Prognostic Significance of Immune Cell Infiltration in Muscle-invasive Bladder Cancer Treated with Definitive Chemoradiation: A Secondary Analysis of RTOG 0524 and RTOG 0712

Chemoradiation therapy (CRT) is a treatment for muscle-invasive bladder cancer (MIBC). Using a novel transcriptomic profiling panel, we validated prognostic immune biomarkers to CRT using 70 pretreatment tumor samples from prospective trials of MIBC (NRG/RTOG 0524 and 0712). Disease-free survival (DFS) and overall survival (OS) were estimated via the Kaplan-Meier method and stratified by genes correlated with immune cell activation. Cox proportional-hazards models were used to assess group differences. Clustering of gene expression profiles revealed that the cluster with high immune cell content was associated with longer DFS (hazard ratio [HR] 0.53, 95% confidence interval [CI] 0.26-1.10; p = 0.071) and OS (HR 0.48, 95% CI 0.24-0.97; p = 0.040) than the cluster with low immune cell content. Higher expression of T-cell infiltration genes (CD8A and ICOS) was associated with longer DFS (HR 0.40, 95% CI 0.21-0.75; p = 0.005) and OS (HR 0.49, 95% CI 0.25-0.94; p = 0.033). Higher IDO1 expression (IFNγ signature) was also associated with longer DFS (HR 0.44, 95% CI 0.24-0.88; p = 0.021) and OS (HR 0.49, 95% CI 0.24-0.99; p = 0.048). These findings should be validated in prospective CRT trials that include biomarkers, particularly for trials incorporating immunotherapy for MIBC. PATIENT SUMMARY: We analyzed patient samples from two clinical trials (NRG/RTOG 0524 and 0712) of chemoradiation for muscle-invasive bladder cancer using a novel method to assess immune cells in the tumor microenvironment. Higher expression of genes associated with immune activation and high overall immune-cell content were associated with better disease-free survival and overall survival for patients treated with chemoradiation.

Long-term Outcomes of Chemoradiation for Muscle-invasive Bladder Cancer in Noncystectomy Candidates. Final Results of NRG Oncology RTOG 0524-A Phase 1/2 Trial of Paclitaxel + Trastuzumab with Daily Radiation or Paclitaxel Alone with Daily Irradiation

BACKGROUND

Chemo-radiation is a well-established alternative to radical cystectomy in patients with muscle-invasive bladder cancer. Many patients due to age or medical comorbidity are unfit for either radical cystectomy, or standard cisplatin- or 5-fluorouracil-based chemoradiation, and do not receive appropriate treatment with curative intent. We treated patients with a less aggressive protocol employing seven weekly doses of paclitaxel and daily irradiation. In those whose tumors showed overexpression of her2/neu, seven weekly doses of trastuzumab were also administered.

OBJECTIVE

To report the long-term survival outcomes and toxicity results of the of NRG Oncology RTOG 0524 study.

DESIGN, SETTING, AND PARTICIPANTS

Seventy patients were enrolled and 65 (median age: 76 yr) were deemed eligible. Patients were assigned to daily radiation and weekly paclitaxel + trastuzumab (group 1, 20 patients) or to daily radiation plus weekly paclitaxel (group 2, 45 patients) based on tumor her2/neu overexpression. Radiation was delivered in 1.8 Gy fractions to a total dose of 64.8 Gy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was unresolved treatment-related toxicity. The secondary endpoints were complete response rate, protocol completion rate, and disease-free and overall survival.

RESULTS AND LIMITATIONS

Protocol therapy was completed by 60% (group 1) and 76% (group 2); complete response rates at 12 wk were 62% in each group. Acute treatment-related adverse events (AEs) of grade ≥3 were observed in 80% in group 1 and 58% in group 2. There was one treatment-related grade 5 AE in group 1. Unresolved acute treatment-related toxicity was 35% in group 1 and 31% in group 2. The median follow-up was 2.3 yr in all patients and 7.2 yr in surviving patients. Overall survival at 5 yr was 25.0% in group 1 and 37.8% in group 2 (33.8% overall). At 5 yr, disease-free survival was 15.0% in group 1 and 31.1% in group 2.

CONCLUSIONS

In a cohort of patients with muscle-invasive bladder cancer who are not candidates for cystectomy or cisplatin chemotherapy, chemoradiation therapy offers a treatment with a significant response rate and 34% 5-yr overall survival. While there were many AEs in this medically fragile group, there were few grade 4 events and one grade 5 event attributable to therapy.

PATIENT SUMMARY

Patients with invasive bladder cancer who cannot tolerate surgery were treated with radiation and systemic therapy without surgically removing their bladders. Most patients tolerated the treatment, were able to keep their bladders, and showed a significant treatment response rate.

Cardiovascular Mortality and Duration of Androgen Deprivation in Locally Advanced Prostate Cancer: Long-term Update of NRG/RTOG 9202

BACKGROUND

Androgen deprivation therapy (ADT) has been associated with coronary heart disease and myocardial infarction (MI) in prostate cancer patients, but controversy persists regarding its effects on cardiovascular mortality (CVM).

OBJECTIVE

We assessed the long-term relationship between ADT and CVM in a prostate cancer randomized trial (NRG Oncology/Radiation Therapy Oncology Group 9202).

DESIGN, SETTING, AND PARTICIPANTS

From 1992 to 1995, 1554 men with locally advanced prostate cancer (T2c-T4, prostate-specific antigen <150 ng/ml) received radiotherapy with 4 mo (short-term [STADT]) versus 28 mo (longer-term [LTADT]) of ADT.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Using the Fine-Gray and Cox regression models, the relationship between ADT and mortality was evaluated.

RESULTS AND LIMITATIONS

With a median follow-up of 19.6 yr, LTADT was associated with improved overall survival (OS) versus STADT (adjusted hazard ratio [HR] 0.88; p = 0.03) and prostate cancer survival (subdistribution HR [sHR] 0.70, p = 0.003). Comparing LTADT with STADT, prostate cancer mortality improved by 6.0% (15.6% [95% confidence interval 13.0-18.3%] vs 21.6% [18.6-24.7%]) at 15 yr, while CVM increased by 2.2% (14.9% [12.4-17.6%] vs 12.7% [10.4-15.3%]). In multivariable analyses, LTADT was not associated with increased CVM versus STADT (sHR 1.22 [0.93-1.59]; p = 0.15). An association between LTADT and MI death was detected (sHR 1.58 [1.00-2.50]; p = 0.05), particularly in patients with prevalent cardiovascular disease (CVD; sHR 2.54 [1.16-5.58]; p = 0.02).

CONCLUSIONS

With 19.6 yr of follow-up, LTADT was not significantly associated with increased CVM in men with locally advanced prostate cancer. Patients may have increased MI mortality with LTADT, particularly those with baseline CVD. Overall, there remained a prostate cancer mortality benefit and no OS detriment with LTADT.

PATIENT SUMMARY

In a long-term analysis of a large randomized prostate cancer trial, radiation with 28 mo of hormone therapy did not increase the risk of cardiovascular death significantly versus 4 mo of hormone therapy. Future studies are needed for patients with pre-existing heart disease, who may have an increased risk of myocardial infarction death with longer hormone use.

Genomic Tumor Correlates of Clinical Outcomes Following Organ-Sparing Chemoradiation Therapy for Bladder Cancer

PURPOSE

There is an urgent need for biomarkers of radiation response in organ-sparing therapies. Bladder preservation with trimodality therapy (TMT), consisting of transurethral tumor resection followed by chemoradiation, is an alternative to radical cystectomy for muscle-invasive bladder cancer (MIBC), but molecular determinants of response are poorly understood.

EXPERIMENTAL DESIGN

We characterized genomic and transcriptomic features correlated with long-term response in a single institution cohort of patients with MIBC homogeneously treated with TMT. Pretreatment tumors from 76 patients with MIBC underwent whole-exome sequencing; 67 underwent matched transcriptomic profiling. Molecular features were correlated with clinical outcomes including modified bladder-intact event-free survival (mBI-EFS), a composite endpoint that reflects long-term cancer control with bladder preservation.

RESULTS

With a median follow-up of 74.6 months in alive patients, 37 patients had favorable long-term response to TMT while 39 had unfavorable long-term response. Tumor mutational burden was not associated with outcomes after TMT. DNA damage response gene alterations were associated with improved locoregional control and mBI-EFS. Of these alterations, somatic ERCC2 mutations stood out as significantly associated with favorable long-term outcomes; patients with ERCC2 mutations had significantly improved mBI-EFS [HR, 0.15; 95% confidence interval (CI), 0.06-0.37; P = 0.030] and improved BI-EFS, an endpoint that includes all-cause mortality (HR, 0.33; 95% CI, 0.15-0.68; P = 0.044). ERCC2 mutant bladder cancer cell lines were significantly more sensitive to concurrent cisplatin and radiation treatment in vitro than isogenic ERCC2 wild-type cells.

CONCLUSIONS

Our data identify ERCC2 mutation as a candidate biomarker associated with sensitivity and long-term response to chemoradiation in MIBC. These findings warrant validation in independent cohorts.

Prognostic Significance of Pretreatment Immune Cell Infiltration in Muscle Invasive Bladder Cancer Treated with Definitive Chemoradiation: Analysis of NRG RTOG 0524 and 0712

PURPOSE/OBJECTIVE(S)

Chemoradiation therapy (CRT) is an organ conserving approach in the treatment of locally advanced bladder cancer. Chemoradiation is thought to potentially result in immunogenic stimulation, and bladder cancer is often a tumor with high immune cell infiltration. Thus, we aimed to profile the tumor immune microenvironment of bladder cancer and identify prognostic immune biomarkers for CRT response by profiling tumor samples from NRG/RTOG 0524 and 0712, two prospective trials of CRT in muscle invasive bladder cancer (MIBC).

MATERIALS/METHODS

Pretreatment tissue samples from both trials were profiled using Cofactor Genomics ImmunoPrism, an RNA sequencing assay that uses gene expression profiles to quantify immune cell populations in the tumor microenvironment (TME). Differential gene expression was estimated for different immune cell type proportions across samples. Kaplan-Meier survival analysis and log rank tests were performed to evaluate differences in overall survival (OS) stratified by genes influenced by immune cell proportions or genes associated with immune response signatures.

RESULTS

A total of 70 samples (43 from RTOG 0524 and 27 from RTOG 0712) underwent analysis using the ImmunoPrism assay. Immune cell proportions were as follows: CD8 T cells: median 1.2%, CD4 T cells: median 0.8%, Treg cells: median 9.2%, CD19 B cells: median 5.1%, M2 macrophages: median 0.8%, M1 macrophages: median 0%. Unbiased clustering based on gene expression profiles driven by immune cell proportions demonstrated two groups: cluster 1 with a low percentage of immune cells and shorter OS (median 31 months) and cluster 2 with a high percentage of immune cells and longer OS (median 101 months, p = 0.036). Higher expression of genes associated with T cell infiltration (CD8A and ICOS) was associated with improved OS (104 vs 35 months, p = 0.028, HR = 0.48 (0.25 - 0.94), p = 0.031) as was higher expression of IDO1, which is associated with the interferon gamma pathway (104 vs 35 months, p = 0.042, HR = 0.49 (0.24 - 0.99), p = 0.046).

CONCLUSION

Bladder tumors have a wide range of immune cell infiltration in the TME. Increased immune cell proportions are prognostic for OS following CRT, as well as a higher expression of genes associated with T cell infiltration interferon gamma signaling. These findings have implications for the integration of immunotherapy in the definitive management of MIBC; and can be explored further in the ongoing NRG/SWOG 1806 trial.

Analysis of a Biopsy-Based Genomic Classifier in High-Risk Prostate Cancer: Meta-Analysis of the NRG Oncology/Radiation Therapy Oncology Group 9202, 9413, and 9902 Phase 3 Randomized Trials

PURPOSE

Decipher is a genomic classifier (GC) prospectively validated postprostatectomy. We validated the performance of the GC in pretreatment biopsy samples within the context of 3 randomized phase 3 high-risk definitive radiation therapy trials.

METHODS AND MATERIALS

A prespecified analysis plan (NRG-GU-TS006) was approved to obtain formalin-fixed paraffin-embedded tissue from biopsy specimens from the NRG biobank from patients enrolled in the NRG/Radiation Therapy Oncology Group (RTOG) 9202, 9413, and 9902 phase 3 randomized trials. After central review, the highest-grade tumors were profiled on clinical-grade whole-transcriptome arrays and GC scores were obtained. The primary objective was to validate the independent prognostic ability for the GC for distant metastases (DM), and secondary for prostate cancer-specific mortality (PCSM) and overall survival (OS) with Cox univariable and multivariable analyses.

RESULTS

GC scores were obtained on 385 samples, of which 265 passed microarray quality control (69%) and had a median follow-up of 11 years (interquartile range, 9-13). In the pooled cohort, on univariable analysis, the GC was shown to be a prognostic factor for DM (per 0.1 unit; subdistribution hazard ratio [sHR], 1.29; 95% confidence interval [CI], 1.18-1.41; P < .001), PCSM (sHR, 1.28; 95% CI, 1.16-1.41; P < .001), and OS (hazard ratio [HR], 1.16; 95% CI, 1.08-1.22; P < .001). On multivariable analyses, the GC (per 0.1 unit) was independently associated with DM (sHR, 1.22; 95% CI, 1.09-1.36), PCSM (sHR, 1.23; 95% CI, 1.09-1.39), and OS (HR, 1.12; 95% CI, 1.05-1.20) after adjusting for age, Prostate Specific Antigen, Gleason score, cT stage, trial, and randomized treatment arm. GC had similar prognostic ability in patients receiving short-term or long-term androgen-deprivation therapy, but the absolute improvement in outcome varied by GC risk.

CONCLUSIONS

This is the first validation of a gene expression biomarker on pretreatment prostate cancer biopsy samples from prospective randomized trials and demonstrates an independent association of GC score with DM, PCSM, and OS. High-risk prostate cancer is a heterogeneous disease state, and GC can improve risk stratification to help personalize shared decision making.

Analysis of MRE11 and Mortality Among Adults With Muscle-Invasive Bladder Cancer Managed With Trimodality Therapy

IMPORTANCE

Bladder-preserving trimodality therapy can be an effective alternative to radical cystectomy for treatment of muscle-invasive bladder cancer (MIBC), but biomarkers are needed to guide optimal patient selection. The DNA repair protein MRE11 is a candidate response biomarker that has not been validated in prospective cohorts using standardized measurement approaches.

OBJECTIVE

To evaluate MRE11 expression as a prognostic biomarker in MIBC patients receiving trimodality therapy using automated quantitative image analysis.

DESIGN, SETTING, AND PARTICIPANTS

This prognostic study analyzed patients with MIBC pooled from 6 prospective phase I/II, II, or III trials of trimodality therapy (Radiation Therapy Oncology Group [RTOG] 8802, 8903, 9506, 9706, 9906, and 0233) across 37 participating institutions in North America from 1988 to 2007. Eligible patients had nonmetastatic MIBC and were enrolled in 1 of the 6 trimodality therapy clinical trials. Analyses were completed August 2020.

EXPOSURES

Trimodality therapy with transurethral bladder tumor resection and cisplatin-based chemoradiation therapy.

MAIN OUTCOMES AND MEASURES

MRE11 expression and association with disease-specific (bladder cancer) mortality (DSM), defined as death from bladder cancer. Pretreatment tumor tissues were processed for immunofluorescence with anti-MRE11 antibody and analyzed using automated quantitative image analysis to calculate a normalized score for MRE11 based on nuclear-to-cytoplasmic (NC) signal ratio.

RESULTS

Of 465 patients from 6 trials, 168 patients had available tissue, of which 135 were analyzable for MRE11 expression (median age of 65 years [minimum-maximum, 34-90 years]; 111 [82.2%] men). Median (minimum-maximum) follow-up for alive patients was 5.0 (0.6-11.7) years. Median (Q1-Q3) MRE11 NC signal ratio was 2.41 (1.49-3.34). Patients with an MRE11 NC ratio above 1.49 (ie, above first quartile) had a significantly lower DSM (HR, 0.50; 95% CI, 0.26-0.93; P = .03). The 4-year DSM was 41.0% (95% CI, 23.2%-58.0%) for patients with an MRE11 NC signal ratio of 1.49 or lower vs 21.0% (95% CI, 13.4%-29.8%) for a ratio above 1.49. MRE11 NC signal ratio was not significantly associated with overall survival (HR, 0.84; 95% CI, 0.49-1.44).

CONCLUSIONS AND RELEVANCE

Higher MRE11 NC signal ratios were associated with better DSM after trimodality therapy. Lower MRE11 NC signal ratios identified a poor prognosis subgroup that may benefit from intensification of therapy.

Biochemical Failure Is Not a Surrogate End Point for Overall Survival in Recurrent Prostate Cancer: Analysis of NRG Oncology/RTOG 9601

PURPOSE

Metastasis-free survival (MFS), but not event-free survival, is a validated surrogate end point for overall survival (OS) in men treated for localized prostate cancer. It remains unknown if this holds true in biochemically recurrent disease after radical prostatectomy. Leveraging NRG/RTOG 9601, we aimed to determine the performance of intermediate clinical end points (ICEs) as surrogate end points for OS in recurrent prostate cancer.

MATERIALS AND METHODS

NRG/RTOG 9601 randomly assigned 760 men with recurrence after prostatectomy to salvage radiation therapy with 2 years of placebo versus bicalutamide 150 mg daily. ICEs assessed were biochemical failure (BF) per NRG/RTOG 9601 (prostate-specific antigen nadir + 0.3-0.5 ng/mL or initiation of salvage hormone therapy; [BF1]) and NRG/RTOG 0534 (prostate-specific antigen nadir+2 ng/mL; [BF2]), distant metastasis (DM), and MFS (DM or death). Surrogacy was assessed by the Prentice criteria and a two-stage meta-analytic approach (condition one assessed at the patient level with Kendall's τ and condition two assessed by randomly dividing the entire trial cohort into 10 pseudo trial centers and calculating the average R2 between treatment hazard ratios for ICE and OS).

RESULTS

BF1, BF2, DM, and MFS satisfied the four Prentice criteria. However, with the two-condition meta-analytic approach, there was strong correlation between MFS and OS (τ = 0.86), moderate correlation between DM and OS (τ = 0.66), and weaker correlation between BF1 (τ = 0.25) or BF2 (τ = 0.40) and OS. Similarly, for condition two, the treatment effect of antiandrogen therapy on MFS and OS were correlated (R2 = 0.67), but this was not true for BF1 (R2 = 0.09), BF2 (R2 = 0.12), or DM (R2 = 0.18) and OS.

CONCLUSION

MFS is also a strong surrogate for OS in men receiving salvage radiation therapy for recurrence after prostatectomy. Caution should be used when inferring survival benefit from effects on BF in biochemically recurrent prostate cancer. Lack of comorbidity data did not allow us to assess whether BF in men with no/minimal comorbidity could serve as a surrogate for OS.

Impact of lymph node yield at prostatectomy on outcomes in NRG/RTOG 9601

265

Background: A recent study ( Fossati et al, 2018) found that higher lymph node count at radical prostatectomy was associated with improved outcomes in patients treated with salvage radiation for elevated prostate-specific antigen (PSA) after surgery. We sought to validate these results in NRG/RTOG 9601, a randomized controlled trial of men with pT2/T3 disease who underwent either radiation (RT) alone or RT+antiandrogen (bicalutamide) therapy for PSA elevation following radical prostatectomy from 1998-2003. Methods: We reviewed available pathology reports for all patients in NRG/RTOG 9601 to determine the nodal count at radical prostatectomy. Clinical data was as of 11/5/2015, same as the primary endpoint for the trial. Cox proportional hazards models were used to assess the effect of number of positive lymph nodes, treatment arm (RT alone or RT+bicalutamide), Gleason score, positive margins, and seminal vesicle invasion on the following endpoints: times to local and distant failure and overall and disease specific survival. Results: Out of the 760 patients originally eligible in the trial, 552 (73%, 276 in each arm) had complete data available. Median node count in the entire cohort was 6 (range 0-33, Q1-Q3 3-9). There were no significant differences between treatment arms in terms of patient demographic or clinical characteristics, including total lymph nodes removed in either arm (RT alone vs RT+bicalutamide median 5 vs 6, p = 0.11). There was no significant association between total lymph nodes and overall survival with both arms combined (HR = 1.00, 95% CI:0.97-1.03, p = 0.87) or in the individual arms alone (RT+Casodex: HR = 1.01, 95% CI:0.97-1.05, p = 0.65; RT+Placebo: HR = 0.98, 95% CI: 0.94-1.03, p = 0.45). There was also no significant association between total lymph nodes and disease-specific survival with both arms combined (HR = 1.00, 95% CI:0.95-1.04, p = 0.84) and in the arms alone (RT+Casodex: HR = 1.00, 95% CI:0.95-1.05, p = 0.92; RT+Placebo: HR = 0.99, 95% CI: 0.92-1.07, p = 0.86). In multivariable analysis performed on the two arms, Gleason score was the only feature associated with worse overall and disease-specific survival, seen only in the RT alone arm. Similar findings were seen when evaluating times to local and distant failure. Conclusions: Lymph node yield in NRG/RTOG 9601 did not show any association with adverse outcomes in the entire cohort, or in either treatment arm alone. The therapeutic benefit of an extensive lymph node dissection in this population remains uncertain. Clinical trial information: NCT00002874.

Multi-institutional matched comparison of radical cystectomy to trimodality therapy for muscle-invasive bladder cancer

433

Background: Prior randomized controlled trials (RCT) comparing bladder preservation to radical cystectomy (RC) for muscle invasive bladder cancer (MIBC) closed early due to lack of accrual. Given that no future RCTs are foreseen, and in the absence of level 1 data, we aimed to provide the best evidence possible on outcomes of matched cohorts comparing trimodality therapy (TMT, maximal transurethral resection of bladder tumor followed by concurrent chemoradiation) to RC in order to guide management. Methods: This retrospective analysis included 703 patients with MIBC clinical stage T2-T3/4aN0M0 MIBC urothelial carcinoma of the bladder, 421 RC and 282 TMT who would have been eligible for both TMT or RC, treated at the Massachusetts General Hospital, Boston; Princess Margaret Cancer Centre, Toronto; and University of Southern California, Los Angeles between 2005-2017. To compare homogeneous cohorts, all patients included in this analysis had solitary tumors < 7 cm, no or unilateral hydronephrosis, and no multifocal carcinoma in situ. Treatment propensity scores were estimated using logistic regression, and patients were matched 3:1 with replacement. Covariates included age, sex, clinical T stage, hydronephrosis, (neo)adjuvant chemotherapy, body mass index, smoking history, and ECOG status. Overall survival (OS) was estimated with adjusted Cox models; cancer-specific survival (CSS), distant failure-free survival, pelvic nodal failure-free survival and metastasis-free survival (combined distant and pelvic nodal failure) were estimated with adjusted competing risk models. Our primary endpoint of interest was metastasis-free survival. The analysis was performed as intent-to-treat. Results: The 3:1 matched cohort comprised of 1,116 patients (834 RC vs 282 TMT). After matching, age (71.3 vs 71.6), cT2 clinical stage (88 vs 90%), presence of hydronephrosis (12 vs 10%), and use of (neo)adjuvant chemotherapy (60 vs 65%) were similar between RC and TMT cohorts. Salvage cystectomy was performed in 38 patients (13%) treated by TMT. At 5 years, metastasis-free (73 vs 78%, p = 0.07), distant failure-free (78 vs 82%, p = 0.14), and pelvic nodal failure-free (96 vs 94%, p = 0.33) survival were not statistically different between RC and TMT, whereas CSS and OS favored TMT (78 vs 85%, p = 0.02; 70 vs 78%, p < 0.001). Outcomes for RC and TMT were not different among centers. Final pT stage in the RC patients was: pT0 14%, pT1 7%, pT2 29%, pT3/4 42% and N+ 24%. Peri RC mortality was 2.1% and median number of nodes removed was 40. NMIBC recurrence occurred in 57/278 (20.5%) TMT patients. Conclusions: This large multi-institutional contemporary study provides the best evidence to date, in the absence of randomized trials, supporting TMT for select patients with MIBC. Oncologic outcomes seem to be equivalent between TMT and RC, affirming the position that TMT should be offered as an effective alternative.

Adding Short-Term Androgen Deprivation Therapy to Radiation Therapy in Men With Localized Prostate Cancer: Long-Term Update of the NRG/RTOG 9408 Randomized Clinical Trial

PURPOSE

For men with localized prostate cancer, NRG Oncology/Radiation Therapy Oncology Group (RTOG) 9408 demonstrated that adding short-term androgen deprivation therapy (ADT) to radiation therapy (RT) improved the primary endpoint of overall survival (OS) and improved disease-specific mortality (DSM), biochemical failure (BF), local progression, and freedom from distant metastases (DM). This study was performed to determine whether the short-term ADT continued to improve OS, DSM, BF, and freedom from DM with longer follow-up.

METHODS AND MATERIALS

From 1994 to 2001, NRG/RTOG 9408 randomized 2028 men from 212 North American institutions with T1b-T2b, N0 prostate adenocarcinoma and prostate-specific antigen (PSA) ≤20ng/mL to RT alone or RT plus short-term ADT. Patients were stratified by PSA, tumor grade, and surgical versus clinical nodal staging. ADT was flutamide with either goserelin or leuprolide for 4 months. Prostate RT (66.6 Gy) was started after 2 months. OS was calculated at the date of death from any cause or at last follow-up. Secondary endpoints were DSM, BF, local progression, and DM. Acute and late toxic effects were assessed using RTOG toxicity scales.

RESULTS

Median follow-up in surviving patients was 14.8 years (range, 0.16-21.98). The 10-year and 18-year OS was 56% and 23%, respectively, with RT alone versus 63% and 23% with combined therapy (HR 0.94; 95% confidence interval [CI], 0.85-1.05; P = .94). The hazards were not proportional (P = .003). Estimated restricted mean survival time at 18 years was 11.8 years (95% CI, 11.4-12.1) with combined therapy versus 11.3 years with RT alone (95% CI, 10.9-11.6; P = .05). The 10-year and 18-year DSM was 7% and 14%, respectively, with RT alone versus 3% and 8% with combined therapy (HR 0.56; 95% CI, 0.41-0.75; P < .01). DM and BF favored combined therapy at 18 years. Rates of late grade ≥3 hepatic, gastrointestinal, and genitourinary toxicity were ≤1%, 3%, and 8%, respectively, with combined therapy versus ≤1%, 2%, and 5% with RT alone.

CONCLUSIONS

Further follow-up demonstrates that OS converges at approximately 15 years, by which point the administration of 4 months of ADT had conferred an estimated additional 6 months of life.

Validation of a 22-Gene Genomic Classifier in Patients With Recurrent Prostate Cancer: An Ancillary Study of the NRG/RTOG 9601 Randomized Clinical Trial

Question

Can a genomic biomarker estimate the risk of prostate cancer clinical end points in men who received salvage radiation for rising prostate-specific antigen levels after surgery?

Findings

In this ancillary study of 352 men randomized to placebo or hormone therapy in the NRG/RTOG 9601 clinical trial of salvage radiation, the Decipher genomic classifier was independently associated with the risk of metastasis, prostate cancer–specific mortality, and overall survival.

Meaning

These findings suggest that the Decipher genomic classifier is a promising biomarker to risk stratify men to better enable hormone therapy treatment decisions for biochemical recurrence of their prostate cancer after surgery.

Importance

Decipher (Decipher Biosciences Inc) is a genomic classifier (GC) developed to estimate the risk of distant metastasis (DM) after radical prostatectomy (RP) in patients with prostate cancer.

Objective

To validate the GC in the context of a randomized phase 3 trial.

Design, Setting, and Participants

This ancillary study used RP specimens from the phase 3 placebo-controlled NRG/RTOG 9601 randomized clinical trial conducted from March 1998 to March 2003. The specimens were centrally reviewed, and RNA was extracted from the highest-grade tumor available in 2019 with a median follow-up of 13 years. Clinical-grade whole transcriptomes from samples passing quality control were assigned GC scores (scale, 0-1). A National Clinical Trials Network–approved prespecified statistical plan included the primary objective of validating the independent prognostic ability of GC for DM, with secondary end points of prostate cancer–specific mortality (PCSM) and overall survival (OS). Data were analyzed from September 2019 to December 2019.

Intervention

Salvage radiotherapy (sRT) with or without 2 years of bicalutamide.

Main Outcomes and Measures

The preplanned primary end point of this study was the independent association of the GC with the development of DM.

Results

In this ancillary study of specimens from a phase 3 randomized clinical trial, GC scores were generated from 486 of 760 randomized patients with a median follow-up of 13 years; samples from a total of 352 men (median [interquartile range] age, 64.5 (60-70) years; 314 White [89.2%] participants) passed microarray quality control and comprised the final cohort for analysis. On multivariable analysis, the GC (continuous variable, per 0.1 unit) was independently associated with DM (hazard ratio [HR], 1.17; 95% CI, 1.05-1.32; P = .006), PCSM (HR, 1.39; 95% CI, 1.20-1.63; P < .001), and OS (HR, 1.17; 95% CI, 1.06-1.29; P = .002) after adjusting for age, race/ethnicity, Gleason score, T stage, margin status, entry prostate-specific antigen, and treatment arm. Although the original planned analysis was not powered to detect a treatment effect interaction by GC score, the estimated absolute effect of bicalutamide on 12-year OS was less when comparing patients with lower vs higher GC scores (2.4% vs 8.9%), which was further demonstrated in men receiving early sRT at a prostate-specific antigen level lower than 0.7 ng/mL (−7.8% vs 4.6%).

Conclusions and Relevance

This ancillary validation study of the Decipher GC in a randomized trial cohort demonstrated association of the GC with DM, PCSM, and OS independent of standard clinicopathologic variables. These results suggest that not all men with biochemically recurrent prostate cancer after surgery benefit equally from the addition of hormone therapy to sRT.

Trial Registration

ClinicalTrials.gov identifier: NCT00002874

Short-term adjuvant versus neoadjuvant hormone therapy in localized prostate cancer: A pooled individual patient analysis of two phase III trials

5584

Background: The timing of systemic therapy in relation to radiotherapy (RT) is important in most malignancies. In contrast, androgen deprivation therapy (ADT) has largely been investigated in relation to its duration rather than its sequencing with RT. Herein, we conduct the first combined individual patient analysis of two phase III randomized trials to determine the optimal timing of ADT with RT in localized prostate cancer (PCa). Methods: Individual patient data was obtained from the Malone et al trial (JCO 2019), which randomized patients to receive neoadjuvant/concurrent or concurrent/adjuvant ADT for 6 months with prostate only RT. This was combined with the prostate only RT arms of RTOG 9413 that randomized patients to 4 months of neoadjuvant/concurrent or adjuvant ADT. The neoadjuvant/concurrent arms of both trials were combined into the “neoadjuvant” group, and the concurrent/adjuvant (Malone) and adjuvant arm (RTOG 9413) were combined in the “adjuvant” group. The Kaplan-Meier method was used to estimate overall survival (OS) and progression-free survival (PFS). Cumulative incidence of distant metastasis (DM), PCa-specific mortality (PCSM) and biochemical failure (BF) were calculated using the Fine-Gray method with non-PCa deaths as competing events. Late genitourinary (GU) and gastrointestinal (GI) toxicity are also reported. Results: The median follow-up was 14.9 years (yrs) and 1065 patients were included (n=531 neoadjuvant, 534 adjuvant). Groups were well balanced for all baseline characteristics. Adjuvant ADT was superior to neoadjuvant ADT in terms of BF (15yr: 33% vs 43%, HR: 1.37 (95%CI: 1.12-1.68), p=0.002), DM (15yr: 12% vs 18%, HR: 1.40 (95%CI: 1.00-1.95), p=0.04), and PFS (15yr: 36% vs 29%, HR: 1.25 (95%CI: 1.07-1.47), p=0.01). Adjuvant ADT yielded lower PCSM (15yr: 15% vs 20%, HR: 1.29 (95%CI: 0.95-1.75), p=0.10), but did not reach statistical significance. This approached statistical significance in high risk PCa (HR 1.39 (95%CI 1.00-1.93), p=0.053). OS was not significantly different between arms (15yr: 39% vs 34%, HR: 1.11 (95%CI: 0.95-1.30), p=0.20). There was no significant difference in either late grade ≥3 GI (p=0.21) or GU (p=0.98) toxicity. Conclusions: We demonstrate for the first time that sequencing of ADT with RT significantly impacts long-term oncologic outcomes in localized PCa, favoring an adjuvant rather than neoadjuvant approach, without increasing late toxicity. This data has important implications to ongoing and future clinical trial design. Clinical trial information: NCT00769548 .

Association of Presalvage Radiotherapy PSA Levels After Prostatectomy With Outcomes of Long-term Antiandrogen Therapy in Men With Prostate Cancer

Importance

In men with recurrent prostate cancer, addition of long-term antiandrogen therapy to salvage radiotherapy (SRT) was associated with overall survival (OS) in the NRG/RTOG 9601 study. However, hormone therapy has associated morbidity, and there are no validated predictive biomarkers to identify which patients derive most benefit from treatment.

Objective

To examine the role of pre-SRT prostate-specific antigen (PSA) levels to personalize hormone therapy use with SRT.

Interventions

Men were randomized to SRT plus high-dose nonsteroidal antiandrogen (bicalutamide, 150 mg/d) or placebo for 2 years.

Design, Setting, and Participants

In this secondary analysis of the multicenter RTOG 9601 double-blind, placebo-controlled randomized clinical trial conducted from 1998 to 2003 by a multinational cooperative group, men with a positive surgical margin or pathologic T3 disease after radical prostatectomy with pre-SRT PSA of 0.2 to 4.0 ng/mL were included. Analysis was performed between March 4, 2019, and December 20, 2019.

Main Outcomes and Measures

The primary outcome was overall survival (OS). Secondary end points included distant metastasis (DM), other-cause mortality (OCM), and grades 3 to 5 cardiac and neurologic toxic effects. Subgroup analyses were performed using the protocol-specified PSA stratification variable (1.5 ng/mL) and additional PSA cut points, including test for interaction. Competing risk analyses were performed for DM and other-cause mortality (OCM).

Results

Overall, 760 men with PSA elevation after radical prostatectomy for prostate cancer were included. The median (range) age of particpants was 65 (40-83) years. Antiandrogen assignment was associated with an OS benefit in the PSA stratum greater than 1.5 ng/mL (n = 118) with a 25% 12-year absolute benefit (hazard ratio [HR], 0.45; 95% CI, 0.25-0.81), but not in the PSA of 1.5 ng/mL or less stratum (n = 642) (1% 12-year absolute difference; HR, 0.87; 95% CI, 0.66-1.16). In a subanalysis of men with PSA of 0.61 to 1.5 (n = 253), there was an OS benefit associated with antiandrogen assignment (HR, 0.61; 95% CI, 0.39-0.94). In those receiving early SRT (PSA ≤0.6 ng/mL, n = 389), there was no improvement in OS (HR, 1.16; 95% CI, 0.79-1.70), an increased OCM hazard (subdistribution HR, 1.94; 95% CI, 1.17-3.20; P = .01), and an increased odds of late grades 3 to 5 cardiac and neurologic toxic effects (odds ratio, 3.57; 95% CI, 1.09-15.97; P = .05).

Conclusions and Relevance

These results suggest that pre-SRT PSA level may be a prognostic biomarker for outcomes of antiandrogen treatment with SRT. In patients receiving late SRT (PSA >0.6 ng/mL, hormone therapy was associated with improved outcomes. In men receiving early SRT (PSA ≤0.6 ng/mL), long-term antiandrogen treatment was not associated with improved OS. Future randomized clinical trials are needed to determine hormonal therapy benefit in this population.

Trial Registration

ClinicalTrials.gov Identifier: NCT00002874.

Transcriptome profiling of NRG Oncology/RTOG 9601: Validation of a prognostic genomic classifier in salvage radiotherapy prostate cancer patients from a prospective randomized trial

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Background: Decipher is a genomic classifier (GC) that estimates risk of prostate cancer (PCa) distant metastases (DM) post-radical prostatectomy (RP). Herein, we validate the GC within the context of a randomized phase 3 trial. Methods: RP specimens from patients on the NRG/RTOG 9601 phase 3 placebo-controlled randomized trial of salvage radiotherapy (sRT) +/- 2 years of bicalutamide (NCT00002874) were centrally reviewed and the highest-grade tumor underwent RNA extraction. Samples passing quality control (QC) were run on a clinical-grade whole-transcriptome assay to assign the GC score (scale 0-1). Our NCTN-CCSC approved pre-specified statistical plan (NRG-GU-TS002 CSC0075) included the primary objective of validating the ability of the GC to independently prognosticate the cumulative incidence of DM, with secondary endpoints of prostate cancer-specific mortality (PCSM) and overall survival (OS). Results: Of patients with tissue available, 352 passed QC and were included for analysis. The final GC cohort was a representative sample of the overall cohort, with a median follow-up of 13 years. On multivariable analysis, the GC (continuous variable) was independently associated with DM (HR 1.19 [95%CI 1.06-1.35], p=0.003), PCSM (HR 1.37 [95%CI 1.18-1.61], p<0.001), and OS (HR 1.16 [95%CI 1.06-1.28], p=0.002) after adjusting for age, race, Gleason score, T-stage, margin status, entry PSA, and treatment arm. The estimated absolute impact of bicalutamide on 12-year OS was less in patients with lower vs higher GC scores (2.4% vs 8.9%), further demonstrated in men receiving early sRT at PSA <0.7 ng/mL (-2.0% vs 5.0%). Conclusions: This is the first validation of this GC in a prospective randomized trial cohort and demonstrates association of the GC with DM and PCSM independent of standard clinicopathologic variables. The GC may help personalize shared decision-making to weigh the absolute benefit from the addition of bicalutamide to sRT.

Association of Black Race With Prostate Cancer-Specific and Other-Cause Mortality

Importance

Black men are more likely to die of prostate cancer than white men. In men with similar stages of disease, the contribution of biological vs nonbiological differences to this observed disparity is unclear.

Objective

To quantify the association of black race with long-term survival outcomes after controlling for known prognostic variables and access to care among men with prostate cancer.

Design, Setting, and Participants

This multiple-cohort study included updated individual patient-level data of men with clinical T1-4N0-1M0 prostate cancer from the following 3 cohorts: Surveillance, Epidemiology, and End Results (SEER [n = 296 273]); 5 equal-access regional medical centers within the Veterans Affairs health system (VA [n = 3972]); and 4 pooled National Cancer Institute-sponsored Radiation Therapy Oncology Group phase 3 randomized clinical trials (RCTs [n = 5854]). Data were collected in the 3 cohorts from January 1, 1992, through December 31, 2013, and analyzed from April 27, 2017, through April 13, 2019.

Exposures

In the VA and RCT cohorts, all patients received surgery and radiotherapy, respectively, with curative intent. In SEER, radical treatment, hormone therapy, or conservative management were received.

Main Outcomes and Measures

Prostate cancer-specific mortality (PCSM). Secondary measures included other-cause mortality (OCM). To adjust for demographic-, cancer-, and treatment-related baseline differences, inverse probability weighting (IPW) was performed.

Results

Among the 306 100 participants included in the analysis (mean [SD] age, 64.9 [8.9] years), black men constituted 52 840 patients (17.8%) in the SEER cohort, 1513 (38.1%) in the VA cohort, and 1129 (19.3%) in the RCT cohort. Black race was associated with an increased age-adjusted PCSM hazard (subdistribution hazard ratio [sHR], 1.30; 95% CI, 1.23-1.37; P < .001) within the SEER cohort. After IPW adjustment, black race was associated with a 0.5% (95% CI, 0.2%-0.9%) increase in PCSM at 10 years after diagnosis (sHR, 1.09; 95% CI, 1.04-1.15; P < .001), with no significant difference for high-risk men (sHR, 1.04; 95% CI, 0.97-1.12; P = .29). No significant differences in PCSM were found in the VA IPW cohort (sHR, 0.85; 95% CI, 0.56-1.30; P = .46), and black men had a significantly lower hazard in the RCT IPW cohort (sHR, 0.81; 95% CI, 0.66-0.99; P = .04). Black men had a significantly increased hazard of OCM in the SEER (sHR, 1.30; 95% CI, 1.27-1.34; P < .001) and RCT (sHR, 1.17; 95% CI, 1.06-1.29; P = .002) IPW cohorts.

Conclusions and Relevance

In this study, after adjustment for nonbiological differences, notably access to care and standardized treatment, black race did not appear to be associated with inferior stage-for-stage PCSM. A large disparity remained in OCM for black men with nonmetastatic prostate cancer.

Molecular biomarkers in bladder preservation therapy for muscle-invasive bladder cancer

Although muscle-invasive bladder cancer is commonly treated with radical cystectomy, a standard alternative is bladder preservation therapy, consisting of maximum transurethral bladder tumour resection followed by radiotherapy with concurrent chemotherapy. Although no successfully completed randomised comparisons are available, the two treatment paradigms seem to have similar long-term outcomes; however, clinicopathologic parameters can be insufficient to provide clear guidance in the selection of one treatment over the other. Recent advances in the molecular understanding of bladder cancer have led to the identification of new predictive biomarkers that ultimately might help guide the tailored selection of therapy on the basis of the intrinsic biology of the tumour. In this Review, we discuss the existing evidence for molecular alterations and genomic signatures as prognostic or predictive biomarkers for bladder preservation therapy. If validated in prospective clinical trials, such biomarkers could enable the identification of subgroups of patients who are more likely to benefit from one treatment over another, and guide the use of combination therapies that include other modalities, such as immunotherapy, which might act synergistically with radiotherapy.

Effect of Chemotherapy With Docetaxel With Androgen Suppression and Radiotherapy for Localized High-Risk Prostate Cancer: The Randomized Phase III NRG Oncology RTOG 0521 Trial

PURPOSE

Radiotherapy (RT) plus long-term androgen suppression (AS) are a standard treatment option for patients with high-risk localized prostate cancer. We hypothesized that docetaxel chemotherapy (CT) could improve overall survival (OS) and clinical outcomes among patients with high-risk prostate cancer.

PATIENTS AND METHODS

The multicenter randomized NRG Oncology RTOG 0521 study enrolled patients with high-risk nonmetastatic disease between 2005 and 2009. Patients were randomly assigned to receive standard long-term AS plus RT with or without adjuvant CT.

RESULTS

A total of 612 patients were enrolled; 563 were evaluable. Median prostate-specific antigen was 15.1 ng/mL; 53% had a Gleason score 9 to 10 cancer; 27% had cT3 to cT4 disease. Median follow-up was 5.7 years. Treatment was well tolerated in both arms. Four-year OS rate was 89% (95% CI, 84% to 92%) for AS + RT and 93% (95% CI, 90% to 96%) for AS + RT + CT (hazard ratio [HR], 0.69; 90% CI, 0.49 to 0.97; one-sided P = .034). There were 59 deaths in the AS + RT arm and 43 in the AS + RT + CT arm, with fewer deaths resulting from prostate cancer in the AS + RT + CT arm versus AS + RT (23 v 16 deaths, respectively). Six-year rate of distant metastasis was 14% for AS + RT and 9.1% for AS + RT + CT, (HR, 0.60; 95% CI, 0.37 to 0.99; two-sided P = .044). Six-year disease-free survival rate was 55% for AS + RT and 65% for AS + RT + CT (HR, 0.76; 95% CI, 0.58 to 0.99; two-sided P = .043).

CONCLUSION

For patients with high-risk nonmetastatic prostate cancer, CT with docetaxel improved OS from 89% to 93% at 4 years, with improved disease-free survival and reduction in the rate of distant metastasis. The trial suggests that docetaxel CT may be an option to be discussed with selected men with high-risk prostate cancer.

Bladder Preservation With Twice-a-Day Radiation Plus Fluorouracil/Cisplatin or Once Daily Radiation Plus Gemcitabine for Muscle-Invasive Bladder Cancer: NRG/RTOG 0712-A Randomized Phase II Trial

PURPOSE

Fluorouracil plus cisplatin and radiation twice a day (FCT) is an established chemoradiation (CRT) regimen for selective bladder-sparing treatment of muscle-invasive bladder cancer. Gemcitabine and once daily radiation (GD) is a well-supported alternative. The current trial evaluates these regimens.

METHODS

Patients with cT2-4a muscle-invasive bladder cancer were randomly assigned to FCT or GD. Patients underwent transurethral resection and induction CRT to 40 Gy. Patients who achieved a complete response (CR) received consolidation CRT to 64 Gy and others underwent cystectomy. We administered adjuvant gemcitabine/cisplatin chemotherapy. The primary end point was the rate of freedom from distant metastasis at 3 years (DMF3). The trial was not statistically powered to compare regimens, but to assess whether either regimen exceeded a DMF3 benchmark of 75%. Toxicity and efficacy end points, including CR and bladder-intact distant metastasis free survival at 3 years (BI-DMFS3), were assessed.

RESULTS

From December 2008 to April 2014, 70 patients were enrolled, of which 66 were eligible for analysis, 33 per arm. Median follow-up was 5.1 years (range, 0.4 to 7.8 years) for eligible living patients. DMF3 was 78% and 84% for FCT and GD, respectively. BI-DMFS3 was 67% and 72%, respectively. Postinduction CR rates were 88% and 78%, respectively. Of 33 patients in the FCT arm, 21 (64%) experienced treatment-related grade 3 and 4 toxicities during protocol treatment, with 18 (55%), two (6%), and two patients (6%) experiencing grade 3 and 4 hematologic, GI, and genitourinary toxicity, respectively. For the 33 patients in the GD arm, these figures were 18 (55%) overall and 14 (42%), three (9%) and two patients (6%), respectively.

CONCLUSION

Both regimens demonstrated DMF3 greater than 75%. There were fewer toxicities observed in the GD arm. Either gemcitabine and once daily radiation or a cisplatin-based regimen could serve as a base for future trials of systemic therapy.

Comparative Effectiveness of Bladder-preserving Tri-modality Therapy Versus Radical Cystectomy for Muscle-invasive Bladder Cancer

INTRODUCTION

There are limited randomized data comparing radical cystectomy (RC) with bladder-sparing tri-modality therapy (TMT) in the treatment of muscle-invasive bladder cancer (MIBC). Both strategies are thought to have similar survival outcomes with different morbidity profiles. We compare the effectiveness of TMT and RC using decision-analytic modeling and the endpoint of quality-adjusted life years (QALYs).

PATIENTS AND METHODS

Using a Markov model, we simulated the lifetime outcomes after TMT versus RC ± neoadjuvant chemotherapy for 67-year-old patients with clinical stage T2-T4aN0M0 MIBC. Model probabilities and utilities were extracted from the literature. The incremental effectiveness was reported in QALYs and sensitivity analyses were performed.

RESULTS

For all patients with MIBC, although the model showed identical survival, TMT was the most effective strategy with an incremental gain of 0.59 QALYs over RC (7.83 vs. 7.24 QALYs, respectively). When limiting the model to favorable, contemporary cohorts in both the TMT and RC strategies, TMT remained more effective with an incremental gain of 1.61 QALYs (9.37 vs. 7.76 QALYs, respectively). One-way sensitivity analyses demonstrated the model was sensitive to the quality of life parameters (ie, the utilities) for RC and TMT. When testing the 95% confidence interval of the RC utility parameter the model demonstrated an incremental gain with TMT from -0.54 to 4.23 QALYs. Probabilistic sensitivity analysis demonstrated that TMT was more effective than RC for 63% of model iterations.

CONCLUSIONS

This modeling study found that treatment of MIBC with organ-sparing TMT in appropriately-selected patients may result in a gain of QALYs relative to RC.

Contemporary Patterns of Multidisciplinary Care in Patients With Muscle-invasive Bladder Cancer

BACKGROUND

Multidisciplinary clinics integrate the expertise of several specialties to provide effective treatment to patients. This exposure is especially relevant in the management of muscle-invasive bladder cancer (MIBC), which requires critical input from urology, radiation oncology, and medical oncology, among other supportive specialties.

MATERIALS AND METHODS

In the present study, we sought to catalog the different styles of multidisciplinary care models used in the management of MIBC and to identify barriers to their implementation. We surveyed providers from academic and community practices regarding their currently implemented multidisciplinary care models, available resources, and perceived barriers using the Bladder Cancer Advocacy Network and the Genitourinary Medical Oncologists of Canada e-mail databases.

RESULTS

Of the 101 responding providers, most practiced at academic institutions in the United States (61%) or Canada (29%), and only 7% were from community practices. The most frequently used model was sequential visits on different days (57%), followed by sequential same-day (39%) and concurrent (1 visit with all providers; 22%) models. However, most practitioners preferred a multidisciplinary clinic involving sequential same-day (41%) or concurrent (26%) visits. The lack of clinic space (58%), funding (41%), staff (40%), and time (32%) were the most common barriers to implementing a multidisciplinary clinic.

CONCLUSION

Most surveyed practitioners at academic centers use some form of a multidisciplinary care model for patients with MIBC. The major barriers to more integrated multidisciplinary clinics were limited time and resources rather than a lack of provider enthusiasm. Future studies should incorporate patient preferences, further evaluate practice patterns in community settings, and assess their effects on patient outcomes.

Genomic profiling of muscle invasive bladder cancer to predict response to bladder-sparing trimodality therapy

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Background: Trimodality therapy with TURBT followed by chemoradiation is an acceptable alternative to cystectomy for muscle invasive bladder cancer (MIBC). Genomic profiling has demonstrated MIBC can be divided into molecular subtypes with differing responses to chemotherapy. We explored the utility of genomic data to select patients for bladder-sparing trimodality therapy. Methods: Transcriptome wide gene expression profiles were generated for 189 MIBC TURBT samples from patients treated with trimodality therapy at a single institution. Of these, 103 passed microarray QC. Molecular subtype and expression of bladder cancer genes were assessed for association with overall and disease-specific survival. Transcriptome wide differential expression analysis was used to explore gene set enrichment in trimodality therapy response groups. Results: The chemoradiation cohort (n = 103) had a median followup of 6.9 years for alive patients, and was classified into four subtypes: basal (n = 44), basal claudin-low (n = 12), infiltrated luminal (n = 17) and luminal tumors (n = 30). There was no significant difference in overall or disease-specific survival by subtype. However, higher expression of the luminal-associated PPARG was correlated with increased survival after adjusting for subtype and clinical factors (HR = 0.52, p = 0.002). In contrast, a p53 signature predicted worse survival after adjusting for clinical factors (HR = 1.92, p = 0.022). Elevated mRNA expression of the DNA damage repair gene MRE11 was associated with improved survival in the trimodality cohort (HR = 0.69, P = 0.031), consistent with its potential role as a predictive biomarker for radiation response. Gene set enrichment revealed differential regulation of immune pathways in trimodality therapy responders relative to non-responders, including enrichment of interferon gamma signaling (p = 0.01) and CXCL9 (p = 0.031), suggestive of an interplay between tumor immunologic microenvironment and response to chemoradiation. Conclusions: Transcriptional profiling of MIBC revealed gene signatures correlated with response to chemoradiation, suggesting the potential of genomics to guide use of trimodality therapy.

Selective bladder preservation with twice-daily radiation plus 5-flourouracil/cisplatin (FCT) or daily radiation plus gemcitabine (GD) for patients with muscle invasive bladder cancer: Primary results of NRG/RTOG 0712—A randomized phase 2 multicenter trial

408

Background: To assess GD or FCT as the chemoradiation (CRT) component of a bladder sparing regimen. Methods: Patients with T2-4a bladder cancer were randomized. Patients had a maximal transurethral resection and induction CRT to 40 Gy followed by cystoscopic assessment. Patients with a complete response (CR) received consolidation CRT to 64 Gy. Others were offered cystectomy and no further CRT. Adjuvant gemcitabine/cisplatin chemotherapy was subsequently administered. The primary endpoint was the rate of distant metastasis at 3 years (DM3). Toxicity and other efficacy related endpoints including CR and bladder intact distant metastasis free survival at 3 years (BI-DMFS3) were also assessed. Using the Clopper-Pearson method, the study required 32 patients per arm, with a benchmark DM3 of 25% and a 1-sided significance level of 0.1. If both arms meet this benchmark, toxicity will be used to select a regimen for future study. This study was not designed to compare arms. Results: From 12/2008 to 4/2014, 70 patients were enrolled; 66 were eligible for analysis (33 per arm). Median follow-up was 4.3 years. DM3 was 22% and 16% for FCT and GD, respectively. BI-DMFS3 was 67% and 72%, respectively. CR rates were 88% and 78%, respectively. Of 33 patients in the FCT group, 32 (97%) completed induction, 27 (93%) completed induction and consolidation, and 18 (55%) completed the entire protocol. Of 33 patients in the GD group, these figures were 31 (94%), 23 (92%), and 16 (49%), respectively. Of 33 patients in the FCT group, 21 (64%) had grade 3-4 toxicity during protocol treatment with 18 (55%), 2 (6%) and 2 (6%) experiencing hematologic, GI and GU toxicity, respectively. For 33 patients in the GD group, these figures were 18 (55%) overall and 14 (43%), 3 (9%) and 2 (6%), respectively. Conclusions: Both regimens are promising, given DM3 rates < 25%. As there was less toxicity in the GD arm, it would be reasonable to consider a gemcitabine based option as well as a cisplatin based regimen for future trials. Daily radiation may be as effective as twice-daily radiation, which may broaden appeal. Clinical trial information: NCT00777491.

Comparative effectiveness of bladder-preserving tri-modality therapy versus radical cystectomy for muscle-invasive bladder cancer

418

Background: Radical cystectomy (RC) has historically been considered the standard of care for muscle invasive bladder cancer (MIBC). An alternative is tri-modality therapy (TMT), a bladder-sparing approach that often achieves preservation of the native bladder. There are limited randomized data comparing these guideline-recommended approaches but, in appropriately selected patients, both are thought to have similar survival outcomes with different morbidity profiles. Therefore this study compared the effectiveness of TMT and RC using decision-analytic modeling with the primary endpoint of quality-adjusted life years (QALYs). Methods: We developed a Markov model simulating the lifetime outcomes for 67-year-old patients after definitive treatment for American Joint Committee on Cancer clinical Stage T2-T4aN0M0 MIBC using two strategies: TMT or RC +/- neoadjuvant chemotherapy (NAC). Probabilities and utilities were extracted from the literature to determine the incremental effectiveness in QALYs. Sensitivity analyses were performed. Results: TMT was the most effective strategy with an incremental gain of 1.13 QALYs over RC (8.37 versus 7.24 QALYs, respectively; Table). One-way sensitivity analyses demonstrated the model was most sensitive to the quality of life (QoL) parameters (i.e. the utilities) for RC and TMT; TMT was more effective than RC irrespective of the RC utility (the 95% confidence interval of the RC parameter demonstrated an incremental gain with TMT of 0.01 to 4.77 QALYs). The model was relatively less sensitive to the probability of death for either strategy. Probabilistic sensitivity analysis demonstrated that TMT was more effective than RC for 75% of model iterations. Conclusions: Treatment of MIBC with organ-sparing TMT in appropriately-selected patients may result in a gain of over 1 QALY relative to RC. Further prospective investigation into the QoL implications of these treatment modalities is warranted. [Table: see text]

Risk Factors for Disease Progression After Postprostatectomy Salvage Radiation: Long-term Results of a Single-institution Experience

BACKGROUND

Salvage radiotherapy (SRT) has been successfully used for recurrent prostate cancer after radical prostatectomy; however, the optimal timing of SRT remains controversial. Our objective was to identify the risk factors for disease progression after SRT, with a focus on the pre-SRT prostate-specific antigen (PSA) levels in the modern era of PSA testing.

PATIENTS AND METHODS

We performed a retrospective review of 551 consecutive patients who had undergone postradical prostatectomy SRT for recurrent prostate cancer from 2000 to 2013. The exclusion criteria were hormonal therapy before or concurrent with SRT, adjuvant RT, distant metastases, and missing data. Disease progression was defined as a repeat PSA level of ≥ 0.2 ng/mL greater than the post-SRT nadir, a continued increase in the PSA level despite SRT, initiation of systemic therapy, local recurrence, nodal failure, and/or distant metastases. Univariate and multivariable Cox regression analysis were performed to identify the predictors of disease progression. Secondarily, PSA kinetics were evaluated in the model and compared using the Akaike information criterion.

RESULTS

Of the 551 patients, 307 underwent SRT, of whom 134 experienced subsequent disease progression. The median interval to recurrence was 6.03 years (95% confidence interval, 3.74-8.36 years). On multivariable analysis, Gleason score, T stage, positive surgical margins, and pre-SRT PSA level were associated with progression; PSA kinetics did not independently predict for progression. When the pre-SRT PSA level was stratified (≤ 0.30, 0.31-0.50, 0.51-1.00, and > 1 ng/mL), incremental elevations were associated with an increased risk of disease progression.

CONCLUSION

Multiple factors predict for progression after SRT. These risk factors could help identify those who would derive the greatest benefit from additional systemic treatment. The findings of the present study also support initiation of early SRT, irrespective of the PSA kinetics.

Outcomes and tolerability of selective bladder preservation by combined modality therapy for invasive bladder cancer in elderly patients

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Background: The median age of patients diagnosed with muscle invasive bladder cancer (MIBC) in the US is 72 years old, and only about half of those over 70 years receive potentially curative therapy (radical cystectomy, chemoradiation, definitive radiation), suggesting a large proportion of patients are undertreated. To address this unmet need, we examined the outcomes and tolerability of chemoradiation (chemoRT) in the elderly. Methods: We conducted an analysis of 455 patients with cT2-T4a disease treated at our institution between 1986 and 2013. Patients underwent induction chemoRT (40Gy) after transurethral resection of bladder tumor (TURBT). Patients achieving a complete response (CR) received consolidation chemoRT to a total goal dose of 64-65Gy. Those with less than a CR or an invasive recurrence were recommended to undergo salvage cystectomy. Elderly was defined as 75 years or older. For comparison with younger patients, propensity score matching was performed based on sex, T-stage, hydronephrosis, completion of TURBT, and decade of treatment. Disease-specific survival (DSS) was evaluated using Kaplan-Meier method. Results: Median age was 66 years (range 27-94). One hundred and one patients (22%) were 75 years or older. Median follow-up was 7.4 years for surviving patients. In a propensity score matched pair analysis of 84 elderly and 84 younger patients, DSS at 5 and 10 years for the elderly was 64.8% and 51%, compared to 71.7% and 62.0% for younger patients (p = 0.28). Elderly patients, compared to the younger patients, had similar rates of ED visits during treatment (10% vs 12%, p = 0.76), hospital admissions for any cause (17% vs. 14%, p = 0.8), unplanned treatment breaks for any cause (24% vs. 12%, p = 0.16), and discontinuation of therapy due to toxicities (6% vs 7%, p = 1.0). Conclusions: In elderly patients with MIBC, outcomes and tolerability of bladder-sparing chemoRT are comparable to that of younger patients. Clinicians should not deny patients potentially curative therapies based on age alone, although further investigation is warranted.

The impact of MRE11 in nuclear to cytoplasmic ratio on outcomes in muscle invasive bladder cancer an analysis of NRG/RTOG 8802, 8903, 9506, 9706, 9906, and 0233

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Background: Biomarkers are needed to help select patients (pts) with muscle invading bladder cancer (MIBC) for bladder sparing chemotherapy and radiation treatment (CRT). Higher MRE11 expression has been identified as a potential RT response marker in MIBC. MRE11 protein is involved in the DNA double strand break repair mechanism. This analysis evaluates associations between MRE11 expression and outcome in pts from 6 NRG/RTOG bladder-sparing RT protocols. Methods: Archival tissue via TMA or unstained slides was used. Cases were stained with anti MRE11 antibody Rabbit mAb, clone EPR3471 (Epitomics at 1:1500 dilution). Slides were scanned on an Aperio FL instrument and analyzed via Automated Quantitative Image analysis (AQUA). MRE11 scores were determined within the nucleus and cytoplasm of urothelial cells and a ratio of nuclear to cytoplasmic (N/C) score calculated. A ratio was used to normalize scores and overcome pre-analytical variation. MRE11 N/C was analyzed by quartile cut points. Cumulative incidence was used to estimate disease-specific mortality (DSM; failure=bladder cancer death) and Fine-Gray models were used to evaluate associations between MRE11 and DSM. Cox models were used for overall survival (OS; death) and bladder-intact survival (BIS; cystectomy/death). Results: Out of 465 eligible pts, tissue was available and MRE11 N/C determined for 135. Analyzable pts were less likely to be white (p=0.0001) and more likely to be T2 (p=0.0003). Median MRE11 N/C was 2.41 (min-max: 0.69-6.03). Pts with MRE11 N/C ≤ 1.49 (lower quartile) were associated with significantly higher DSM (HR= 2, 95% CI: 1.1, 3.8, p=0.03). The 4-year DSM was 41% for pts with MER11 N/C ≤ 1.49 vs. 21% for pts with MER11 N/C was >1.49. MRE11 N/C was not associated with OS or BIS. Conclusions: AQUA analysis allows precise measurement of this marker in tissue samples. Low expression of MRE11 N/C (≤1.49) is associated with significantly higher DSM. This adds further evidence of MRE11 as a potential RT response biomarker for selection of pts most likely to respond to bladder-sparing CRT. Supported by NCI grants U10CA180868, U10CA180822, UG1CA189867,U24CA196067.

Subtyping muscle-invasive bladder cancer to assess clinical response to trimodality therapy

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Background: Trimodality therapy with TURBT followed by chemoradiation is an acceptable alternative to cystectomy for muscle invasive bladder cancer (MIBC). Recently, genomic profiling has demonstrated MIBC can be divided into three or more subtypes with differing responses to chemotherapy, suggesting genomic subtype may impact therapeutic response. Here, we explore the utility of genomic information to better select patients for bladder-sparing trimodality therapy. Methods: Transcriptome-wide gene expression profiles were generated for 189 MIBC TURBT samples from patients undergoing trimodality therapy at the Massachusetts General Hospital. Of these, 108 passed microarray QC and 100 had complete clinical information. The patient tumors were classified as basal, basal claudin-low, infilrated luminal or luminal subtype. The subtype and the expression of a number of bladder cancer genes were assessed for their association with need for salvage cystectomy and for overall survival. Finally, transcriptome-wide differential expression analysis was used to explore gene set enrichment in trimodality therapy response groups. Results: Our chemoradiation cohort (n = 108) was classified into the four subtypes: basal (n = 45), basal claudin low (n = 13), infiltrated luminal (n = 17) and luminal tumors (n = 33). Survival analysis (n = 100) showed that patients of the luminal subtype trended to better overall survival, but did not reach significance (HR = 0.63, p = 0.1). Fewer patients with infiltrated luminal tumors (12%) required a salvage cystectomy compared to all other subtypes (34+/-1.5%, p = 0.08). We found high expression of BLACAT1 and NORAD (a lncRNA with a role in genome stability) correlated with worse (p = 0.01) and better prognosis (p = 0.008), respectively. Likewise, patients with high levels of the luminal-associated PPARG showed a significant increase in overall survival (p = 0.0002). Gene set enrichment revealed differential regulation of immune pathways in the trimodality therapy responders relative to the non-responders (p < 0.05). Conclusions: Preliminary data exploring MIBC subtyping suggests the possibility of using genomics to predict response to trimodality bladder-sparing therapy.

The prognostic utility of hemoglobin and lymphocytopenia in bladder-sparing therapy

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Background: Many patients with bladder cancer are found to have laboratory derrangements such as anemia and lymphocytopenia prior to treatment, though their prognostic value is unknown. We examined pretreatment lab values and clinical outcomes in patients with muscle-invasive bladder cancer (MIBC) who underwent bladder sparing trimodality therapy (TMT). Methods: We performed a retrospective analysis of 181 patients with T2-T4a bladder cancer who underwent TMT between 2001 and 2013. Pretreatment absolute lymphocyte count (ALC), neutrophil to lymphocyte ratio (NLR), and hemoglobin (Hgb) values were collected, and cut-off values were established to be 1.5*10^9/L, 3.12, and 12 g/dl, respectively. Overall survival (OS), disease-specific survival (DSS), and disease-free survival (DFS) were compared with Kaplan Meier survival probabilities and univariate and multivariate Cox regression analysis, controlling for gender, age, completeness of TURBT, response to TMT, cystectomy, clinical T stage, and hydronephrosis. Results: Median follow-up was 47 months. On univariate analysis, patients with a low pretreatment lymphocyte count had poorer OS (p = 0.03) than patients with a higher pretreatment lymphocyte count (5 year OS rates: 54% and 71%, respectively). Patients with pretreatment anemia had poorer OS (p = 0.001) and DSS (p < 0.001) than patients with a higher pretreatment hemoglobin count, (5 year OS rates: 39% and 65%; 5 year DSS rates: 39% and 72%, respectively). On multivariate analysis, pretreatment anemia was significantly associated with poorer OS (HR 2.58, 95% CI 1.36–4.90) and DSS (HR 3.23, 95% CI 1.62–6.43), whereas complete response to TMT was significantly associated with improved OS (HR 0.24, 95% CI 0.13–0.43) and DSS (HR 0.29, 95% CI 0.14–0.59). Complete response to TMT was significantly associated with improved DFS (HR 0.36, 95% CI 0.21–0.61), and a higher clinical T stage was associated with poorer DFS (HR 2.38, 95% CI 1.19–4.75). Conclusions: When adjusting for clinical factors, pretreatment anemia remained an independent predictor of overall and disease-specific survival following TMT. Further prospective validation of lab values and clinical outcomes in MIBC are needed.

Radiation with or without Antiandrogen Therapy in Recurrent Prostate Cancer

BACKGROUND

Salvage radiation therapy is often necessary in men who have undergone radical prostatectomy and have evidence of prostate-cancer recurrence signaled by a persistently or recurrently elevated prostate-specific antigen (PSA) level. Whether antiandrogen therapy with radiation therapy will further improve cancer control and prolong overall survival is unknown.

METHODS

In a double-blind, placebo-controlled trial conducted from 1998 through 2003, we assigned 760 eligible patients who had undergone prostatectomy with a lymphadenectomy and had disease, as assessed on pathological testing, with a tumor stage of T2 (confined to the prostate but with a positive surgical margin) or T3 (with histologic extension beyond the prostatic capsule), no nodal involvement, and a detectable PSA level of 0.2 to 4.0 ng per milliliter to undergo radiation therapy and receive either antiandrogen therapy (24 months of bicalutamide at a dose of 150 mg daily) or daily placebo tablets during and after radiation therapy. The primary end point was the rate of overall survival.

RESULTS

The median follow-up among the surviving patients was 13 years. The actuarial rate of overall survival at 12 years was 76.3% in the bicalutamide group, as compared with 71.3% in the placebo group (hazard ratio for death, 0.77; 95% confidence interval, 0.59 to 0.99; P=0.04). The 12-year incidence of death from prostate cancer, as assessed by means of central review, was 5.8% in the bicalutamide group, as compared with 13.4% in the placebo group (P<0.001). The cumulative incidence of metastatic prostate cancer at 12 years was 14.5% in the bicalutamide group, as compared with 23.0% in the placebo group (P=0.005). The incidence of late adverse events associated with radiation therapy was similar in the two groups. Gynecomastia was recorded in 69.7% of the patients in the bicalutamide group, as compared with 10.9% of those in the placebo group (P<0.001).

CONCLUSIONS

The addition of 24 months of antiandrogen therapy with daily bicalutamide to salvage radiation therapy resulted in significantly higher rates of long-term overall survival and lower incidences of metastatic prostate cancer and death from prostate cancer than radiation therapy plus placebo. (Funded by the National Cancer Institute and AstraZeneca; RTOG 9601 ClinicalTrials.gov number, NCT00002874 .).

Long-term Outcomes After Bladder-preserving Tri-modality Therapy for Patients with Muscle-invasive Bladder Cancer: An Updated Analysis of the Massachusetts General Hospital Experience

BACKGROUND

Tri-modality therapy (TMT) is a recognized treatment strategy for selected patients with muscle-invasive bladder cancer (MIBC).

OBJECTIVE

Report long-term outcomes of patients with MIBC treated by TMT.

DESIGN, SETTING, AND PARTICIPANTS

Four hundred and seventy-five patients with cT2-T4a MIBC were enrolled on protocols or treated as per protocol at the Massachusetts General Hospital between 1986 and 2013.

INTERVENTION

Patients underwent transurethral resection of bladder tumor followed by concurrent radiation and chemotherapy. Patients with less than a complete response (CR) to chemoradiation or with an invasive recurrence were recommended to undergo salvage radical cystectomy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Disease-specific survival (DSS) and overall survival (OS) were calculated using the Kaplan-Meier method.

RESULTS AND LIMITATIONS

Median follow-up for surviving patients was 7.21 yr. Five- and 10-yr DSS rates were 66% and 59%, respectively. Five- and 10-yr OS rates were 57% and 39%, respectively. The risk of salvage cystectomy at 5 yr was 29%. In multivariate analyses, T2 disease (OS hazard ratio [HR]: 0.57, 95% confidence interval [CI]: 0.44-0.75, DSS HR: 0.51, 95% CI: 0.36-0.73), CR to chemoradiation (OS HR: 0.61, 95% CI: 0.46-0.81, DSS HR: 0.49, 95% CI: 0.34-0.71), and presence of tumor-associated carcinoma in situ (OS HR: 1.56, 95% CI: 1.17-2.08, DSS HR: 1.50, 95% CI: 1.03-2.17) were significant predictors for OS and DSS. When evaluating our cohort over treatment eras, rates of CR improved from 66% to 88% and 5-yr DSS improved from 60% to 84% during the eras of 1986-1995 to 2005-2013, while the 5-yr risk of salvage radical cystectomy rate decreased from 42% to 16%.

CONCLUSIONS

These data demonstrate high rates of CR and bladder preservation in patients receiving TMT, and confirm DSS rates similar to modern cystectomy series. Contemporary results are particularly encouraging, and therefore TMT should be discussed and offered as a treatment option for selected patients.

PATIENT SUMMARY

Tri-modality therapy is an alternative to radical cystectomy for patients with muscle-invasive bladder cancer, and is associated with comparable long-term survival and high rates of bladder preservation.

Long-term results of adjuvant versus early salvage postprostatectomy radiation: A large single-institutional experience

PURPOSE

The purpose of this study was to evaluate freedom from biochemical failure (FFBF), freedom from androgen deprivation therapy (FFADT), freedom from distant metastases (FFDM), and overall survival (OS) after adjuvant radiation therapy (ART) versus early salvage radiation therapy (ESRT) in men with prostate cancer and adverse pathologic features (pT3 and/or positive surgical margins).

METHODS AND MATERIALS

Of 718 patients consecutively treated with postoperative radiation therapy (RT) for prostate cancer between 1992 and 2013, we retrospectively identified 171 men receiving ART and 230 receiving ESRT (RT delivered at a prostate-specific antigen level ≤0.5 ng/mL) who had adverse pathologic features. Postirradiation FFBF (BF was defined as prostate-specific antigen level rise to ≥0.2 ng/mL), FFADT, FFDM, and OS were compared using Kaplan-Meier and Cox regression methods. Propensity score (PS)-matching was performed to estimate treatment effects while accounting for covariates predicting treatment allocation.

RESULTS

Median follow-up was 7.4 and 8.0 years for patients treated with ART and ESRT, respectively. Ten-year FFBF (69% vs 56%, P = .003) and 10-year FFADT (88% vs 81%, P = .046) rates were higher after ART; however, FFDM and OS did not significantly differ. After PS-matching, ART was associated with improved FFBF (P < .0001), FFADT (P = .0001), and FFDM (P = .02). Findings were confirmed in multivariable analyses in unmatched and PS-matched cohorts. Sensitivity analyses showed that FFBF benefit associated with ART lost statistical significance only after 38% of ART patients were assumed to have been cured by surgery and excluded from the model. This corresponds to the upper bound of patients with adverse pathologic features who did not recur after observation in prior randomized trials.

CONCLUSIONS

Postoperative RT confers excellent long-term cancer control. These results suggest ART may be associated with improved FFBF, FFADT, and FFDM, but comparable OS. Given the retrospective study design, these findings should be interpreted with caution. Optimal timing of postoperative RT further awaits results of ongoing trials.

Acute and late urinary toxicity following radiation in men with an intact prostate gland or after a radical prostatectomy: A secondary analysis of RTOG 94-08 and 96-01

INTRODUCTION

To estimate the contribution of the prostate gland and prostatic urethral inflammation to urinary symptoms after radiation therapy for prostate cancer, we performed a secondary analysis of urinary toxicity after primary radiation to an intact prostate vs. postprostatectomy radiation to the prostatic fossa in protocols RTOG 94-08 and 96-01, respectively.

MATERIALS AND METHODS

Patients randomized to the radiation-alone arms (without hormone therapy) of the 2 trials were evaluated, including 104 men receiving primary prostate radiation to 68.4Gy on RTOG 94-08 and 371 men receiving 64.8Gy to the prostatic fossa on RTOG 96-01. Acute and late urinary toxicity were scored prospectively by RTOG scales. Chi-square test/logistic regression and cumulative incidence approach/Fine-Gray regression model were used for analyses of acute and late toxicity, respectively.

RESULTS

Grade≥2 acute urinary toxicity was significantly higher after primary prostatic radiation compared with postprostatectomy radiation (30.8% vs. 14.0%; P<0.001), but acute grade≥3 toxicity did not differ (3.8% vs. 2.7%; P = 0.54). After adjusting for age, primary radiation resulted in significantly higher grade≥2 acute urinary toxicity (odds ratio = 3.72; 95% CI: 1.65-8.37; P = 0.02). With median follow-up of 7.1 years, late urinary toxicity was not significantly different with primary vs. postprostatectomy radiation (5-year grade≥2: 16.7% vs. 18.3%; P = 0.65; grade≥3: 6.0% vs. 3.3%; P = 0.24).

CONCLUSIONS

Primary radiation to an intact prostate resulted in higher grade≥2 acute urinary toxicity than radiation to the prostatic fossa, with no difference in late urinary toxicity. Thus, a proportion of acute urinary toxicity in men with an intact prostate may be attributable to inflammation of the prostatic gland or urethra.

Risk factors for disease progression after post-prostatectomy salvage radiation: Long-term results of a large institutional experience

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Background: Salvage radiotherapy (SRT) has been successfully used to treat recurrent prostate cancer following radical prostatectomy (RP). The objective of this study was to identify risk factors for disease progression post-SRT. Methods: Retrospective review of 719 consecutive patients who had RP and received post-operative radiation (adjuvant/SRT) for recurrent prostate cancer from 1992-2013. Disease progression was defined by a prostate specific antigen (PSA) ≥0.2 ng/ml, local recurrence, nodal failure, or distant metastases. Analysis was restricted to patients treated after 2000, when the PSA detectability threshold decreased to 0.2. Univariable and multivariable Cox regression analysis with backwards selection was performed with the following variables: demographics (age, race), pathological features (Gleason score, positive margins, pT-stage), surgery type, radiation details, hormone therapy, and pre-SRT PSA. Secondarily, we included PSA velocity and doubling-time as continuous variables in the model. Results: 384 patients received SRT after 2000, of which 152 had disease progression, with a median time to recurrence of 6.2 years (95% CI 4.1-7.6 years). Multivariable analysis results are reported in the Table. Gleason score, T-stage, seminal vesicle invasion, and pre-SRT PSA were associated with progression. Pre-SRT PSA ≤ 0.3 conferred the lowest rate of disease progression. In a secondary model, PSA kinetics was evaluated in which doubling-time was associated with progression (HR 0.98 per month increase, 95% CI 0.96-1.00; p=0.03). Conclusions: The lowest rate of disease progression was found amongst patients treated with a PSA ≤ 0.3. A shorter DT may also be a useful predictor of disease progression after SRT. [Table: see text]

Exploring multidisciplinary practice patterns in the management of muscle invasive bladder cancer (MIBC) across the U.S. and Canada in 2015

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Background: Effective treatment of MIBC requires a multidisciplinary (multiD) approach including surgical, radiation, and chemotherapeutic modalities, which are further supported by pathology, radiology, nursing, social work, nutrition, pharmacy, and psychologic expertise. As surgical and bladder preservation approaches have not been directly compared, practice patterns are heterogeneous. Our primary objective was to catalogue the different styles of multiD approaches or lack thereof in the management of MIBC. Secondary objectives were to assess physician interest, capture examples of successful approaches, and describe barriers to implementation. Methods: We conducted an international online survey regarding the type of multiD approach and available resources used by clinicians managing MIBC. We collaborated with the Bladder Cancer Advocacy Network and the Genitourinary Medical Oncologists of Canada to reach a wide variety of academic and community practices. Results: Of the 101 clinicians surveyed, most practiced at NCI designated comprehensive cancer centers (46%) or Canadian academic institutions (29%). The median number of cases per month was 5 (0-40).Of the different multiD styles, sequential (separate) visits on different days was the most common (60%) followed by sequential same day (41%), concurrent (one visit with all providers, 23%), and none (5%). However, most preferred a sequential same day (44%) or concurrent (28%) approach. Although most academic practices had some form of multiD approach, reported barriers for implementing the preferred strategy were lack of clinic space (63%), funding (46%), staff (46%), and time (34%). The majority felt a multiD approach enriched their practice. Conclusions: Most surveyed practitioners at academic centers integrate a multiD strategy in the management of MIBC. The major barriers are not attitudinal but rather insufficient resources and time. Thus, most physicians employ a sequential rather than a concurrent approach. Future goals include developing strategies to overcome these obstacles and integrating these results with patient preferences to optimize the management of MIBC patients.

NRG Oncology/RTOG 9601, a phase III trial in prostate cancer patients: Anti-androgen therapy (AAT) with bicalutamide during and after salvage radiation therapy (RT) following radical prostatectomy (RP) and an elevated PSA

3

Background: Previous reports suggested that AAT when combined with salvage RT following RP in patients may improve prostate cancer control outcomes. Methods: Post-RP patients with pT3pN0 or with pT2pN0 and positive margins who had or developed elevated PSA levels from 0.2 to 4.0 ng/ml were randomized on a phase III, double-blind, trial of RT + placebo (64.8 Gy in 36 fractions of 1.8 Gy) vs. RT + AAT (24 months bicalutamide, 150 mg daily) during and after RT. The primary end-point was overall survival. Trial design required 725 patients and provided 80% power to detect a reduction in death rate by at least 28.5% and a 1-sided significance level of 0.046. Results: From 3/98 to 3/03, 761 eligible patients (median age 65) were randomized to RT + AAT (384) or RT + placebo (377). 248 patients (33%) were pT2pN0 and 513 (67%) were pT3pN0. 671 (88%) had a PSA nadir after RP of < 0.5 ng/ml. 649 (85%) had an entry PSA value of <1.6, 112 patients (15%) had an entry PSA of 1.6-4. Median follow up was 12.6 years. Actuarial overall survival at 10 years was 82% for RT plus AAT and 78% for RT + placebo and a hazard ratio of 0.75 (95% CI: 0.58-0.98) with a 1-sided p value of 0.018 (2-sided p = 0.036). The 12-year incidence of PC central-reviewed deaths were 2.3% for RT + AAT and 7.5% for RT + placebo ( p< 0.001).The cumulative incidence of metastatic PC at 12 years was less in the RT + AAT arm, 14% (51 patients), vs. 23% (83 patients) in the RT + placebo arm (p < 0.001). Subgroup analyses of the relative benefits of the addition of AAT to RT are planned and will be presented. Late grade III and IV toxicity were similar in the AAT and placebo arms. The combined grade III and IV toxicities for RT + AAT and RT + placebo were: bladder 7.0% vs. 6.7%, bowel 2.7% vs. 1.6%. Gynecomastia differed significantly by treatment arm, 70% vs. 11%. Conclusions: 24 months of AAT using 150mg bicalutamide daily during and after salvage RT significantly improved long term overall survival and reduced the incidence of metastatic PC and PC death. Support: NCI grants U10CA21661, U10CA180868, U10CA180822, and U10CA37422 and AstraZeneca. Clinical trial information: NCT00002874.

Renal function in bladder cancer patients after trimodality therapy: Long-term results of a large institutional experience

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Background: Maintenance of renal function following treatment of bladder cancer presents an ongoing challenge. The decline following radical cystectomy is well documented. However, in patients undergoing trimodality bladder-sparing therapy consisting of transurethral resection (TURBT) and concurrent chemoradiation followed by adjuvant chemotherapy, renal function is poorly understood. Methods: We performed a retrospective review of 178 patients with muscle-invasive bladder cancer who underwent bladder-sparing therapy between 2001 and 2013 and collected nadir creatinine values in the month preceding TURBT and at 1, 3, 5, 7, and 9 years post treatment initiation. Wilcoxon signed-rank test and mixed effects analysis were performed to compare the pre-treatment and post-treatment levels of creatinine and EGFR and to analyze their temporal change. Results: Median follow-up was 48 months (range: 1 to 162 months). The mean pre-treatment creatinine and EGFR were 1.12 mg/dl and 71 mg/dl, respectively. Cr increased to 1.21 mg/dl and EGFR decreased to 65 mg/dl at 1 year following treatment initiation (p = 0.001, p = 0.002). All post-treatment values were also significantly different from pre-treatment values (all p values < 0.002), but there was no significant difference between the post-treatment values over time. Conclusions: Following bladder-sparing therapy for muscle invasive bladder cancer, renal function was generally well preserved in the long term. Although there was a modest yet statistically significant decrease in renal function that occurred during the first year, there was no further decline up to 9 years. While this initial decrease in function is of unknown clinical significance, the lack of further decline after 1 year is different from similar studies following cystectomy.

Long-term outcomes after bladder-preserving combined-modality therapy for patients with muscle-invasive bladder cancer

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Background: Transurethral resection of bladder tumor (TURBT), chemotherapy (CT), and radiation therapy (RT) is an established treatment paradigm for muscle-invasive bladder cancer (MIBC). Herein we report long-term outcomes for MIBC patients treated with combined-modality therapy (CMT). Methods: We analyzed 465 patients with MIBC (cT2-T4a) treated on successive protocols at a single center between 1986 and 2012. Patients underwent TURBT followed by concurrent cisplatin-based chemoradiation (CRT). A subset of patients received neoadjuvant CT. Repeat cystoscopy was performed after 40 Gy. Patients with a complete response (CR) received consolidation CRT to 64-65 Gy, while those with less than a CR or invasive recurrence were recommended to undergo salvage RC. Overall survival (OS) and disease-specific survival (DSS) were evaluated using Kaplan-Meier method and Cox proportional hazards regression. Results: Median follow-up was 4.8 years for all patients and 7.5 years for surviving patients. CR to induction CRT was achieved in 76% patients; 84% of patients with a complete TURBT achieved a CR vs. 59% with an incomplete TURBT, p< 0.001. When evaluated in four-year intervals, the CR rate improved from 64% in 1986-1990 to 96% in 2010-2012. Salvage RC was performed in 125 patients (27%), 55 for less than CR and 70 for superficial or invasive recurrence. Among patients with a CR, the 10-year actuarial rates for non-invasive, invasive, pelvic, and distant failure were 32%, 16%, 14%, and 29%, respectively. Median OS was 6.4 years. Five- and 10-year OS rates were 57% and 39% (T2 = 66%, 46%; T3-T4a = 41%, 26%), respectively. Five- and 10-year DSS rates were 66% and 59% (T2 = 75%, 66%; T3-T4a = 50%, 45%), respectively. In multivariate analyses, T2 disease (vs. T3-4; HR 0.55, 95%CI 0.40-0.76) and CR to induction therapy (HR 0.40, 95%CI 0.28-0.55) were significant predictors for improved OS. Age was not associated with DSS (HR 1.01, 95%CI 0.99-1.03). Conclusions: These data support the high rates of CR and bladder preservation in patients receiving CMT, and demonstrate long-term DSS similar to modern cystectomy series. CMT should be considered as an alternative treatment strategy for selected patients with MIBC.

Early salvage versus adjuvant post-prostatectomy radiation therapy: Long-term results of a large institutional experience

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Background: Randomized trials and consensus statements support consideration of adjuvant radiation therapy (ART) after radical prostatectomy (RP) for adverse pathologic features (pT3, positive margins), although its use remains low. Whether early salvage radiation therapy (ESRT) is as effective as ART remains unknown. The objective of this study was to compare outcomes after ART and ESRT. Methods: We performed a retrospective institutional analysis of 719 consecutive patients receiving post-RP RT from 1992 to 2013. ESRT was defined as RT for biochemical failure (BF) with post-RP PSA ≤ 0.5 ng/ml. All included ART and ESRT patients had adverse surgical pathologic features. Outcomes examined were freedom from BF (FFBF; rising PSA ≥ 0.2 ng/ml with subsequent confirmation), freedom from subsequent androgen deprivation therapy (FFADT), freedom from distant metastases (FFDM), and overall survival (OS). ART and ESRT were compared using multivariable analyses (MVA) with propensity score (PS) matching for pre-RP PSA, age at RT, Gleason score, pT-stage, and margin status. Results: 537 patients received salvage RT, of whom 195 received ESRT; 181 patients received ART. Median follow-up from RP was 7.0 and 8.1 years in the ART and ESRT cohorts, respectively. Median time to BF after RT was 4.4 and 4.7 years in the ART and ESRT cohorts, respectively. On MVA, ART was associated with improved 10-year FFBF (74 vs 60%, HR 0.36 [95% CI: 0.23-0.58], P < 0.0001) and 10-yr FFADT (91 vs 83%, HR 0.37 [95% CI: 0.18-0.76], P = 0.007). There were no significant differences in FFDM (96 vs 92%, HR 0.58 [95% CI: 0.19-1.7], P = 0.3), and OS (98 vs 95%, HR 1.24 [95% CI: 0.4-3.89], P = 0.7). After PS matching, ART (n = 169) remained significantly associated with improved FFBF (p < 0.0001) and FFADT (p = 0.01), compared to ESRT (n = 176). Conclusions: Post-prostatectomy RT confers excellent long-term prostate cancer control, a finding supported by the long follow-up in this series. ART is associated with improved FFBF and FFADT compared to ESRT, although there were no statistically significant differences in FFDM and OS. Optimal timing of postoperative RT further awaits the results of ongoing randomized trials.

A Phase 3 Trial of 2 Years of Androgen Suppression and Radiation Therapy With or Without Adjuvant Chemotherapy for High-Risk Prostate Cancer: Final Results of Radiation Therapy Oncology Group Phase 3 Randomized Trial NRG Oncology RTOG 9902

PURPOSE

Long-term (LT) androgen suppression (AS) with radiation therapy (RT) is a standard treatment of high-risk, localized prostate cancer (PCa). Radiation Therapy Oncology Group 9902 was a randomized trial testing the hypothesis that adjuvant combination chemotherapy (CT) with paclitaxel, estramustine, and oral etoposide plus LT AS plus RT would improve overall survival (OS).

METHODS AND MATERIALS

Patients with high-risk PCa (prostate-specific antigen 20-100 ng/mL and Gleason score [GS] ≥ 7 or clinical stage ≥ T2 and GS ≥ 8) were randomized to RT and AS (AS + RT) alone or with adjuvant CT (AS + RT + CT). CT was given as four 21-day cycles, delivered beginning 28 days after 70.2 Gy of RT. AS was given as luteinizing hormone-releasing hormone for 24 months, beginning 2 months before RT plus an oral antiandrogen for 4 months before and during RT. The study was designed based on a 6% improvement in OS from 79% to 85% at 5 years, with 90% power and a 2-sided alpha of 0.05.

RESULTS

A total of 397 patients (380 eligible) were randomized. The patients had high-risk PCa, 68% with GS 8 to 10 and 34% T3 to T4 tumors, and median prostate-specific antigen of 22.6 ng/mL. The median follow-up period was 9.2 years. The trial closed early because of excess thromboembolic toxicity in the CT arm. The 10-year results for all randomized patients revealed no significant difference between the AS + RT and AS + RT + CT arms in OS (65% vs 63%; P=.81), biochemical failure (58% vs 54%; P=.82), local progression (11% vs 7%; P=.09), distant metastases (16% vs 14%; P=.42), or disease-free survival (22% vs 26%; P=.61).

CONCLUSIONS

NRG Oncology RTOG 9902 showed no significant differences in OS, biochemical failure, local progression, distant metastases, or disease-free survival with the addition of adjuvant CT to LT AS + RT. The trial results provide valuable data regarding the natural history of high-risk PCa treated with LT AS + RT and have implications for the feasibility of clinical trial accrual and tolerability using CT for PCa.

A phase III protocol of androgen suppression (AS) and 3DCRT/IMRT versus AS and 3DCRT/IMRT followed by chemotherapy (CT) with docetaxel and prednisone for localized, high-risk prostate cancer (RTOG 0521)

LBA5002

Background: High-risk, localized prostate cancer (PCa) patients have a relatively poor prognosis. We hypothesized that the addition of adjuvant docetaxel and prednisone to long-term (24 month) AS and radiation therapy (RT) would improve overall survival (OS). Methods: RTOG 0521 opened December 2005 and closed August 2009 with targeted accrual of 600 cases. It was designed to detect improvement in 4-year OS from 86% to 93% with a 51% hazard reduction (HR = 0.49). Under a 0.05 1-sided type I error and 90% power, at least 78 deaths were required to analyze the OS endpoint. Patients had 1) Gleason (Gl) 7-8, any T-stage, and PSA > 20, or 2) Gl 8, ≥ T2, any PSA, or 3) Gl 9-10, any T-stage, any PSA. All had PSA ≤ 150. RT dose was 75.6 Gy. CT consisted of 6, 21-day cycles of docetaxel + prednisone starting 28 days after RT. Results: Of 612 enrolled, 50 were excluded for eligibility issues, leaving 562 evaluable. Median age = 66, median PSA = 15.1, 53% had Gl 9-10, 27% had cT3-4. Median follow-up = 5.5 yrs. 4-yr OS rates were 89% [95% CI: 84-92%] for the AS+RT arm and 93% [95% CI: 90-96%] for the AS+RT+CT arm (1-sided p = 0.03, HR = 0.68 [95% CI: 0.44, 1.03]). There were 52 centrally-reviewed deaths in the AS+RT arm and 36 in the AS+RT+CT arm, with fewer deaths both due to PCa/treatment (20 vs 16) and due to other causes/unknown (32 vs 20) in the AS+RT+CT arm. 5-yr disease-free survival rates were 66% for AS+RT and 73% for AS+RT+CT (2-sided p = 0.05, HR = 0.76 [95% CI: 0.57, 1.00]). There was 1, Gr 5 unlikely-related adverse event (AE) in the AS+RT arm and 2, Gr 5 possibly/probably-related AEs with AS+RT+CT. Conclusions: For high-risk, localized PCa, adjuvant CT improved the OS from 89% to 93% at 4 years. Toxicity was acceptable. This trial was designed with a short OS assessment period and additional follow-up is warranted to determine the long-term benefit of CT to the current standard of care of long-term AS+RT. This project was supported by grants U10CA21661, U10CA180868, U10CA180822, from the National Cancer Institute and Sanofi with additional support from AstraZeneca for Australian site participation. Clinical trial information: NCT00288080.