Prognostic factors after salvage radiotherapy alone in patients with biochemical recurrence after radical prostatectomy

Association between preradiation therapy prostate-specific antigen levels and radiation therapy failure after prostatectomy: a propensity score matched analysis

Purpose

We sought to determine the association between the pre-radiation therapy prostate-specific antigen (pre-RT PSA) 0.5 and RT failure in post-radical prostatectomy (post-RP) patients. Our study also investigated the prognostic factors for the failure of RT given concurrently with hormone therapy (HT) after RP.

Materials and methods

We retrospectively reviewed our institutional RP data from July 2004 to November 2021. Patients without concurrent hormone therapy were excluded. Propensity score matching was performed. Kaplan-Meier (KM) curve analysis was employed for RT failure-free survival, overall survival (OS), and cancer-specific survival (CSS). Cox regression analysis was used for the RT failure hazard ratio (HR).

Results

After propensity score matching, 193 patients were assigned to the pre-RT PSA ≥0.5 (high-P) arm, and 193 patients were assigned to the pre-RT PSA <0.5 (low-P) arm. There were no significant differences between the two arms after propensity score matching in terms of baseline characteristics and pathologic outcomes. High-P was associated with RT failure-free survival (P = 0.004), OS (P = 0.046), and CSS (P = 0.027). In a multi-variable Cox proportional hazards regression analysis, seminal vesicle invasion, lymph node invasion, the absence of prostatic intraepithelial neoplasia (PIN), and high-P were identified as significant risk factors for RT failure.

Conclusion

High-P was significantly unfavorable with RT failure-free survival, OS, and CSS in patients who underwent RT after radical prostatectomy with concurrent HT. Seminal vesicle invasion, lymph node invasion, and the absence of PIN were identified as significant prognostic factors for RT failure.

Long-term outcomes of salvage transurethral high-dose-rate brachytherapy combined with external beam radiation therapy for anastomotic recurrence of prostate cancer after radical prostatectomy: A retrospective analysis

BACKGROUND

High-dose-rate brachytherapy (HDR-BT) delivers high-dose radiation to local lesions within a short treatment period. There are no reports of salvage transurethral HDR-BT for biochemical recurrence (BCR) after radical prostatectomy. Thus, we aimed to evaluate the usefulness of salvage transurethral HDR-BT with external beam radiation therapy (EBRT) for anastomotic prostate cancer recurrence.

METHODS AND MATERIALS

Patients with postoperative prostate cancer who underwent salvage transurethral HDR-BT with EBRT for anastomotic recurrence at our hospital between January 2002 and July 2009 were retrospectively evaluated. The Kaplan-Meier method was used to estimate biochemical freedom from failure (bFFF), cause-specific survival (CSS), and overall survival (OS) rates.

RESULTS

Nine patients were included in this study. The median follow-up period and age were 13.1 (range 4.3-18.4) years and 67 (range 63-78) years, respectively. The dose of HDR-BT ranged from 13 to 24 Gy per 2 to 5 fractions, while that of EBRT ranged from 30 to 44 Gy per 15 to 22 fractions. The 1-year, 5-year, and 10-year bFFF rates were 77.8%, 41.7%, and 13.9%, respectively. The 10-year and 15-year CSS rates were 100% each. The 10-year and 15-year OS rates were 100% and 64.3%, respectively. Six patients were diagnosed with BCR. Two patients experienced Grade 3 hematuria as a late adverse event. There was no exacerbation of urinary incontinence.

CONCLUSIONS

No prostate cancer-related deaths were observed, even after a long-term follow-up. Salvage transurethral HDR-BT after radical prostatectomy is safe and feasible and may be a useful treatment option.

The Prognostic Value of DCE-MRI Findings before Salvage Radiotherapy after Radical Prostatectomy

BACKGROUND

To investigate the predictive role of dynamic contrast-enhanced-magnetic resonance imaging (DCE-MRI) findings before salvage radiotherapy after radical prostatectomy (RP).

METHODS

This retrospective study selected patients with biochemical failure (BF) after RP restaged with DCE-MRI. Patients underwent sRT in 30 fractions delivering 66-69 Gy and 73.5 Gy to the prostatic fossa and to the local failure as per DCE-MRI, respectively. Pelvic nodes were treated to 54 Gy in selected patients. The endpoint was BF after sRT.

RESULTS

In total, 236 patients were analyzed and 146 (61.9%) had presumed local failure at DCE-MRI: 54.8%, 23.8% and 21.4% were found at the vesico-urethral anastomosis (VUA), the bladder neck and the retro-vesical space, respectively. The presence of a local failure at DCE-MRI halved the risk of BF; VUA-only location and lesion volume were independently correlated with survival without evidence of biochemical failure (bNED) at multivariable analysis. For patients with VUA-only disease up to 0.4 cc, the 4-year-bNED was 94.6% (95%CI: 80.2-98.6%) as opposed to 80.9% (95%CI: 71.6-87.4%) and 73.7% (95%CI: 63.1-81.8%) for other lesions and no macrodisease, respectively.

CONCLUSIONS

DCE-MRI at restaging for BF after RP provides predictive and therapeutic information. Patients with small lesions at the VUA have an excellent prognosis after sRT.

Stereotactic Radiotherapy after Radical Prostatectomy in Patients with Prostate Cancer in the Adjuvant or Salvage Setting: A Systematic Review

Simple Summary

Stereotactic body radiotherapy, a type of high-precision radiotherapy delivering high doses within few treatment sessions has proven to be effective and well tolerated in prostate cancer patients treated with definite radiotherapy. This systematic review summarizes the available data and analyzes whether this modern treatment may routinely be offered to prostate cancer patients after radical prostatectomy.

Abstract

(1) Background: Prostate cancer is the most common cancer in men and can be treated with radical prostatectomy (RPE) or radiotherapy in the primary setting. Stereotactic radiotherapy (SBRT) has proven to be effective and well tolerated in this setting. However, if SBRT is an equally promising treatment option if applied in the adjuvant or salvage setting after RPE remains unknown. (2) Methods: We searched the PubMed and Embase databases with the following full-text queries in August 2021 for any combination of the terms “SBRT”, “prostate”, “adjuvant”, “postoperative”, “salvage”, “stereotactic radiotherapy”, “prostate bed”. There were no limitations regarding publication date or language. We adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. (3) Results: We identified 11 individual studies that were included in this systematic review. Three publications included patients without prior radiotherapy and the remaining eight patients with prior radiotherapy. In all but two publications the radiation target was the macroscopic recurrence. SBRT was overall well tolerated with acceptable rates of acute and late gastrointestinal or genitourinary toxicity. Quality of life was published for two phase I trials with good results. There was a very heterogeneous reporting on biochemical control after SBRT. (4) Conclusions: At this point, ultra-hypofractionated RT using SBRT to the prostate bed remains experimental and its use should be restricted to clinical trials. Given the biological rationale for extreme hypofractionation in patients with prostate cancer and the acceptable toxicity rates that have been reported, further exploration of this field is warranted.

Comparison Between Dose-Escalated Intensity Modulated Radiation Therapy and 3-Dimensional Conformal Radiation Therapy for Salvage Radiation Therapy After Prostatectomy

Purpose

To compare long-term outcomes and late toxicity between patients treated with 3-dimensional conformal radiation therapy (3D-CRT) and with dose-escalated intensity modulated radiation therapy (IMRT) as salvage radiation therapy (SRT) after prostatectomy.

Methods and Materials

A total of 110 patients who had been treated at our institution between 2010 and 2018 with SRT for biochemical recurrence after radical prostatectomy were included. The patients were treated either by 3D-CRT with 64 Gy (59 patients) or by IMRT with 70 Gy (51 patients). The irradiation target was the prostate bed only (106 patients) or the prostate bed and pelvic region (4 patients). Twelve patients (11%) received concurrent androgen deprivation therapy. The differences in clinical outcomes and late gastrointestinal (GI) and genitourinary (GU) toxicity between the 3D-CRT and IMRT groups were retrospectively assessed. Toxicities were recorded using the Common Terminology Criteria for Adverse Events, version 5.0. Prostate-specific antigen (PSA) progression after SRT was defined as an increase in the serum PSA level of 0.2 ng/mL from the PSA nadir after SRT and confirmed by a second PSA measurement that was higher than the first.

Results

The median follow-up time was 7.8 years for 3D-CRT (range:,0.3-9.2 years) and 3.1 years for IMRT (range, 0.4-7.2 years). There was no significant difference in the 4-year biochemical no-evidence-of-disease (bNED) rate between the 3D-CRT and IMRT groups (43.5% vs 52.1%; P = .20). Toxicity analysis showed no significant difference in late GI or GU toxicities of grade 2 or greater between the 3D-CRT and IMRT groups. The respective 4-year cumulative rates of toxicity in the 3D-CRT and IMRT groups were as follows: grade ≥2 GI toxicity, 8.8% and 4.4% (P = .42); grade ≥2 GU toxicity, 19.1% and 20.3% (P = .93); and grade ≥2 hematuria, 5.3% and 8.0% (P = .67). In the 3D-CRT group, the 8-year cumulative rates of GI toxicity, GU toxicity, and hematuria of grade 2 or greater were 8.8%, 28.4%, and 12.6%, respectively.

Conclusions

Dose-escalated IMRT showed no improvements in bNED or late toxicity compared with 3D-CRT. In addition, the results suggest that GU toxicity can occur after a long period (even after 6 years), whereas GI toxicity is seldom newly observed after 4 years.

Prognostic risk classification for biochemical relapse-free survival in patients with oligorecurrent prostate cancer after [68Ga]PSMA-PET-guided metastasis-directed therapy

PURPOSE

Since the success of prostate-specific membrane antigen-positron emission tomography (PSMA-PET) imaging for patients with oligorecurrent prostate cancer (ORPC), it is increasingly used for radiotherapy as metastasis-directed therapy (MDT). Therefore, we developed a prognostic risk classification for biochemical relapse-free survival (bRFS) for patients after PSMA-PET-guided MDT after radical prostatectomy.

METHODS

We analyzed 292 patients with local recurrence (LR) and/or pelvic lymph node (LN) lesions and/or up to five distant LN, bone (BM), or visceral metastases (VM) detected with [⁶⁸Ga]PSMA-PET imaging. Median follow-up was 16 months (range 0-57). The primary endpoint was bRFS after MDT. Cox regression analysis for risk factors was incorporated into a recursive partitioning analysis (RPA) with classification and regression tree method.

RESULTS

PSA at recurrence ≥ 0.8 ng/mL, BM, and VM was significantly associated with biochemical relapse. RPA showed five groups with tenfold cross-validation of 0.294 (SE 0.032). After building risk classes I to IV (p < 0.0001), mean bRFS was 36.3 months (95% CI 32.4-40.1) in class I (PSA < 0.8 ng/mL, no BM) and 25.8 months (95% CI 22.5-29.1) in class II (PSA ≥ 0.8 ng/mL, no BM, no VM). LR and/or pelvic LNs caused relapse in classes I and II. Mean bRFS was 16.0 months (95% CI 12.4-19.6) in class III (PSA irrelevant, present BM) and 5.7 months (95% CI 2.7-8.7) in class IV (PSA ≥ 0.8 ng/mL, no BM, present VM).

CONCLUSION

We developed and internally validated a risk classification for bRFS after PSMA-PET-guided MDT. Patients with PSA < 0.8 ng/mL and local relapse only (LR and/or pelvic LNs) had the most promising bRFS. PSA ≥ 0.8 ng/mL and local relapse only (LR and/or pelvic LNs) indicated intermediate risk for failure. Patients with BM were at higher risk regardless of the PSA. However, those patients still show satisfactory bRFS. In patients with VM, bRFS is heavily decreased. MDT in such cases should be discussed individually.

Adjuvant versus early salvage radiotherapy: outcome of patients with prostate cancer treated with postoperative radiotherapy after radical prostatectomy

Background

Adjuvant (ART) and salvage radiotherapy (SRT) are two common concepts to enhance biochemical relapse free survival (BCRFS) in patients with prostate cancer (PC). We analyzed differences in outcome between ART and SRT in patients with steep decline of PSA-levels after surgery to compare outcome.

Methods

We evaluated 253 patients treated with postoperative RT with a median age of 66 years (range 42–85 years) treated between 2004 and 2014. Patients with additive radiotherapy due to PSA persistence and patients in the SRT group, who did not achieve a postoperative PSA level <0.1 ng/mL were excluded. Hence, data of 179 patients was evaluated. We used propensity score matching to build homogenous groups. A Cox regression model was used to determine differences between treatment options. Median follow-up was 32.5 months (range 1.4–128.0 months).

Results

Early SRT at PSA levels <0.3 ng/mL was associated with significant longer BCRFS than late SRT (HR: 0.32, 95%-CI: 0.14–0.75, p = 0.009). Multiple Cox regression showed pre-RT PSA level, tumor stage, and Gleason score as predictive factors for biochemical relapse. In the overall group, patients treated with either ART or early SRT showed no significant difference in BCRFS (HR: 0.17, 95%-CI: 0.02–1.44, p = 0.1). In patients with locally advanced PC (pT3/4) BCRFS was similar in both groups as well (HR: 0.21, 95%-CI:0.02–1.79, p = 0.15).

Conclusion

For patients with PSA-triggered follow-up, close observation is essential and early initiation of local treatment at low PSA levels (<0.3 ng/mL) is beneficial. Our data suggest, that SRT administered at early PSA rise might be equieffective to postoperative ART in patients with locally advanced PC. However, the individual treatment decision must be based on any adverse risk factors and the patients’ postoperative clinical condition.

Study registration

The present work is approved by the Ethics Commission of the Technical University of Munich (TUM) and is registered with the project number 320/14.

Importance of the site of positive surgical margin in salvage external beam radiation therapy for biochemical recurrence of prostate cancer after radical prostatectomy

The aim of this study was to examine long‐term outcomes in patients who received salvage radiotherapy (SRT) for biochemical recurrence (BRec) of prostate cancer after radical prostatectomy (RP). One hundred and twenty patients with prostate cancer who underwent SRT for BRec after RP without evidence of clinical disease were identified in our institution from 2002 to 2014. Prescription doses to prostate beds were 64.8 Gy with a fractional dose of 1.8 Gy in 96.7% of the patients. In three‐dimensional conformal radiation therapy (3D‐CRT), the seminal vesicle bed (SVB) was not included in the radiation fields. The prognostic factors for BRec‐free survival (BRFS) and incidence of acute and late toxicities were investigated. Median follow‐up duration after SRT was 64.9 months. The 5‐year rates of BRFS, overall survival (OS), cause‐specific survival (CSS), and clinical recurrence‐free survival (CRFS) were 39.2%, 98.3%, 97.0%, and 91.9%, respectively. Only two patients experienced late grade 3 toxicity of hematuria. Multivariate analysis revealed that BRFS was significantly favorable in patients with prostate‐specific antigen (PSA) values <0.5 ng/mL at the initiation of SRT and pathological Gleason score not including Gleason grade 5. In patients treated with 3D‐CRT, a positive surgical margin at the base of the prostate influenced BRFS unfavorably in comparison with positive surgical margins at other sites. SRT for patients with BRec after RP was performed very safely in our institution. However, to improve BRFS, adequate inclusion of the SVB appears mandatory, especially in cases of positive surgical margins at the base of the prostate.

Adjuvant and Salvage Radiotherapy after Radical Prostatectomy in Prostate Cancer Patients

CONTEXT

Prostate cancer (PCa) patients found to have adverse pathologic features following radical prostatectomy (RP) are less likely to be cured with surgery alone.

OBJECTIVE

To analyze the role of postoperative radiotherapy (RT) in patients with aggressive PCa.

EVIDENCE ACQUISITION

We performed a systematic literature review of the Medline and EMBASE databases. The search strategy included the terms radical prostatectomy, adjuvant radiotherapy, and salvage radiotherapy, alone or in combination. We limited our search to studies published between January 2009 and August 2016.

EVIDENCE SYNTHESIS

Three randomized trials demonstrated that immediate RT after RP reduces the risk of recurrence in patients with aggressive PCa. However, immediate postoperative RT is associated with an increased risk of acute and late side effects ranging from 15% to 35% and 2% to 8%, respectively. Retrospective studies support the oncologic efficacy of initial observation followed by salvage RT administered at the first sign of recurrence; however, the impact of this delay on long-term control remains uncertain. Hopefully, ongoing randomized trials will shed light on the role of adjuvant RT versus observation±salvage RT in individuals with adverse features at RP. Accurate patient selection based on clinical characteristics and molecular profile is crucial. Dose escalation, whole-pelvis RT, novel techniques, and the use of hormonal therapy might improve the outcomes of postoperative RT.

CONCLUSIONS

Immediate RT reduces the risk of recurrence after RP in patients with aggressive disease. However, this approach is associated with an increase in the incidence of short- and long-term side effects. Observation followed by salvage RT administered at the first sign of recurrence might be associated with durable cancer control, but prospective randomized comparison with adjuvant RT is still awaited. Dose escalation, refinements in the technique, and the concomitant use of hormonal therapies might improve outcomes of patients undergoing postoperative RT.

PATIENT SUMMARY

Postoperative radiotherapy has an impact on oncologic outcomes in patients with aggressive disease characteristics. Salvage radiotherapy administered at the first sign of recurrence might be associated with durable cancer control in selected patients but might compromise cure in others.