Unification of a common biochemical failure definition for prostate cancer treated with brachytherapy or external beam radiotherapy with or without androgen deprivation

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.

Escalated-dose versus control-dose conformal radiotherapy for prostate cancer: long-term results from the MRC RT01 randomised controlled trial

BACKGROUND

The aim of this trial was to compare dose-escalated conformal radiotherapy with control-dose conformal radiotherapy in patients with localised prostate cancer. Preliminary findings reported after 5 years of follow-up showed that escalated-dose conformal radiotherapy improved biochemical progression-free survival. Based on the sample size calculation, we planned to analyse overall survival when 190 deaths occurred; this target has now been reached, after a median 10 years of follow-up.

METHODS

RT01 was a phase 3, open-label, international, randomised controlled trial enrolling men with histologically confirmed T1b-T3a, N0, M0 prostate cancer with prostate specific antigen of less than 50 ng/mL. Patients were randomly assigned centrally in a 1:1 ratio, using a computer-based minimisation algorithm stratifying by risk of seminal vesicle invasion and centre to either the control group (64 Gy in 32 fractions, the standard dose at the time the trial was designed) or the escalated-dose group (74 Gy in 37 fractions). Neither patients nor investigators were masked to assignment. All patients received neoadjuvant androgen deprivation therapy for 3-6 months before the start of conformal radiotherapy, which continued until the end of conformal radiotherapy. The coprimary outcome measures were biochemical progression-free survival and overall survival. All analyses were done on an intention-to-treat basis. Treatment-related side-effects have been reported previously. This trial is registered, number ISRCTN47772397.

FINDINGS

Between Jan 7, 1998, and Dec 20, 2001, 862 men were registered and 843 subsequently randomly assigned: 422 to the escalated-dose group and 421 to the control group. As of Aug 2, 2011, 236 deaths had occurred: 118 in each group. Median follow-up was 10·0 years (IQR 9·1-10·8). Overall survival at 10 years was 71% (95% CI 66-75) in each group (hazard ratio [HR] 0·99, 95% CI 0·77-1·28; p=0·96). Biochemical progression or progressive disease occurred in 391 patients (221 [57%] in the control group and 170 [43%] in the escalated-dose group). At 10 years, biochemical progression-free survival was 43% (95% CI 38-48) in the control group and 55% (50-61) in the escalated-dose group (HR 0·69, 95% CI 0·56-0·84; p=0·0003).

INTERPRETATION

At a median follow-up of 10 years, escalated-dose conformal radiotherapy with neoadjuvant androgen deprivation therapy showed an advantage in biochemical progression-free survival, but this advantage did not translate into an improvement in overall survival. These efficacy data for escalated-dose treatment must be weighed against the increase in acute and late toxicities associated with the escalated dose and emphasise the importance of use of appropriate modern radiotherapy methods to reduce side-effects.

FUNDING

UK Medical Research Council.

Five-year outcomes after iodine-125 seed brachytherapy for low-risk prostate cancer at three cancer centres in the UK

OBJECTIVE

To report the outcomes of >1000 men with low-risk prostate cancer treated with low-dose-rate (LDR) brachytherapy at three large UK cancer centres.

PATIENTS AND METHODS

A total of 1038 patients with low-risk prostate cancer (prostate-specific antigen [PSA] ≤10 ng/mL, Gleason score 6, ≤T2b disease) were treated with LDR iodine 125 (I-125) brachytherapy between 2002 and 2007. Patients were treated at three UK centres. PSA and clinical follow-up was performed at each centre. Biochemical recurrence-free survival was reported for the cohort.

RESULTS

The median (range) PSA follow-up for the whole group was 5 years (4 months to 9 years). A total of 79 patients had biochemical failure, defined by a rise in PSA level: 16 patients fulfilled the ASTRO definition of biochemical failure, 25 patients fulfilled the Phoenix definition and 38 patients fulfilled both definitions. The 5-year biochemical relapse-free survival (bRFS) rate was 94.1% by the ASTRO definition and 94.2% by the Phoenix definition. The absence of neoadjuvant hormone therapy was predictive of inferior biochemical control as defined by the Phoenix definition (P = 0.033).

CONCLUSIONS

Our prospective multicentre series showed excellent bRFS with LDR I-125 brachytherapy for patients with low-risk prostate cancer. Further work is necessary to define the role of neoadjuvant androgen deprivation therapy in combination with brachytherapy.

Biochemical control of prostate cancer with iodine-125 brachytherapy alone: experience from a single institution

AIM

Brachytherapy is an adequate option as monotherapy for localised prostate cancer. The objective of this study was to evaluate and compare biochemical failure free survival (BFFS) after low-dose-rate brachytherapy (LDRB) alone for patients with prostate cancer using ASTRO and Phoenix criteria, and detect prognostic factors.

METHODS

Data on 220 patients treated between 1998 and 2002 with LDRB were retrospectively analysed. Neoadjuvant hormone therapy was used in 74 (33.6%) patients.

RESULTS

Median follow-up was 53.5 months (24-116). Five year BFFS was 83.0% and 83.7% using, respectively, the ASTRO and Phoenix criteria. Low -and intermediate- risk patients presented, respectively, 86.7% and 77.8% 5-year BFFS using the ASTRO definition (p=0.069), and 88.5% and 78.6% considering the Phoenix criteria (p=0.016). Bounce was observed in 66 (30%) patients. Multivariate analysis detected PSA at diagnosis <10 ng/ml and less than 50% positive biopsy fragments as favourable prognostic factors, regarding BF using both criteria. For the Phoenix criteria, also Gleason score <7 and low-risk group were identified as independent favourable prognostic factors.

CONCLUSIONS

LDRB alone should be considered mostly for low-risk patients. PSA level was a strong independent prognostic factor. We support the use of the Phoenix criteria for detection of BF in patients submitted to LDRB alone.

[Tumour recurrence]

In Chap. 6 the German S3 guideline on prostate cancer addresses the issue of tumour recurrence following primary local treatment with curative intent, i.e. after radical prostatectomy or a form of radiotherapy. PSA recurrence after radical surgery is defined as a rising PSA of 0.2 ng/ml and after radiotherapy as an increase of at least 2 ng/ml above the individual nadir. Factors for the clinical judgement that a local recurrence is likely are empirical indicators from the primary tumour diagnosis and the PSA course after primary treatment. Salvage external beam radiotherapy after radical surgery does not require the histological proof of a local recurrence and should be initiated early (PSA < 0.5 ng/ml). Before salvage radical prostatectomy, which carries a higher complication rate, the presence of a local recurrence should be histologically verified.

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.

Extreme-risk prostate adenocarcinoma presenting with prostate-specific antigen (PSA)>40 ng/ml: prognostic significance of the preradiation PSA nadir

PURPOSE

To examine the impact of patient, disease, and treatment characteristics on survival outcomes in patients treated with neoadjuvant androgen deprivation therapy (ADT) and radical external-beam radiotherapy (RT) for clinically localized, extreme-risk prostate adenocarcinoma with a presenting prostate-specific antigen (PSA) concentration of >40 ng/ml.

METHODS AND MATERIALS

A retrospective chart review was conducted of 64 patients treated at a single institution between 1991 and 2000 with ADT and RT for prostate cancer with a presenting PSA level of >40 ng/ml. The effects of patient age, tumor (presenting PSA level, Gleason score, and T stage), and treatment (total ADT duration and pre-RT PSA level) characteristics on rates of biochemical disease-free survival (bDFS), prostate cancer-specific survival (PCSS), and overall survival (OS) were examined.

RESULTS

Median follow-up time was 6.45 years (range, 0.09-15.19 years). Actuarial bDFS, PCSS, and OS rates at 5 years were 39%, 87%, and 78%, respectively, and 17%, 64%, and 45%, respectively, at 10 years. On multivariate analysis, the pre-RT PSA level (≤0.1 versus >0.1 ng/ml) was the single most significant prognostic factor for bDFS (p=0.033) and OS (p=0.018) rates, whereas age, T stage, Gleason score, and ADT duration (≤6 versus >6 months) were not predictive of outcomes.

CONCLUSION

In prostate cancer patients with high presenting PSA levels, >40 ng/ml, treated with combined modality, neoadjuvant ADT, and RT, the pre-RT PSA nadir, rather than ADT duration, was significantly associated with improved survival. This observation supports the use of neoadjuvant ADT to drive PSA levels to below 0.1 ng/ml before initiation of RT, to optimize outcomes for patients with extreme-risk disease.

Optimized Prostate Brachytherapy Minimizes the Prognostic Impact of Percent of Biopsy Cores Involved With Adenocarcinoma

PURPOSE

A higher percent of positive biopsy cores predicts poor biochemical failure-free survival. The highest dose covering at least 90% of the prostate is a standard method of measuring implant quality. We tested the hypothesis that the percentage of positive biopsy cores loses its adverse prognostic impact in patients who receive implants with a highest dose covering at least 90% of the prostate of 100% or greater of the prescription dose.

MATERIALS AND METHODS

A total of 568 patients with intermediate to high risk adenocarcinoma of the prostate who were previously treated with brachytherapy in a prospective, randomized study were evaluated. The relationship between the percentage of positive biopsy cores, the highest dose covering at least 90% of the prostate and biochemical failure was examined.

RESULTS

At a median followup of 50 months the rate of 5-year biochemical failure-free survival was 87% for the entire group and 92% vs 81% for patients with less than 50% vs 50% or greater positive biopsy cores (log rank p = 0.009). The mean highest dose covering at least 90% of the prostate was statistically lower in failing vs nonfailing cases (p = 0.03). Gleason score, prostate specific antigen, 50% or greater positive biopsy cores and the highest dose covering at least 90% of the prostate were the only statistically significant predictive factors for biochemical failure-free survival on multivariate Cox regression analysis. When regression analysis was restricted to the 237 patients who received implants with a highest dose covering at least 90% of the prostate of 100% or greater, 50% or greater positive biopsy cores lost predictive value but prostate specific antigen and Gleason score remained independent prognostic factors.

CONCLUSIONS

A total of 50% or greater positive biopsy cores is an independent predictor of poor biochemical failure-free survival in patients treated with brachytherapy. High quality prostate brachytherapy, defined by a highest dose covering at least 90% of the prostate of 100% or greater, minimize the adverse effect of 50% or greater positive biopsy cores on time to biochemical failure.

Effect of obesity on prostate-specific antigen recurrence after radiation therapy for localized prostate cancer as measured by the 2006 Radiation Therapy Oncology Group-American Society for Therapeutic Radiation and Oncology (RTOG-ASTRO) Phoenix consensus definition

BACKGROUND

Given the limited data regarding the impact of obesity on treatment outcomes after external beam radiation therapy (EBRT) for the definitive treatment of prostate cancer, the authors sought to evaluate the effect of obesity as measured by body mass index (BMI) on biochemical disease recurrence (BCR) using the most current 2006 Radiation Therapy Oncology Group-American Society for Therapeutic Radiation and Oncology (RTOG-ASTRO) Phoenix consensus definition (prostate-specific antigen [PSA] nadir + 2 ng/mL).

METHODS

A retrospective cohort study identified men who underwent primary EBRT for localized prostate cancer between 1989 and 2003 using the Center for Prostate Disease Research (CPDR) Multi-center National Database. BMI was calculated (in kg/m(2)) and the data were analyzed. Univariate and multivariate Cox proportional hazards regression analyses were used to determine whether BMI significantly predicted BCR.

RESULTS

Of the 1868 eligible patients, 399 (21%) were obese. The median age of the patients and pretreatment PSA level were 70.2 years and 8.2 ng/mL, respectively. Of 1320 patients for whom data were available with which to calculate PSA recurrence (PSA nadir + 2 ng/mL), a total of 554 men (42.0%) experienced BCR. On univariate analysis, BMI was found to be an independent predictor of PSA recurrence (P = .02), as was race, pretreatment PSA level, EBRT dose, clinical T classification, Gleason score, PSA nadir, and the use of androgen-deprivation therapy (ADT). On multivariate analysis, BMI remained a significant predictor of BCR (P = .008).

CONCLUSIONS

To the authors' knowledge, this is the first study to report the association between obesity and BCR after EBRT for localized prostate cancer as measured by the updated 2006 RTOG-ASTRO definition. A higher BMI is associated with greater odds of BCR after undergoing definitive EBRT.

Modern brachytherapy for treatment of prostate cancer

BACKGROUND

Prostate cancer is the most common cancer diagnosed in men. An increasing number of these patients are seeking minimally invasive procedures such as transperineal interstitial permanent radioactive seed prostate brachytherapy.

METHODS

This paper reviews the historical perspective and the current advances in transperineal interstitial permanent radioactive seed prostate brachytherapy. The 10- to 15-year results data now published for brachytherapy alone or in combination with external-beam irradiation are also reviewed.

RESULTS

Modern brachytherapy using transperineal interstitial permanent radioactive seed prostate brachytherapy offers patients an excellent quality of life with convenient outpatient treatment with long-term (10- to 15-year) biochemical relapse-free survival rates ranging from 67% to 87%, depending on risk stratification.

CONCLUSIONS

Modern-day brachytherapy utilizing either radioactive iodine-125 or palladium-103 alone or in combination with supplemental external-beam treatment offers patients a successful treatment outcome with acceptable toxicity.

Escalated-dose versus standard-dose conformal radiotherapy in prostate cancer: first results from the MRC RT01 randomised controlled trial

BACKGROUND

In men with localised prostate cancer, conformal radiotherapy (CFRT) could deliver higher doses of radiation than does standard-dose conventional radical external-beam radiotherapy, and could improve long-term efficacy, potentially at the cost of increased toxicity. We aimed to present the first analyses of effectiveness from the MRC RT01 randomised controlled trial.

METHODS

The MRC RT01 trial included 843 men with localised prostate cancer who were randomly assigned to standard-dose CFRT or escalated-dose CFRT, both administered with neoadjuvant androgen suppression. Primary endpoints were biochemical-progression-free survival (bPFS), freedom from local progression, metastases-free survival, overall survival, and late toxicity scores. The toxicity scores were measured with questionnaires for physicians and patients that included the Radiation Therapy Oncology Group (RTOG), the Late Effects on Normal Tissue: Subjective/Objective/Management (LENT/SOM) scales, and the University of California, Los Angeles Prostate Cancer Index (UCLA PCI) scales. Analysis was done by intention to treat. This trial is registered at the Current Controlled Trials website http://www.controlled-trials.com/ISRCTN47772397.

FINDINGS

Between January, 1998, and December, 2002, 843 men were randomly assigned to escalated-dose CFRT (n=422) or standard-dose CFRT (n=421). In the escalated group, the hazard ratio (HR) for bPFS was 0.67 (95% CI 0.53-0.85, p=0.0007). We noted 71% bPFS (108 cumulative events) and 60% bPFS (149 cumulative events) by 5 years in the escalated and standard groups, respectively. HR for clinical progression-free survival was 0.69 (0.47-1.02; p=0.064); local control was 0.65 (0.36-1.18; p=0.16); freedom from salvage androgen suppression was 0.78 (0.57-1.07; p=0.12); and metastases-free survival was 0.74 (0.47-1.18; p=0.21). HR for late bowel toxicity in the escalated group was 1.47 (1.12-1.92) according to the RTOG (grade >/=2) scale; 1.44 (1.16-1.80) according to the LENT/SOM (grade >/=2) scales; and 1.28 (1.03-1.60) according to the UCLA PCI (score >/=30) scale. 33% of the escalated and 24% of the standard group reported late bowel toxicity within 5 years of starting treatment. HR for late bladder toxicity according to the RTOG (grade >/=2) scale was 1.36 (0.90-2.06), but this finding was not supported by the LENT/SOM (grade >/=2) scales (HR 1.07 [0.90-1.29]), nor the UCLA PCI (score >/=30) scale (HR 1.05 [0.81-1.36]).

INTERPRETATION

Escalated-dose CFRT with neoadjuvant androgen suppression seems clinically worthwhile in terms of bPFS, progression-free survival, and decreased use of salvage androgen suppression. This additional efficacy is offset by an increased incidence of longer term adverse events.

Biochemical disease-free survival rates following definitive low-dose-rate prostate brachytherapy with dose escalation to biologic target volumes identified with SPECT/CT capromab pendetide

PURPOSE

To report biochemical disease-free survival (bDFS) after conformal brachytherapy with dose escalation to biological target volumes (BTVs) identified by Capromab Pendetide with single photon emission computed tomography and computed tomography image fusion (SPECT/CT).

METHODS AND MATERIALS

Two hundred thirty-nine (T1c-T3b NxM0) consecutive patients were evaluated by SPECT/CT before treatment. Intraprostatic SPECT/CT BTVs were identified and targeted for 150% dose escalation during brachytherapy seed implant (SI). Patients received either SI alone (n = 150) or external beam radiation therapy (EBRT) plus SI boost (EBRT+SI) (n = 89), with (n = 50) and without (n = 189) neoadjuvant hormone ablation therapy. Risk factors (RF) (prostate-specific antigen [PSA] >10 ng/mL, Stage > or = T2b, and Gleason grade > or = 7) defined risk group (RG) categories [none, 1, and > or = 2 RF define low, intermediate, and high RG] for bDFS calculations using four failure criteria: American Society for Therapeutic Radiology and Oncology (ASTRO) consensus definition, PSA >1.0 ng/mL (PSA >1), PSA >0.5 ng/mL after nadir (PSA >0.5), and PSA nadir+2 ng/mL rise in PSA clinical nadir (CN+2). Median followup was 47.2 months (range, 24.8-96.1).

RESULTS

Seven-year actuarial bDFS rates were 88.0%, 82.1%, 80.4%, and 79.9% using the ASTRO, PSA >1, PSA >0.5, and CN+2 failure criteria, respectively. ASTRO-defined bDFS rates were 96.0%, 87.0%, and 72.5% for low, intermediate, and high RG's.

CONCLUSION

The data presented here demonstrate the feasibility of performing SPECT/CT BTV dose escalation in a mature series.