cancer staging with variable diagnostic performance. Especially, the last years have seen remarkable technological advances in magnetic resonance imaging technology, enabling referring clinicians and radiologists to obtain even more valuable data regarding staging of prostate cancer. Marked improvements have been seen in detection of the index prostate lesion and evaluation of extraprostatic extension while further improvements are still needed in identifying metastatic lymph nodes. Novel approaches such as whole-body MRI are emerging for more accurate and reproducible assessment of bone metastasis. Post-treatment assessment of prostate cancer using radiological imaging is a topic with rapidly changing clinical context and special consideration is needed for the biochemical setting, that is, the relatively high serum prostate-specific antigen levels in studies assessing the value of radiological imaging for post-treatment assessment and emerging therapeutic approaches such as early salvage radiation therapy. The scope of this review is to provide the reader insight into the various ways radiology contribute to staging of prostate cancer in the context of both primary staging and post-treatment assessment. The strengths and limitations of each imaging modality are highlighted as well as topics that warrant future research.

Parameter identification of a model for prostate cancer treated by intermittent therapy

Adenocarcinoma is the most frequent cancer affecting the prostate walnut-size gland in the male reproductive system. Such cancer may have a very slow progression or may be associated with a "dark prognosis" when tumor cells are spreading very quickly. Prostate cancers have the particular properties to be marked by the level of prostate specific antigen (PSA) in blood which allows to follow its evolution. At least in its first phase, prostate adenocarcinoma is most often hormone-dependent and, consequently, hormone therapy is a possible treatment. Since few years, hormone therapy started to be provided intermittently for improving patient's quality of life. Today, durations of on- and off-treatment periods are still chosen empirically, most likely explaining why there is no clear benefit from the survival point of view. We therefore developed a model for describing the interaction between the tumor environment, the PSA produced by hormone-dependent and hormone-independent tumor cells, respectively, and the level of androgens. Model parameters were identified using a genetic algorithm applied to the PSA time series measured in a few patients who initially received prostatectomy and were then treated by intermittent hormone therapy (LHRH analogs and anti-androgen). The measured PSA time series is quite correctly reproduced by free runs over the whole follow-up. Model parameter values allow for distinguishing different types of patient (age and Gleason score) meaning that the model can be individualized. We thus showed that the long-term evolution of the cancer can be affected by durations of on- and off-treatment periods.

Characterising potential bone scan overuse amongst men treated with radical prostatectomy

OBJECTIVES

To characterise bone scan use, and potential overuse, after radical prostatectomy (RP) using data from a large, national integrated delivery system. Overuse of imaging is well documented in the setting of newly diagnosed prostate cancer, but whether overuse persists after RP remains unknown.

PATIENTS AND METHODS

We identified 12 269 patients with prostate cancer treated with RP between 2005 and 2008 using the Veterans Administration Central Cancer Registry. We used administrative and laboratory data to examine rates of bone scan use, including preceding prostate-specific antigen (PSA) levels, and receipt of adjuvant or salvage therapy. We then performed multivariable logistic regression to identify factors associated with post-RP bone scan use.

RESULTS

At a median follow-up of 6.8 years, one in five men (22%) underwent a post-RP bone scan at a median PSA level of 0.2 ng/mL. Half of bone scans (48%) were obtained in men who did not receive further treatment with androgen-deprivation or radiation therapy. After adjustment, post-RP bone scan was associated with a prior bone scan (adjusted odds ratio [aOR] 1.55, 95% confidence interval [CI] 1.32-1.84), positive surgical margin (aOR 1.68, 95% CI 1.40-2.01), preoperative PSA level (aOR 1.02, 95% CI 1.01-1.03), as well as Hispanic ethnicity, Black race, and increasing D'Amico risk category, but not with age or comorbidity.

CONCLUSION

We found a substantial rate of bone scan utilisation after RP. The majority were performed for PSA levels of <1 ng/mL where the likelihood of a positive test is low. More judicious use of imaging appears warranted in the post-RP setting.

Glucose impairments and insulin resistance in prostate cancer: the role of obesity, nutrition and exercise

BACKGROUND

Hyperinsulinemia, obesity and related metabolic diseases are associated with prostate cancer development. Prostate cancer patients undergoing androgen deprivation therapy (ADT) are at increased risk for metabolic syndrome, cardiovascular disease and diabetes, while pre-existing metabolic conditions may be exacerbated.

PURPOSE

An integrative approach is used to describe the interactions between insulin, glucose metabolism, obesity and prostate cancer. The potential role of nutrition and exercise will also be examined.

FINDINGS

Hyperinsulinemia is associated with prostate cancer development, progression and aggressiveness. Prostate cancer patients who undergo ADT are at risk of diabetes in survivorship. It is unclear whether this is a direct result of treatment or related to pre-existing metabolic features (e.g. hyperinsulinemia and obesity). Obesity and metabolic syndrome are also associated with prostate cancer development and poorer outcomes for cancer survivors, which may be driven by hyperinsulinemia, pro-inflammation, hyperleptinemia and/or hypoadiponectinemia.

CONCLUSIONS

Independently evaluating changes in glucose metabolism near the time of prostate cancer diagnosis and during long-term ADT treatment is important to distinguish their unique contributions to the development of metabolic disturbances. Integrative approaches, including metabolic, clinical and body composition measures, are needed to understand the role of adiposity and insulin resistance in prostate cancer and to develop effective nutrition and exercise interventions to improve secondary diseases in survivorship.

Management Options for Biochemically Recurrent Prostate Cancer

Prostate cancer is the most common solid tumor malignancy in men worldwide. Treatment with surgery and radiation can be curative in organ-confined disease. Unfortunately, about one third of men develop biochemically recurrent disease based only on rising prostate-specific antigen (PSA) in the absence of visible disease on conventional imaging. For these patients with biochemical recurrent prostate cancer, there is no uniform guideline for subsequent management. Based on available data, it seems prudent that biochemical recurrent prostate cancer should initially be evaluated for salvage radiation or prostatectomy, with curative intent. In selected cases, high-intensity focused ultrasound and cryotherapy may be considered in patients that meet very narrow criteria as defined by non-randomized trials. If salvage options are not practical or unsuccessful, androgen deprivation therapy (ADT) is a standard option for disease control. While some patients prefer ADT to manage the disease immediately, others defer treatment because of the associated toxicity. In the absence of definitive randomized data, patients may be followed using PSA doubling time as a trigger to initiate ADT. Based on retrospective data, a PSA doubling time of less than 3-6 months has been associated with near-term development of metastasis and thus could be used signal to initiate ADT. Once treatment is begun, patients and their providers can choose between an intermittent and continuous ADT strategy. The intermittent approach may limit side effects but in patients with metastatic disease studies could not exclude a 20% greater risk of death. In men with biochemical recurrence, large studies have shown that intermittent therapy is non-inferior to continuous therapy, thus making this a reasonable option. Since biochemically recurrent prostate cancer is defined by technological limitations of radiographic detection, as new imaging (i.e., PSMA) strategies are developed, it may alter how the disease is monitored and perhaps managed. Furthermore, patients have no symptoms related to their disease and thus many prefer options that minimize toxicity. For this reason, herbal agents and immunotherapy are under investigation as potential alternatives to ADT and its accompanying side effects. New therapeutic options combined with improved imaging to evaluate the disease may markedly change how biochemically recurrent prostate cancer is managed in the future.

Post-prostatectomy radiation therapy for locally recurrent prostate cancer

INTRODUCTION

Approximately 15-30% of men with localized prostate cancer will experience biochemical recurrence (BCR) after radical prostatectomy. Postoperative radiation therapy is used in men with adverse pathological features to reduce the risk of BCR or with curative intent in men with known BCR. In this study, we review the evidence for the adjuvant and salvage radiation therapy after radical prostatectomy. Areas covered: A literature review of the Medline and Embase databases was performed. The search strategy included the following terms: prostate cancer, adjuvant radiotherapy, salvage radiotherapy, radical prostatectomy, biochemical recurrence, and prostate cancer recurrence. Prospective randomized trials for the adjuvant radiotherapy and observational studies supporting salvage radiotherapy were included for discussion. Expert commentary: As postoperative radiotherapy is associated with non-trivial risks of acute and long-term toxicity and given the absence of compelling data supporting adjuvant over early salvage radiotherapy, the authors advocate, with rare exceptions, close observation and timely (early) salvage radiotherapy for patients with BCR and long life expectancy. Adjuvant radiotherapy may be considered in patients at high-risk for recurrence. Observation is appropriate in patients with limited life expectancy and/or absence of adverse features.

The value of multimodality imaging in the investigation of a PSA recurrence after radical prostatectomy in the Irish hospital setting

INTRODUCTION

The diagnostic evaluation of a PSA recurrence after RP in the Irish hospital setting involves multimodality imaging with MRI, CT, and bone scanning, despite the low diagnostic yield from imaging at low PSA levels. We aim to investigate the value of multimodality imaging in PC patients after RP with a PSA recurrence.

METHODS

Forty-eight patients with a PSA recurrence after RP who underwent multimodality imaging were evaluated. Demographic data, postoperative PSA levels, and imaging studies performed at those levels were evaluated.

RESULTS

Eight (21%) MRIs, 6 (33%) CTs, and 4 (9%) bone scans had PCa-specific findings. Three (12%) patients had a positive MRI with a PSA <1.0 ng/ml, while 5 (56%) were positive at PSA ≥1.1 ng/ml (p = 0.05). Zero patient had a positive CT TAP at a PSA level <1.0 ng/ml, while 5 (56%) were positive at levels ≥1.1 ng/ml (p = 0.03). Zero patient had a positive bone at PSA levels <1.0 ng/ml, while 4 (27%) were positive at levels ≥1.1 ng/ml (p = 0.01).

CONCLUSION

The diagnostic yield from multimodality imaging, and isotope bone scanning in particular, in PSA levels <1.0 ng/ml, is low. There is a statistically significant increase in the frequency of positive findings on CT and bone scanning at PSA levels ≥1.1 ng/ml. MRI alone is of investigative value at PSA <1.0 ng/ml. The indication for CT, MRI, or isotope bone scanning should be carefully correlated with the clinical question and how it will affect further management.

Prostate-Specific Antigen and Prostate-Specific Antigen Kinetics in Predicting 18F-Sodium Fluoride Positron Emission Tomography-Computed Tomography Positivity for First Bone Metastases in Patients with Biochemical Recurrence after Radical Prostatectomy

We evaluated the association between serum prostate specific antigen (PSA) level and kinetics to predict ¹⁸F-sodium fluoride positron emission tomography-computed tomography (¹⁸F-NaF PET-CT) positivity for first bone metastases in men with biochemical recurrence after radical prostatectomy. All ¹⁸F-NaF PET-CT scans that were performed at our institution during 2010–2014 were queried to find patients who demonstrated biochemical recurrence after radical prostatectomy. Records were reviewed to obtain data on PSA levels and kinetics at the time of ¹⁸F-NaF PET-CT and pathologic features of the prostatectomy specimen, which were then used for receiver operating characteristic (ROC) analysis to determine predictability for ¹⁸F-NaF PET positivity. Thirty-six patients met our inclusion criteria. Of these, 8 (22.2%) had positive ¹⁸F-NaF PET-CT scans. Mean values for PSA, PSA doubling time (PSADT), and PSA velocity (PSAV) were 2.02 ng/ml (range: 0.06–11.7 ng/ml), 13.2 months (range: 1.11–60.84), and 1.28 ng/ml/year (range: 0.1–5.28) for ¹⁸F-NaF PET-CT negative scans, and 4.11 ng/ml (range: 0.04–14.38 ng/ml), 8.9 months (range; 0.7–27.8), and 9.06 ng/ml/year (range: 0.04–50.2) for ¹⁸F-NaF PET-CT positive scans, respectively (P = 0.07, 0.47, and 0.02, respectively, for PSA, PSADT, and PSAV). ROC analysis for ¹⁸F-NaF PET-CT positivity resulted in area under the curve (AUC) values of 0.634 for PSA, 0.598 for PSADT, and 0.688 for PSAV. ROC analysis with combined models gave AUC values of 0.723 for a combination of PSA and PSADT, 0.689 for a combination of PSA and PSAV, and 0.718 for grouping of PSA, PSADT, and PSAV. There was no significant association between ¹⁸F-NaF PET-CT positivity and primary tumor Gleason score, TN staging, and status of surgical margins. ¹⁸F-NaF PET-CT detected first-time osseous metastases in 22.2% of our patients with biochemical recurrence after prostatectomy with the PSA level range ≤11.7 ng/ml. PSAV was statistically significant in predicting ¹⁸F-NaF PET-CT positivity. ROC analysis demonstrated higher AUCs when PSA was combined with PSA kinetics parameters.

Updates of prostate cancer staging: Prostate-specific membrane antigen

The ability to accurately stage prostate cancer in both the primary and secondary staging setting can have a major impact on management. Until recently radiological staging has relied on computer tomography, magnetic resonance imaging, and nuclear bone scans to evaluate the extent of disease. However, the utility of these imaging technologies has been limited by their sensitivity and specificity especially in detecting early recurrence. Functional imaging using positron-emission tomography with a radiolabeled ligand targeted to prostate-specific membrane antigen has transformed the prostate cancer imaging landscape. Initial results suggest that it is a substantial improvement over conventional imaging in the setting of recurrence following primary therapy by having a superior ability to detect disease and to do so at an earlier stage. Additionally, it appears that the benefits seen in the secondary staging setting may also exist in the primary staging setting.

Obesity and Prostate Cancer: A Focused Update on Active Surveillance, Race, and Molecular Subtyping

CONTEXT

In 2012, we published a detailed review on obesity and prostate cancer. Since then, new studies have brought further understanding regarding the role of obesity in selecting active surveillance candidates, and differing associations between obesity and prostate cancer as a function of race and molecular subtype of prostate cancer.

OBJECTIVE

To review new manuscripts on these new concepts for which there were limited data before 2012.

EVIDENCE ACQUISITION

A PubMed search from July 2012 to March 2016 was performed using the terms "prostate cancer" and "obesity". Of 450 articles, we included 15 related to these three topics.

EVIDENCE SYNTHESIS

Among men on active surveillance or candidates for active surveillance, multiple studies suggest that the risk of upgrading is higher for obese men. No study has shown long-term oncologic differences, and the risk of prostate cancer mortality remains low. One study suggested that the link between obesity and prostate cancer risk is stronger among black men; however, other studies found that obesity is correlated with aggressive disease regardless of race. Two studies found that the associations between obesity and prostate cancer (ie, fewer low-grade cancers and yet more aggressive cancers) was limited to men with TMPRSS2-ERG-positive tumors.

CONCLUSIONS

The past 4 yr has seen much new work on the obesity-prostate cancer link. If confirmed in other studies, these findings provide novel insights into not only the link between obesity and prostate cancer but also prostate cancer biology in general.

PATIENT SUMMARY

While their outcomes may be slightly worse, obese men with localized prostate cancer should not be discouraged from active surveillance. Early studies suggest there may be subtypes of patients in whom obesity is more strongly linked to aggressive disease.

Comparison between Use of PSA Kinetics and Bone Marrow Micrometastasis to Define Local or Systemic Relapse in Men with Biochemical Failure after Radical Prostatectomy for Prostate Cancer

BACKGROUND

Treatment of biochemical failure after radical prostatectomy for prostate cancer is largely empirically based. The use of PSA kinetics has been used as a guide to determine local or systemic treatment of biochemical failure. We here compared PSA kinetics with detection of bone marrow micrometastasis as methods to determine local or systemic relapse.

MATERIALS AND METHODS

A transversal study was conducted of men with biochemical failure, defined as a serum PSA >0.2ng/ml after radical prostatectomy. Consecutive patients having undergone radical prostatectomy and with biochemical failure were enrolled and clinical and pathological details were recorded. Bone marrow biopsies were obtained from the iliac crest and touch prints made, micrometastasis (mM) being detected using anti-PSA. The clinical parameters of total serum PSA, PSA velocity, PSA doubling time and time to biochemical failure, age, Gleason score and pathological stage were registered.

RESULTS

A total of 147 men, mean age 71.6 ± 8.2 years, with a median time to biochemical failure of 5.5 years (IQR 1.0-6.3 years) participated in the study. Bone marrow samples were positive for micrometastasis in 98/147 (67%) of patients at the time of biochemical failure. The results of bone marrow micrometastasis detected by immunocytochemistry were not concordant with local relapse as defined by PSA velocity, time to biochemical failure or Gleason score. In men with a PSA doubling time of < six months or a total serum PSA of >2,5ng/ml at the time of biochemical failure the detection of bone marrow micrometastasis was significantly higher.

CONCLUSIONS

The detection of bone marrow micrometastasis could be useful in defining systemic relapse, this minimally invasive procedure warranting further studies with a larger group of patients.

Obesity and prostate cancer-specific mortality after radical prostatectomy: results from the Shared Equal Access Regional Cancer Hospital (SEARCH) database

Background:

At the population level, obesity is associated with prostate cancer (PC) mortality. However, few studies analyzed the associations between obesity and long-term PC-specific outcomes after initial treatment.

Methods:

We conducted a retrospective analysis of 4268 radical prostatectomy patients within the Shared Equal Access Regional Cancer Hospital (SEARCH) database. Cox models accounting for known risk factors were used to examine the associations between body mass index (BMI) and PC-specific mortality (PCSM; primary outcome). Secondary outcomes included biochemical recurrence (BCR) and castration-resistant PC (CRPC). BMI was used as a continuous and categorical variable (normal <25 kg/m², overweight 25–29.9 kg/m² and obese ⩾30 kg/m²). Median follow-up among all men who were alive at last follow-up was 6.8 years (interquartile range=3.5–11.0). During this time, 1384 men developed BCR, 117 developed CRPC and 84 died from PC. Hazard ratios were analyzed using competing-risks regression analysis accounting for non-PC death as a competing risk.

Results:

On crude analysis, higher BMI was not associated with risk of PCSM (P=0.112), BCR (0.259) and CRPC (P=0.277). However, when BMI was categorized, overweight (hazard ratio (HR) 1.99, P=0.034) and obesity (HR 1.97, P=0.048) were significantly associated with PCSM. Obesity and overweight were not associated with BCR or CRPC (all P⩾0.189). On multivariable analysis adjusting for both clinical and pathological features, results were little changed in that obesity (HR=2.05, P=0.039) and overweight (HR=1.88, P=0.061) were associated with higher risk of PCSM, but not with BCR or CRPC (all P⩾0.114) with the exception that the association for overweight was no longer statistical significant.

Conclusions:

Overweight and obesity were associated with increased risk of PCSM after radical prostatectomy. If validated in larger studies with longer follow-up, obesity may be established as a potentially modifiable risk factor for PCSM.

Radiation Therapy after Radical Prostatectomy: Implications for Clinicians

Depending on the pathological findings, up to 60% of prostate cancer patients who undergo radical prostatectomy (RP) will develop biochemical relapse and require further local treatment. Radiotherapy (RT) immediately after RP may potentially eradicate any residual localized microscopic disease in the prostate bed, and it is associated with improved biochemical, clinical progression-free survival, and overall survival in patients with high-risk pathological features according to published randomized trials. Offering immediate adjuvant RT to all men with high-risk pathological factors we are over-treating around 50% of patients who would anyway be cancer-free, exposing them to unnecessary toxicity and adding costs to the health-care system. The current dilemma is, thus, whether to deliver adjuvant immediate RT solely on the basis of high-risk pathology, but in the absence of measurable prostate-specific antigen, or whether early salvage radiotherapy would yield equivalent outcomes. Randomized trials are ongoing to definitely answer this question. Retrospective analyses suggest that there is a dose–response favoring doses >70 Gy to the prostate bed. The evidence regarding the role of androgen deprivation therapy is emerging, and ongoing randomized trials are underway.

A pilot study of the utility of choline PET-CT in prostate cancer biochemical relapse following radical prostatectomy

INTRODUCTION

To evaluate the detection rate of positive choline PET-CT and its clinical role in assisting with management decisions and the correlation between positive choline PET-CT and clinical/pathological parameters in prostate cancer patients with biochemical relapse following radical prostatectomy.

METHODS

This was a longitudinal observational pilot study of 34 patients who received choline PET-CT scans with biochemical relapse after radical prostatectomy. Variables including peak PSA, PSA doubling time (DT), Gleason score, age, initial PSA at diagnosis, use of ADT prior to PET and initial clinical staging were statistically analysed to assess for independent predictive factors for positive PET findings.

RESULTS

Choline PET-CT was positive in 38.2% of patients (13/34). The only statistically significant predictor for positive PET-CT was the use of ADT prior to PET-CT, with OR 18.7 (95% CI, 2.87-122.45), P < 0.01. Mean peak PSA for patients with positive PET-CT was 5.5 ± 4.8 ng/mL. Patients with positive PET-CT had a mean PSA DT of 5.1 ± 3.8 months and mean total Gleason of 7.6 ± 0.8. Although these variables were not statistically significant, they showed a tendency towards significance. At Receiver Operator Characteristics (ROC) analysis, a peak PSA value of 1.65 ng/mL and PSA DT of 4.4 months were determined to be the optimal cut-off values predicting positive PET-CT.

CONCLUSION

Choline PET-CT has its potential as a diagnostic modality enabling the detection of occult prostate cancer recurrence and to differentiate localised disease from systemic disease thus guiding management. Use of ADT prior to PET-CT is a significant predictor of positive PET-CT. Patients with a short PSA DT, high-peak PSA and high Gleason score should also be considered for choline PET-CT.

Recurrent prostate cancer detection with anti-3-[(18)F]FACBC PET/CT: comparison with CT

PURPOSE

To compare the diagnostic performance of the synthetic amino acid analogue PET radiotracer anti-3-[(18)F]FACBC (fluciclovine) with that of CT in the detection of recurrent prostate carcinoma.

METHODS

This was a retrospective analysis of 53 bone scan-negative patients with suspected recurrent prostate carcinoma who underwent fluciclovine PET/CT and routine clinical CT within 90 days of each other. The correlation between imaging findings and histology and clinical follow-up was evaluated. Positivity rates and diagnostic performance were calculated for fluciclovine PET/CT and CT.

RESULTS

Of 53 fluciclovine PET/CT and 53 CT examinations, 41 (77.4 %) and 10 (18.9 %), respectively, had positive findings for recurrent disease. Positivity rates were higher with fluciclovine PET/CT than with CT at all prostate-specific antigen (PSA) levels, PSA doubling times and original Gleason scores. In the prostate/bed, fluciclovine PET/CT was true-positive in 31 and CT was true-positive in 4 of 51 patients who met the reference standard. In extraprostatic regions, fluciclovine PET/CT was true-positive in 12 and CT was true-positive in 3 of 41 patients who met the reference standard. Of the 43 index lesions used to prove positivity, 42 (97.7 %) had histological proof. In 51 patients with sufficient follow-up to calculate diagnostic performance in the prostate/bed, fluciclovine PET/CT demonstrated a sensitivity of 88.6 %, a specificity of 56.3 %, an accuracy of 78.4 %, a positive predictive value (PPV) of 81.6 %, and a negative predictive value (NPV) of 69.2 %; the respective values for CT were 11.4 %, 87.5 %, 35.3 %, 66.7 % and 31.1 %. In 41 patients with sufficient follow-up to calculate diagnostic performance in extraprostatic regions, fluciclovine PET/CT demonstrated a sensitivity of 46.2 %, a specificity of 100 %, an accuracy of 65.9 %, a PPV of 100 %, and an NPV of 51.7 %; the respective values for CT were 11.5 %, 100 %, 43.9 %, 100 % and 39.5 %.

CONCLUSION

The diagnostic performance of fluciclovine PET/CT in recurrent prostate cancer is superior to that of CT and fluciclovine PET/CT provides better delineation of prostatic from extraprostatic recurrence.

Validation of a bone scan positivity risk table in non-metastatic castration-resistant prostate cancer

OBJECTIVES

To test the external validity of a previously developed risk table, designed to predict the probability of a positive bone scan among men with non-metastatic (M0) castration-resistant prostate cancer (CRPC), in a separate cohort.

PATIENTS AND METHODS

We retrospectively analysed 429 bone scans of 281 patients with CRPC, with no known previous metastases, treated at three Veterans Affairs Medical Centers. We assessed the predictors of a positive scan using generalized estimating equations. Area under the curve (AUC), calibration plots and decision-curve analysis were used to assess the performance of our previous model to predict a positive scan in the current data.

RESULTS

A total of 113 scans (26%) were positive. On multivariable analysis, the only significant predictors of a positive scan were log-transformed prostate-specific antigen (PSA): hazard ratio (HR) 2.13; 95% confidence interval (CI) 1.71-2.66 (P < 0.001) and log-transformed PSA doubling time (PSADT): HR 0.53; 95% CI 0.41-0.68 (P < 0.001). Among men with a PSA level <5 ng/mL, the rate of positive scans was 5%. The previously developed risk table had an AUC of 0.735 to predict positive bone scan with excellent calibration, and provided additional net benefit in the decision-curve analysis.

CONCLUSION

We have validated our previously developed table to predict the risk of a positive bone scan among men with M0/Mx CRPC. Use of this risk table may allow better tailoring of patients' scanning to identify metastases early, while minimizing over-imaging. Regardless of PSADT, positive bone scans were rare in men with a PSA <5 ng/mL.

PSA doubling time as a screening test to predict bone scan positivity

Aims:

The aim of this article is to compare the effectiveness of PSADT and tPSA as predictors of bony metastases in patients’ with prostate cancer pre-definitive treatment, and help guide clinicians with the selective ordering of bone scans (BS).

Materials and methods:

PSA measurements were retrospectively analysed for 330 men with prostate cancer, investigated with BS between 2009 and 2012. Exclusion criteria included previous positive BS, other malignancy, prostatectomy/radiotherapy and any prostate-specific condition or treatment initiated between the PSA levels used to calculate doubling time. PSADT (months) = log2 × dT/(log(PSA1)–log(PSA2)).

Results:

A total of 273 men had negative BS and 57 had positive findings of metastases. Those with positive BS had significantly ( p < 0.05) faster median PSADT (4.5 vs 15.2 months) and higher median tPSA (94 vs 24.5 ng/ml). On ROC curve analysis, PSADT outperformed tPSA as a predictor of bone scan result, with area-under-the-curve of 0.85 vs 0.76 ( p = 0.02). A ratio (R) of tPSA/PSADT was no better than PSADT alone ( p = 0.65).

Conclusions:

In the absence of clinical reasons to suspect metastatic disease, it is appropriate to withhold ordering a BS for non-prostatectomy/radiotherapy patients with rising PSA levels, until the PSADT is less than 18 months. This has a sensitivity of 100.0% and a specificity of 41.0%.

Predicting bone scan positivity in non-metastatic castration-resistant prostate cancer

Objectives

To evaluate PSA levels and kinetic cutoffs to predict positive bone scans for men with non-metastatic castrate resistant prostate cancer (CRPC) from the Shared Equal Access Regional Cancer Hospital (SEARCH) cohort.

Methods

Retrospective analysis of 531 bone scans of 312 clinically CRPC patients with no known metastases at baseline treated with a variety of primary treatment types in the SEARCH database. The association of patients’ demographics, pathological features, PSA levels and kinetics with risk of a positive scan was tested using generalized estimating equations.

Results

A total of 149 (28%) scans were positive. Positive scans were associated with younger age (OR=0.98; P=0.014), higher Gleason scores (relative to Gleason 2-6, Gleason 3+4: OR=2.03, P=0.035; Gleason 4+3 and 8-10: OR=1.76, P=0.059), higher pre-scan PSA (OR=2.11; P<0.001), shorter pre-scan PSA doubling time (PSADT; OR=0.53; P<0.001), higher PSA velocity (OR=1.74; P<0.001) and more remote scan year (OR=0.92; P=0.004). Scan positivity was 6%, 14%, 29% and 57% for men with PSA <5, 5-14.9, 15-49.9 and ≥50ng/mL, respectively (P-trend <0.001). Men with PSADT ≥15, 9-14.9, 3-8.9 and <3 months had a scan positivity of 11%, 22%, 34% and 47%, correspondingly (P-trend <0.001). Tables were constructed using PSA and PSADT to predict the likelihood of a positive bone scan.

Conclusions

PSA levels and kinetics were associated with positive bone scans. We developed tables to predict the risk of positive bone scans by PSA and PSADT. Combining PSA levels and kinetics may help select patients with CRPC for bone scans.

Clinical utility of (18)F-fluorocholine positron-emission tomography/computed tomography (PET/CT) in biochemical relapse of prostate cancer after radical treatment: results of a multicentre study

OBJECTIVE

To evaluate (18)F-fluorocholine positron-emission tomography (PET)/computed tomography (CT) in restaging patients with a history of prostate adenocarcinoma who have biochemical relapse after early radical treatment, and to correlate the technique's disease detection rate with a set of variables and clinical and pathological parameters.

PATIENTS AND METHODS

This was a retrospective multicentre study that included 374 patients referred for choline-PET/CT who had biochemical relapse. In all, 233 patients who met the following inclusion criteria were analysed: diagnosis of prostate cancer; early radical treatment; biochemical relapse; main clinical and pathological variables; and clinical, pathological and imaging data needed to validate the results. Criteria used to validate the PET/CT: findings from other imaging techniques, clinical follow-up, treatment response and histological analysis. Different statistical tests were used depending on the distribution of the data to correlate the results of the choline-PET/CT with qualitative [T stage, N stage, early radical prostatectomy (RP) vs other treatments, hormone therapy concomitant to choline-PET/CT] and quantitative [age, Gleason score, prostate-specific antigen (PSA) levels at diagnosis, PSA nadir, PSA level on the day of the choline-PET/CT (Trigger PSA) and PSA doubling time (PSADT)] variables. We analysed whether there were independent predictive factors associated with positive PET/CT results.

RESULTS

Choline-PET/CT was positive in 111 of 233 patients (detection rate 47.6%) and negative in 122 (52.4%). Disease locations: prostate or prostate bed in 26 patients (23.4%); regional and/or distant lymph nodes in 52 (46.8%); and metastatic bone disease in 33 (29.7%). Positive findings were validated by: results from other imaging techniques in 35 patients (15.0%); at least 6 months of clinical follow-up in 136 (58.4%); treatment response in 24 (10.3%); histological analysis of lesions in 17 (7.3%); and follow-up plus imaging results in 21 (9.0%). The statistical analysis of qualitative variables, corresponding to patients' clinical characteristics, and the positive/negative final PET/CT results revealed that only whether or not early treatment with RP was done was statistically significant (P < 0.001), with the number of positive results higher in patients who did not undergo a RP. Among the quantitative variables, Gleason score, Trigger PSA and PSADT clearly differentiated the two patient groups (positive and negative choline-PET/CT: P = 0.010, P = 0.001 and P = 0.025, respectively). A Gleason score of <5 or ≥ 8 clearly differentiated positive from negative PET. Trigger PSA: mean of 8 ng/mL for positive PET/CT vs 2.8 ng/mL for negative PET/CT; PSADT: mean of 8 months for positive vs 12.6 months for negative. The optimal threshold values were: 3 ng/mL for Trigger PSA level and 6 months for PSADT (Youden index/receiver operating characteristic curve). Analysing these two variables together showed that PSADT was more conclusive in patients with lower Trigger PSA levels. Analysing variables by location showed that only PSADT was able to differentiate between those with disease confined to the prostate compared with the other two locations (lymph nodes and bone), with shorter PSADT in these two, which was statistically significant (P < 0.002). In the patient group with a PSA level of <1.5 ng/mL, 30.8% had the disease, 7% of whom had metastatic bone disease. In the multivariate logistic regression, the risks factors that were clearly independent for those with positive PET/CT were: PSA level of >3 ng/mL, no early RP, and Gleason score of ≥ 8.

CONCLUSION

Our results support the usefulness of (18)F-fluorocholine PET/CT in biochemical relapse of prostate cancer after radical treatment, with an overall disease detection rate close to 50%, and it can be recommended as first-line treatment. As mentioned above, besides Trigger PSA levels, there are other clinical and pathological variables that need to be considered so as to screen patients properly and thus minimise the number of nodular lesions and increase the diagnostic accuracy of the examination.

Economic evaluation of diagnostic localization following biochemical prostate cancer recurrence

OBJECTIVES

The aim of this study was to assess potential cost-effectiveness of using a prostate cancer specific functional imaging technology capable of identifying residual localized disease versus small volume metastatic disease for asymptomatic men with low but detectable prostate specific antigen (PSA) elevation following radical prostatectomy.

METHODS

Markov modeling was used to estimate the incremental impact on healthcare system costs (2012 USD) and quality-adjusted life-years (QALYs) of two alternative strategies: (i) using the new diagnostic to guide therapy versus (ii) current usual care-using a combination of computed tomography, magnetic resonance imaging, and bone scan to guide therapy. Costs were based on estimates from literature and Medicare reimbursement. Prostate cancer progression, survival, utilities, and background risk of all-cause mortality were obtained from literature. Base-case diagnostic sensitivity (75 percent), specificity (90 percent), and cost (USD 2,500) were provided by our industry partner GE Healthcare.

RESULTS

The new diagnostic strategy provided an average gain of 1.83 (95 percent uncertainty interval [UI]: 1.24-2.64) QALYs with added costs of USD 15,595 (95 percent UI: USD -6,330-44,402) over 35 years. The resulting incremental cost-effectiveness ratio was USD 8,516/QALY (95 percent UI: USD -2,947-22,372). RESULTS were most influenced by the utility discounting rate and test performance characteristics; however, the new diagnostic provided clinical benefits over a wide range of sensitivity and specificity.

CONCLUSION

This analysis suggests a diagnostic technology capable of identifying whether men with biochemical recurrence after radical prostatectomy have localized versus metastatic disease would be a cost-effective alternative to current standard work-up. The results support additional investment in development and validation of such a diagnostic.

The natural history and predictors of outcome following biochemical relapse in the dose escalation era for prostate cancer patients undergoing definitive external beam radiotherapy

BACKGROUND

The management of biochemical failure (BF) following external beam radiotherapy (EBRT) for prostate cancer is controversial, due to both the heterogeneous disease course following a BF and a lack of clinical trials in this setting.

OBJECTIVE

We sought to characterize the natural history and predictors of outcome for patients experiencing BF in a large cohort of men with localized prostate cancer undergoing definitive dose-escalated EBRT.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective analysis included 2694 patients with localized prostate cancer treated with EBRT at a large academic center. Of these, 609 experienced BF, defined as prostate-specific antigen (PSA) nadir + 2 ng/ml. The median follow-up was 83 mo for all patients and 122 mo for BF patients.

INTERVENTION(S)

All patients received EBRT at doses of 75.6-86.4 Gy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary objective of this study was to determine predictors of distant progression at the time of BF. Cox proportional hazards models were used in univariate and multivariate analyses of distant metastases (DM), and a competing risks method was used to analyze prostate cancer-specific mortality (PCSM).

RESULTS AND LIMITATIONS

From the date of BF, the median times to DM and PCSM mortality were 5.4 yr and 10.5 yr, respectively. Shorter posttreatment PSA doubling time, a higher initial clinical tumor stage, a higher pretreatment Gleason score, and a shorter interval from the end of radiotherapy to BF were independent predictors for clinical progression following BF. Patients with two of these risk factors had a significantly higher incidence of DM and PCSM following BF than those with zero or one risk factor. The main limitations of this study are its retrospective nature and heterogeneous salvage interventions.

CONCLUSIONS

Clinical and pathologic factors can help identify patients at high risk of clinical progression following BF.

PATIENT SUMMARY

In this report, we look at predictors of outcome for patients with prostate cancer recurrence, as determined by prostate-specific antigen (PSA) levels, following radiation treatment. We found that the approximate median times to distant metastasis and death from prostate cancer for patients in this situation were 5 yr and 10 yr, respectively. Furthermore, we found that patients with a rapid increase in PSA levels following treatment, a short time to PSA recurrence, invasion of extraprostatic organs, or a high Gleason score had worse outcomes.

Disease-specific outcomes of radical prostatectomies in Northern Norway; a case for the impact of perineural infiltration and postoperative PSA-doubling time

Background

Prostate cancer is the most common male malignancy and a mayor cause of mortality in the western world. The impact of clinicopathological variables on disease related outcomes have mainly been reported from a few large US series, most of them not reporting on perineural infiltration. We therefore wanted to investigate relevant cancer outcomes in patients undergoing radical prostatectomy in two Norwegian health regions with an emphasis on the impact of perineural infiltration (PNI) and prostate specific antigen- doubling time (PSA-DT).

Methods

We conducted a retrospective analysis of 535 prostatectomy patients at three hospitals between 1995 and 2005 estimating biochemical failure- (BFFS), clinical failure- (CFFS) and prostate cancer death-free survival (PCDFS) with the Kaplan-Meier method. We investigated clinicopathological factors influencing risk of events using cox proportional hazard regression.

Results

After a median follow-up of 89 months, 170 patients (32%) experienced biochemical failure (BF), 36 (7%) experienced clinical failure and 15 (3%) had died of prostate cancer. pT-Stage (p = 0.001), preoperative PSA (p = 0.047), Gleason Score (p = 0.032), non-apical positive surgical margins (PSM) (p = 0.003) and apical PSM (p = 0.031) were all independently associated to BFFS. Gleason score (p = 0.019), PNI (p = 0.012) and non-apical PSM (p = 0.002) were all independently associated to CFFS while only PNI (P = 0.047) and subgroups of Gleason score were independently associated to PCDFS. After BF, patients with a shorter PSA-DT had independent and significant worse event-free survivals than patients with PSA-DT > 15 months (PSA-DT = 3-9 months, CFFS HR = 6.44, p < 0.001, PCDFS HR = 13.7, p = 0.020; PSA-DT < 3 months, CFFS HR = 11.2, p < 0.001, PCDFS HR = 27.5, p = 0.006).

Conclusions

After prostatectomy, CFFS and PCDFS are variable, but both are strongly associated to Gleason score and PNI. In patients with BF, PSA-DT was most strongly associated to CF and PCD. Our study adds weight to the importance of PSA-DT and re-launches PNI as a strong prognosticator for clinically relevant endpoints.

A paradigm shift from anatomic to functional and molecular imaging in the detection of recurrent prostate cancer

Approximately a third of men with localized prostate cancer who are treated with external beam radiation therapy (EBRT) or radical prostatectomy (RP) develop biochemical failure (BF). Presumably, BF will progress to distant metastasis and prostate cancer-specific mortality in some patients over subsequent years. Accurate detection of recurrent disease is important because it allows for appropriate treatment selection (e.g., local vs systemic therapy) and early delivery of therapy (e.g., salvage EBRT), which affect patient outcome. In this article, we discuss the paradigm shift in imaging technology in the detection of recurrent prostate cancer. First, we discuss the commonly used morphological and anatomical imaging modalities and their role in the post-RP and post-EBRT settings of BF. Second, we discuss the accuracy of functional and molecular imaging techniques, many of which are under investigation. Further studies are needed to establish the role of imaging techniques for detection of cancer recurrence and clinical decision-making.

Predicting bone scan positivity after biochemical recurrence following radical prostatectomy in both hormone-naive men and patients receiving androgen-deprivation therapy: results from the SEARCH database

BACKGROUND

To evaluate the factors associated with positive bone scans after biochemical recurrence (BCR) following radical prostatectomy in both hormone-naive subjects and subjects after androgen-deprivation therapy (ADT).

METHODS

Retrospective analysis of 380 bone scans of 301 hormone-naive subjects and 214 bone scans of 137 subjects after ADT following BCR from the Shared Equal Access Regional Cancer Hospital database. Generalized estimating equations and local regression plots were used to evaluate bone scan positivity by patients' demographics, pathological features, PSA levels and kinetics.

RESULTS

Among hormone-naive subjects and subjects on ADT, bone scan positivity was seen in 24 (6%) and 65 (30%) subjects, respectively. In hormone-naive subjects, the higher prescan PSA, higher PSA velocity (PSAV) and shorter PSA doubling time (PSADT) were significantly associated with positive scans (P=0.008, P<0.001 and P<0.001, respectively). In subjects after ADT, the prescan PSA, PSAV and PSADT were significantly associated with positive scans (P=0.011, P<0.001 and P=0.002, respectively). Regression plots showed increased scan positivity with increasing PSA levels and shortening PSADT (all P<0.001) for both hormone-naive subjects and subjects after ADT. For a given PSA level and PSADT, subjects on ADT had higher bone scan positivity.

CONCLUSIONS

In both hormone-naive subjects and subjects after ADT, more aggressive and advanced disease identified by higher PSA levels, higher PSAV and shorter PSADT were associated with higher bone scan positivity. For the same PSA level and PSADT, subjects after ADT had higher bone scan positivity than hormone-naive subjects. Therefore, PSA levels and kinetics may be used as selection criteria for bone scan in these patients.

Predicting the risk of bone metastasis in prostate cancer

The ability to identify prostate cancer patients at 'high risk' for bone metastasis development could allow early selection of those most likely to benefit from interventions to prevent or delay bone metastasis. This review is aimed to identify potential predictors of risk for bone metastasis in newly diagnosed patients and in those who have already received treatment. At diagnosis, established predictors of prostate cancer aggressiveness (e.g. PSA level, clinical stage, Gleason score) can identify patients at risk for bone metastasis. Following treatment of the disease, increasing evidence suggests that absolute PSA levels and other measures of PSA kinetics are useful to aid prediction of bone metastasis risk in patients both with and without a history of ADT. However, which PSA parameter most accurately predicts risk and the cut-off values that should be employed are unclear. Inclusion of PSA parameters to identify a high risk population may be beneficial in whom bone-modifying treatments are being considered. Other novel (but unvalidated) biomarkers that potentially predict the development of bone metastases have been identified, although it is unclear whether they will have value as independent markers or when combined with other parameters (e.g. measures of PSA kinetics). Further prospective studies of PSA kinetics and other predictive markers are, therefore, required to define the optimal criteria for identifying patients at high risk of bone metastases and those who are most likely to benefit from intensive monitoring and therapeutic intervention.

[Single center experience of (18F)-fluorocholine positron emission tomography: analysis of its impact on salvage local therapy in patients with prostate adenocarcinoma]

PURPOSE

To assess usefulness of ((18)F)-fluorocholine positron emission tomography (PET) for localizing relapse in patients with biochemical relapse from prostate adenocarcinoma and its impact on indications of salvage local therapy.

PATIENTS AND METHODS

An ((18)F)-fluorocholine PET coupled with computed tomography was performed in 28 patients with biochemical progression from prostate adenocarcinoma. At the time of ((18)F)-fluorocholine PET, median prostate specific antigen (PSA) was 3.0 ng/mL (from 0.34 to 93 ng/mL) and 17 patients (60.7%) received hormone therapy. Eighteen patients from this cohort were potentially candidates to salvage radiotherapy.

RESULTS

A pathologic uptake was shown in 11 patients (39.3%) and 17 patients (60.7%) had no pathologic uptake. Median PSA was 2.4 ng/mL (0.33 to 36 ng/mL) in case of negative ((18)F)-fluorocholine PET, versus 6.75 ng/mL (1.21 to 93 ng/mL) in case of pathologic uptake (P=0.04). Among the 17 patients candidates to salvage radiotherapy, ((18)F)-fluorocholine PET helped deciding for salvage radiotherapy in five patients, since it showed only centropelvic pathologic uptake (27.7%). In one patient, it showed metastatic and radiotherapy was contraindicated. After prostatectomy, ((18)F)-fluorocholine PET was positive in only one patient candidate to salvage radiotherapy (9.1%), showing anastomotic relapse.

CONCLUSION

((18)F)-fluorocholine was positive in about a third of patients with biochemical progression. Its clinical impact is being prospectively investigated.

Management of biochemical recurrence after primary treatment of prostate cancer: a systematic review of the literature

CONTEXT

Despite excellent cancer control with the treatment of localized prostate cancer (PCa), some men will experience a recurrence of disease. The optimal management of recurrent disease remains uncertain.

OBJECTIVE

To systematically review recent literature regarding management of biochemical recurrence after primary treatment for localized PCa.

EVIDENCE ACQUISITION

A comprehensive systematic review of the literature was performed from 2000 to 2012 to identify articles pertaining to management after recurrent PCa. Search terms included prostate cancer recurrence, salvage therapy, radiorecurrent prostate cancer, post HIFU, post cryoablation, postradiation, and postprostatectomy salvage. Studies were selected according to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines and required to provide a comprehensive description of primary and secondary treatments along with outcomes.

EVIDENCE SYNTHESIS

The data from 32 original publications were reviewed. The most common option for local salvage therapy after radical prostatectomy (RP) was radiation. Options for local salvage therapy after primary radiation included RP, brachytherapy, and cryotherapy. Different definitions of recurrence and risk profiles among patients make comparative assessment among salvage treatment modalities difficult. Triggers for intervention and factors predicting response to salvage therapy vary.

CONCLUSIONS

Radiation therapy (RT) after RP can provide durable prostate-specific antigen (PSA) responses in a sizeable percentage of men, especially when given early (ie, PSA <1 ng/ml). Though a few studies suggest improvements in mortality, prospective randomized trials are needed and underway. The role of salvage treatment after RT is less clear.

Role of ¹⁸F-choline PET/CT in suspicion of relapse following definitive radiotherapy for prostate cancer

PURPOSE

The aims of the study were (a) to evaluate the diagnostic role, by means of positive detection rate (PDR), of ¹⁸F-choline (CH) positron emission tomography (PET)/CT in patients with prostate cancer treated with radiotherapy, with curative intent, and suspicion of relapse during follow-up, (b) to correlate the PDR with trigger prostate-specific antigen (PSA), (c) to investigate the possible influence of androgen deprivation therapy (ADT) at the time of scan on PDR and (d) to assess distribution of metastatic spread.

METHODS

¹⁸F-CH PET/CT exams from 46 consecutive patients (mean age 71.3 years, range 51-84 years) with prostate cancer (mean Gleason score 6.4, range 5-8) previously treated by definitive radiotherapy and with suspicion of relapse with negative or inconclusive conventional imaging were retrospectively evaluated. Of the 46 patients, 12 were treated with brachytherapy and 34 with external beam radiation therapy. Twenty-three patients were under ADT at the time of the examination. Trigger PSA was measured within 1 month before the exam (mean value 6.5 ng/ml, range 1.1-49.4 ng/ml). Patients were subdivided into four groups according to their PSA level: 1.0 < PSA ≤ 2.0 ng/ml (11 patients), 2.0 < PSA ≤ 4.0 ng/ml (16 patients), 4.0 < PSA ≤ 6.0 ng/ml (9 patients) and PSA > 6.0 ng/ml (10 patients). Correlation between ADT and PDR was investigated as well as between PSA and distribution of metastatic spread.

RESULTS

The overall PDR of ¹⁸F-CH PET/CT was 80.4% (37/46 patients), increasing with the increase of trigger PSA. PDR of ¹⁸F-CH PET/CT is not influenced by ADT (p = 0.710) even if PET performed under ADT demonstrated an overall higher PDR (82.6%). The majority of the patients (59%, 22/37 patients) showed local relapse only, confined to the prostatic bed; 22% of the PET/CT-positive patients (8/37 patients) showed distant relapse only (bone localizations in all of them), while the remaining 19% (7/37 patients) showed both local and distant (lymph node and bone) spread.

CONCLUSION

¹⁸F-CH PET/CT showed a high overall detection rate (80%), proportional to the trigger PSA (both for local and distant relapse) not influenced by ADT. ¹⁸F-CH PET/CT is proposed as a first-line imaging procedure in restaging prostate cancer patients primarily treated with radiotherapy.

Unmet needs in the prediction and detection of metastases in prostate cancer

The therapeutic landscape for the treatment of advanced prostate cancer is rapidly evolving, especially for those patients with metastatic castration-resistant prostate cancer (CPRC). Despite advances in therapy options, the diagnostic landscape has remained relatively static, with few guidelines or reviews addressing the optimal timing or methodology for the radiographic detection of metastatic disease. Given recent reports indicating a substantial proportion of patients with CRPC thought to be nonmetastatic (M0) are in fact metastatic (M1), there is now a clear opportunity and need for improvement in detection practices. Herein, we discuss the current status of predicting the presence of metastatic disease, with a particular emphasis on the detection of the M0 to M1 transition. In addition, we review current data on newer imaging technologies that are changing the way metastases are detected. Whether earlier detection of metastatic disease will ultimately improve patient outcomes is unknown, but given that the therapeutic options for those with metastatic and nonmetastatic CPRC vary, there are considerable implications of how and when metastases are detected.

11C-choline PET/CT and PSA kinetics

The role of PET/CT with radiolabelled (18)F-choline or (11)C-choline in patients with prostate cancer after primary treatment has not been established yet and there are no guidelines on the appropriate use of this emerging modality. According to the literature, choline PET/CT may have a role in restaging the disease in patients with biochemical relapse for the detection of local and/or lymph node and/or distant recurrence. The aim of this brief review is to summarize the results of the most relevant published studies with particular focus on the relationship between prostate-specific antigen levels and kinetics and the sensitivity of choline PET/CT for optimizing the selection of patients who may benefit the most from this diagnostic procedure, especially early after biochemical recurrence.

Risk Stratification after Biochemical Failure following Curative Treatment of Locally Advanced Prostate Cancer: Data from the TROG 96.01 Trial

Purpose. Survival following biochemical failure is highly variable. Using a randomized trial dataset, we sought to define a risk stratification scheme in men with locally advanced prostate cancer (LAPC). Methods. The TROG 96.01 trial randomized 802 men with LAPC to radiation ± neoadjuvant androgen suppression therapy (AST) between 1996 and 2000. Ten-year follow-up data was used to develop three-tier post-biochemical failure risk stratification schemes based on cutpoints of time to biochemical failure (TTBF) and PSA doubling time (PSADT). Schemes were evaluated in univariable, competing risk models for prostate cancer-specific mortality. The performance was assessed by c-indices and internally validated by the simple bootstrap method. Performance rankings were compared in sensitivity analyses using multivariable models and variations in PSADT calculation. Results. 485 men developed biochemical failure. c-indices ranged between 0.630 and 0.730. The most discriminatory scheme had a high risk category defined by PSADT < 4 months or TTBF < 1 year and low risk category by PSADT > 9 months or TTBF > 3 years. Conclusion. TTBF and PSADT can be combined to define risk stratification schemes after biochemical failure in men with LAPC treated with short-term AST and radiotherapy. External validation, particularly in long-term AST and radiotherapy datasets, is necessary.

Obesity and prostate cancer: weighing the evidence

CONTEXT

Obesity and prostate cancer (PCa) affect substantial proportions of Western society. Mounting evidence, both epidemiologic and mechanistic, for an association between the two is of public health interest. An improved understanding of the role of this modifiable risk factor in PCa etiology is imperative to optimize screening, treatment, and prevention.

OBJECTIVE

To consolidate and evaluate the evidence for an epidemiologic link between obesity and PCa, in addition to examining the proposed underlying molecular mechanisms.

EVIDENCE ACQUISITION

A PubMed search for relevant articles published between 1991 and July 2012 was performed by combining the following terms: obesity, BMI, body mass index and prostate cancer risk, prostate cancer incidence, prostate cancer mortality, radical prostatectomy, androgen-deprivation therapy, external-beam radiation, brachytherapy, prostate cancer and quality of life, prostate cancer and active surveillance, in addition to obesity, BMI, body mass index and prostate cancer and insulin, insulin-like growth factor, androgen, estradiol, leptin, adiponectin, and IL-6. Articles were selected based on content, date of publication, and relevancy, and their references were also searched for relevant articles.

EVIDENCE SYNTHESIS

Increasing evidence suggests obesity is associated with elevated incidence of aggressive PCa, increased risk of biochemical failure following radical prostatectomy and external-beam radiotherapy, higher frequency of complications following androgen-deprivation therapy, and increased PCa-specific mortality, although perhaps a lower overall PCa incidence. These results may in part relate to difficulties in detecting and treating obese men. However, multiple molecular mechanisms could explain these associations as well. Weight loss slows PCa in animal models but has yet to be fully tested in human trials.

CONCLUSIONS

Obesity appears to be linked with aggressive PCa. We suggest clinical tips to better diagnose and treat obese men with PCa. Whether reversing obesity slows PCa growth is currently unknown, although it is an active area of research.

(11)C-Choline PET/CT in patients with hormone-resistant prostate cancer showing biochemical relapse after radical prostatectomy

PURPOSE

To determine the diagnostic efficacy of (11)C-choline PET/CT in patients with prostate cancer (PC) after radical prostatectomy who presented with increasing PSA levels during follow-up in spite of being on hormone treatment (HT), and therefore showing HT resistance.

METHODS

We evaluated a large series of 157 consecutive PC patients previously treated by radical prostatectomy who presented with biochemical recurrence with increasing PSA levels in spite of ongoing HT (HT-resistant patients). At the time of (11)C-choline PET/CT, the mean value of trigger PSA level was 8.3 (range 0.2 - 60.6 ng/mL), the mean PSA doubling time (PSAdt) was 5.3 (range 0.4 - 35 months), and the mean PSA velocity (PSAvel) was 22.1 ng/mL/year (range 0.12 - 82 ng/mL/year). (11)C-Choline PET/CT was performed following a standard procedure at our centre to investigate increasing PSA levels, either as the first imaging procedure or in patients with negative conventional imaging. At the time of (11)C-choline PET/CT all patients were receiving HT (61 were receiving monotherapy and 96 multidrug therapy). PET-positive findings were validated by: (a) transrectal US-guided biopsy in patients with recurrence in the prostatic bed, (b) surgical pelvic lymphadenectomy, (c) other imaging modalities, including repeated (11)C-choline PET/CT, performed during a minimum follow-up of 12-months.

RESULTS

(11)C-Choline PET/CT showed positive findings in 104 of the 157 patients (66 %). (11)C-choline PET/CT detected: a single lesion in 40 patients (7 in the prostate bed, 10 in lymph nodes, 22 in bone, 1 at another site); two lesions in 18 patients (7 in lymph nodes, 7 in bone, 4 in both lymph nodes and bone); three or four lesions in 7 patients (4 in lymph nodes, 2 in bone, 1 at another site); and more than four lesions in the remaining 39 patients (2 in the prostate bed, 12 in lymph nodes, 12 in bone, 11 in both lymph nodes and bone, 2 at other sites). In (11)C-choline PET-negative patients, the mean values of trigger PSA, PSAdt and PSAvel were 3.8 ng/mL (range 0.2-11.9 ng/mL) 7.0 months (range 1.21 - 35 months) and 5.8 ng/mL/year (range 0.12 - 30.1) respectively, while in (11)C-Choline-PET-positive patients they were 10.5 ng/mL (range 0.2 - 60.6), 4.4 months (range 0.4 - 19.7) and 15.9 ng/mL/year (range 0.5 - 82.0) respectively. The differences between PET-negative and PET-positive patients were statistically significant for all these parameters: trigger PSA, p < 0.01; PSAdt, p < 0.01; PSAvel, p = 0.03.

CONCLUSION

In our patient population, (11)C-choline PET/CT was able to detect relapsed disease in a large proportion of HT-resistant PC patients during HT. These data, obtained in a large series, suggest that HT withdrawal before performing a (11)C-choline PET/CT scan may not be necessary for the detection of recurrent disease if PSA levels are increasing and PSA kinetics are rapid.

Operational characteristics of (11)c-choline positron emission tomography/computerized tomography for prostate cancer with biochemical recurrence after initial treatment

PURPOSE

We examined the performance of (11)C-choline positron emission tomography/computerized tomography for its ability to delineate prostate cancer distribution and extent after initial therapy.

MATERIALS AND METHODS

A consecutive series retrospective review was performed of all patients with prostate cancer who were evaluated using (11)C-choline positron emission tomography/computerized tomography from September 2007 to November 2010 at the Mayo Clinic. Statistical analysis was performed to determine the sensitivity, specificity, positive predictive value, negative predictive value and prostate specific antigen threshold for the detection of recurrent lesions.

RESULTS

In the study period 176 patients with biochemical recurrence after primary treatment failure underwent (11)C-choline positron emission tomography/computerized tomography. Using patient based analysis (11)C-choline positron emission tomography yielded a sensitivity, specificity, positive predictive value and negative predictive value of 93%, 76%, 91% and 81%, respectively. Of the 176 positron emission tomography/computerized tomography scans performed 56 (32%) were deemed clinically useful as defined by the ability to identify lesions not delineated using conventional imaging, thereby prompting changes in clinical management. The optimal prostate specific antigen for lesion detection was 2.0 ng/ml. On multivariate analysis prostate specific antigen at positron emission tomography (HR 1.37, p = 0.04) and clinical stage at initial diagnosis of prostate cancer (HR 5.19, p = 0.0035) were significant predictors of positive (11)C-choline positron emission tomography/computerized tomography.

CONCLUSIONS

(11)C-choline positron emission tomography/computerized tomography performs well in men with biochemical recurrence after primary treatment failure. The optimal prostate specific antigen value for lesion detection is approximately 2.0 ng/ml. We found that (11)C-choline positron emission tomography/computerized tomography substantially enhances the rate of prostate cancer lesion detection by approximately 32% beyond what can be garnered using conventional imaging techniques and at a lower prostate specific antigen value.