Changing the patterns of failure for high-risk prostate cancer patients by optimizing local control

Trimodality Therapy With Iodine-125 Brachytherapy, External Beam Radiation Therapy, and Short- or Long-Term Androgen Deprivation Therapy for High-Risk Localized Prostate Cancer: Results of a Multicenter, Randomized Phase 3 Trial (TRIP/TRIGU0907)

PURPOSE

This phase 3 randomized investigation was designed to determine whether 30 months of androgen deprivation therapy (ADT) was superior to 6 months of ADT when combined with brachytherapy and external beam radiation therapy (EBRT) for localized high-risk prostate cancer.

METHODS AND MATERIALS

This study was conducted at 37 hospitals on men aged 40 to 79 years, with stage T2c-3a, prostate-specific antigen >20 ng/mL, or Gleason score >7, who received 6 months of ADT combined with iodine-125 brachytherapy followed by EBRT. After stratification, patients were randomly assigned to either no further treatment (short arm) or 24 months of adjuvant ADT (long arm). According to the Phoenix definition of failure, the primary endpoint was the cumulative incidence of biochemical progression. Secondary endpoints included clinical progression, metastasis, salvage treatment, disease-specific mortality, overall survival, and grade 3+ adverse events. An intention-to-treat analysis was conducted using survival estimates determined using competing risk analyses.

RESULTS

Of 332 patients, 165 and 167 were randomly assigned to the short and long arms, respectively. The median follow-up period was 9.2 years. The cumulative incidence of biochemical progression at 7 years was 9.0% (95% CI, 5.5-14.5) and 8.0% (4.7-13.5) in the short and long arms, respectively (P = .65). The outcomes of secondary endpoints did not differ significantly between the arms. Incidence rates of endocrine- and radiation-related grade 3+ adverse events for the short versus long arms were 0.6 versus 1.8% (P = .62) and 1.2 versus 0.6% (P = .62), respectively.

CONCLUSIONS

Both treatment arms showed similar efficacy among selected populations with high-risk features. The toxicity of the trimodal therapy was acceptable. The present investigation, designed as a superiority trial, failed to demonstrate that 30-month ADT yielded better biochemical control than 6-month ADT when combined with brachytherapy and EBRT. Therefore, a noninferiority study is warranted to obtain further evidence supporting these preliminary results.

A Prospective Phase 2 Trial of Transperineal Ultrasound-Guided Brachytherapy for Locally Recurrent Prostate Cancer After External Beam Radiation Therapy (NRG Oncology/RTOG-0526)

PURPOSE

Only retrospective data are available for low-dose-rate (LDR) salvage prostate brachytherapy for local recurrence after external beam radiation therapy (EBRT). The primary objective of this prospective phase 2 trial (NCT00450411) was to evaluate late gastrointestinal and genitourinary adverse events (AEs) after salvage LDR brachytherapy.

METHODS AND MATERIALS

Eligible patients had low- or intermediate-risk prostate cancer before EBRT and biopsy-proven recurrence >30 months after EBRT, with prostate-specific antigen levels <10 ng/mL and no regional/distant disease. The primary endpoint was grade 3 or higher late treatment-related gastrointestinal or genitourinary AEs occurring 9 to 24 months after brachytherapy. These AEs were projected to be ≤10%, with ≥20% considered unacceptable. All events were graded with National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. Multivariate analyses investigated associations of pretreatment or treatment variables with AEs.

RESULTS

One hundred patients from 20 centers were registered from May 2007 to January 2014. The 92 analyzable patients had a median follow-up of 54 months (range, 4-97) and a median age of 70 years (interquartile range [IQR], 65-74). The initial Gleason score was 7 in 48% of patients. The median dose of EBRT was 74 Gy (IQR, 70-76) at a median interval of 85 months previously (IQR, 60-119). Only 16% had androgen deprivation at study entry. Twelve patients (14%) had late grade 3 gastrointestinal/genitourinary AEs, with no treatment-related grade 4 or 5 AEs. No pretreatment variable predicted late AEs, including prior EBRT dose and elapsed interval. Higher V100 (percentage of prostate enclosed by prescription isodose) predicted both occurrence of late AEs (odds ratio, 1.24; 95% confidence interval, 1.02-1.52; P = .03) and earlier time to first occurrence (hazard ratio, 1.18; 95% CI, 1.03-1.34; P = .02).

CONCLUSIONS

This prospective multicenter trial reports outcomes of salvage LDR brachytherapy for post-EBRT recurrence. The rate of late grade 3 AEs did not exceed the unacceptable threshold. The only factor predictive of late AEs was implant dosimetry reflected by V100. Efficacy outcomes will be reported at a minimum of 5-year follow-up.

The role of salvage brachytherapy for local relapse after external beam radiotherapy for prostate cancer

Prostate cancer is the most prevalent cancer amongst men. For localized disease, there currently exist several reliable treatment modalities including surgery, radiotherapy and brachytherapy. Our growing understanding of this disease indicates that local control plays a very important role in prevention of subsequent dissemination. Many improvements to external beam radiotherapy over recent years have decreased toxicity and improved outcomes, but nonetheless, local relapse remains common. Many salvage options exist for locally recurrent prostate cancer, but are rarely offered, partly because of the fear of toxicity. Many men with isolated local recurrence therefore do not receive potentially curative second line treatment and are instead treated with palliative androgen suppression. Selection plays an important role in determining which individuals are likely to benefit from salvage. Those at high risk of pre-existing micro-metastatic disease despite negative staging scans are unlikely to benefit. Prostate brachytherapy has evolved over the more than 3 decades of experience. Modern techniques allow more precise tumor localization and dose delivery. Better understanding of dosimetric parameters can distinguish optimal from suboptimal implants. Salvage brachytherapy can be an effective treatment for locally recurrent prostate cancer after prior external beam radiotherapy. We review the literature pertaining to both low dose rate (LDR) and high dose rate (HDR) salvage brachytherapy and discuss patient selection, optimal dose, treatment volume and toxicity avoidance.

Impact of Androgen Deprivation Therapy on Overall Mortality in Prostate Brachytherapy Patients With Low Pretreatment Testosterone Levels

OBJECTIVES

To evaluate whether the use of androgen deprivation therapy (ADT) in prostate brachytherapy patients impacts overall mortality (OM) in patients with lower pretreatment serum testosterone levels compared with those with normal or high baseline serum testosterone.

MATERIALS AND METHODS

From October 2001 to May 2014, 1916 patients underwent brachytherapy and had a pretreatment serum testosterone. Baseline serum testosterone values were collected prospectively before initiation of therapy. Median follow-up was 7.2 years. In total, 26% of the patients received ADT, primarily men with higher risk disease. OM and prostate cancer-specific mortality were examined to determine whether men with lower baseline serum testosterone were at increased risk of mortality when ADT was used, compared with men with baseline normal or higher testosterone.

RESULTS

Prostate cancer-specific mortality and OM at 10 years was 0.8% and 22.0%. Age, tobacco use, diabetes, cardiovascular disease, and percent positive biopsies were the strongest predictors of OM. ADT use by itself was not associated with an increased risk of OM on multivariate analysis (P=0.695). However, ADT use in men with lower baseline testosterone was associated with a significantly higher risk of OM (P<0.01). ADT use in men with normal or higher baseline testosterone was not associated with an increased OM risk (P=0.924).

CONCLUSIONS

Men with lower baseline testosterone may be at increased risk of premature death when ADT is utilized compared with men with baseline normal or higher testosterone. Further analysis of this potential risk factor is warranted to further identify subsets of men who may be at higher risk of long-term adverse sequelae from ADT.

Clinical Significance of Neoadjuvant Combined Androgen Blockade for More Than Six Months in Patients with Localized Prostate Cancer Treated with Prostate Brachytherapy

INTRODUCTION

The aim of this study is to clarify the clinical significance of neoadjuvant combined androgen blockade (CAB) for ≥ 6 months in patients with localized prostate cancer.

PATIENTS AND METHODS

A total of 431 patients with localized prostate cancer who underwent prostate brachytherapy (BT) with or without neoadjuvant CAB for ≥ 6 months with mean follow-up time of 64.6 months (range 24-108 months) were evaluated retrospectively. Of those 431, 232 patients received BT in combination with neoadjuvant CAB for ≥ 6 months. Biochemical recurrence-free rates (BRFRs) in 364 patients with at least 3 years of follow-up were evaluated by log-rank test.

RESULTS

BRFR in patients with low-, intermediate- and high-risk prostate cancer were 98.1, 94.2 and 89.1%, respectively. In patients with intermediate-risk prostate cancer only, neoadjuvant CAB was significantly associated with BRFR (p = 0.0468). Especially in patients with intermediate-risk prostate cancer with radiation dose received by 90% of the prostate (D90) < 180 Gy, neoadjuvant CAB exerted a favorable impact on BRFR (p = 0.0429). On multivariate analyses, neoadjuvant CAB and D90 were independent predictors of BRFR (p = 0.0061 and p < 0.0001, respectively).

CONCLUSIONS

Neoadjuvant CAB for ≥ 6 months has a favorable impact on BRFR in patients with intermediate-risk prostate cancer, particularly in patients with relatively low radiation doses of D90.

Prognostic factors for newly diagnosed prostate cancer and their role in treatment selection

Adenocarcinoma of the prostate is extremely heterogeneous, ranging from an indolent chronic illness to an aggressive rapidly fatal systemic malignancy. The classic prognostic factors of tumor stage, prostate specific antigen level, and Gleason score have been used for over a decade to categorize patients at the time of diagnosis into broad risk groups that help to determine appropriate management. Although the grouping of patients into favorable, intermediate, and high-risk categories has become standard, and the categories continue to define distinct prognostic subgroups, considerable heterogeneity exists within each risk group. As a range of management options are available, additional prognostic factors can be considered when determining the treatment approach for an individual patient. We review these additional prognostic variables under the headings of patient-related, tumor-related, and treatment-related. The influence of each of these factors may vary depending on treatment factors such as dose, the radiation modality, or the use of concomitant androgen ablation.

Permanent seed brachytherapy for locally recurrent prostate cancer after radical prostatectomy: a case report and review of the literature

PURPOSE

To describe the management of a patient with locally recurrent prostate cancer in the prostate bed, 10 years after a radical prostatectomy.

METHODS AND MATERIALS

A 71-year-old man had a radical prostatectomy for a Gleason 7 clinical T2a carcinoma of the prostate in 2000. Final pathologic stage was pT3a pN0. Postoperatively his prostate-specific antigen was undetectable, but by 2008 it was 1.0ng/mL and in 2011 it reached to 1.43ng/mL. He was referred for consideration of salvage radiotherapy. Staging workup was negative but transrectal ultrasound revealed a 15cc recurrence in the prostate bed. A combination of external beam radiation therapy (4600/23/4.5 weeks to the pelvis) and a brachytherapy boost (115Gy) was selected for definitive management. Androgen ablation was not used.

RESULTS

The treatment was well tolerated. The brachytherapy boost was planned in a similar fashion to a de novo implant for an intact prostate. The postimplant dosimetry was evaluated using magnetic resonance imaging-computed tomography (MR-CT) fusion and appeared satisfactory. Acute toxicity was minimal. Six months after brachytherapy, the prostate-specific antigen had fallen from 1.43 to 0.05ng/mL.

CONCLUSIONS

Dose escalation with combined external beam and brachytherapy may be feasible if recurrent disease can be visualized using transrectal ultrasound and encompassed in an implanted volume. Although longer followup and a larger series of patients are required to demonstrate safety and efficacy, consideration should be given this approach.

Tri-Modality therapy with I-125 brachytherapy, external beam radiation therapy, and short- or long-term hormone therapy for high-risk localized prostate cancer (TRIP): study protocol for a phase III, multicenter, randomized, controlled trial

Background

Patients with high Gleason score, elevated prostate specific antigen (PSA) level, and advanced clinical stage are at increased risk for both local and systemic relapse. Recent data suggests higher radiation doses decrease local recurrence and may ultimately benefit biochemical, metastasis-free and disease-specific survival. No randomized data is available on the benefits of long-term hormonal therapy (HT) in these patients. A prospective study on the efficacy and safety of trimodality treatment consisting of HT, external beam radiation therapy (EBRT), and brachytherapy (BT) for high-risk prostate cancer (PCa) is strongly required.

Methods/Design

This is a phase III, multicenter, randomized controlled trial (RCT) of trimodality with BT, EBRT, and HT for high-risk PCa (TRIP) that will investigate the impact of adjuvant HT following BT using iodine-125 (¹²⁵I-BT) and supplemental EBRT with neoadjuvant and concurrent HT. Prior to the end of September 2012, a total of 340 patients with high-risk PCa will be enrolled and randomized to one of two treatment arms. These patients will be recruited from more than 41 institutions, all of which have broad experience with ¹²⁵I-BT. Pathological slides will be centrally reviewed to confirm patient eligibility. The patients will commonly undergo 6-month HT with combined androgen blockade (CAB) before and during ¹²⁵I-BT and supplemental EBRT. Those randomly assigned to the long-term HT group will subsequently undergo 2 years of adjuvant HT with luteinizing hormone-releasing hormone agonist. All participants will be assessed at baseline and every 3 months for the first 30 months, then every 6 months until 84 months from the beginning of CAB.

The primary endpoint is biochemical progression-free survival. Secondary endpoints are overall survival, clinical progression-free survival, disease-specific survival, salvage therapy non-adaptive interval, and adverse events.

Discussion

To our knowledge, there have been no prospective studies documenting the efficacy and safety of trimodality therapy for high-risk PCa. The present RCT is expected to provide additional insight regarding the potency and limitations of the addition of 2 years of adjuvant HT to this trimodality approach, and to establish an appropriate treatment strategy for high-risk PCa.

Trial registration

UMIN000003992

[Seminal vesicle biopsies: Interest in the prostate cancer staging before radiation therapy or brachytherapy]

OBJECTIVE

Seminal vesicle biopsies (SVB) in the staging of prostate cancer are controversial. Our main objective was to assess their contribution before radiation therapy or brachytherapy. Our secondary objective was to compare pathologic findings of the SVB to the magnetic resonance imaging's (MRI) results.

PATIENTS AND METHODS

From 2000 to 2008, 135 men (median age: 70 years) with prostate cancer (cT1a to cT3) underwent SVB right and left. The median PSA was 12 ng/ml. The median Gleason score was 7. Forty-one patients had an endorectal MRI. The median follow-up was 47 months.

RESULTS

Seminal vesicle involvement was found in 10% of patients. In 9.2% of cases, the biopsy was not contributive. The risk of invasion was significantly associated with the stage T3, the Gleason score up to 7 and the percentage of prostate positive biopsies. A MRI was performed in 41 cases: the correlation between MRI and SVB for the invasion of seminal vesicle was significant but moderate (kappa=0.38). The complications rate of SVB was 10%.

CONCLUSION

SVB were a simple and profitable method. They have provided supplementary information that could improve the staging and that could lead to the make use of an appropriate treatment. This information was comparable to the information provided by MRI. Further studies should establish their role in relation to MRI and in particular confirm the best specificity of the SVB.

Low-dose rate brachytherapy for men with localized prostate cancer

BACKGROUND

Localized prostate cancer is a slow growing tumor for many years for the majority of affected men. Low-dose rate brachytherapy (LDR-BT) is short-distance radiotherapy using low-energy radioactive sources. LDR-BT has been recommended for men with low risk localized prostate cancer.

OBJECTIVES

To assess the benefit and harm of LDR-BT compared to radical prostatectomy (RP), external beam radiotherapy (EBRT), and no primary therapy (NPT) in men with localized prostatic cancer.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 1950), and EMBASE (from 1980) were searched in June 2010 as well as online trials registers and reference lists of reviews.

SELECTION CRITERIA

Randomized, controlled trials comparing LDR-BT versus RP, EBRT, and NPT in men with clinically localized prostate cancer.

DATA COLLECTION AND ANALYSIS

Data on study methods, participants, treatment regimens, observation period and outcomes were recorded by two reviewers independently.

MAIN RESULTS

We identified only one RCT (N = 200; mean follow up 68 months). This trial compared LDR-BT and RP. The risk of bias was deemed high. Primary outcomes (overall survival, cause-specific mortality, or metastatic-free survival) were not reported. Biochemical recurrence-free survival at 5 years follow up was not significantly different between LDR-BT (78/85 (91.8%)) and RP (81/89 (91.0%)); P = 0.875; relative risk 0.92 (95% CI: 0.35 to 2.42).For severe adverse events reported at 6 months follow up, results favored LDR-BT for urinary incontinence (LDR-BT 0/85 (0.0%) versus RP 16/89 (18.0%); P < 0.001; relative risk 0) and favored RP for urinary irritation (LDR-BT 68/85 (80.0%) versus RP 4/89 (4.5%); P < 0.001; relative risk 17.80, 95% CI 6.79 to 46.66). The occurrence of urinary stricture did not significantly differ between the treatment groups (LDR-BT 2/85 (2.4%) versus RP 6/89 (6.7%); P = 0.221; relative risk 0.35, 95% CI: 0.07 to 1.68). Long-term information was not available.We did not identify significant differences of mean scores between treatment groups for patient-reported outcomes function and bother as well as generic health-related quality of life.

AUTHORS' CONCLUSIONS

Low-dose rate brachytherapy did not reduce biochemical recurrence-free survival versus radical prostatectomy at 5 years. For short-term severe adverse events, low-dose rate brachytherapy was significantly more favorable for urinary incontinence, but radical prostatectomy was significantly more favorable for urinary irritation. Evidence is based on one RCT with high risk of bias.

Failure to adhere to protocol specified radiation therapy guidelines was associated with decreased survival in RTOG 9704--a phase III trial of adjuvant chemotherapy and chemoradiotherapy for patients with resected adenocarcinoma of the pancreas

PURPOSE

In Radiation Therapy Oncology Group 9704, as previously published, patients with resected pancreatic adenocarcinoma received continuous infusion 5-FU and concurrent radiotherapy (5FU-RT). 5FU-RT treatment was preceded and followed by randomly assigned chemotherapy, either 5-FU or gemcitabine. This analysis explored whether failure to adhere to specified RT guidelines influenced survival and/or toxicity.

METHODS AND MATERIALS

RT requirements were protocol specified. Adherence was scored as per protocol (PP) or less than per protocol (<PP). Scoring occurred after therapy but before trial analysis and without knowledge of individual patient treatment outcomes. Scoring was done for all tumor locations and for the subset of pancreatic head location.

RESULTS

RT was scored for 416 patients: 216 PP and 200 <PP. For all pancreatic sites (head, body/tail) median survival (MS) for PP vs. <PP was 1.74 vs. 1.46 years (log-rank p = 0.0077). In multivariate analysis, PP vs. <PP score correlated more strongly with MS than assigned treatment arm (p = 0.014, p = NS, respectively); for patients with pancreatic head tumors, both PP score and gemcitabine treatment correlated with improved MS (p = 0.016, p = 0.043, respectively). For all tumor locations, PP score was associated with decreased risk of failure (p = 0.016) and, for gemcitabine patients, a trend toward reduced Grade 4/5 nonhematologic toxicity (p = 0.065).

CONCLUSIONS

This is the first Phase III, multicenter, adjuvant protocol for pancreatic adenocarcinoma to evaluate the impact of adherence to specified RT protocol guidelines on protocol outcomes. Failure to adhere to specified RT guidelines was associated with reduced survival and, for patients receiving gemcitabine, trend toward increased nonhematologic toxicity.

High-risk prostate cancer with Gleason score 8-10 and PSA level ≤15 ng/mL treated with permanent interstitial brachytherapy

PURPOSE

With widespread prostate-specific antigen (PSA) screening, there has been an increase in men diagnosed with high-risk prostate cancer defined by a Gleason score (GS) ≥8 coupled with a relatively low PSA level. The optimal management of these patients has not been defined. Cause-specific survival (CSS), biochemical progression-free survival (bPFS), and overall survival (OS) were evaluated in brachytherapy patients with a GS ≥8 and a PSA level ≤15 ng/mL with or without androgen-deprivation therapy (ADT).

METHODS AND MATERIALS

From April 1995 to October 2005, 174 patients with GS ≥8 and a PSA level ≤15 ng/mL underwent permanent interstitial brachytherapy. Of the patients, 159 (91%) received supplemental external beam radiation, and 113 (64.9%) received ADT. The median follow-up was 6.6 years. The median postimplant Day 0 minimum percentage of the dose covering 90% of the target volume was 121.1% of prescription dose. Biochemical control was defined as a PSA level ≤0.40 ng/mL after nadir. Multiple parameters were evaluated for impact on survival.

RESULTS

Ten-year outcomes for patients without and with ADT were 95.2% and 92.5%, respectively, for CSS (p = 0.562); 86.5% and 92.6%, respectively, for bPFS (p = 0.204); and 75.2% and 66.0%, respectively, for OS (p = 0.179). The median post-treatment PSA level for biochemically controlled patients was <0.02 ng/mL. Multivariate analysis failed to identify any predictors for CSS, whereas bPFS and OS were most closely related to patient age.

CONCLUSIONS

Patients with GS ≥8 and PSA level ≤15 ng/mL have excellent bPFS and CSS after brachytherapy with supplemental external beam radiotherapy. The use of ADT did not significantly impact bPFS, CSS, or OS.

Impact of ultrahigh baseline PSA levels on biochemical and clinical outcomes in two Radiation Therapy Oncology Group prostate clinical trials

PURPOSE

To assess ultrahigh (UH; prostate-specific antigen [PSA] levels ≥50 ng/ml) patient outcomes by comparison to other high-risk patient outcomes and to identify outcome predictors.

METHODS AND MATERIALS

Prostate cancer patients (PCP) from two Phase III Radiation Therapy Oncology Group clinical trials (studies 9202 and 9413) were divided into two groups: high-risk patients with and without UH baseline PSA levels. Predictive variables included age, Gleason score, clinical T stage, Karnofsky performance score, and treatment arm. Outcomes included overall survival (OS), distant metastasis (DM), and biochemical failure (BF). Unadjusted and adjusted hazard ratios (HRs) were calculated using either the Cox or Fine and Gray's regression model with associated 95% confidence intervals (CI) and p values.

RESULTS

There were 401 patients in the UH PSA group and 1,792 patients in the non-UH PSA PCP group of a total of 2,193 high-risk PCP. PCP with UH PSA were found to have inferior OS (HR, 1.19; 95% CI, 1.02-1.39, p = 0.02), DM (HR, 1.51; 95% CI, 1.19-1.92; p = 0.0006), and BF (HR, 1.50; 95% CI, 1.29-1.73; p < 0.0001) compared to other high-risk PCP. In the UH cohort, PSA level was found to be a significant factor for the risk of DM (HR, 1.01; 95% CI, 1.001-1.02) but not OS and BF. Gleason grades of 8 to 10 were found to consistently predict for poor OS, DM, and BF outcomes (with HR estimates ranging from 1.41-2.36) in both the high-risk cohort and the UH cohort multivariable analyses.

CONCLUSIONS

UH PSA levels at diagnosis are related to detrimental changes in OS, DM, and BF. All three outcomes can be modeled by various combinations of all predictive variables tested.

Treatment strategies for high-risk locally advanced prostate cancer

High-risk prostate cancer can be defined by the assessment of pretreatment prognostic factors such as clinical stage, Gleason score, and PSA level. High-risk features include PSA >20 ng/ml, Gleason score 8-10, and stage T3 tumors. Patients with adverse prognostic factors have historically fared poorly with monotherapeutic approaches. Multimodal treatment utilizing combined androgen suppression and radiotherapy has improved survival rates for patients with high-risk prostate cancer. In addition, multiple randomized trials in patients treated with primary radical prostatectomy have demonstrated improved outcomes with the addition of adjuvant radiotherapy. Improved radiotherapy techniques that allow for dose escalation, and new systemic therapy approaches such as adjuvant chemotherapy, present promising future therapeutic alternatives for patients with high-risk prostate cancer.

Relationship between prostate cancer mortality and number of unfavourable risk factors in men treated with definitive brachytherapy

OBJECTIVE

To explore whether the number of unfavourable pretreatment risk factors predicts cause-specific mortality in men treated with prostate brachytherapy.

PATIENTS AND METHODS

Between April 1995 and March 2006, 739 patients were treated who had at least one of the following adverse risk factors: pretreatment prostate-specific antigen (PSA) level of >10 ng/mL, a Gleason score of > or =7, clinical stage > or =T2b, or a PSA velocity (PSAV) of >2 ng/mL/year. Supplemental external beam radiotherapy (EBRT) was delivered to 464 (62.8%) men and 301 (40.7%) received androgen deprivation therapy (ADT). Of men with more than two risk factors, 87% received EBRT and 62% received ADT.

RESULTS

The biochemical progression-free survival (bPFS), cause-specific survival (CSS) and overall survival for all patients were 95.0%, 97.9% and 70.0% at 12 years. Men with three or four risk factors had a prostate cancer-specific mortality (PCSM) at 12 years of 5.3%, vs 1.7% for men with one or two risk factors (P= 0.006). When 'percentage of positive biopsy cores >50%' replaced PSAV as a risk factor, men with two or more risk factors had a PCSM of 8.9%, vs 1.0% for men with one or two risk factors (P= 0.001). There was no difference in all-cause mortality between the groups in either analysis.

CONCLUSION

Multimodal brachytherapy results in high rates of bPFS and CSS, even for men with several unfavourable risk factors. Men with two or more unfavourable risk factors had a slightly greater risk of PCSM and no difference in all-cause mortality. The presence of three or four unfavourable intermediate-risk factors does not appear to clearly identify a group that requires further treatment intensification, although the percentage of positive cores might be more predictive than PSAV.

Metastasis after radical prostatectomy or external beam radiotherapy for patients with clinically localized prostate cancer: a comparison of clinical cohorts adjusted for case mix

PURPOSE

We assessed the effect of radical prostatectomy (RP) and external beam radiotherapy (EBRT) on distant metastases (DM) rates in patients with localized prostate cancer treated with RP or EBRT at a single specialized cancer center.

PATIENTS AND METHODS

Patients with clinical stages T1c-T3b prostate cancer were treated with intensity-modulated EBRT (> or = 81 Gy) or RP. Both cohorts included patients treated with salvage radiotherapy or androgen-deprivation therapy for biochemical failure. Salvage therapy for patients with RP was delivered a median of 13 months after biochemical failure compared with 69 months for EBRT patients. DM was compared controlling for patient age, clinical stage, serum prostate-specific antigen level, biopsy Gleason score, and year of treatment.

RESULTS

The 8-year probability of freedom from metastatic progression was 97% for RP patients and 93% for EBRT patients. After adjustment for case mix, surgery was associated with a reduced risk of metastasis (hazard ratio, 0.35; 95% CI, 0.19 to 0.65; P < .001). Results were similar for prostate cancer-specific mortality (hazard ratio, 0.32; 95% CI, 0.13 to 0.80; P = .015). Rates of metastatic progression were similar for favorable-risk disease (1.9% difference in 8-year metastasis-free survival), somewhat reduced for intermediate-risk disease (3.3%), and more substantially reduced in unfavorable-risk disease (7.8% in 8-year metastatic progression).

CONCLUSION

Metastatic progression is infrequent in men with low-risk prostate cancer treated with either RP or EBRT. RP patients with higher-risk disease treated had a lower risk of metastatic progression and prostate cancer-specific death than EBRT patients. These results may be confounded by differences in the use and timing of salvage therapy.

Brachytherapy for prostate cancer: a systematic review

Low-dose rate brachytherapy has become a mainstream treatment option for men diagnosed with prostate cancer because of excellent long-term treatment outcomes in low-, intermediate-, and high-risk patients. To a great extend due to patient lead advocacy for minimally invasive treatment options, high-quality prostate implants have become widely available in the US, Europe, and Japan. High-dose-rate (HDR) afterloading brachytherapy in the management of localised prostate cancer has practical, physical, and biological advantages over low-dose-rate seed brachytherapy. There are no free live sources used, no risk of source loss, and since the implant is a temporary procedure following discharge no issues with regard to radioprotection use of existing facilities exist. Patients with localized prostate cancer may benefit from high-dose-rate brachytherapy, which may be used alone in certain circumstances or in combination with external-beam radiotherapy in other settings. The purpose of this paper is to present the essentials of brachytherapies techniques along with the most important studies that support their effectiveness in the treatment of prostate cancer.

Risk of Death From Prostate Cancer After Brachytherapy Alone or With Radiation, Androgen Suppression Therapy, or Both in Men With High-Risk Disease

Purpose

We estimated the risk of prostate cancer (PC) –specific mortality (PCSM) after brachytherapy alone or in conjunction with androgen suppression therapy (AST), external-beam radiation therapy (EBRT), or both in men with high-risk PC.

Patients and Methods

The study cohort comprised 1,342 men with a prostate-specific antigen level more than 20 ng/mL and clinical T3 or 4 and/or Gleason score 8 to 10 disease. Competing risks multivariable regression was performed to estimate the risk of PCSM in men treated with brachytherapy alone or with supplemental AST, EBRT, or both, adjusting for age, year of treatment, and known PC prognostic factors.

Results

Despite higher baseline probabilities of PCSM after a median follow-up of 5.1 years, there was a significant reduction in the risk of PCSM (adjusted hazard ratio [AHR], 0.32; 95% CI, 0.14 to 0.73; P = .006) in men treated with brachytherapy and both AST and EBRT as compared with neither. When compared with brachytherapy alone, a significant decrease in the risk of PCSM was not observed in men treated with either supplemental AST (AHR, 0.63; 95% CI, 0.27 to 1.47; P = .28) or EBRT (AHR, 0.57; 95% CI, 0.21 to 1.52; P = .26). There was a near-significant reduction (AHR, 0.53; 95% CI, 0.27 to 1.07; P = .079) in the risk of PCSM in men treated with tri- as compared with bimodality therapy.

Conclusion

Supplemental AST and EBRT but not either supplement compared with brachytherapy alone was associated with a decreased risk of PCSM in men with high-risk PC.

Multicenter analysis of effect of high biologic effective dose on biochemical failure and survival outcomes in patients with Gleason score 7-10 prostate cancer treated with permanent prostate brachytherapy

PURPOSE

To investigate the biochemical control rates and survival for Gleason score 7-10 prostate cancer patients undergoing permanent prostate brachytherapy as a function of the biologic effective dose (BED).

METHODS AND MATERIALS

Six centers provided data on 5,889 permanent prostate brachytherapy patients, of whom 1,078 had Gleason score 7 (n = 845) or Gleason score 8-10 (n = 233) prostate cancer and postimplant dosimetry results available. The median prostate-specific antigen level was 7.5 ng/mL (range, 0.4-300). The median follow-up for censored patients was 46 months (range, 5-130). Short-term hormonal therapy (median duration, 3.9 months) was used in 666 patients (61.8%) and supplemental external beam radiotherapy (EBRT) in 620 (57.5%). The patients were stratified into three BED groups: <200 Gy (n = 645), 200-220 Gy (n = 199), and >220 Gy (n = 234). Biochemical freedom from failure (bFFF) was determined using the Phoenix definition.

RESULTS

The 5-year bFFF rate was 80%. The bFFF rate stratified by the three BED groups was 76.4%, 83.5%, and 88.3% (p < 0.001), respectively. Cox regression analysis revealed Gleason score, prostate-specific antigen level, use of hormonal therapy, EBRT, and BED were associated with bFFF (p < 0.001). Freedom from metastasis improved from 92% to 99% with the greatest doses. The overall survival rate at 5 years for the three BED groups for Gleason score 8-10 cancer was 86.6%, 89.4%, and 94.6%, respectively (p = 0.048).

CONCLUSION

These data suggest that permanent prostate brachytherapy combined with EBRT and hormonal therapy yields excellent bFFF and survival results in Gleason score 7-10 patients when the delivered BEDs are >220 Gy. These doses can be achieved by a combination of 45-Gy EBRT with a minimal dose received by 90% of the target volume of 120 Gy of (103)Pd or 130 Gy of (125)I.

Radiotherapy and survival in prostate cancer patients: a population-based study

PURPOSE

To investigate the association of overall and disease-specific survival with the five standard treatment modalities for prostate cancer (CaP): radical prostatectomy (RP), brachytherapy (BT), external beam radiotherapy, androgen deprivation therapy, and no treatment (NT) within 6 months after CaP diagnosis.

METHODS AND MATERIALS

The study population included 10,179 men aged 65 years and older with incident CaP diagnosed between 1999 and 2001. Using the linked Ohio Cancer Incidence Surveillance System, Medicare, and death certificate files, overall and disease-specific survival through 2005 among the five clinically accepted therapies were analyzed.

RESULTS

Disease-specific survival rates were 92.3% and 23.9% for patients with localized vs. distant disease at 7 years, respectively. Controlling for age, race, comorbidities, stage, and Gleason score, results from the Cox multiple regression models indicated that the risk of CaP-specific death was significantly reduced in patients receiving RP or BT, compared with NT. For localized disease, compared with NT, in the monotherapy cohort, RP and BT were associated with reduced hazard ratios (HR) of 0.25 and 0.45 (95% confidence intervals 0.13-0.48 and 0.23-0.87, respectively), whereas in the combination therapy cohort, HR were 0.40 (0.17-0.94) and 0.46 (0.27-0.80), respectively.

CONCLUSIONS

The present population-based study indicates that RP and BT are associated with improved survival outcomes. Further studies are warranted to improve clinical determinates in the selection of appropriate management of CaP and to improve predictive modeling for which patient subsets may benefit most from definitive therapy vs. conservative management and/or observation.

Evidence-based radiation oncology: Definitive, adjuvant and salvage radiotherapy for non-metastatic prostate cancer

The standard treatment options based on the risk category (stage, Gleason score, PSA) for localized prostate cancer include surgery, radiotherapy and watchful waiting. The literature does not provide clear-cut evidence for the superiority of surgery over radiotherapy, whereas both approaches differ in their side effects. The definitive external beam irradiation is frequently employed in stage T1b-T1c, T2 and T3 tumors. There is a pretty strong evidence that intermediate- and high-risk patients benefit from dose escalation. The latter requires reduction of the irradiated normal tissue (using 3-dimensional conformal approach, intensity modulated radiotherapy, image-guided radiotherapy, etc.). Recent data suggest that prostate cancer may benefit from hypofractionation due to relatively low alpha/beta ratio; these findings warrant confirmation though. The role of whole pelvis irradiation is still controversial. Numerous randomized trials demonstrated a clinical benefit in terms of biochemical control, local and distant control, and overall survival from the addition of androgen suppression to external beam radiotherapy in intermediate- and high-risk patients. These studies typically included locally advanced (T3-T4) and poor-prognosis (Gleason score >7 and/or PSA >20 ng/mL) tumors and employed neoadjuvant/concomitant/adjuvant androgen suppression rather than only adjuvant setting. The ongoing trials will hopefully further define the role of endocrine treatment in more favorable risk patients and in the setting of the dose escalated radiotherapy. Brachytherapy (BRT) with permanent implants may be offered to low-risk patients (cT1-T2a, Gleason score <7, or 3+4, PSA <or=10 ng/mL), with prostate volume of <or=50 ml, no previous transurethral prostate resection and a good urinary function. Some recent data suggest a benefit from combining external beam irradiation and BRT for intermediate-risk patients. EBRT after radical prostatectomy improves disease-free survival and biochemical and local control rates in patients with positive surgical margins or pT3 tumors. Salvage radiotherapy may be considered at the time of biochemical failure in previously non-irradiated patients.