Combination of [18F]FDG and [18F]PSMA-1007 PET/CT predicts tumour aggressiveness at staging and biochemical failure postoperatively in patients with prostate cancer

PURPOSE

[18F]fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) has limitations in prostate cancer (PCa) detection owing to low glycolysis in the primary tumour. Recently, prostate-specific membrane antigen (PSMA) PET/CT has been useful for biochemical failure detection and radioligand therapy (RLT) guidance. However, few studies have evaluated its use in primary prostate tumours using PSMA and [18F]FDG PET/CT. This study aimed to evaluate [18F]PSMA-1007 and [18F]FDG PET/CT for primary tumour detection and understand the association of metabolic heterogeneity with clinicopathological characteristics at staging and postoperatively.

METHOD

This prospective study included 42 index tumours (27 acinar and 15 ductal-dominant) in 42 patients who underwent [18F]PSMA-1007 and [18F]FDG PET/CT and subsequent radical prostatectomy. All patients were followed for a median of 26 mo, and serum prostate-specific antigen levels were measured every 3 mo to evaluate biochemical failure. One-way analysis of variance, Tukey's multiple comparison test, and Fisher's exact test were performed.

RESULTS

All 42 index tumours were detected on [18F]PSMA-1007 PET/CT, whereas only 15 were detected on [18F]FDG PET/CT (62.3% vs. 37.7%, p < 0.0001). A high SUVmax for [18F]PSMA-1007 was observed in tumours with high Gleason scores (GS 6-7 vs. GS 8-10; 12.1 vs. 20.1, p < 0.05). Tumours with [18F]FDG uptake were mostly ductal dominant (acinar-dominant 4/27; ductal-dominant; 11/15, p < 0.001), with lower [18F]PSMA-1007 uptake than tumours without [18F]FDG uptake (SUVmax 16.58 vs. 11.19, p < 0.001). There were 16.6% (7/42) of patients with pStage IV in whom the primary tumours were [18F]FDG positive. Biochemical failure was observed in 14.8% (4/27) of patients with [18F]FDG negative tumours but in 53.3% (8/15) of patients with [18F]FDG positive tumours (p = 0.013).

CONCLUSIONS

[18F]PSMA-1007 PET/CT was superior to [18F]FDG PET/CT in detecting primary PCa. In contrast, tumours with [18F]FDG uptake are associated with larger size, a ductal-dominant type, and likely to undergo metastasis at staging and biochemical failure postoperatively.

The significance of metabolic response to neoadjuvant androgen deprivation therapy detected with [68Ga]Ga-PSMA-11-PET/CT in high-risk prostate cancer patients treated with definitive radiotherapy

PURPOSE

We examined the prognostic significance of early changes in primary tumor SUV measured with Gallium-68-labeled prostate-specific membrane antigen positron emission tomography ([68Ga]Ga-PSMA-11-PET/CT) and serum PSA values after neoadjuvant androgen deprivation treatment (nADT) in high-risk prostate cancer (PCa) patients treated with definitive radiotherapy (RT).

METHODS

The clinical data and SUV parameters of 71 PCa patients were reviewed retrospectively. The serum PSA and primary tumor SUV values were calculated before and after the start of ADT. Using univariable and multivariable analyses, the prognostic factors predicting biochemical disease free survival (bDFS) and prostate cancer specific survival (PCSS) were investigated. In addition, logistic regression analysis was used to identify predictors of biochemical failure (BF).

RESULTS

All but one patient responded with a 98.8% reduction in serum PSA (21.8 ng/mL vs. 0.3 ng/mL; p < 0.001), and 64 patients (91.1%) had a median 66.6% decrease in primary tumor SUV after ADT (13.2 vs. 4.8, p < 0.001). The primary tumor SUV response rate was significantly higher in patients with Gleason score (GS) of 7 than in patients with GS > 7 (59.5% vs. 40.5%; p = 0.04), and it was significantly lower in patients with inadequate treatment response than in those with complete (CR) or partial response (PR) (1.1% vs. 66.1%; p < 0.001). There was a strong and significant correlation (Spearman = 0.41, p < 0.001) and a high concordance (91.5%) between PSA response and SUV response after ADT. With a median follow-up time of 76.1 months, the 5-year bDFS and PCSS rates were 77.2% and 92.2%, respectively. Nineteen patients (26.7%) patients had recurrence at a median of 44.6 months after the completion of RT. In multivariate analysis, lymph node metastasis, GS greater than 7, and SD/PD after nADT were independent predictors of worse bDFS. However, no significant factor for PCSS was identified. In the multivariable logistic regression analysis, advanced age, GS of  > 7 disease, lymph node metastasis, and SD or PD after nADT were independent predictors of BF.

CONCLUSION

These results imply that the metabolic response measured with [68Ga]Ga-PSMA-11-PET/CT after nADT could be used to predict progression in high-risk PCa patients treated with definitive RT.

Biochemical outcomes and toxicities in young men with prostate cancer after permanent iodine-125 seed implantation: Prospective cohort study in 6662 patients

PURPOSE

We evaluated the effect of age, <60 and ≥60 years, on biochemical outcomes and toxicities in patients with prostate cancer who underwent permanent seed implantation (PI) ± external beam radiation therapy ± hormone therapy in a national Japanese prospective cohort study (J-POPS).

METHODS AND MATERIALS

The safety and efficacy analyses included 6721 and 6662 patients, respectively. We categorized patients into two age groups: <60 (n = 716) and ≥60 (n = 6,005) years. We used propensity score matching (PSM) to estimate the marginal effect of age on biochemical freedom from failure (bFFF) using a Phoenix definition and Cox proportional hazard models.

RESULTS

The median followup period was 60.0 months. Without PSM, men <60 years demonstrated similar 5-year bFFF (96.3%) compared with men ≥60 years (95.6%; p = 0.576); percent positive biopsies, biologically effective dose, Gleason score, risk classification, and supplemental external beam radiation therapy (p <0.001, <0.001, <0.001, 0.008, and <0.001) were significantly associated with bFFF while age was not (p = 0.576). With PSM, bFFF was not significantly different between age groups (p = 0.664); however, men <60 years showed a significantly lower incidence of declining erectile function, grade ≥2 all urinary toxicities, urinary frequency/urgency, and rectal bleeding (p <0.001, 0.024, 0.031, and 0.010) than men ≥60 years.

CONCLUSIONS

After PI, men <60 years achieved a comparable 5-year biochemical control rate and showed a lower incidence of several toxicities compared to men ≥60 years. This suggests that PI should be an excellent treatment option for men <60 years with prostate cancer.

The prognostic value of mean apparent diffusion coefficient measured with diffusion-weighted magnetic resonance image in patients with prostate cancer treated with definitive radiotherapy

PURPOSE

To assess the correlation between initial tumor apparent diffusion coefficient (ADC) values and clinicopathological parameters in prostate cancer (PCa) patients treated with definitive radiotherapy (RT). Additionally, the prognostic factors for freedom from biochemical failure (FFBF) and progression-free survival (PFS) in this patient cohort were analyzed.

MATERIALS AND METHODS

The clinical data of 503 patients with biopsy-confirmed PCa were evaluated retrospectively. All patients had clearly evident tumors on diffusion-weighted magnetic resonance imaging (DW-MRI) for ADC values. Univariable and multivariable analyses were used to determine prognostic factors for FFBF and PFS.

RESULTS

The median follow-up was 72.9 months. The 5-year FFBF and PFS rates were 93.2% and 86.2%, respectively. Significantly lower ADC values were found in patients with a high PSA level; advanced clinical stage; higher ISUP score, and higher risk group than their counterparts. Receiver operating characteristic (ROC) curve analysis revealed an ADC cut-off value of 0.737 × 10^-3 mm²/sec for tumor recurrence. Patients who progressed had a lower mean ADC value than those who did not (0.712±0.158 vs. 1.365±0.227 × 10^-3 mm²/sec; p<0.001). There was a significant difference in 5-year FFBF (96.3% vs. 90%; p<0.001) and PFSrates (83.8% vs. 73.5%; p=0.002) between patients with higher and lower mean ADC values. The FFBF and PFS were found to be correlated with tumor ADC value and ISUP grades in multivariable analysis. Additionally, older age was found to be a significant predictor of worse PFS.

CONCLUSIONS

Lower ADC values were found in patients with high-risk characteristics such as a high serum PSA level, stage or grade of tumor, or high-risk disease, implying that ADC values could be used to predict prognosis. Lower ADC values and higher ISUP grades were associated with an increased risk of BF and progression, implying that treatment intensification may be required in these patients.

Primary tumour PSMA intensity is an independent prognostic biomarker for biochemical recurrence-free survival following radical prostatectomy

Purpose

The prognostic value of PSMA intensity on PSMA PET/CT due to underlying biology and subsequent clinical implications is an emerging topic of interest. We sought to investigate whether primary tumour PSMA PET intensity contributes to pre- and post-operative prediction of oncological outcomes following radical prostatectomy.

Methods

We performed a retrospective cohort study of 848 men who underwent all of multiparametric MRI (mpMRI), transperineal prostate biopsy, and ⁶⁸ Ga-PSMA PET/CT prior to radical prostatectomy. PSMA intensity, quantified as maximum standard uptake value (SUVmax), and other clinical variables were considered relative to post-operative biochemical recurrence-free survival (BRFS) using Cox regression and Kaplan–Meier analysis.

Results

After a median follow-up of 41 months, 219 events occurred; the estimated 3-year BRFS was 79% and the 5-year BRFS was 70%. Increasing PSMA intensity was associated with less favourable BRFS overall (Log rank p < 0.001), and within subgroups of Gleason score category (Log rank p < 0.03). PSMA intensity was significantly associated with shorter time to biochemical recurrence, after adjusting for pre-operative (HR per 5-unit SUVmax increase = 1.15) and post-operative (HR per 5-unit SUVmax increase = 1.10) parameters.

Conclusion

These results in a large series of patients confirm PSMA intensity to be a novel, independent prognostic factor for BRFS.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00259-022-05756-2.

Focal brachytherapy for localized prostate cancer: 5.7-year clinical outcomes and a pair-matched study with radical prostatectomy

OBJECTIVES

To report experience with focal brachytherapy (FB) and compare its clinical outcomes with those of radical prostatectomy (RP) in localized prostate cancer.

METHODS

Fifty-one patients with low- to intermediate-risk prostate cancer underwent low-dose-rate FB. Survival rates free from biochemical failure (BF), additional treatment (AT) including re-FB, and whole-gland or systemic salvage therapy (ST) were calculated and oncological risk factors were investigated. Patient-reported outcomes on genitourinary function were also assessed. Using propensity scoring, 51 pair-matched RP patients were selected. Oncological control, urinary continence, and ejaculation status after FB and RP were compared.

RESULTS

During a median 5.7-year follow-up, BF, AT, and ST occurred in 12 (24%), 10 (20%), and 4 FB patients (8%), respectively. 6 of 10 AT patients were managed with re-FB alone. In the RP cohort, 3 patients (6%) underwent ST. 5-year BF-free survival rate after FB was 79%. Compared to 5-year ST-free survival rate of 94% after RP, ST-free and AT-free survival rates after FB were 93% (P = 0.813) and 87% (P = 0.049), respectively. Multivariate analyses of FB-treated patients showed that time to PSA nadir was negatively associated with BF and AT (hazard ratio 0.84 and 0.83, respectively, P <0.001 for each). The difference in oncological outcomes between low- and intermediate-risk categories was not significant. At 2 years after FB and RP, pad-free continence rates were 100% and 81%, respectively (P = 0.001). Ejaculation was preserved in 67% and 0% of patients who had been capable of ejaculation at baseline, respectively (P <0.001).

CONCLUSION

In low- to intermediate-risk prostate cancer, FB-treated patients achieved superior genitourinary function compared to pair-matched RP patients. The need for ST was not substantially different between the 2 treatment cohorts. Over half of patients requiring AT could be managed by re-focal treatment rather than whole-gland ST. Early PSA nadir may predict poor oncological control after FB.

Refining the definition of biochemical failure in the era of stereotactic body radiation therapy for prostate cancer: The Phoenix definition and beyond

BACKGROUND AND PURPOSE

The Phoenix definition for biochemical failure (BCF) after radiotherapy uses nadir PSA (nPSA) + 2 ng/mL to classify a BCF and was derived from conventionally fractionated radiotherapy, which produces significantly higher nPSAs than stereotactic body radiotherapy (SBRT). We investigated whether an alternative nPSA-based threshold could be used to define post-SBRT BCFs.

MATERIALS AND METHODS

PSA kinetics data on 2038 patients from 9 institutions were retrospectively analyzed for low- and intermediate-risk PCa patients treated with SBRT without ADT. We evaluated the performance of various nPSA-based definitions. We also investigated the relationship of relative PSA decline (rPSA, PSA_18month/PSA_6month) and timing of reaching nPSA + 2 with BCF.

RESULTS

Median follow-up was 71.9 months. BCF occurred in 6.9% of patients. Median nPSA was 0.16 ng/mL. False positivity of nPSA + 2 was 30.2%, compared to 40.9%, 57.8%, and 71.0% for nPSA + 1.5, nPSA + 1.0, and nPSA + 0.5, respectively. Among patients with BCF, the median lead time gained from an earlier nPSA + threshold definition over the Phoenix definition was minimal. Patients with BCF had significantly lower rates of early PSA decline (mean rPSA 1.19 vs. 0.39, p < 0.0001) and were significantly more likely to reach nPSA + 2 ≥ 18 months (83.3% vs. 21.1%, p < 0.0001). The proposed criterion (rPSA ≥ 2.6 or nPSA + 2 ≥ 18 months) had a sensitivity and specificity of 92.4% and 81.5%, respectively, for predicting BCF in patients meeting the Phoenix definition and decreased its false positivity to 6.4%.

CONCLUSION

The Phoenix definition remains an excellent definition for BCF post-SBRT. Its high false positivity can be mitigated by applying additional criteria (rPSA ≥ 2.6 or time to nPSA + 2 ≥ 18 months).

The Effect of Maximum Tumor Diameter by MRI on Disease Control in Intermediate and High-risk Prostate Cancer Patients Treated With Brachytherapy Boost

BACKGROUND

Larger maximum tumor diameter (MTD) has been associated with worse prostate cancer (PCa) outcomes. However, the impact of MTD in PCa treated with external beam radiotherapy and brachytherapy boost (EBRT+BB) remains unknown.

MATERIALS AND METHODS

Patients with PCa treated with EBRT+BB were identified from an institutional database. Clinical data including MTD, age, androgen deprivation therapy (ADT) use, prostate specific antigen (PSA), International Society of Urologic Pathology (ISUP) group, clinical T-stage, and presence of adverse pathology on imaging were retrospectively collected. Multivariable and univariable cox proportional hazards models for biochemical failure (BF) and distant metastasis (DM) were produced with MTD grouped by receiver operating characteristic (ROC) cut-point. Cumulative hazard functions for BF and DM were compared with log-rank test and stratified by ISUP group.

RESULTS

Of 191 patients treated with EBRT+BB, 113 had MTD measurements available. Larger MTD was associated with increased ADT use and seminal vesicle involvement. ROC optimization identified MTD of 24 mm as the optimal cut-point for both BF and DM. MTD was independently associated with both BF (HR 8.61, P = .048, 95% CI 1.02-72.97) and DM (HR 8.55, P = .05, 95% CI 1.00-73.19). In patients with ISUP group 4 to 5 disease, MTD > 24 mm was independently associated with increased risk of DM (HR 10.13, P = .04, 95% CI 1.13-91.12).

CONCLUSIONS

This is the first study to evaluate MTD in the setting of EBRT+BB. These results demonstrate that MTD is independently associated with BF and metastasis. This suggests a possible role for MTD in risk assessment models and clinical decision-making for men receiving EBRT+BB.

[CAPRA score vs minimal residual disease as predictors of biochemical recurrence after radical prostatectomy.]

OBJECTIVE

To compare the classification CAPRA (based on clinical-pathological findings) and minimal residual disease (MRD) (based on biological characteristics) to predict biochemical failure (BF).

METHOD AND PATIENTS

The clinical-pathological findings of the prostate biopsy were used to determine the CAPRA score, classifying patients into low, intermediate and high risk. Blood and bone marrow samples to detect circulating prostate cells (CPCs) and micro-metastasis were taken. The samples were classified as positive if ≥1 prostate cell was detected, forming three subgroups; Group A (MRD negative), Group B (micro-metastasis positive, CPC negative) and Group C (CPC positive). Patients were followed-up for 10 yearsor BF. Kaplan-Meier biochemical failure free survival (BFFS) curves, a predictive flexible parameter survival model and mean restricted survival times (MRST) were determined.

RESULTS

347 men participated, BF risk increased with increasing CAPRA score, HR 1.21 intermediate, 1.64 high risk; versus MRD HR 1.91 and 4.43 for Groups Band C. After 10 years the BFFS and MRST were 76%, 50% and 17% and 9, 7 and 5 years respectively for CAPRA versus 94%, 57% and 26% and 10, 9 and 6 years respectively for MRD. The concordance between observed and predicted BFFS was acceptable for CAPRA (Harrell´s C 0.64) and very good (0.92) for MRD. The BFFS curves for MRD were not proportional with time, they were similar for 5 years for Groups A and B, with increasing BFFS in Group B there after.The CAPRA score did not distinguish between Groups A and B, one third of low risk CAPRA patients had CPCs detected.

CONCLUSIONS

The MRD classification was superior to CAPRA, differentiating between early and late failure.

Impact of statin use on overall and time to biochemical failure following radical prostatectomy or radiation therapy

OBJECTIVES

To assess the impact of statin use on overall and time to biochemical failure following primary treatment of localized prostate cancer (PCa).

SUBJECTS/PATIENTS AND METHODS

1581 patients undergoing radical prostatectomy (RP) or radiation therapy (RT) for primary treatment of PCa between July 2007 and January 2020 were evaluated for statin use, demographic/oncologic characteristics, and biochemical outcomes. Rate of biochemical failure (BF) was assessed overall and at 1, 3, and 5 years; time to BF was estimated with Kaplan-Meier. Logistic and linear regression were used to control for treatment modality and disease characteristics.

RESULTS

The average age was 63.0 ± 7.5 years and median pre-treatment PSA was 6.55 (IQR 4.94). 1473 (93.2%) and 108 (6.8%) underwent RP and RT, respectively. RP patients were younger, had lower pre-PSA, lower BMI, and lower risk disease. At 3.4 ± 2.7 years follow-up, 323 (20.4%) experienced BF. When stratified by statin use, BF overall and within 1, 3, and 5 years were not different. Time to BF, was lower in patients using statins (1.8 ± 1.9 years vs. 2.4 ± 2.6 years; p = 0.016). These results persisted in multivariate analysis, wherein statin use was not associated with BF but was associated with a shorter time to BF.

CONCLUSION

Overall, statin use was not associated with a reduced risk of BF in RP or RT patients. However, for patients with BF, statin use was associated with a decreased time to BF. Future investigations are warranted to further elucidate the impact of statin use on PCa recurrence.

Tumor location on MRI determines outcomes of patients with prostate cancer after total prostate cryoablation

We investigated the association between tumor location on multiparametric magnetic resonance imaging (mpMRI) and outcomes of prostate cancer patients after primary total prostate cryoablation (PTPC). Between March 2010 and December 2012, consecutive 192 prostate cancer patients receiving PTPC were enrolled. Tumor locations were determined and classified as anterior apex (AA), anterior midgland (AM), anterior base (AB), posterior apex (PA), posterior midgland (PM) and posterior base (PB) using mpMRI. Midline location, central location, seminal vesicle invasion, extraprostatic extension, multiple tumors, and tumor volume were also identified. Prostate local recurrence and biochemical failure were considered as primary and secondary endpoints, respectively. Tumors on mpMRI were identified in 148 (77.1%) patients. Tumor locations were most frequently noted in PM (89, 46.4%), followed by AM (55, 28.6%), PB (53, 27.6%), PA (46, 24%), AA (35, 18.2%) and AB (31, 16.1%). Midline and central tumors were observed in 34 (17.7%) and 14 (7.3%) patients, respectively. During a median follow-up duration of 81 months (range, 2-114 months), 71 (37.0%) and 29 (40.8%) patients experienced biochemical failure and local recurrence, respectively. Multivariable analyses revealed only AA tumors increased the risk of local recurrences (HR = 2.98, 95% CI. 1.36-6.49). None of location-related parameters was associated with biochemical failure. Tumor location on mpMRI has a significant association with local tumor recurrence in patients receiving PTPC. Physicians should be cautious when conducting cryoablation for prostate tumors in AA location.

Increased risk of disease progression in younger men: Analysis of factors predicting biochemical failure and castration-resistant prostate cancer after high-dose intensity-modulated radiation therapy for nonmetastatic prostate cancer

BACKGROUND

The aim of this study was to investigate the clinical significance of the effect of age on disease control in men who received high-dose intensity-modulated radiation therapy (IMRT) for nonmetastatic prostate cancer (NMPCa).

METHODS

NMPCa patients with favorable intermediate to very high-risk features (National Comprehensive Cancer Network risk classification) treated with IMRT at our institution between September 2000 and May 2011 were analyzed retrospectively. Treatment consisted of high-dose IMRT (74-78 Gy/37-39 fractions) combined with 6 months of neoadjuvant hormonal therapy. Multivariable analysis using Fine and Gray's regression model was performed to evaluate whether age at initiation of IMRT was associated with biochemical failure (BF) and castration-resistant prostate cancer (CRPC) progression.

RESULTS

A total of 367 patients were analyzed. The median follow-up period was 8.8 years after IMRT. The 5- and 10-year BF rates were 22.1 and 31.7%, and those of CRPC rates were 4.5 and 12.6%, respectively. Multivariable analysis revealed that a younger age (cut-off: 70 years old) at the initiation of IMRT was significantly correlated with both a higher BF rate (hazard ratio: 1.691, P= 0.0064) and higher CRPC rate (hazard ratio: 2.579, P = 0.0079).

CONCLUSIONS

Younger men with NMPCa had increased risks of BF and CRPC after high-dose IMRT, and may benefit from more intensive treatments. Our findings should be further tested in prospective studies.

MRI detected extaprostatic extension (EPE) in prostate cancer: Do all T3a patients have the same outcomes?

MRI-detected T3a prostate cancer is a heterogeneous disease. This post-hoc analysis of a prospective trial found that patients with T3a disease presenting obliteration of the recto-prostatic angle, contact-asymmetry of neuro-vascular bundle and periprostatic fat invasion, may be at higher risk of biochemical failure and metastases.

Focal HIFU therapy for anterior compared to posterior prostate cancer lesions

Objective

To compare cancer control in anterior compared to posterior prostate cancer lesions treated with a focal HIFU therapy approach.

Materials and methods

In a prospectively maintained national database, 598 patients underwent focal HIFU (Sonablate^®500) (March/2007–November/2016). Follow-up occurred with 3-monthly clinic visits and PSA testing in the first year with PSA, every 6–12 months with mpMRI with biopsy for MRI-suspicion of recurrence. Treatment failure was any secondary treatment (ADT/chemotherapy, cryotherapy, EBRT, RRP, or re-HIFU), tumour recurrence with Gleason ≥ 3 + 4 on prostate biopsy without further treatment or metastases/prostate cancer-related mortality. Cases with anterior cancer were compared to those with posterior disease.

Results

267 patients were analysed following eligibility criteria. 45 had an anterior focal-HIFU and 222 had a posterior focal-HIFU. Median age was 64 years and 66 years, respectively, with similar PSA level of 7.5 ng/ml and 6.92 ng/ml. 84% and 82%, respectively, had Gleason 3 + 4, 16% in both groups had Gleason 4 + 3, 0% and 2% had Gleason 4 + 4. Prostate volume was similar (33 ml vs. 36 ml, p = 0.315); median number of positive cores in biopsies was different in anterior and posterior tumours (7 vs. 5, p = 0.009), while medium cancer core length, and maximal cancer percentage of core were comparable. 17/45 (37.8%) anterior focal-HIFU patients compared to 45/222 (20.3%) posterior focal-HIFU patients required further treatment (p = 0.019).

Conclusion

Treating anterior prostate cancer lesions with focal HIFU may be less effective compared to posterior tumours.

[Circulating prostate cells and bone marrow micro-metastasis and not treatment modality determine the risk and time to biochemical failure in low risk prostate cancer.]

INTRODUCTION

Minimal residual disease (MRD) is that which persists after curative treatment for prostate cancer. It has the potential to grow and cause metastasis. The detection of circulating prostate cells (CPCs) and bone marrow micro-metastasis could represent different sub-types of MRD.

OBJECTIVE

To determine biochemical failure free survival and time to failure, the presence of circulating prostate cells and bone marrow micro-metastasis in men treated for low risk prostate cancer.

HYPOTHESIS

The presence of MRD and not the treatment modality determines the results of therapy.

METHODS

Blood and bone marrow samples were taken one month after completing treatment to detect CPCs and micro-metastasis. Patients were classified into three groups; A: CPC negative, micro-metastasis negative, B: CPC negative, micro-metastasis positive and C: CPC positive. Biochemical failure was defined as a PSA >0.2ng/ml after radical prostatectomy and >2.0ng/ml post nadir after radiotherapy. After 10 years of follow up the Kaplan-Meier survival curve was determined and using a flexible adjusted parametric model the mean restricted survival time (MRST) was calculated for all groups.

RESULTS

343 men participated, 183 post surgery and 160 post radiotherapy, 181 (53%) had clinical stage T1 and 162 (47%) clinical stage T2a. There were no differences in treatment results between prostatectomy and radiotherapy. T1 patients had a significantly lower frequency of MRD than T2 patients (20% versus 67% p<0.001). Patients negative for MRD (Group A) had a 97% 10-year survival rate and a MRST to failure of 9.9 years. Men with only micro-metastasis (Group B) had a survival rate similar to Group A during the first five years, afterwards there was increasing treatment failure (late failure). Men positive for CPCs had a high risk of early failure.

CONCLUSIONS

The treatment results of surgery and radiotherapy are similar and depend on the sub-type of MRD. Men negative for MRD could be considered cured with a biochemical failure free survival of >95% at 10 years. The sub-type of MRD determines early or late failure and could be useful in the risk classification of patients after curative treatment.

Racial differences in the PSA bounce in predicting prostate cancer outcomes after brachytherapy: Evidence from the Department of Veterans Affairs

PURPOSE

African American men have historically had poorer prostate cancer biochemical and survival outcomes than Caucasians. However, emerging data suggest nononcologic factors drive much of this disparity. Prior evidence has suggested an association between a transient prostate specific antigen (PSA) bounce and improved biochemical control. However, racial differences in this relationship have remained relatively unexplored.

METHODS AND MATERIALS

We identified 4477 men treated for low- or intermediate-risk prostate cancer within the U.S. Department of Veterans Affairs (VA) from 2000 to 2010 with brachytherapy alone or in combination with external beam radiotherapy without androgen deprivation. Longitudinal PSA data were used to define to biochemical failure and PSA bounce. Cox proportional hazard models were used explore racial differences in the relationship between the PSA bounce and time to biochemical failure.

RESULTS

Thirty-one percent of our sample experienced a PSA bounce, with African Americans more likely to experience a bounce (42%) compared with Caucasians (29%); p < 0.001. Despite this, African Americans had a higher likelihood of biochemical failure (hazard ratio [HR] 1.4; p = 0.006). However, African American men experiencing a PSA bounce were less likely to experience a biochemical failure (HR = 0.64; p = 0.046), whereas this relationship was not statistically significant for Caucasians (HR = 0.78; p = 0.092). On multivariate analysis, African Americans receiving brachytherapy alone were most sensitive to the protective benefit of the PSA bounce (HR = 0.64).

CONCLUSIONS

A PSA bounce was associated with improved biochemical control among patients receiving brachytherapy as part of their treatment for low- or intermediate-risk prostate cancer at the VA. African American men treated with brachytherapy had a particularly pronounced biochemical control benefit of a PSA bounce.

Multiparametric magnetic resonance imaging-guided salvage radiotherapy in prostate cancer

Aim

To analyse the efficacy and toxicity of postprostatectomy SRT in patients with a BCR evaluated with mpMRI.

Background

Multiparametric magnetic resonance imaging (mpMRI) has the ability to detect the site of pelvic recurrence in patients with biochemical recurrence (BCR) after radical prostatectomy (RP). However, we do not know the oncological outcomes of mpMRI-guided savage radiotherapy (SRT).

Results

Local, lymph node, and pelvic bone recurrence was observed in 13, 4 and 2 patients, respectively. PSA levels were significantly lower in patients with negative mpMRI (0.4 ng/mL [0.4]) vs. positive mpMRI (2.2 ng/mL [4.1], p = 0.003). Median planning target volume doses in patients with visible vs. non-visible recurrences were 76 Gy vs. 70 Gy. Overall, mean follow-up was 41 months (6-81). Biochemical relapse-free survival (bRFS) at 3 years was 82.3% and 82.5%, respectively, for the negative and positive mpMRI groups (p = 0.800). Three-year rates of late grade ≥2 urinary and rectal toxicity were 14.8% and 1.9%, respectively; all but one patient recovered without sequelae.

Conclusion

SRT to the macroscopic recurrence identified by mpMRI is a feasible and well-tolerated option. In this study, there were no differences in bRFS between MRI-positive and MRI-negative patients, indicating effective targeting of MRI-positive lesions.

Biochemical outcomes and predictive factors by risk group after permanent iodine-125 seed implantation: Prospective cohort study in 2,316 patients

PURPOSE

To evaluate the biochemical freedom from failure (bFFF) by risk group and treatment modality and the predictive factors of bFFF by risk group in patients with prostate cancer undergoing permanent seed implantation (PI) with or without external beam radiation therapy (EBRT) in a nationwide prospective cohort study (Japanese Prostate Cancer Outcome Study of Permanent Iodine-125 [I-125] Seed Implantation) in Japan during the first 2 years.

METHODS AND MATERIALS

The analyses included 2,316 participants in 42 institutions; bFFF was evaluated using the Phoenix definition and calculated using the Kaplan-Meier method, and the Cox proportional hazards model was used to identify the factors associated with bFFF.

RESULTS

Median followup period was 60.0 months. The 5-year bFFF rates in all patients, 1,028 low-risk patients, 1,114 intermediate-risk patients, and 133 high-risk patients were 93.6%, 94.9%, 92.7%, and 91.1%, respectively. The 5-year bFFF rates in the PI group and EBRT combination therapy group were 93.7% and 93.3%, respectively. In a multivariate analysis, younger age, higher Gleason score (GS), higher percent positive biopsies (%PB), and lower prostate V₁₀₀ (p = 0.0012, 0.0030, 0.0026, and 0.0368) in all patients; younger age, higher pretreatment prostate-specific antigen, and lower prostate V₁₀₀ (p = 0.0002, 0.0048, and 0.0012) in low-risk patients; higher GS, higher %PB, and no hormonal treatment (p = 0.0005, 0.0120, and 0.0022) in intermediate-risk patients; and higher GS and higher %PB (p = 0.0329 and 0.0120) in high-risk patients were significantly associated with bFFF.

CONCLUSIONS

PI with or without EBRT resulted in excellent short-term biochemical outcomes in all risk groups, especially in high-risk patients. Age, pretreatment prostate-specific antigen, and prostate V₁₀₀ in low-risk patients; GS, %PB, and hormonal treatment in intermediate-risk patients; and GS and %PB in high-risk patients were independently affected bFFF.

[Circulating prostate cells and bone marrow micrometastasis are determinant in risk and time to biochemical progression in localized prostate cancer.]

INTRODUCTION

Minimal residual disease (MRD) is that which remains after curative therapy for prostate cancer. It has the potential for growth and later cause metastasis. After radical prostatectomy, the detection of circulating prostate cells (CPCs) and bone marrow micro-metastasis could represent different types of MRD. We proposed to determine the biochemical failure free survival rates, the time to biochemical failure after 10 years of follow-up and the presence of CPCs and micro-metastasis in patients treated with RP for pathologically organ confined prostate cancer.

METHODS AND PATIENTS

One month after RP monotherapy for prostate cancer, blood and bone marrow samples were taken to detect CPCs and micro-metastasis. Men were classified as: group A (CPC negative and micro-metastasis negative), group B (CPC negative and micro-metastasis positive), group C (CPC positive and micro-metastasis negative), and group D (CPC positive and micro-metastasis positive). All subjects were followed with serial total PSA levels, recording the time at which failure occurred defined as a serum PSA > 0.2ng/ ml on two separate occasions. After ten years of follow- up for each group Kaplan-Meier survival curves were determined and using an adjusted flexible parametric model (FP), the Restricted Mean Survival Times for groups A, B, C and D were calculated. RESULTS: 191 men participated, 10-year biochemical failure survival rates were; group A (N=114) with a Kaplan-Meier of 98.7%; group B (N=39) 65.1%; group C (N=12) 10.4% and in group D (N=28) 12.8%. The Restricted Mean Survival Times (years) were group A: 9.95; group B: 9.45, group C: 5.11 and group D: 6.18 (p-value <0.001 between groups: A versus C, Aversus D, B versus C and B versus D). Frequency and time to failure was dependent on the type of MRD, those men CPC positive had a significantly higher failure rate and early failure. Those men only micro-metastasis positive had lower failure rate and late failure when compared with men negative for MRD.

CONCLUSIONS

CPC positive men have a more aggressive disease with increased early failure; those men who are only positive for micro-metastasis are at risk for late or delayed failure. These two forms of measuring MRD represent different stages in the disease progression and may be used to guide clinical treatment decisions before increases in PSA levels.

Prognostic Significance of Serum PSA Level and Telomerase, VEGF and GLUT-1 Protein Expression for the Biochemical Recurrence in Prostate Cancer Patients after Radical Prostatectomy

The aim of the study was to evaluate prognosis for biochemical recurrence (BR) by analysing the pathological and biological characteristics of prostate cancer (PCa) after radical prostatectomy (RP). There were 130 men with clinically localized PCa in whom pretreatment serum PSA level and Ki-67, prostate specific membrane antigen (PSMA), glucose transporter-1 (GLUT-1), vascular endothelial growth factor (VEGF), microvessel density (MVD) and human telomerase reverse transcriptase (hTERT) proteins expression, based on number of immunohistochemically positive cells (labelling index), were retrospectively studied. In order to assess the prognostic significance of analysed variables in univariate and multivariate Cox analysis, patients were dichotomized based on cut-off points chosen by receiver operating characteristic (ROC) curves. There were 83 males (63.8%) at pT stage 1–2 and 47 (36.1%) at pT stage 3–4, respectively, with median (range) age of 62.8 years (49–77), and median follow-up of 78.5 months (12–148). In 42 (32.3%) men BR was found. In univariate analysis, tumour biological features: PSA ≤ 8 ng/mL (p = 0.006), Ki-67LI ≤ 12.7% (p = 0.015), VEGFLI>11.0% (p = 0.030), and hTERTLI>6.7% (p = 0.016), but not clinicopathological parameters, appeared to be positive prognosticators for BRFS. In the Cox analysis, Ki-67 lost its significance, and clinicopathological parameters appeared to be nonsignificant. The independent negative prognostic factors for BRFS were: PSA > 8.0 ng/mL, (Hazard ratio = 2.75, p = 0.003), GLUT-1 > 19.1% (HR = 2.1, p = 0.032), VEGF≤11.0% (HR = 1, p = 0.024) and hTERT≤6.7% (HR = 1, p = 0.017). High PSA level, and GLUT-1 expression and lower VEGF and nuclear hTERT expression may indicate the great role of hypoxia in BR induction in PCa.

Primary Whole-gland Cryoablation for Prostate Cancer: Biochemical Failure and Clinical Recurrence at 5.6 Years of Follow-up

We retrospectively evaluated complications and functional and oncologic outcomes of 94 consecutive men who underwent primary whole-gland cryoablation for localized prostate cancer (PCa) from 2002 to 2012. Kaplan-Meier and multivariable Cox regression analyses were performed using a landmark starting at 6 mo of follow-up. In total, 75% patients had D'Amico intermediate- (48%) or high- (27%) risk PCa. Median follow-up was 5.6 yr. Median time to prostate-specific antigen (PSA) nadir was 3.3 mo, and 70 patients reached PSA <0.2ng/ml postcryoablation. The 90-d high-grade (Clavien Grade IIIa) complication rate was 3%, with no rectal fistulas reported. Continence and potency rates were 96% and 11%, respectively. The 5-yr biochemical failure-free survival (PSA nadir+2ng/ml) was 81% overall and 89% for low-, 78% for intermediate-, and 80% for high-risk PCa (p=0.46). The median follow-up was 5.6 and 5.1 yr for patients without biochemical failure and with biochemical failure, respectively. The 5-yr clinical recurrence-free survival was 83% overall and 94% for low-, 84% for intermediate-, and 69% for high-risk PCa (p=0.046). Failure to reach PSA nadir <0.2ng/ml within 6 mo postcryoablation was an independent predictor for biochemical failure (p=0.006) and clinical recurrence (p=0.03). The 5-yr metastases-free survival was 95%. Main limitation is retrospective evaluation. Primary whole-gland cryoablation for PCa provides acceptable medium-term oncologic outcomes and could be an alternative for radiation therapy or radical prostatectomy. PATIENT SUMMARY: Cryoablation is a safe, minimally-invasive procedure that uses cold temperatures delivered via probes through the skin to kill prostate cancer (PCa) cells. Whole-gland cryoablation may offer an alternative treatment option to surgery and radiotherapy. We found that patients had good cancer outcomes 5 yr after whole-gland cryoablation, and those with a prostate-specific antigen value ≥0.2ng/ml within 6 mo after treatment were more likely to have PCa recurrence.

11C-choline PET/CT predicts survival in prostate cancer patients with PSA < 1 NG/ml

PURPOSE

The main drawback of ¹¹C-choline PET/CT for restaging prostate cancer (PCa) patients with biochemical failure is the relatively low positive detection rate for prostate specific antigen (PSA) < 1 ng/ml. This study assessed whether ¹¹C-choline PET/CT predicts survival in PCa patients with PSA < 1 ng/ml.

METHODS

This retrospective study included 210 PCa patients treated with radical prostatectomy who underwent ¹¹C-choline PET/CT from December 1, 2004 to July 31, 2007 due to biochemical failure. PCa-specific survival was estimated using Kaplan-Meier curves. Cox regression analysis was used to evaluate the association between clinicopathologic variables and PCa-specific survival. PCa-specific survival was computed as the interval from radical prostatectomy to PCa-specific death.

RESULTS

Median follow-up after radical prostatectomy was 6.9 years (95% confidence interval, CI, 2.0-14.5 years). ¹¹C-choline PET/CT was positive in 20.5% of patients. Median PCa-specific survival was 13.4 years (95% CI, 9.9-16.8 years) in patients with positive ¹¹C-choline PET/CT, and it was not achieved in patients with negative ¹¹C-choline PET/CT (log-rank, chi-square = 15.0, P < 0.001). Ten-year survival probabilities for patients with negative ¹¹C-choline PET/CT and for patients with positive ¹¹C-choline PET/CT were 86.0% (95% CI: 80.7%-91.3%) and 63.6% (95% CI: 54.5-72.7%). At multivariate analysis, only ¹¹C-choline PET/CT significantly predicted PCa-specific survival (hazard ratio = 2.54, 95% CI, 1.05-6.13, P = 0.038). Patients with pathological ¹¹C-choline uptake in the prostatic bed or in pelvic lymph nodes had longer PCa-specific survival in comparison to patients with pathological tracer uptake in the skeleton (log-rank: chi-square = 27.4, P < 0.001).

CONCLUSION

Despite the relatively low positive detection rate for PSA < 1 ng/ml, positive ¹¹C-choline PET/CT predicts PCa-specific survival in this low PSA range. As long as more sensitive radiotracers, such as ⁶⁸Ga-PSMA-11, do not become more widely available, these results might support a broader use of radiolabeled choline in restaging PCa for PSA < 1 ng/ml.

[Primary circulating prostate cells, age and prostatic volumen predict the presence of prostate cancer in men with indication of a second prostate biopsy.]

INTRODUCTION

The limitations of serumPSA as a screening test to detect prostate cancer remainproblematic, especially after an initial negative prostatebiopsy. Detection of primary circulating prostate cells(CPCs) has been reported to be useful in the detectionof prostate cancer in men with a serum PSA>4.0ng/ml.We present a prospective study comparing the detectionof CPCs, total PSA, percent free PSA, digital rectal examination(DRE) and prostate volumen (PV) to establisha predictive model for the detection of prostate cancerin men with an indication for a second prostate biopsy.

OBJECTIVE

To establish a predictive model for the detectionof prostate cancer using the number of CPCs detectedper sample, DRE, age, total serum PSA, percentfree PSA and PV in men with an indication for a secondprostate biopsy.

METHODS AND PATIENTS

A prospective, observationalstudy carried out in the Hospital de Carabineros deChile, between 2006 and 2014 including 199 menundergoing a second prostate biopsy. The variables,number of CPCs detected (nCPC), DRE, age, PSA, percentfree PSA and PV were registered for each patientand based on these findings and comparing them withthe results of the prostate biopsy a multivariate logistic regressionanalysis incorporating forward predictors. Themodel was evaluated for co-lineal tendency, reliabilityand error specificity, and analyzed using non-parametricreceiver operating characteristics and area under thecurve decision for the combined model and for eachvariable separately.

RESULTS

The single variable nCPC had a superior predictivevalue with an area under the curve of 0.89 (95%CI 0.83-0.94). The final model incorporated nCPC (OR:2.03 95% CI 1.63-2.53) age (OR: 1.1 95% CI 1.04-1.17) and PV (OR: 0.96 95% CI 0.93-0.99) with anarea under the curve for the combined model of 0.92(95% CI 0.88-0.97). The combined model performedbetter than the variables used alone.

CONCLUSIONS

The model incorporating nCPC, ageand PV had a greater diagnostic yield for the predictingprostate cancer at second biopsy.

Initial experience of Ga-68 prostate-specific membrane antigen positron emission tomography/computed tomography imaging in evaluation of biochemical recurrence in prostate cancer patients

Gallium-68 labeled prostate-specific membrane antigen (Ga-68 PSMA) ligand (HBED-CC) is a novel tracer used for prostate cancer imaging. The aim of the study was to investigate the performance of Ga-68 PSMA positron emission tomography/computed tomography (PET/CT) in patients with biochemical recurrence (BCR) after definitive treatment. Scans of 96 consecutive patients were analyzed. Sixty-two patients received external beam radiotherapy, 34 underwent radical prostatectomy (RP), and 20 patients were on androgen deprivation therapy. Patients with prostate-specific antigen (PSA) level ≥>0.2 ng/mL following RP and PSA rise by 2 ng/mL or more above the nadir PSA following RT (Phoenix criteria) was considered as BCR, respectively. All patients underwent contrast-enhanced PET/CT after injection of 67–111 MBq Ga-68 PSMA ligand. Detection rates were correlated with serum PSA level. Detection rate for nodal metastases was compared with CT. Results of the scan were validated by using either biopsy or follow-up imaging or clinical follow-up. Seventy-four (77%) patients showed abnormal finding in Ga-68 PSMA PET/CT. The median serum PSA level of the population was 5.5 ng/ml (range 0.2–123 ng/ml). The median PSA of the positive scans was higher than that of the negative scans (6 vs. 1.7 ng/ml) and was statistically significant (P = 0.001 by Mann–Whitney U-test). In post-RP group, the detection rates were 23%, 50%, and 82% for PSA <1, 1–2, and >2 ng/ml, respectively. For post-RT, the detection was 86%, 85%, and 95% for PSA 2–5, 5.1–10, and >10 ng/ml, respectively. PSMA PET/CT revealed nodal metastases in 52 (54%) patients while CT showed pathological nodes only in 27 (28%) patients. Overall PSMA PET/CT revealed more number of nodes than CT (111 vs. 48 nodal station). PSMA PET/CT showed relapse in prostate/prostatic bed in 26 (27%) patients, nodal metastases in 50 (52%), skeletal metastases in 20 (21%), and other sites in 4 (4%) patients. Ga-68 PSMA PET/CT has high detection rate for localizing the site of recurrence in patients with biochemical failure and is superior to CT scan in the detection of nodal disease.

Risk factors for biochemical recurrence after a tissue-ablative prostate-specific antigen <0.2 ng/mL

PURPOSE

A prostate-specific antigen (PSA) nadir <0.2 ng/mL is generally considered as tissue ablative and at low risk for recurrence. After attaining such a low PSA nadir, we analyzed risk factors for recurrence.

METHODS AND MATERIALS

We identified patients from our institutionalized database with either D'Amico low- or intermediate-risk prostate cancer that was treated with either low-dose-rate prostate brachytherapy or external beam radiotherapy as monotherapy. We compared patients who attained a nadir <0.2 ng/mL and subsequently developed biochemical failure to patients who did not experience biochemical failure by using χ² test and Student t test. Survival analysis was performed using the Kaplan-Meier method (log-rank test).

RESULTS

Of 892 patients, 560 (63%) achieved a nadir <0.2 ng/mL. Only 23 (4.1%) later developed a biochemical recurrence. The 7-year Kaplan-Meier biochemical recurrence-free survival after a PSA nadir of <0.2 ng/mL was 96%. Patients who later experienced biochemical recurrence were more likely to have Cancer of the Prostate Risk Assessment Score intermediate- or high-risk cancer: (74% vs. 40%, p < 0.001). Patients were more likely to have a diagnostic PSA >6.0 ng/mL: (66% vs. 43% p < 0.001) and have a Gleason score ≥ 3  + 4: (52% vs. 34%, p = 0.005). They were also more likely to be older (p = 0.003): mean (SD) 70.3 (6.4) vs. 66.2 (6.5) and have a time to PSA nadir that was significantly shorter (p = 0.013): mean (SD) 51.8 (29.6) vs. 65.2 (25.1).

CONCLUSIONS

Biochemical recurrence after attaining a PSA nadir <0.2 ng/mL is rare and more frequent in patients with intermediate risk cancer and older patients. These patients can benefit from a prolonged followup with specialized physicians.

The impact of the definition of biochemical recurrence following salvage radiotherapy on outcomes and prognostication in patients with recurrent prostate cancer after radical prostatectomy: a comparative study of three definitions

Purpose

The clinical management and follow-up of patients with recurrent prostate cancer after salvage radiotherapy (SRT) has not yet been established, and no standardized definition of biochemical recurrence (BCR) after SRT exists. We compared the impact of applying three different definitions of BCR following SRT on patient outcomes and prognostication.

Subjects

Patients who received salvage androgen-deprivation therapy before the completion of SRT were excluded. The data of 118 men who had undergone salvage radiation as monotherapy for BCR after radical prostatectomy were reviewed. In all patients, SRT comprised irradiation to the prostatic bed (70 Gy) using three-dimensional conformal radiotherapy techniques. Treatment outcomes, including BCR-free survival and prognostic factors, were analyzed and compared among three definitions: The Nara, Radiation Therapy Oncology Group (RTOG) 9601, and GETUG-AFU 16 definitions.

Results

The BCR rate differed significantly among the applied definitions. Multivariate analyses identified the same four independent prognostic factors, including primary Gleason pattern 4 or 5, negative resection margin, prostate-specific antigen (PSA) level before SRT 0.5 or more, and PSA doubling time before SRT <6 months, using the RTOG 9601 and GETUG-AFU 16 definitions, whereas only two of the four factors were identified using the Nara definition. Although the results obtained using the RTOG 9601 and GETUG-AFU 16 definitions were similar, the prognostic value of the four factors differed. According to the RTOG 9601 definition of BCR, a negative resection margin on prostatectomy specimens and short PSA doubling time before SRT were associated with no subsequent response in PSA level.

Conclusions

The applied definition of BCR after SRT can influence the reported BCR-free rate and the potential prognostic factors. Establishment of the standardized definition is needed for the optimal management of patients with recurrent prostate cancer undergoing SRT.

Prostate-specific antigen nadir within 12 months as an early surrogate marker of biochemical failure and distant metastasis after low-dose-rate brachytherapy or external beam radiotherapy for localized prostate cancer

Prostate-specific antigen nadir (nPSA) after radiotherapy for localized prostate cancer has been investigated as a predictor. However, nPSA usually requires several years, limiting its clinical utility. We investigated the significance of nPSA within 12 months (nPSA12) after low-dose-rate prostate brachytherapy (LDR-PB) or external beam radiotherapy (EBRT) on treatment outcomes. Between 2006 and 2014, 663 patients with prostate cancer were treated with LDR-PB or EBRT at two institutions. Four hundred and seventy-four men received LDR-PB and 189 men received EBRT, without androgen deprivation therapy. The Kaplan-Meier method was used for biochemical failure (BF)-free survival (BFFS) and distant metastasis (DM)-free survival (DMFS) analyses, and multivariable Cox regression analysis was performed. The median follow-up was 61.3 months. The median nPSA12 in the LDR-PB and EBRT cohorts was 0.7 and 1.0 ng/mL, respectively. The 7-year BFFS and DMFS rates in LDR-PB patients with nPSA12 ≤ 0.7 ng/mL were 99.1% and 99.5%, respectively; when nPSA12 was >0.7 ng/mL, they were 90.2% and 94.8%, respectively. In EBRT patients with nPSA12 ≤ 1.0 ng/mL, BFFS and DMFS rates were 85.4% and 98.5%, respectively; when nPSA12 was >1.0 ng/mL, they were 67.1% and 87.2%, respectively. nPSA12 was an independent predictor of BF and DM in both cohorts (LDR-PB, P = 0.004 and 0.020, respectively; EBRT, P = 0.005 and 0.041, respectively). The nPSA12 after LDR-PB or EBRT is significantly associated with treatment outcomes of prostate cancer. Higher nPSA12 may identify patients at high risk of relapse who might benefit from salvage treatment.

The relationship between local recurrences and distant metastases in prostate cancer: can 11C-choline PET/CT contribute to understand the link?

PURPOSE

Previous studies in prostate cancer (PCa) patients tried to correlate the onset of local recurrence (LR) with the development of distant metastases and formulated, based on theoretical and experimental data, hypotheses linking the two events. We aimed to address this issue with ¹¹C-choline positron emission tomography/computed tomography (PET/CT).

METHODS

This retrospective study included 491 PCa patients previously treated with radical prostatectomy who had undergone ¹¹C-choline PET/CT owing to biochemical failure. Further inclusion criteria were availability of clinical and pathological variables for survival analysis. Statistical significance was taken at P < 0.05.

RESULTS

Seventy-two patients (14.7%) had evidence of LR at ¹¹C-choline PET/CT. The frequency of LR increased from 13.8% in the interval 0-4 years after prostatectomy, to 23.9% in the 12-16-year interval (P = 0.080). On the contrary, the frequency of lymph node metastases (overall rate in the 0-16 years interval after prostatectomy: 26.3%) and of bone metastases (overall rate: 13.8%) decreased significantly over time. Kaplan-Meier curves showed no significant group difference in the rates of lymph node or bone metastases between patients with LR and patients without LR. LR significantly predicted PCa-specific survival at univariate analysis, but the statistical significance was lost at multivariate analysis.

CONCLUSION

We found no differences in the rates of lymph node and bone metastases between patients with and without LR. An inverse time-dependent trend was observed in the frequency of LR on one side and of lymph node and bone metastases on the other side. These findings were discussed in relation to previous theories linking LR to distant metastases and our study design.

How localized is pathologically localized prostate cancer? The use of secondary circulating prostate cells as a marker of minimal residual disease and their association with patient outcome

Objective

To determine the prognostic value of secondary circulating prostate cells (CPCs) in men with pT2 prostate cancer treated with radical prostatectomy.

Material and methods

Prospective observational study was performed in men with pathologically confined prostate cancer who had been treated with radical prostatectomy. CPCs were obtained by differential gel centrifugation from 8 mL venous blood and identified by standard immunocytochemistry using anti-Prostate Specific Antigen (PSA) monoclonal antibody. A positive test was defined as ≥1 PSA staining cell/blood sample. Biochemical failure was defined as a serum PSA >0.2 ng/mL. Age, PSA at diagnosis, pT2a versus pT2b/c, Gleason score and the presence/absence of CPCs were compared with patient outcomes using Kaplan-Meier curves and Cox's hazard model.

Results

Hundred and ninety-one men participated in the study, 107 (44.0%) had pT2b/c disease, 25 (13.1%) had a Gleason score ≥7, and 39 (20.4%) were positive for CPCs. Biochemical failure occurred in 39 (20.4%) patients which was associated with a Gleason score ≥ 7 and CPCs (+). Survival rates at 3, 5 and 10 years for men with CPC (-) and CPC (+) were 100%, 100% and 89.6%, and 74.4%, 64.1% and 18.5% respectively (HR: 18.70). The median time to failure was 5.1 years in CPC (+) men versus 8.1 years in CPC (-) patients.

Conclusion

Secondary CPC is a marker for minimal residual disease and it is associated with a worse prognosis. The lead time to failure over serum PSA is approximately 5 years. However they do not define whether the failure is local or systemic.

Studying the efficacy of escalated dose conformal radiation therapy in prostate carcinoma - Pakistan experience

BACKGROUND

Our objective in this study was to evaluate the role and benefits in terms of local toxicity and biochemical disease-free survival (bDFS) following escalated-dose conformal radiation therapy in prostate adenocarcinoma.

METHODS

The study population was composed of 53 patients with histologically proven T1b-T4, NO, MO prostate adenocarcinoma, having any Gleason score with prostate-specific antigen (PSA) of less than 50 ng/mL at diagnosis, given escalated dose EBRT (74 Gy) during the period between January 2011 and December 2013, retrospectively and evaluated for a period of 2 years post-radiation. Patients were followed up for a period of 2 years, beginning after completion of escalated dose external beam radiotherapy (EBRT) for biochemical failure as defined in ASTRO consensus committee guidelines 1996 and investigated for gastrointestinal, genitourinary skin toxicity.

RESULTS

Out of 53 patients, 35 showed no biochemical failure at the end of 2 years following the completion of definitive escalated dose conformal radiotherapy while 18 were observed to have biochemical relapse. Acute gastrointestinal grade 1 toxicity was found in 26 patients, grade 2 in 24, and grade 3 only in 3 patients. Late gastrointestinal grade 0 toxicity was found in 16 patients, grade 1 in 28, grade 2 in 7 and grade 3 only in 2 patients. Grade 1 acute genitourinary toxicity was the highest in frequency observed in 28 of the total population followed by grade 2 in 21, grade 0 and grade 3 each, only in 2 patients. Late genitourinary Grade 0 toxicity was observed in 32 patients, grade 1 in 19, grade 2 and 3 only in 1 patient of the total population, respectively.

CONCLUSION

Our data were comparable to international studies of dose escalation using 3D and beneficial as compared to conventional radiation therapy delivered by 2D in terms of biochemical failure rate and treatment related toxicity.

Flexible modeling of the hazard rate and treatment effects in long-term survival studies

The effects of predictors on time to failure may be difficult to assess in cancer studies with longer follow-up, as the commonly used assumption of proportionality of hazards holding over an extended period is often questionable. Motivated by a long-term prostate cancer clinical trial, we contrast and compare four powerful methods for estimation of the hazard rate. These four methods allow for varying degrees of smoothness as well as covariates with effects that vary over time. We pay particular attention to an extended multiresolution hazard estimator, which is a flexible, semi-parametric, Bayesian method for joint estimation of predictor effects and the hazard rate. We compare the results of the extended multiresolution hazard model to three other commonly used, comparable models: Aalen's additive model, Kooperberg's hazard regression model, and an extended Cox model. Through simulations and the analysis of a large-scale randomized prostate cancer clinical trial, we use the different methods to examine patterns of biochemical failure and to estimate the time-varying effects of androgen deprivation therapy treatment and other covariates.

Development and internal validation of prediction models for biochemical failure and composite failure after focal salvage high intensity focused ultrasound for local radiorecurrent prostate cancer: Presentation of risk scores for individual patient prognoses

PURPOSE

Patient selection for focal salvage remains difficult. Therefore, we developed and internally validated prediction models for biochemical failure (BF) and a composite endpoint (CE) following focal salvage high intensity focused ultrasound (HIFU) for radiorecurrent prostate cancer.

MATERIALS AND METHODS

A prospective HIFU registry identified 150 cases (November 2006-August 2015). Recurrence was assessed with multiparametric magnetic resonance imaging (MRI) combined with template prostate mapping biopsies, targeted biopsies, or systematic transrectal ultrasound-guided biopsies. Metastatic disease was ruled out with a positron emission tomography-computed tomography and a bone scan. Focal salvage HIFU consisted of quadrant-ablation, hemi-ablation, or index-lesion ablation. Cox-regression was used for BF (Phoenix-definition) and CE (BF/MRI+/biopsies+/local or systemic treatment/metastases+/prostate cancer specific mortality+). Internal validation was performed using bootstrap resampling (500 datasets) after which C-statistic and hazard ratios were adjusted. Models were calibrated and risk scores created.

RESULTS

Median follow-up was 35 months (interquartile range: 22-52). Median biochemical disease-free survival (DFS) was 33 months (95% CI: 23-45). Median CE-free survival was 24 months (95% CI: 21-35). After multivariable analysis, DFS interval after primary radiotherapy, presalvage prostate-specific antigen (PSA), PSA-doubling time, prostatic volume, and T-stage (both MRI based) predicted BF. For the CE, PSA-doubling time was not predictive but additionally, primary Gleason score was. The adjusted C-statistics were 0.68 and 0.64 for BF and CE, respectively. Calibration was accurate until 48 months. The risk scores showed 3 groups, with biochemical DFS of 60%, 35%, and 7% and CE-free survival of 40%, 24%, and 0% at 4 years.

CONCLUSION

Our model, once externally validated, could allow for better selection of patients for focal salvage HIFU.

Magnetic resonance imaging for prostate cancer before radical and salvage radiotherapy: What radiation oncologists need to know

External beam radiotherapy (EBRT) is one of the principal curative treatments for patients with prostate cancer (PCa). Risk group classification is based on prostate-specific antigen (PSA) level, Gleason score, and T-stage. After risk group determination, the treatment volume and dose are defined and androgen deprivation therapy is prescribed, if appropriate. Traditionally, imaging has played only a minor role in T-staging due to the low diagnostic accuracy of conventional imaging strategies such as transrectal ultrasound, computed tomography, and morphologic magnetic resonance imaging (MRI). As a result, a notable percentage of tumours are understaged, leading to inappropriate and imprecise EBRT. The development of multiparametric MRI (mpMRI), an imaging technique that combines morphologic studies with functional diffusion-weighted sequences and dynamic contrast-enhanced imaging, has revolutionized the diagnosis and management of PCa. As a result, mpMRI is now used in staging PCa prior to EBRT, with possible implications for both risk group classification and treatment decision-making for EBRT. mpMRI is also being used in salvage radiotherapy (SRT), the treatment of choice for patients who develop biochemical recurrence after radical prostatectomy. In the clinical context of biochemical relapse, it is essential to accurately determine the site of recurrence - pelvic (local, nodal, or bone) or distant - in order to select the optimal therapeutic management approach. Studies have demonstrated the value of mpMRI in detecting local recurrences - even in patients with low PSA levels (0.3-0.5 ng/mL) - and in diagnosing bone and nodal metastasis. The main objective of this review is to update the role of mpMRI prior to radical EBRT or SRT. We also consider future directions for the use and development of MRI in the field of radiation oncology.

Prostate-specific antigen percentage: An early predictive tool after iodine-125 interstitial brachytherapy for prostate cancer

BACKGROUND

After interstitial prostate iodine-125 brachytherapy (BT), prostate-specific antigen (PSA) evolution in time could predict overall biochemical relapse, but, considering the single patient, it is influenced by the presentation PSA amount and by the prostatic volume. It is also challenging to differentiate a PSA bounce from a biochemical relapse.

PURPOSE

To determine the usefulness of PSA percentage (PP) defined as the rate between PSA presented by a patient at time "t" and the PSA that the same patient had presented at the time of diagnosis (t0) assumed as 100% in predicting biochemical relapse and in differentiating them from PSA Bounces.

METHODS AND MATERIALS

We included 721 patients from Milan S. Raffaele Turro (399) and Lucca Campo di Marte (then S. Luca) Hospital (322). The mean age of patients was 66.5 years (range, 50-79). Mean followup was 150 months (range, 24-180). For each patient, PSA was recorded before and after iodine-125 BT, and PPs were calculated. Cox regression model, relative operating characteristic curves, and Kaplan-Meier regression model were elaborated, and a cutoff of 20% was defined.

RESULTS

We observed that PP >20% is an independent variable highly associated with relapse risk (p < 0.0001) with a sensitivity of 79.7%, a specificity of 82%, and an hazard ratio of 12.1, since the 6 months of followup. A PSA increase above the nadir should be because of bounce (sensitivity and specificity of 81.4%, p < 0.0001) if patient had experienced at 6 months a PP <20%.

CONCLUSIONS

PP might represent an early and useful tool, predictive of clinical outcome in patients after BT for prostate cancer.

High-dose-rate brachytherapy as salvage modality for locally recurrent prostate cancer after definitive radiotherapy : A systematic review

PURPOSE

To review the current status of interstitial high-dose-rate brachytherapy as a salvage modality (sHDR BRT) for locally recurrent prostate cancer after definitive radiotherapy (RT).

MATERIALS AND METHODS

A literature search was performed in PubMed using "high-dose-rate, brachytherapy, prostate cancer, salvage" as search terms. In all, 51 search results published between 2000 and 2016 were identified. Data tables were generated and summary descriptions created. The main outcome parameters used were biochemical control (BC) and toxicity scores.

RESULTS

Eleven publications reported clinical outcome and toxicity with follow-up ranging from 4-191 months. A variety of dose and fractionation schedules were described, including 19.0 Gy in 2 fractions up to 42.0 Gy in 6 fractions. The 5‑year BC ranged from 18-77%. Late grade 3 genitourinary and gastrointestinal toxicity was 0-32% and 0-5.1%, respectively.

CONCLUSIONS

sHDR BRT appears as safe and effective salvage modality for the reirradiation of locally recurrent prostate cancer after definitive RT.

Long-term prognostic significance of rising PSA levels following radiotherapy for localized prostate cancer - focus on overall survival

Background

The aim of this study was to evaluate the long-term prognostic significance of rising PSA levels, particularly focussing on overall survival.

Methods

Two hundred ninety-five patients with localized prostate cancer were either treated with low-dose-rate (LDR) brachytherapy with I-125 seeds as monotherapy (n = 94; 145Gy), high-dose-rate (HDR) brachytherapy with Ir-192 as a boost to external beam RT (n = 66; 50.4Gy in 1.8Gy fractions EBRT + 18Gy in 9Gy fractions HDR) or EBRT alone (70.2Gy in 1.8Gy fractions; n = 135). “PSA bounce” was defined as an increase of at least 0.2 ng/ml followed by spontaneous return to pre-bounce level or lower, biochemical failure was defined according to the Phoenix definition.

Results

Median follow-up after the end of radiotherapy was 108 months. A PSA bounce showed to be a significant factor for biochemical control (BC) and overall survival (OS) after ten years (BC10 of 83% with bounce vs. 34% without, p < 0.01; OS10 of 82% with bounce vs. 59% without bounce, p < 0.01). The occurrence of a bounce, a high nadir and the therapy modality (LDR-BT vs. EBRT and HDR-BT + EBRT vs. EBRT) proved to be independent factors for PSA recurrence in multivariate Cox regression analysis. A bounce was detected significantly earlier than a PSA recurrence (median 20 months vs. 32 months after RT; p < 0.01; median PSA doubling time 5.5 vs. 5.0 months, not significant). PSA doubling time was prognostically significant in case of PSA recurrence (OS10 of 72% vs. 36% with PSA doubling time ˃ 5 months vs. ≤ 5 months; p < 0.01).

Conclusions

Rising PSA levels within the first two years can usually be classified as a benign PSA bounce, with favourable recurrence-free and overall survival rates. PSA doubling time is an important predictor for overall survival following the diagnosis of a recurrence.

Gleason Grading, Biochemical Failure, and Prostate Cancer-Specific Death

OBJECTIVES

To examine the relationship between the recently defined Gleason grade groups and prostate cancer-specific mortality.

METHODS

If the probability of prostate cancer-specific death is symbolized as P(PSD), the probability of biochemical failure is symbolized as P(BF), and the probability of prostate cancer-specific death after biochemical failure is symbolized as P(PSD | BF), then the rules of probability provide a way to estimate P(PSD) as P(PSD) = P(PSD | BF) * P(BF) Using this model and data from the literature for P(PSD | BF) and P(BF), I estimate here values of P(PSD) for the five newly described Gleason grade groups.

RESULTS

The expected probability of prostate cancer- specific death is closely related to the new Gleason grade groups and ranges from a low of 0.014 for grade group 1 to a high of 0.15 for grade group 5.

CONCLUSIONS

Although using the original study patient population may require years of additional follow-up to examine prostate cancer-specific mortality, the evidence available now indicates that these new Gleason grade groups relate to prostate cancer-specific mortality.

Evaluation of tumor recurrences after radical prostatectomy using 18F-Choline PET/CT and 3T multiparametric MRI without endorectal coil: a single center experience

BACKGROUND

To evaluate and compare the utility of 18F-fluorocholine (18F-CH) PET/CT versus 3-Tesla multiparametric MRI (mpMRI) without endorectal coil to detect tumor recurrences in patients with biochemical relapse following radical prostatectomy (RP). Secondarily, to identify possible prognostic variables associated with mpMRI and 18F-CH PET/CT findings.

METHODS

Retrospective study of 38 patients who developed biochemical recurrence after RP between the years 2011 and 2015 at our institution. PET/CT and mpMRI were both performed within 30 days of each other in all patients. The PET/CT was reviewed by a nuclear medicine specialist while the mpMRI was assessed by a radiologist, both of whom were blinded to outcomes.

RESULTS

The median prostate-specific antigen (PSA) value pre-MRI/PET-CT was 0.9 ng/mL (interquartile range 0.4-2.2 ng/mL). There were no differences in the detection rate between 18F-CH PET/CT and mpMRI for local recurrence (LR), lymph node recurrence (LNR) and bone metastases (BM). Separately, mpMRI and 18F-CH PET/CT were positive for recurrence in 55.2% and 52.6% of cases, respectively, and in 65.7% of cases when findings from both modalities were considered together. The detection of LR was better with combined mpMRI and choline PET/CT versus choline PET/CT alone (34.2% vs 18.4%, p = 0.04). Salvage treatment was modified in 22 patients (57.8%) based on the imaging findings. PSA values on the day of biochemical failure were significantly associated with mpMRI positivity (adjusted odds ratio (OR): 30.9; 95% confidence interval (CI): 1.5-635.8). Gleason score > 7 was significantly associated with PET/CT positivity (OR: 13.9; 95% CI: 1.5-125.6). A significant association was found between PSA doubling time (PSADT) (OR: 1.3; 95% CI: 1.0-1.7), T stage (OR: 21.1; 95% CI: 1.6-272.1), and LR.

CONCLUSIONS

Multiparametric MRI and 18F-CH PET/CT yield similar detection rates for LR, LNR and pelvic BM. The combination of both imaging techniques provides a better LR detection versus choline PET/CT alone. The initially planned salvage treatment was modified in 57.8% of patients due to imaging findings. In addition to PSA values, Gleason score, T stage, and PSADT may provide valuable data to identify those patients that are most likely to benefit from undergoing both imaging procedures.

The impact of body mass index on treatment outcomes for patients with low-intermediate risk prostate cancer

Background

Little is known about the relationship between preoperative body mass index and need for adjuvant radiation therapy (RT) following radical prostatectomy. The goal of this study was to evaluate the utility of body mass index in predicting adverse clinical outcomes which require adjuvant RT among men with organ-confined prostate cancer (PCa).

Methods

We used a prospective cohort of 1,170 low-intermediate PCa risk men who underwent radical prostatectomy and evaluated the effect of body mass index on adverse pathologic features and freedom from biochemical failure (FFbF). Clinical and pathologic variables were compared across the body mass index groups using an analysis of variance model for continuous variables or χ² for categorical variables. Factors related to adverse pathologic features were examined using logistic regression models. Time to biochemical recurrence was compared across the groups using a log-rank survivorship analysis. Multivariable analysis predicting biochemical recurrence was conducted with a Cox proportional hazards model.

Results

Patients with elevated body mass index (defined as body mass index ≥25 kg/m²) had greater extraprostatic extension (p = 0.004), and positive surgical margins (p = 0.01). Elevated body mass index did not correlate with preoperative risk groupings (p = 0.94). However, when compared with non-obese patients (body mass index <30 kg/m²), obese patients (body mass index ≥30 kg/m²) were much more likely to have higher rate of adverse pathologic features (p = 0.006). In patients with low- and intermediate- risk disease, obesity was strongly associated with rate of pathologic upgrading of tumors (p = 0.01 and p = 0.02), respectively. After controlling for known preoperative risk factors, body mass index was independently associated with ≥2 adverse pathologic features (p = 0.002), an indicator for adjuvant RT as well as FFbF (p = 0.001).

Conclusions

Body mass index of ≥30 kg/m² is independently associated with adverse pathologic features, which is an indicator for additional RT, particularly in patients with low-intermediate risk disease. Future studies may determine if this select group of patients may be best treated with definitive RT to reduce toxicity from additional RT following radical prostatectomy. We propose including body mass index in clinical decision-making for appropriate treatment recommendation for patients with low-intermediate risk PCa.

Development and internal validation of a multivariable prediction model for biochemical failure after whole-gland salvage iodine-125 prostate brachytherapy for recurrent prostate cancer

BACKGROUND

Localized recurrent prostate cancer after primary radiotherapy can be curatively treated using salvage iodine-125 ((125)I) brachytherapy. Selection is hampered by a lack of predictive factors for cancer control. This study aims to develop and internally validate a prognostic model for biochemical failure (BF) after salvage (125)I brachytherapy.

METHODS AND MATERIALS

Whole-gland salvage (125)I brachytherapy patients were treated between 1993 and 2010 in two radiotherapy centers in the Netherlands. Multivariable Cox regression was performed to assess the predictive value of clinical parameters related to BF (Phoenix-definition [prostate-specific antigen [PSA]-nadir + 2.0 ng/mL]). Missing data were handled by multiple imputation. The model's discriminatory ability was assessed with Harrell's C-statistic. Internal validation was performed using bootstrap resampling (2000 data sets). Goodness-of-fit was evaluated with calibration plots. All analyses were performed using the recently published TRIPOD (Transparent reporting of a multivariable prediction model for individual prognosis or diagnosis) statement.

RESULTS

After median followup of 74 months (range 5-138), 43 of a total 62 patients developed BF. In multivariable analysis, disease-free survival interval (DFSI) after primary therapy and pre-salvage prostate-specific antigen doubling time (PSADT) were predictors of BF: corrected hazard ratio (HR) 0.99 (95% confidence interval 0.97-0.999; p = 0.04) and 0.94 (95% confidence interval 0.89-0.99; p = 0.03), both for a 1-month increase (optimism-adjusted C-statistic 0.70). Calibration was accurate up to 36 months. Of patients with PSADT >30 months and DFSI >60 months, 36-month biochemical disease-free survival was >75%. Every 12-month increase in DFSI will allow 3-month decrease in PSADT while maintaining the same biochemical recurrence-free rates.

CONCLUSIONS

We have presented results from a cohort of patients undergoing salvage (125)I-brachytherapy. Our data show that better selection of patients is possible with the DFSI and PSADT.

Uroncor consensus statement: Management of biochemical recurrence after radical radiotherapy for prostate cancer: From biochemical failure to castration resistance

Management of patients who experience biochemical failure after radical radiotherapy with or without hormonal therapy is highly challenging. The clinician must not only choose the type of treatment, but also the timing and optimal sequence of treatment administration. When biochemical failure occurs, numerous treatment scenarios are possible, thus making it more difficult to select the optimal approach. Moreover, rapid and ongoing advances in treatment options require that physicians make decisions that could impact both survival and quality of life. The aim of the present consensus statement, developed by the Urological Tumour Working Group (URONCOR) of the Spanish Society of Radiation Oncology (SEOR), is to provide cancer specialists with the latest, evidence-based information needed to make the best decisions for the patient under all possible treatment scenarios. The structure of this consensus statement follows the typical development of disease progression after biochemical failure, with the most appropriate treatment recommendations given for each stage. The consensus statement is organized into three separate chapters, as follows: biochemical failure with or without local recurrence and/or metastasis; progression after salvage therapy; and treatment of castration-resistant patients.

Single application of high-intensity focused ultrasound as primary therapy of localized prostate cancer: Treatment-related predictors of biochemical outcomes

Objective

Recent reports on high-intensity focused ultrasound (HIFU) treatment of localized prostate cancer suggest that preoperative risk groups of tumor recurrence are strong predictors of oncological outcomes. The purpose of this study is to determine the prognostic significance of treatment-related factors in relation to patient characteristics for biochemical outcomes after HIFU.

Methods

This retrospective single-center study included patients treated from December 2002 to December 2010 for localized prostate cancer with two generations of Ablatherm^® HIFU devices (A1 and A2). All the patients underwent single HIFU treatment session under the concept of whole-gland therapy. Prostate surgery was performed before HIFU to downsize enlarged glands. Androgen deprivation therapy (ADT) was discontinued before HIFU. Biochemical failure (BCF) was defined as prostate specific antigen (PSA) nadir + 1.2 ng/mL (Stuttgart definition). Predictors of BCF were determined using Cox regression models. As covariates, patient-related factors (age, tumor characteristics, ADT) were compared with treatment-related factors (prostate volume, HIFU device generation, conduct of therapy, prostate edema, patient movement, anesthetic modalities).

Results

Three hundred and twenty-three (98.8%) out of 327 consecutive patients were evaluable for BCF. Median (interquartile range) follow-up was 51.2 (36.6-80.4) months. The overall BCF-rate was 23.8%. In multivariate analyses, higher initial PSA-values (Hazard ratio [HR]: 1.03; p < 0.001) and higher D'Amico risk stages (HR: 3.45; p < 0.001) were patient-related predictors of BCF. Regarding treatment-related factors, the A2 HIFU device was associated with a decreased risk of BCF (HR: 0.51; p = 0.007), while prostate edema had an adverse effect (HR: 1.8; p = 0.027). Short follow-up and retrospective study design are the primary limitations.

Conclusion

Success in a single HIFU session depends not merely on tumor characteristics, but also on treatment-related factors. Ablation is more efficacious with the technically advanced A2 HIFU device. Heat-induced prostate edema might adversely affect the outcome.

African-american race is a predictor of seminal vesicle invasion after radical prostatectomy

INTRODUCTION

The purpose of the study was to determine whether racial differences exist in the pattern of local disease progression among men treated with radical prostatectomy (RP) for localized prostate cancer (PCa), which is currently unknown. In this study we evaluated the pattern of adverse pathologic features in an identical cohort of African-American (AA) and Caucasian (CS) men with PCa.

PATIENTS AND METHODS

The overall cohort consisted of 1104 men (224 AA, and 880 CS) who underwent RP between 1990 and 2012. We compared preoperative factors and pathologic outcomes after RP across race groups. Multivariate analysis was used to identify factors predictive of adverse pathologic outcomes. The effect of race on adverse pathologic outcomes and biochemical control rate (BCR) was evaluated using multivariate regression model and Kaplan-Meier analysis.

RESULTS

The 10-year BCR was 59% versus 82% in AA and CS men, respectively (P = .003). There was no significant difference in extraprostatic spread (P = .14), positive surgical margin (P = .81), lymph node involvement (P = .71), or adverse pathologic features (P = .16) across race groups. However, among patients with ≥ 1 adverse pathologic features, AA men had higher rate of seminal vesicle invasion (SVI) compared with CS men (51% vs. 30%; P = .01). After adjusting for known predictors of adverse pathologic features AA race remained a predictor of SVI.

CONCLUSION

AA men have an increased risk of SVI after RP, particularly among men with Gleason ≤ 6 disease. This might represent racial differences in the biology of PCa disease progression, which contribute to poorer outcomes in AA men.

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.

African American men with low-grade prostate cancer have increased disease recurrence after prostatectomy compared with Caucasian men

PURPOSE

To explore whether disparities in outcomes exist between African American (AA) and Caucasian (CS) men with low-grade prostate cancer and similar cancer of the prostate risk assessment-postsurgery (CAPRA-S) features following prostatectomy (RP).

METHODS

The overall cohort consisted of 1,265 men (234 AA and 1,031 CS) who met the National comprehensive cancer network criteria for low- to intermediate-risk prostate cancer and underwent RP between 1990 and 2012. We first evaluated whether clinical factors were associated with adverse pathologic outcomes and freedom from biochemical failure (FFbF) using the entire cohort. Next, we studied a subset of 705 men (112 AA and 593 CS) who had pathologic Gleason score≤6 (low-grade disease). Using this cohort, we determined whether race affected FFbF in men with RP-proven low-grade disease and similar CAPRA-S scores.

RESULTS

With a median follow-up time of 27 months, the overall 7-year FFbF rate was 86% vs. 79% in CS and AA men, respectively (P = 0.035). There was no significant difference in one or more adverse pathologic features between CS vs. AA men (27% vs. 31%; P = 0.35) or CAPRA-S score (P = 0.28). In the subset analysis of patients with low-grade disease, AA race was associated with worse FFbF outcomes (P = 0.002). Furthermore, AA race was a significant predictor of FFbF in men with low-grade disease (hazard ratio = 2.01, 95% CI: 1.08-3.72; P = 0.029).

CONCLUSIONS

AA race is a predictor of worse FFbF outcomes in men with low-grade disease after RP. These results suggest that a subset of AA men with low-grade disease may benefit from more aggressive treatment.

Prostate-specific antigen bounce after high-dose-rate prostate brachytherapy and hypofractionated external beam radiotherapy

PURPOSE

To report the frequency, timing, and magnitude of prostate-specific antigen (PSA) bounce (PB) in patients who received high-dose-rate (HDR) brachytherapy (HDRB) plus hypofractionated external beam radiation therapy (HypoRT) and to assess a possible correlation between PB and biochemical failure (BF).

METHODS AND MATERIALS

Patients with intermediate-risk prostate cancer received 10Gy single-fraction (192)Ir HDRB followed by 50Gy in 20 daily fractions of HypoRT without androgen deprivation therapy. All patients had a minimum 2-year followup. The PB was defined as PSA elevation higher than 0.2ng/mL from previous measurement with subsequent drop to pre-bounce level. The BF was defined as PSA nadir+2ng/mL.

RESULTS

A total of 114 patients treated between 2001 and 2009 were eligible for analysis. At a median followup of 66 months, the PB was found in 45 (39%) patients with a median time to bounce of 16 months (range, 3-76 months). The median time to PSA normalization after a PB was 9 months (range, 2-40 months). The median magnitude of PB was 0.45ng/mL (range, 0.2-6.62). The BF occurred in 12 (10.5%) patients of whom three had a PB. Median time to BF was 52.5 months. Four patients (3.5%) in the PB group fit the criteria for BF.

CONCLUSIONS

The PB is common after HDRB and HypoRT and can occur up to 76 months after treatment. It can rarely fit the criteria for BF. The time to PB is shorter than the time to BF. There is a lower incidence of BF in patients with a PB. An acknowledgment of this phenomenon should be made when interpreting PSA results during followup to prevent unnecessary interventions.

Focal salvage iodine-125 brachytherapy for prostate cancer recurrences after primary radiotherapy: a retrospective study regarding toxicity, biochemical outcome and quality of life

PURPOSE

Whole-gland salvage for recurrent prostate cancer (PCa) shows high failure and toxicity rates. Early and adequate localization of recurrences enables focal salvage, thereby potentially improving functional outcomes, while maintaining cancer control.

MATERIALS AND METHODS

Retrospective analysis yielded 20 focal salvage I125 brachytherapy patients for locally recurrent PCa after primary radiotherapy. Tumor was defined by multiparametric MRI and correspondence with transrectal biopsies. Dose data were obtained intra-operatively. The tumor was prescribed ⩾144 Gy. Toxicity was scored by the Common Terminology Criteria for Adverse Events version 4 (CTCAE-4). Biochemical failure (BF) was defined using the Phoenix criteria (PSA-nadir + 2.0 ng/ml). Quality of life (QoL) was measured by SF-36 Health Survey and European Organization of Research and Treatment of Cancer (EORTC) C30+3 and PR25 questionnaires.

RESULTS

With a median follow-up of 36 months (range 10-45), six patients experienced BF, of which three had no initial response. Grade 3 genitourinary (GU) toxicity occurred in one patient (a urethral stricture). The five previously potent patients retained erectile function. QoL remained decreased with regard to urinary symptoms.

CONCLUSION

Focal salvage I125 brachytherapy showed one grade 3 GU toxicity in the 20 treated patients. Biochemical response and QoL were acceptable.

Enzalutamide in castration-resistant prostate cancer patients progressing after docetaxel and abiraterone

BACKGROUND

Abiraterone, an androgen synthesis inhibitor, has been successfully used in the treatment of castration-resistant prostate cancer (CRPC) for 2 yr. Enzalutamide is a second-generation nonsteroidal antiandrogen that has recently been approved for the same indication.

OBJECTIVE

This is the first study to evaluate the effectiveness of enzalutamide after failure of abiraterone.

DESIGN, SETTING, AND PARTICIPANTS

Thirty-five patients were identified as having received sequential therapy with abiraterone followed by enzalutamide. All patients had undergone prior docetaxel chemotherapy, and no patient had received ketoconazole.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Posttreatment changes in prostate-specific antigen (PSA) were used to determine the activity of enzalutamide in patients who had received prior abiraterone.

RESULTS AND LIMITATIONS

The median duration of abiraterone treatment was 9.0 mo (range: 2.0-19.0 mo). Of the 35 patients, 16 (45.7%) achieved a >50% decline in PSA, and 14 (40%) had a rising PSA as the best response. The median duration of subsequent enzalutamide treatment was 4.9 mo (Kaplan-Meier estimate; 95% confidence interval [CI], 2.4-7.4). Seven of 16 CRPC patients who were initially abiraterone-sensitive (43.8%) and 3 of 19 CRPC patients who were initially abiraterone-insensitive (15.8%) showed a >50% PSA decline while taking enzalutamide. Of the 35 patients, 17 (48.6%) were primarily enzalutamide-resistant and showed a rising PSA as the best response. Median time to progression was 4.0 mo (95% CI, 2.0-6.0) for 18 of 35 patients with at least one declining PSA value while taking enzalutamide (51.4%). Of the 17 patients who were assessable radiologically, only 1 (2.9%) attained a confirmed partial response. Small sample size was the major limitation.

CONCLUSIONS

Enzalutamide treatment achieved only a modest response rate in patients progressing after abiraterone. Although cross-resistance between abiraterone and enzalutamide was a common phenomenon, it was not inevitable, and a small but significant number of patients showed significant benefit from sequential treatment.