Current Opinion on Adjuvant and Salvage Treatment after Radical Prostatectomy

Adding 6 months of androgen deprivation therapy to postoperative radiotherapy for prostate cancer: a comparison of short-course versus no androgen deprivation therapy in the RADICALS-HD randomised controlled trial

BACKGROUND

Previous evidence indicates that adjuvant, short-course androgen deprivation therapy (ADT) improves metastasis-free survival when given with primary radiotherapy for intermediate-risk and high-risk localised prostate cancer. However, the value of ADT with postoperative radiotherapy after radical prostatectomy is unclear.

METHODS

RADICALS-HD was an international randomised controlled trial to test the efficacy of ADT used in combination with postoperative radiotherapy for prostate cancer. Key eligibility criteria were indication for radiotherapy after radical prostatectomy for prostate cancer, prostate-specific antigen less than 5 ng/mL, absence of metastatic disease, and written consent. Participants were randomly assigned (1:1) to radiotherapy alone (no ADT) or radiotherapy with 6 months of ADT (short-course ADT), using monthly subcutaneous gonadotropin-releasing hormone analogue injections, daily oral bicalutamide monotherapy 150 mg, or monthly subcutaneous degarelix. Randomisation was done centrally through minimisation with a random element, stratified by Gleason score, positive margins, radiotherapy timing, planned radiotherapy schedule, and planned type of ADT, in a computerised system. The allocated treatment was not masked. The primary outcome measure was metastasis-free survival, defined as distant metastasis arising from prostate cancer or death from any cause. Standard survival analysis methods were used, accounting for randomisation stratification factors. The trial had 80% power with two-sided α of 5% to detect an absolute increase in 10-year metastasis-free survival from 80% to 86% (hazard ratio [HR] 0·67). Analyses followed the intention-to-treat principle. The trial is registered with the ISRCTN registry, ISRCTN40814031, and ClinicalTrials.gov, NCT00541047.

FINDINGS

Between Nov 22, 2007, and June 29, 2015, 1480 patients (median age 66 years [IQR 61-69]) were randomly assigned to receive no ADT (n=737) or short-course ADT (n=743) in addition to postoperative radiotherapy at 121 centres in Canada, Denmark, Ireland, and the UK. With a median follow-up of 9·0 years (IQR 7·1-10·1), metastasis-free survival events were reported for 268 participants (142 in the no ADT group and 126 in the short-course ADT group; HR 0·886 [95% CI 0·688-1·140], p=0·35). 10-year metastasis-free survival was 79·2% (95% CI 75·4-82·5) in the no ADT group and 80·4% (76·6-83·6) in the short-course ADT group. Toxicity of grade 3 or higher was reported for 121 (17%) of 737 participants in the no ADT group and 100 (14%) of 743 in the short-course ADT group (p=0·15), with no treatment-related deaths.

INTERPRETATION

Metastatic disease is uncommon following postoperative bed radiotherapy after radical prostatectomy. Adding 6 months of ADT to this radiotherapy did not improve metastasis-free survival compared with no ADT. These findings do not support the use of short-course ADT with postoperative radiotherapy in this patient population.

FUNDING

Cancer Research UK, UK Research and Innovation (formerly Medical Research Council), and Canadian Cancer Society.

Timing of radiotherapy after radical prostatectomy (RADICALS-RT): a randomised, controlled phase 3 trial

BACKGROUND

The optimal timing of radiotherapy after radical prostatectomy for prostate cancer is uncertain. We aimed to compare the efficacy and safety of adjuvant radiotherapy versus an observation policy with salvage radiotherapy for prostate-specific antigen (PSA) biochemical progression.

METHODS

We did a randomised controlled trial enrolling patients with at least one risk factor (pathological T-stage 3 or 4, Gleason score of 7-10, positive margins, or preoperative PSA ≥10 ng/mL) for biochemical progression after radical prostatectomy (RADICALS-RT). The study took place in trial-accredited centres in Canada, Denmark, Ireland, and the UK. Patients were randomly assigned in a 1:1 ratio to adjuvant radiotherapy or an observation policy with salvage radiotherapy for PSA biochemical progression (PSA ≥0·1 ng/mL or three consecutive rises). Masking was not deemed feasible. Stratification factors were Gleason score, margin status, planned radiotherapy schedule (52·5 Gy in 20 fractions or 66 Gy in 33 fractions), and centre. The primary outcome measure was freedom from distant metastases, designed with 80% power to detect an improvement from 90% with salvage radiotherapy (control) to 95% at 10 years with adjuvant radiotherapy. We report on biochemical progression-free survival, freedom from non-protocol hormone therapy, safety, and patient-reported outcomes. Standard survival analysis methods were used. A hazard ratio (HR) of less than 1 favoured adjuvant radiotherapy. This study is registered with ClinicalTrials.gov, NCT00541047.

FINDINGS

Between Nov 22, 2007, and Dec 30, 2016, 1396 patients were randomly assigned, 699 (50%) to salvage radiotherapy and 697 (50%) to adjuvant radiotherapy. Allocated groups were balanced with a median age of 65 years (IQR 60-68). Median follow-up was 4·9 years (IQR 3·0-6·1). 649 (93%) of 697 participants in the adjuvant radiotherapy group reported radiotherapy within 6 months; 228 (33%) of 699 in the salvage radiotherapy group reported radiotherapy within 8 years after randomisation. With 169 events, 5-year biochemical progression-free survival was 85% for those in the adjuvant radiotherapy group and 88% for those in the salvage radiotherapy group (HR 1·10, 95% CI 0·81-1·49; p=0·56). Freedom from non-protocol hormone therapy at 5 years was 93% for those in the adjuvant radiotherapy group versus 92% for those in the salvage radiotherapy group (HR 0·88, 95% CI 0·58-1·33; p=0·53). Self-reported urinary incontinence was worse at 1 year for those in the adjuvant radiotherapy group (mean score 4·8 vs 4·0; p=0·0023). Grade 3-4 urethral stricture within 2 years was reported in 6% of individuals in the adjuvant radiotherapy group versus 4% in the salvage radiotherapy group (p=0·020).

INTERPRETATION

These initial results do not support routine administration of adjuvant radiotherapy after radical prostatectomy. Adjuvant radiotherapy increases the risk of urinary morbidity. An observation policy with salvage radiotherapy for PSA biochemical progression should be the current standard after radical prostatectomy.

FUNDING

Cancer Research UK, MRC Clinical Trials Unit, and Canadian Cancer Society.

Salvage radiotherapy following biochemical relapse after radical prostatectomy: proceedings of the Genito-Urinary Radiation Oncologists of Canada consensus meeting

For patients with recurrent prostate cancer after radical prostatectomy, salvage radiotherapy is the only potentially curative treatment option. However, until recently there has been a paucity of data on the effectiveness of this approach. In light of recently published studies, the Genito-Urinary Radiation Oncologists of Canada (GUROC) met and crafted a consensus statement regarding the current place of salvage radiotherapy. GUROC also identified gaps in current knowledge and identified ongoing study protocols that will advance our knowledge in this area.This report summarizes the main conclusions of the meeting and the commentary provided during the consensus-building process, and outlines the consensus statement that was subsequently adopted.

Adjuvant radiotherapy use and patterns of care analysis for margin-positive prostate adenocarcinoma with extracapsular extension: postprostatectomy adjuvant radiotherapy: a SEER analysis

OBJECTIVES

To perform a patterns of care analysis for patients with prostate cancer and high-risk pathologic factors following radical prostatectomy with regards to adjuvant radiation.

METHODS

A retrospective analysis was conducted using the Surveillance, Epidemiology and End Results (SEER) Program. We identified men from 2004 to 2005 with prostate adenocarcinoma (PA) who had undergone radical prostatectomy (RP) and were found to have extracapsular extension (ECE) with positive margins.

RESULTS

We identified 1427 PA patients with ECE and positive margins after an RP. Most were clinically staged as T1 or T2 before surgery (95.8%). Using the D'Amico Risk Stratification, 52.0% were high-risk, 39.7% were intermediate-risk, and 8.3% were low-risk. Of these, 18.2% (260) received ART, whereas 81.8% (1167) did not. Those who received ART had worse prognostic factors, such as Gleason scores > 7 (38.5% vs 24.8%; P < .0001), prostate-specific antigen level > 10 (44.6% vs 35.2%; P = .0045), pathologically positive lymph nodes (11.5% vs 6.4%; P = .006), and D'Amico high-risk disease (66.8% vs 48.7%; P < .0001). The use of ART based on geographic region ranged from 8.3%-34.2%.

CONCLUSIONS

Less than 20% of patients with pT3 disease and positive margins received ART in the study period just before the publication of randomized data demonstrating an improvement in biochemical failure with ART in this SEER retrospective analysis. This is the largest patterns of care analysis to date of ART in patients with margin-positive pT3 prostate adenocarcinoma.

Management of biochemical failure following radical prostatectomy: salvage radiotherapy - a case series

A retrospective analysis of the outcome of radical prostatectomy (RP) for prostate cancer in a single centre and assessment of the role of salvage radiotherapy (RT) for patients with biochemical relapse. Hundred and thirty-seven patients underwent RP for adenocarcinoma of the prostate in our centre between December 1994 and June 2003. Fifty-four of these patients developed a biochemical relapse prostate-specific antigen (PSA > or = 0.2 ng/ml). Thirty-two patients including five from elsewhere (one with a palpable local recurrence) received salvage RT. Twenty-five of these had positive margins at resection and four had involvement of seminal vesicles. Nine had Gleason score > or = 8. Median PSA before RT was 0.55 ng/ml (range 0.2-5.0). Median age at surgery was 63.5 years (range 52-71). Median age at RT was 65 years (range 53-73). Median time from surgery to biochemical relapse was 11 months (range 0-37) and median interval from surgery to RT was 22 months (range 3-71). Twenty-seven patients received 64 Gy in 32 fractions, three patients received 55 Gy in 20 fractions and two patients received 50 Gy in 20 fractions. Twenty-seven patients were managed by observation or hormone therapy. Twenty-seven patients (84%) achieved complete biochemical remission following RT. Eighteen (56%) remain in complete remission with a median follow-up since RT for the whole group of 30 months (range 8-85). Fourteen patients have relapsed, eight of whom had either clear margins or PSA >1.0 ng/ml at the time of RT (PSA > or = 0.2 ng/ml). Salvage RT is an effective treatment for achieving biochemical remission in selected patients who relapse following RP.

Patients at high risk of progression after radical prostatectomy: Do they all benefit from immediate post-operative irradiation? (EORTC trial 22911)

EORTC trial 22911 demonstrated that immediate postoperative irradiation significantly improved biochemical failure free survival (BPFS) compared to wait-and-see (W and S) until relapse in patients with pT2-3 tumours and pathological risk factors after radical prostatectomy. In this study, we have investigated the heterogeneity of the treatment benefit across defined subgroups of patients. Data from 972 patients were used. A risk model was developed in the W and S group and the Log-rank test for heterogeneity was applied (alpha=0.05). Positive surgical margin (SM+), seminal vesicle invasion (SV+), WHO differentiation grade, pre- and post-operative PSA were independent predictors for BPFS in the W and S group. Men with SV+ were at higher risk of relapse whereas those with SM+ but no capsule infiltration (ECE-) did not seem to differ from those with SM-ECE+ or with SM+ECE+. Postoperative irradiation improved biochemical progression-free survival in all patient groups. Longer follow-up is needed to assess the endpoint of clinical progression-free survival.