Impact of timing on salvage radiation therapy adverse events following radical prostatectomy: A secondary analysis of the RTOG 9601 cohort

The Longitudinal Course of Prospectively Recorded Patient-reported Outcomes in Prostate Cancer Patients Treated with Surgery and Salvage Radiotherapy

Background

Patient-reported outcome measures (PROMs) after prostate cancer (PC) treatment, including both radical prostatectomy (RP) and salvage radiation therapy (SRT), are under-reported.

Objective

To investigate PROMs longitudinally from before SRT until 18 mo after SRT for men treated with contemporary treatment modalities.

Design setting and participants

This prospective, longitudinal cohort study included 120 men (whole cohort) treated with SRT administered with volumetric modulated arc radiotherapy from 2016 to 2021 at the University Hospital of North Norway. The whole cohort was followed from before SRT until 18 mo after SRT. A subcohort of 48 men was followed from before RP until 18 mo after SRT.

Outcome measurements and statistical analysis

PROMs were collected with the Expanded Prostate Cancer Index-26 (EPIC-26), covering symptoms of urinary incontinence, urinary irritative, bowel, sexual, and hormonal domains. The domain scores were inquired before RP, 3 mo after RP, before SRT, at SRT termination, and 3 and 18 mo after SRT. We used linear mixed models with repeated measurements design to assess changes in PROMs throughout the treatment period.

Results and limitations

The median age before SRT was 63 yr. For the whole cohort, all five domains worsened at 3 and 18 mo after SRT compared with those before SRT. The estimated mean changes from before SRT to 18 mo after SRT are as follows: urinary incontinence -13.1, urinary irritative function -10.4, bowel -16.8, sexual function -9.1, and hormonal function -20.2 (at clinically important levels for all domains but sexual). For the subcohort, the mean urinary incontinence, bowel, sexual, and hormonal functions were significantly worsened 3 and 18 mo after SRT compared with those before RP at clinically important levels.

Conclusions

Men treated for PC report particular increased severity of urinary, bowel, sexual, and hormonal symptoms after SRT compared with baseline status.

Patient summary

For men with prostate cancer, the treatment combination of surgery and salvage radiotherapy worsens urinary incontinence and bowel, sexual, and hormonal functions.

Anti-Androgen Therapy Overcomes the Time Delay in Initiation of Salvage Radiation Therapy and Rescues the Oncological Outcomes in Men with Recurrent Prostate Cancer After Radical Prostatectomy: A Post Hoc Analysis of the RTOG-9601 Trial Data

Background

It is unknown whether the addition of anti-androgen therapy (AAT) to late salvage radiation therapy (sRT) can lead to oncological outcomes equivalent to that of early sRT in men with recurrent prostate cancer (CaP) after surgery.

Methods

Data on 670 men who participated in the Radiation Therapy Oncology Group (RTOG)-9601 trial and who experienced biochemical recurrence were extracted using the National Clinical Trials Network (NCTN) data archive platform. Patients were stratified into four treatment groups: early sRT (pre-sRT prostate-specific antigen [PSA] < 0.7 ng/mL) and late sRT (pre-sRT PSA ≥ 0.7 ng/mL) with/without concomitant AAT, based on cut-offs reported in the original trial. Time-varying Cox proportional hazards and Fine–Gray competing-risk regression analyses assessed the adjusted hazards of overall mortality, CaP-specific mortality, and metastasis among the four treatment groups.

Results

At 15-years (median follow-up of 14.7 years), for patients treated with early sRT, early sRT with AAT, late sRT, and late sRT with AAT, the overall mortality, CaP-specific mortality, and metastasis rates were 22.9, 22.8, 40.1, and 22.9% (log-rank p = 0.0039), 12.1, 3.9, 22.7, and 8.0% (Gray’s p = 0.0004), and 18.8, 14.6, 35.9, and 19.5% (Gray’s p = 0.0004), respectively. Time-varying multivariable adjusted analysis demonstrated increased hazards of overall mortality in patients receiving delayed sRT versus early sRT (hazards ratio [HR] 1.49, 95% confidence interval [CI] 1.02–2.17); however, no difference remained after the addition of concomitant AAT to late sRT (HR 0.85, 95% CI 0.55–1.32, referent early sRT). Likewise, the hazards of cancer-specific mortality and metastatic progression were worse for late sRT when compared with early sRT, but were no different after the addition of AAT to late sRT.

Conclusions

Poorer outcomes associated with late sRT in men with recurrent CaP may be rescued by delivery of concomitant AAT.

Pathological stage, surgical margin and lymphovascular invasion as prognostic factors after salvage radiotherapy for post-prostatectomy relapsed prostate cancer - outcomes and optimization strategies

Background

Salvage radiotherapy (sRT) is the main potentially curative treatment after biochemical failure/locoregional relapse post-radical prostatectomy (RP). The aim of the study was to characterize the population who underwent sRT after RP at our Department, to understand the influence of several potential prognosis factors, and to determine possible optimization strategies.

Materials and methods

We retrospectively analyzed patients undergoing sRT at our department between 2012 and 2017, evaluating patient, tumor and treatment characteristics, restaging procedures and clinical outcomes - namely biochemical relapse-free survival (BC-RFS), clinical relapse-free survival (C-RFS), additional hormone therapy-free survival (HT-FS) and overall survival (OS). We assessed potential prognostic factors by univariate and multivariate models (MVA).

Results

We included 277 patients (median age 68 years). Median pre-sRT PSA was > 0.5ng/mL in 54.9%. All underwent prostate bed irradiation. Pelvic lymph nodes were included in 9.7%. Outcome analysis was performed for 264 patients (35.6 months median follow-up). At 3 years, BC-RFS was 61.4%, C-RFS was 81.3%, HT-FS was 79.9% and OS was 96.6%. Most relapses occurred in regional lymph nodes only (47.9% patients who relapsed). On MVA, lymphovascular invasion, advanced pT-stages and negative margins negatively influenced BC-RFS (p = 0.029, p = 0.002 and p < 0.001) and HT-FS (p = 0.001, p = 0.029 and p = 0.002). C-RFS was worsened by lymphovascular invasion (p = 0.009) and negative margins (p = 0.015). These had no effect on OS. BC-RFS and HT-FS were improved when sRT started while PSA ≤ 0.5 ng/mL (p < 0.05).

Conclusion

Lymphovascular invasion, higher pT-stages and negative margins negatively affected prognosis. An early start of sRT (PSA ≤ 0.5 ng/mL) predicted better BC-RFS and HT-FS.

Identification of patients at risk for biochemical recurrence after radical prostatectomy with intra-operative frozen section

OBJECTIVE

To identify patients at risk for biochemical recurrence (BCR) of prostate cancer (PCa) after radical prostatectomy (RP) with intra-operative whole-mount frozen section (FS) of the prostate.

MATERIAL AND METHODS

We examined differences in BCR between patients with initial negative surgical margins at FS, patients with final negative surgical margins with initial positive margins at FS without residual PCa after secondary tumour resection, and patients with final negative surgical margins with initially positive margins at FS with residual PCa in the secondary tumour resection specimen. Institutional data of 883 consecutive patients undergoing RP were collected. Intra-operative whole-mount FS was routinely used to check for margin status and, if necessary, to resect more periprostatic tissue in order to achieve negative margins. Patients with lymph node-positive disease or final positive surgical margins were excluded from the analysis. Kaplan-Meier curves and multivariable Cox proportional hazards regression analyses adjusting for clinical covariates were employed to examine differences in biochemical recurrence-free survival (BRFS) according to the resection status mentioned above.

RESULTS

The median follow-up was 22.4 months. The 1- and 2-year BRFS rates in patients with (81.0% and 72.9%, respectively; P = 0.001) and without residual PCa (90.3% and 82.3%, respectively; P = 0.033) after secondary tumour resection were significantly lower compared to patients with initial R0 status (93.4% and 90.9%, respectively). On multivariable Cox regression only residual PCa in the secondary tumour resection was associated with a higher risk of BCR compared to initial R0 status (hazard ratio 1.99, 95% confidence interval 1.01-3.92; P = 0.046).

CONCLUSION

Despite being classified as having a negative surgical margin, patients with residual PCa in the secondary tumour resection specimen face a high risk of BCR. These findings warrant closer post-RP surveillance of this particular subgroup. Further research of this high-risk subset of patients should focus on examining whether these patients benefit from early salvage therapy and how resection status impacts oncological outcomes in the changing landscape of PCa treatment.