Prostate cancer progression has been shown to be dependent on the development of autonomic nerves into the tumour microenvironment. Sympathetic nerves activate adrenergic neurosignalling that is ...necessary in early stages of tumour progression and for initiating an angiogenic switch, whereas parasympathetic nerves activate cholinergic neurosignalling resulting in tumour dissemination and metastasis. The innervation of prostate cancer seems to be initiated by neurotrophic growth factors, such as the precursor to nerve growth factor secreted by tumour cells, and the contribution of brain-derived neural progenitor cells has also been reported. Current experimental, epidemiological and clinical evidence shows the stimulatory effect of tumour innervation and neurosignalling in prostate cancer. Using nerves and neurosignalling could have value in the management of prostate cancer by predicting aggressive disease, treating localized disease through denervation and relieving cancer-associated pain in bone metastases.
Summary Background The TROG 96.01 trial assessed whether 3-month and 6-month short-term neoadjuvant androgen deprivation therapy (NADT) decreases clinical progression and mortality after radiotherapy ...for locally advanced prostate cancer. Here we report the 10-year results. Methods Between June, 1996, and February, 2000, 818 men with T2b, T2c, T3, and T4 N0 M0 prostate cancers were randomly assigned to receive radiotherapy alone, 3 months of NADT plus radiotherapy, or 6 months of NADT plus radiotherapy. The radiotherapy dose for all groups was 66 Gy, delivered to the prostate and seminal vesicles (excluding pelvic nodes) in 33 fractions of 2 Gy per day (excluding weekends) over 6·5–7·0 weeks. NADT consisted of 3·6 mg goserelin given subcutaneously every month and 250 mg flutamide given orally three times a day. NADT began 2 months before radiotherapy for the 3-month NADT group and 5 months before radiotherapy for the 6-month NADT group. Primary endpoints were prostate-cancer-specific mortality and all-cause mortality. Treatment allocation was open label and randomisation was done with a minimisation technique according to age, clinical stage, tumour grade, and initial prostate-specific antigen concentration (PSA). Analysis was by intention-to-treat. The trial has been closed to follow-up and all main endpoint analyses are completed. The trial is registered with the Australian New Zealand Clinical Trials Registry , number ACTRN12607000237482. Findings 802 men were eligible for analysis (270 in the radiotherapy alone group, 265 in the 3-month NADT group, and 267 in the 6-month NADT group) after a median follow-up of 10·6 years (IQR 6·9–11·6). Compared with radiotherapy alone, 3 months of NADT decreased the cumulative incidence of PSA progression (adjusted hazard ratio 0·72, 95% CI 0·57–0·90; p=0·003) and local progression (0·49, 0·33–0·73; p=0·0005), and improved event-free survival (0·63, 0·52–0·77; p<0·0001). 6 months of NADT further reduced PSA progression (0·57, 0·46–0·72; p<0·0001) and local progression (0·45, 0·30–0·66; p=0·0001), and led to a greater improvement in event-free survival (0·51, 0·42–0·61, p<0·0001), compared with radiotherapy alone. 3-month NADT had no effect on distant progression (0·89, 0·60–1·31; p=0·550), prostate cancer-specific mortality (0·86, 0·60–1·23; p=0·398), or all-cause mortality (0·84, 0·65–1·08; p=0·180), compared with radiotherapy alone. By contrast, 6-month NADT decreased distant progression (0·49, 0·31–0·76; p=0·001), prostate cancer-specific mortality (0·49, 0·32–0·74; p=0·0008), and all-cause mortality (0·63, 0·48–0·83; p=0·0008), compared with radiotherapy alone. Treatment-related morbidity was not increased with NADT within the first 5 years after randomisation. Interpretation 6 months of neoadjuvant androgen deprivation combined radiotherapy is an effective treatment option for locally advanced prostate cancer, particularly in men without nodal metastases or pre-existing metabolic comorbidities that could be exacerbated by prolonged androgen deprivation. Funding Australian Government National Health and Medical Research Council, Hunter Medical Research Institute, AstraZeneca, and Schering-Plough.
We evaluated whether the timing of fatal myocardial infarction (MI) was influenced by the administration of androgen suppression therapy (AST).
The study cohort comprised 1,372 men who were enrolled ...onto three randomized trials between February 1995 and June 2001. In the three trials, the men were randomly assigned to receive radiation therapy with 0 versus 3 versus 6, 3 versus 8, or 0 versus 6 months of AST. Fine and Gray's regression was used to determine the clinical factors associated with the time to fatal MI, and estimates of time to fatal MI were calculated using a cumulative incidence method. When comparing the cumulative incidence estimates using Gray's k-sample P values, increased weight was ascribed to the earlier data because recovery of testosterone is expected for most men within 2 years after short-course AST.
Men age 65 years or older who received 6 months of AST experienced shorter times to fatal MIs compared with men in this age group who did not receive AST (P = .017) and men younger than 65 years (P = .016). No significant difference (P = .97) was observed in the time to fatal MIs in men age 65 years or older who received 6 to 8 months of AST compared with 3 months of AST.
The use of AST is associated with earlier onset of fatal MIs in men age 65 years or older who are treated for 6 months compared with men who are not treated with AST.
Summary Background We investigated whether 18 months of androgen suppression plus radiotherapy, with or without 18 months of zoledronic acid, is more effective than 6 months of neoadjuvant androgen ...suppression plus radiotherapy with or without zoledronic acid. Methods We did an open-label, randomised, 2 × 2 factorial trial in men with locally advanced prostate cancer (either T2a N0 M0 prostatic adenocarcinomas with prostate-specific antigen PSA ≥10 μg/L and a Gleason score of ≥7, or T2b–4 N0 M0 tumours regardless of PSA and Gleason score). We randomly allocated patients by computer-generated minimisation—stratified by centre, baseline PSA, tumour stage, Gleason score, and use of a brachytherapy boost—to one of four groups in a 1:1:1:1 ratio. Patients in the control group were treated with neoadjuvant androgen suppression with leuprorelin (22·5 mg every 3 months, intramuscularly) for 6 months (short-term) and radiotherapy alone (designated STAS); this procedure was either followed by another 12 months of androgen suppression with leuprorelin (intermediate-term; ITAS) or accompanied by 18 months of zoledronic acid (4 mg every 3 months for 18 months, intravenously; STAS plus zoledronic acid) or by both (ITAS plus zoledronic acid). The primary endpoint was prostate cancer-specific mortality. This analysis represents the first, preplanned assessment of oncological endpoints, 5 years after treatment. Analysis was by intention-to-treat. This trial is registered with ClinicalTrials.gov , number NCT00193856. Findings Between Oct 20, 2003, and Aug 15, 2007, 1071 men were randomly assigned to STAS (n=268), STAS plus zoledronic acid (n=268), ITAS (n=268), and ITAS plus zoledronic acid (n=267). Median follow-up was 7·4 years (IQR 6·5–8·4). Cumulative incidences of prostate cancer-specific mortality were 4·1% (95% CI 2·2–7·0) in the STAS group, 7·8% (4·9–11·5) in the STAS plus zoledronic acid group, 7·4% (4·6–11·0) in the ITAS group, and 4·3% (2·3–7·3) in the ITAS plus zoledronic acid group. Cumulative incidence of all-cause mortality was 17·0% (13·0–22·1), 18·9% (14·6–24·2), 19·4% (15·0–24·7), and 13·9% (10·3–18·8), respectively. Neither prostate cancer-specific mortality nor all-cause mortality differed between control and experimental groups. Cumulative incidence of PSA progression was 34·2% (28·6–39·9) in the STAS group, 39·6% (33·6–45·5) in the STAS plus zoledronic acid group, 29·2% (23·8–34·8) in the ITAS group, and 26·0% (20·8–31·4) in the ITAS plus zoledronic acid group. Compared with STAS, no difference was noted in PSA progression with ITAS or STAS plus zoledronic acid; however, ITAS plus zoledronic acid reduced PSA progression (sub-hazard ratio SHR 0·71, 95% CI 0·53–0·95; p=0·021). Cumulative incidence of local progression was 4·1% (2·2–7·0) in the STAS group, 6·1% (3·7–9·5) in the STAS plus zoledronic acid group, 1·5% (0·5–3·7) in the ITAS group, and 3·4% (1·7–6·1) in the ITAS plus zoledronic acid group; no differences were noted between groups. Cumulative incidences of bone progression were 7·5% (4·8–11·1), 14·6% (10·6–19·2), 8·4% (5·5–12·2), and 7·6% (4·8–11·2), respectively. Compared with STAS, STAS plus zoledronic acid increased the risk of bone progression (SHR 1·90, 95% CI 1·14–3·17; p=0·012), but no differences were noted with the other two groups. Cumulative incidence of distant progression was 14·7% (10·7–19·2) in the STAS group, 17·3% (13·0–22·1) in the STAS plus zoledronic acid group, 14·2% (10·3–18·7) in the ITAS group, and 11·1% (7·6–15·2) in the ITAS plus zoledronic acid group; no differences were recorded between groups. Cumulative incidence of secondary therapeutic intervention was 25·6% (20·5–30·9), 28·9% (23·5–34·5), 20·7% (16·1–25·9), and 15·3% (11·3–20·0), respectively. Compared with STAS, ITAS plus zoledronic acid reduced the need for secondary therapeutic intervention (SHR 0·67, 95% CI 0·48–0·95; p=0·024); no differences were noted with the other two groups. An interaction between trial factors was recorded for Gleason score; therefore, we did pairwise comparisons between all groups. Post-hoc analyses suggested that the reductions in PSA progression and decreased need for secondary therapeutic intervention with ITAS plus zoledronic acid were restricted to tumours with a Gleason score of 8–10, and that ITAS was better than STAS in tumours with a Gleason score of 7 or lower. Long-term morbidity and quality-of-life scores were not affected adversely by 18 months of androgen suppression or zoledronic acid. Interpretation Compared with STAS, ITAS plus zoledronic acid was more effective for treatment of prostate cancers with a Gleason score of 8–10, and ITAS alone was effective for tumours with a Gleason score of 7 or lower. Nevertheless, these findings are based on secondary endpoint data and post-hoc analyses and must be regarded cautiously. Long- term follow-up is necessary, as is external validation of the interaction between zoledronic acid and Gleason score. STAS plus zoledronic acid can be ruled out as a potential therapeutic option. Funding National Health and Medical Research Council of Australia, Novartis Pharmaceuticals Australia, Abbott Pharmaceuticals Australia, New Zealand Health Research Council, New Zealand Cancer Society, University of Newcastle (Australia), Calvary Health Care (Calvary Mater Newcastle Radiation Oncology Fund), Hunter Medical Research Institute, Maitland Cancer Appeal, Cancer Standards Institute New Zealand.
Aims
Perineural invasion (PNI) by prostatic adenocarcinoma is debated as a prognostic parameter. This study investigates the prognostic predictive value of PNI in a series of patients with locally ...advanced prostate cancer treated with radiotherapy and androgen deprivation using 10 years outcome data from the TROG 03.04 RADAR trial.
Methods
Diagnostic prostate biopsies from 976 patients were reviewed and the presence of PNI noted. Patients were followed for 10 years according to the trial protocol or until death. The primary endpoint for the study was time to bone metastasis. Secondary endpoints included time to soft tissue metastasis, transition to castration resistance, prostate cancer‐specific mortality and all‐cause mortality.
Results
PNI was detected in 449 cases (46%), with 234 cases (24%) having PNI in more than one core. The presence of PNI was significantly associated with higher ISUP grade, clinical T staging category, National Comprehensive Cancer Network risk group, and percent positive biopsy cores. The cumulative probability of bone metastases according to PNI status was significant over the 10 years follow‐up interval of the study (log‐rank test P < 0.0001). PNI was associated with all endpoints on univariable analysis. After adjusting for baseline clinicopathological and treatment factors, bone metastasis was the only endpoint in which PNI retained its prognostic significance (hazard ratio 1.42, 95% confidence interval 1.05–1.92, P = 0.021).
Conclusions
The association between PNI and the development of bone metastases supports the inclusion of this parameter as a component of the routine histology report. Further this association suggests that evaluation of PNI may assist in selecting those patients who should be monitored more closely during follow‐up.
Summary Background Androgen suppression therapy and radiotherapy are used to treat locally advanced prostate cancer. 3 years of androgen suppression confers a small survival benefit compared with 6 ...months of therapy in this setting, but is associated with more toxic effects. Early identification of men in whom radiotherapy and 6 months of androgen suppression is insufficient for cure is important. Thus, we assessed whether prostate-specific antigen (PSA) values can act as an early surrogate for prostate cancer-specific mortality (PCSM). Methods We systematically reviewed randomised controlled trials that showed improved overall and prostate cancer-specific survival with radiotherapy and 6 months of androgen suppression compared with radiotherapy alone and measured lowest PSA concentrations (PSA nadir) and those immediately after treatment (PSA end). We assessed a cohort of 734 men with localised or locally advanced prostate cancer from two eligible trials in the USA and Australasia that randomly allocated participants between Feb 2, 1996, and Dec 27, 2001. We used Prentice criteria to assess whether reported PSA nadir or PSA end concentrations of more than 0·5 ng/mL were surrogates for PCSM. Findings Men treated with radiotherapy and 6 months of androgen suppression in both trials were significantly less likely to have PSA end and PSA nadir values of more than 0·5 ng/mL than were those treated with radiotherapy alone (p<0·0001). Presence of candidate surrogates (ie, PSA end and PSA nadir values >0·5 ng/mL) alone and when assessed in conjunction with the randomised treatment group increased risk of PCSM in the US trial (PSA nadir p=0·0016; PSA end p=0·017) and Australasian trial (PSA nadir p<0·0001; PSA end p=0·0012). In both trials, the randomised treatment group was no longer associated with PCSM (p≥0·20) when the candidate surrogates were included in the model. Therefore, both PSA metrics satisfied Prentice criteria for surrogacy. Interpretation After radiotherapy and 6 months of androgen suppression, men with PSA end values exceeding 0·5 ng/mL should be considered for long-term androgen suppression and those with localised or locally advanced prostate cancer with PSA nadir values exceeding 0·5 ng/mL should be considered for inclusion in randomised trials investigating the use of drugs that have extended survival in castration-resistant metastatic prostate cancer. Funding None.
Purpose:
For prostate cancer treatment, comparable or superior biochemical control was reported when using External-Beam-Radiotherapy (EBRT) with High-Dose-Rate-Brachytherapy (HDRB)-boost, compared ...to dose-escalation with EBRT alone. The conformal doses produced by HDRB could allow further beneficial prostate dose-escalation, but increase in dose is limited by normal tissue toxicity. Previous works showed correlation between urethral dose and incidence of urinary toxicity, but there is a lack of established guidelines on the dose constraints to this organ. This work aimed at fitting a Normal-Tissue-Complication-Probability model to urethral stricture data collected at one institution and validating it with an external cohort, looking at neo-adjuvant androgen deprivation as dose-modifying factor.
Materials and Methods:
Clinical and dosimetric data of 258 patients, with a toxicity rate of 12.8%, treated at a single institution with a variety of prescription doses, were collected to fit the Lyman–Kutcher–Burman (LKB) model using the maximum likelihood method. Due to the different fractionations, doses were converted into 2 Gy-equivalent doses (α/β = 5 Gy), and urethral stricture was used as an end-point. For validation, an external cohort of 187 patients treated as part of the TROG (Trans Tasman Radiation Oncology Group) 03.04 RADAR trial with a toxicity rate of 8.7%, was used. The goodness of fit was assessed using calibration plots. The effect of neo-adjuvant androgen deprivation (AD) was analyzed separating patients who had received it prior to treatment from those who did not receive it.
Results:
The obtained LKB parameters were TD50 = 116.7 Gy and
m
= 0.23;
n
was fixed to 0.3, based on numerical optimization of the likelihood. The calibration plot showed a good agreement between the observed toxicity and the probability predicted by the model, confirmed by bootstrapping. For the external validation, the calibration plot showed that the observed toxicity obtained with the RADAR patients was well-represented by the fitted LKB model parameters. When patients were stratified by the use of AD TD50 decreased when AD was not present.
Conclusions:
Lyman–Kutcher–Burman model parameters were fitted to the risk of urethral stricture and externally validated with an independent cohort, to provide guidance on urethral tolerance doses for patients treated with a HDRB boost. For patients that did not receive AD, model fitting provided a lower TD50 suggesting a protective effect on urethra toxicity.
Dose information from organ sub-regions has been shown to be more predictive of genitourinary toxicity than whole organ dose volume histogram information. This study aimed to identify ...anatomically-localized regions where 3D dose is associated with genitourinary toxicities in healthy tissues throughout the pelvic anatomy.
Dose distributions for up to 656 patients of the Trans-Tasman Radiation Oncology Group 03.04 RADAR trial were deformably registered onto a single exemplar CT dataset. Voxel- based multiple comparison permutation dose difference testing, Cox regression modeling and LASSO feature selection were used to identify regions where 3D dose-increase was associated with late grade ≥ 2 genitourinary dysuria, incontinence and frequency, and late grade ≥ 1 haematuria. This was externally validated by registering dose distributions from the RT01 (up to
= 388) and CHHiP (up to
= 247) trials onto the same exemplar and repeating the voxel-based tests on each of these data sets. All three datasets were then combined, and the tests repeated.
Voxel-based Cox regression and multiple comparison permutation dose difference testing revealed regions where increased dose was correlated with genitourinary toxicity. Increased dose in the vicinity of the membranous and spongy urethra was associated with dysuria for all datasets. Haematuria was similarly correlated with increased dose at the membranous and spongy urethra, for the RADAR, CHHiP, and combined datasets. Some evidence was found for the association between incontinence and increased dose at the internal and external urethral sphincter for RADAR and the internal sphincter alone for the combined dataset. Incontinence was also strongly correlated with dose from posterior oblique beams. Patients with fields extending inferiorly and posteriorly to the CTV, adjacent to the membranous and spongy urethra, were found to experience increased frequency.
Anatomically-localized dose-toxicity relationships were determined for late genitourinary symptoms in the urethra and urinary sphincters. Low-intermediate doses to the extraprostatic urethra were associated with risk of late dysuria and haematuria, while dose to the urinary sphincters was associated with incontinence.
Summary Background Surrogate endpoints for prostate cancer-specific mortality after curative primary treatment are not well established. We sought to assess time to biochemical failure (TTBF) and ...prostate-specific antigen doubling time (PSADT) after failure of curative treatment as candidates for this endpoint. Methods PSA and survival data from the Trans-Tasman Radiation Oncology Group (TROG) 96.01 trial were used to assess surrogate candidates. Between June 28, 1996, and Feb 16, 2000, 802 eligible men with locally advanced prostate cancer were randomly allocated to prostatic irradiation alone, or to 3 or 6 months of maximum short-term androgen deprivation (STAD) before and during radiation. Successful surrogates were required to satisfy the Prentice criteria and to predict the trial finding. The TROG 96.01 trial is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12607000237482. Findings 6 months of STAD was shown to significantly decrease prostate cancer-specific mortality compared with radiation alone, but 3 months of STAD did not result in a decrease. Relative to radiation alone, the hazard ratio of prostate cancer-specific mortality from randomisation was 0·95 (95% CI 0·63–1·41; p=0·79) in the 3-month STAD treatment arm and 0·56 (0·36–0·88; p=0·01) in the 6-month arm. PSADT predicted the trial finding and satisfied all four Prentice criteria at the cutpoints of less than 12 months and less than 15 months, with proportion of treatment effect ratios between 0·36 and 0·56. Time to biochemical failure was better than PSADT at predicting the trial finding and satisfying all four Prentice criteria at cutpoints of less than 1·5, less than 2, and less than 2·5 years, with proportion of treatment effect ratios between 0·45 and 0·64. Interpretation This study provides proof of principle that TTBF and PSADT can be useful as surrogate endpoints for prostate cancer-specific mortality and offer potential to substantially reduce follow up in clinical trials. These endpoints now require assessment in multi-trial meta-analyses before use in clinical trials. Funding National Health and Medical Research Council (Australia; Project Grant Applications 9936572, 209801, 455520); Hunter Medical Research Institute (Newcastle, NSW, Australia); AstraZeneca (Sydney, NSW, Australia); and Schering-Plough (Sydney, NSW, Australia).
The optimal duration of hormonal therapy when combined with radiation for men with high-risk and locally advanced prostate cancer remains under active study. Based on the results of randomized ...controlled trials, durations of androgen suppression therapy of at least 6 months have been shown to prolong survival in men with Gleason score 7 prostate cancer, irrespective of clinical stage. For men with locally advanced prostate cancer and 2 high-risk factors (particularly Gleason 8-10 tumors with evidence of extracapsular extension or seminal vesicle invasion on digital rectal examination) or pelvic nodal involvement, longer durations of 28-36 months appear best, although shorter durations (eg, 18 months) remain under study. Trials are also ongoing to determine whether radiation dose escalation and/or nonhormonal agents, such as zoledronic acid and docetaxel, will reduce the need for supplementary androgen suppression therapy.
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