Long-Term Outcomes of NRG/RTOG 0126, a Randomized Trial of High Dose (79.2 Gy) vs. Standard Dose (70.2 Gy) Radiation Therapy (RT) for Men with Localized Prostate Cancer

PURPOSE/OBJECTIVE(S)

NRG/RTOG 0126, a phase III trial for men with localized prostate cancer testing whether dose escalation to 79.2 Gy with 3DCRT/IMRT improved overall survival (OS). Long-term results of this trial are presented.

MATERIALS/METHODS

Patients with clinical stage T1b-T2b and either Gleason Score (GS) 2-6 and 10 ≤ PSA < 20 or GS 7 and PSA < 15 were eligible and randomized to receive 79.2 Gy or 70.2 Gy. No previous or concurrent androgen withdrawal therapy was administered. Treatment was delivered with 3DCRT/IMRT to a dose of 79.2 Gy in 44 fractions or 70.2 Gy in 39 fractions to the PTV encompassing the prostate and seminal vesicles. Image guidance was not required. ASTRO and Phoenix definitions were used for biochemical failure (ABF and PBF, respectively). OS was estimated by the Kaplan-Meier method and arms compared with the log-rank test. ABF, PBF, local progression (LP), distant metastases (DM) and time to late GI/GU toxicities were estimated by the cumulative incidence method and arms compared with Gray's test.

RESULTS

One thousand five hundred thirty-two men were randomized, 763 to 79.2 Gy and 769 to 70.2 Gy. 1499 were eligible, 748 and 751 in the 79.2 Gy and 70.2 Gy arms respectively. Median age was 71, 70% had PSA < 10 ng/ml, 84% with GS 7, 57% had T1 disease, and 66% treated with 3D-CRT. Outcomes are shown in the TABLE: . With a median follow up of 12 years, there was no significant difference in OS. There was a statistically significant decrease in the cumulative incidence of ABF, PBF, DM, LP, and salvage therapies in the 79.2 Gy arm. There were significantly higher rates of grade 2+ GI and GU toxicity in the 79.2 Gy arm. There were no statistically significant differences in the rates of grade 3+ GU or GI toxicity between either arm.

CONCLUSION

Long term follow up confirms no improvement in OS with dose escalation in this study population. However, there are significant improvements in ABF, PBF, DM, LP, and need for salvage therapy. Despite the use of more salvage therapy in the low dose arm, dose escalated RT resulted in lower rates of DM, a clinically relevant endpoint. Patients receiving dose escalation do experience a higher rate of grade 2+ GU and GI toxicity but no worse grade 3+ toxicities.

Genomic Classifier Performance in Intermediate-Risk Prostate Cancer: Results From NRG Oncology/RTOG 0126 Randomized Phase 3 Trial

PURPOSE

Intermediate-risk prostate cancer is a heterogeneous disease state with diverse treatment options. The 22-gene Decipher genomic classifier (GC) retrospectively has shown to improve risk stratification in these patients. We assessed the performance of the GC in men with intermediate-risk disease enrolled in NRG Oncology/RTOG 01-26 with updated follow-up.

METHODS AND MATERIALS

After National Cancer Institute approval, biopsy slides were collected from NRG Oncology/RTOG 01-26, a randomized phase 3 trial of men with intermediate-risk prostate cancer randomized to 70.2 Gy versus 79.2 Gy of radiation therapy without androgen deprivation therapy. RNA was extracted from the highest-grade tumor foci to generate the locked 22-gene GC model. The primary endpoint for this ancillary project was disease progression (composite of biochemical failure, local failure, distant metastasis, prostate cancer-specific mortality, and use of salvage therapy). Individual endpoints were also assessed. Fine-Gray or cause-specific Cox multivariable models were constructed adjusting for randomization arm and trial stratification factors.

RESULTS

Two-hundred fifteen patient samples passed quality control for analysis. The median follow-up was 12.8 years (range, 2.4-17.7). On multivariable analysis, the 22-gene GC (per 0.1 unit) was independently prognostic for disease progression (subdistribution hazard ratio [sHR], 1.12; 95% confidence interval [CI], 1.00-1.26; P = .04), biochemical failure (sHR, 1.22; 95% CI, 1.10-1.37; P < .001), distant metastasis (sHR, 1.28; 95% CI, 1.06-1.55; P = .01), and prostate cancer-specific mortality (sHR, 1.45; 95% CI, 1.20-1.76; P < .001). Ten-year distant metastasis in GC low-risk patients was 4% compared with 16% for GC high-risk patients. In patients with lower GC scores, the 10-year difference in metastasis-free survival rate between arms was -7%, compared with 21% for higher GC patients (P-interaction = .04).

CONCLUSIONS

This study represents the first validation of a biopsy-based gene expression classifier, assessing both its prognostic and predictive value, using data from a randomized phase 3 trial of intermediate-risk prostate cancer. Decipher improves risk stratification and can aid in treatment decision-making in men with intermediate-risk disease.

Quality-adjusted survival in women with gynecologic malignancies receiving IMRT after surgery: A Ppatient Rreported Ooutcome study of NRG oncology's RTOG 1203

INTRODUCTION

NRG/RTOG 1203 compared 3-D conformal radiotherapy (3D CRT) to intensity-modulated radiotherapy (IMRT) in patients with endometrial or cervical cancer requiring post-operative radiotherapy after hysterectomy. The purpose of this study was to report the first quality-adjusted survival analysis comparing the two treatments.

METHODS

NRG/RTOG 1203 randomized patients having undergone hysterectomy to either 3DCRT or IMRT. Stratification factors included RT dose, chemotherapy, and disease site. The EQ-5D, both index and visual analog scale (VAS), were obtained at baseline, 5 weeks after the start of RT, 4-6 weeks post RT and 1 and 3-years post RT. EQ-5D index and VAS scores along with quality-adjusted survival (QAS) were compared between treatment arms using the t-test at a two-sided significance level of 0.05.

RESULTS

NRG/RTOG 1203 enrolled 289 patients of which 236 consented to participate in the patient reported outcome (PRO) assessments. QAS was higher in women treated with IMRT, 1374 vs 1333 days (p = 0.5) compared to patients treated with 3DCRT, but this difference was not statistically different. Patients treated with IMRT had less of a decline in VAS score 5 weeks post RT, -5.04, compared to patients treated with 3DCRT, -7.48, although not statistically significant (p = 0.38).

CONCLUSION

This is the first report of the use of the EQ-5D comparing two radiotherapy techniques in the treatment of gynecologic malignancies after surgery. While there were no significant differences in QAS and VAS scores between patients who received IMRT vs. 3DCRT, RTOG 1203 was not powered to show statistical differences in these secondary endpoints.

Body composition and mortality in men receiving prostate radiotherapy: A pooled analysis of NRG/RTOG 9406 and NRG/RTOG 0126

PURPOSE

To validate the association between body composition and mortality in men treated with radiation for localized prostate cancer (PCa). Secondarily, to integrate body composition as a factor to classify patients by risk of all-cause mortality.

MATERIALS AND METHODS

Participants of NRG/Radiation Therapy Oncology Group (RTOG) 9406 and NRG/RTOG 0126 with archived computed tomography were included. Muscle mass and muscle density were estimated by measuring the area and attenuation of the psoas muscles on a single slice at L4-L5. Bone density was estimated by measuring the attenuation of the vertebral body at mid-L5. Survival analyses, including Cox proportional hazards models, assessed the relationship between body composition and mortality. Recursive partitioning analysis (RPA) was used to create a classification tree to classify participants by risk of death.

RESULTS

Data from 2066 men were included in this study. In the final multivariable model, psoas area, comorbidity score, baseline prostate serum antigen, and age were significantly associated with survival. The RPA yielded a classification tree with four prognostic groups determined by age, comorbidity, and psoas area. Notably, the classification among older (≥70 years) men into prognostic groups was determined by psoas area.

CONCLUSIONS

This study strongly supports that body composition is related to mortality in men with localized PCa. The inclusion of psoas area in the RPA classification tree suggests that body composition provides additive information to age and comorbidity status for mortality prediction, particularly among older men. More research is needed to determine the clinical impact of body composition on prognostic models in men with PCa.

Use of the Toxicity Index in Evaluating Adverse Events in Anal Cancer Trials: Analysis of RTOG 9811 and RTOG 0529

Novel toxicity metrics that account for all adverse event (AE) grades and the frequency of may enhance toxicity reporting in clinical trials. The Toxicity Index (TI) accounts for all AE grades and frequencies for categories of interest. We evaluate the feasibility of using the TI methodology in 2 prospective anal cancer trials and to evaluate whether more conformal radiation (using Intensity Modulated Radiation Therapy) results in improved toxicity as measured by the TI. Patients enrolled on NRG/RTOG 0529 or nonconformal RT enrolled on the 5-Fluorouracil/Mitomycin arm of NRG/RTOG 9811 were compared using the TI. Patients treated on NRG/RTOG 0529 had lower median TI compared with patients treated with nonconformal RT on NRG/RTOG 9811 for combined GI/GU/Heme/Derm events (3.935 vs 3.996, P=0.014). The TI methodology is a feasible method to assess all AEs of interest and may be useful as a composite metric for future efforts aimed at treatment de-escalation or escalation.

Intensity-Modulated Radiation Therapy Reduces Patient-Reported Chronic Toxicity Compared With Conventional Pelvic Radiation Therapy: Updated Results of a Phase III Trial

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned coprimary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.The purpose of this update was to determine differences in patient-reported chronic toxicity and disease outcomes with intensity-modulated radiation therapy (IMRT) compared with conventional pelvic radiation. Patients with cervical and endometrial cancers who received postoperative pelvic radiation were randomly assigned to conventional radiation therapy (CRT) or IMRT. Toxicity and quality of life were assessed using Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events, Expanded Prostate Cancer Index Composite (EPIC) bowel and urinary domains, and Functional Assessment of Cancer Therapy-General. Between 2012 and 2015, 279 eligible patients were enrolled to the study with a median follow-up of 37.8 months. There were no differences in overall survival (P = .53), disease-free survival (P = .21), or locoregional failure (P = .81). One year after RT, patients in the CRT arm experienced more high-level diarrhea frequency (5.8% IMRT v 15.1% CRT, P = .042) and a greater number had to take antidiarrheal medication two or more times a day (1.2% IMRT v 8.6% CRT, P = .036). At 3 years, women in the CRT arm reported a decline in urinary function, whereas the IMRT arm continued to improve (mean change in EPIC urinary score = 0.5, standard deviation = 13.0, IMRT v -6.0, standard deviation = 14.3, CRT, P = .005). In conclusion, IMRT reduces patient-reported chronic GI and urinary toxicity with no difference in treatment efficacy at 3 years.

Validation of the performance of the Decipher biopsy genomic classifier in intermediate-risk prostate cancer on the phase III randomized trial NRG Oncology/RTOG 0126

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Background: The 22-gene Decipher genomic classifier (GC) is a prognostic biomarker that has been validated in phase III trials in high-risk localized, post-prostatectomy, and metastatic and non-metastatic castration-resistant prostate cancer. Herein, we report the first validation of the biopsy GC in intermediate-risk prostate cancer from the phase III randomized trial NRG/RTOG 0126. Methods: After National Cancer Institute approval, biopsy slides were collected from the NRG biobank from RTOG 0126, a phase III randomized trial of men with intermediate-risk prostate cancer randomized to 70.2 Gy versus 79.2 Gy of radiotherapy without the use of concomitant hormone therapy. RNA was extracted from the highest grade tumor foci and processed through a quality control (QC) pipeline prior to generation of the previously locked 22-gene GC model. After GC data was generated it was linked with clinical outcomes to assess prognostic performance. The primary endpoint for this ancillary project was disease progression, defined as biochemical failure, local failure, distant metastasis or prostate cancer-specific mortality, as well as use of salvage therapy. Secondary endpoints included the previous individual endpoints, metastasis-free survival, and overall survival. Independent GC prognostic performance was assessed using cause-specific Cox or competing risk adjusted Fine-Gray multivariable models that included randomization arm and prognostic stratification factors. Death without events were treated as competing risks. Results: A total of 215 patient samples passed QC of the 449 that had suitable cDNA for expression analysis. The median follow-up was 12.8 years (range 2.4-17.7), and 61% had Gleason 3+4, 24% had Gleason 4+3, and the median PSA was 7.2 ng/mL (IQR 5.0-10.2). On multivariable analysis the 22-gene GC (per 0.1 unit) was independently prognostic for disease progression (subdistribution hazard ratio [sHR] 1.13, 95%CI (1.01-1.26), p = 0.03), biochemical failure (sHR 1.23, 95%CI 1.10-1.37, p < 0.001), distant metastasis (sHR 1.28, 95%CI 1.06-1.54, p = 0.01), and PCSM (sHR 1.45, 95%CI 1.20-1.76, p < 0.001). In patients with lower GC scores the 10-year distant metastasis rate difference between the 70.2 Gy and 79.2 Gy was 5%, as compared with 26% for higher GC patients. Conclusions: This study represents the first validation of any biopsy-based gene expression classifier in intermediate-risk prostate cancer. Decipher is independently prognostic and can identify patients that have low rates of metastatic events despite not receiving concurrent hormone therapy, and can be used to help personalize therapy in this setting. Clinical trial information: NCT00033631.

Improvement in Patient-Reported Outcomes With Intensity-Modulated Radiotherapy (RT) Compared With Standard RT: A Report From the NRG Oncology RTOG 1203 Study

PURPOSE

In oncology trials, the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) is the standard tool for reporting adverse events (AEs), but it may underreport symptoms experienced by patients. This analysis of the NRG Oncology RTOG 1203 compared symptom reporting by patients and clinicians during radiotherapy (RT).

PATIENTS AND METHODS

Patients with cervical or endometrial cancer requiring postoperative RT were randomly assigned to standard 4-field RT or intensity-modulated RT (IMRT). Patients completed the 6-item patient-reported outcomes version of the CTCAE (PRO-CTCAE) for GI toxicity assessing abdominal pain, diarrhea, and fecal incontinence at various time points. Patients reported symptoms on a 5-point scale. Clinicians recorded these AEs as CTCAE grades 1 to 5. Clinician- and patient-reported AEs were compared using McNemar's test for rates > 0%.

RESULTS

Of 278 eligible patients, 234 consented and completed the PRO-CTCAE. Patients reported high-grade abdominal pain 19.1% (P < .0001), high-grade diarrhea 38.5% (P < .0001), and fecal incontinence 6.8% more frequently than clinicians. Similar effects were seen between grade ≥ 1 CTCAE toxicity and any-grade patient-reported toxicity. Between-arm comparison of patient-reported high-grade AEs revealed that at 5 weeks of RT, patients who received IMRT experienced fewer GI AEs than patients who received 4-field pelvic RT with regard to frequency of diarrhea (18.2% difference; P = .01), frequency of fecal incontinence (8.2% difference; P = .01), and interference of fecal incontinence (8.5% difference; P = .04).

CONCLUSION

Patient-reported AEs showed a reduction in symptoms with IMRT compared with standard RT, whereas clinician-reported AEs revealed no difference. Clinicians also underreported symptomatic GI AEs compared with patients. This suggests that patient-reported symptomatic AEs are important to assess in this disease setting.

Expanded validation of the EPIC bowel and urinary domains for use in women with gynecologic cancer undergoing postoperative radiotherapy

OBJECTIVE

Women with endometrial or cervical cancer at risk for recurrence receive postoperative radiation therapy (RT). A patient reported outcomes (PRO) instrument to assess bowel and urinary toxicities is the Expanded Prostate Cancer Index Composite (EPIC), which has been validated in men with prostate cancer. As this instrument specifically measures bowel toxicity and the degree to which this is a problem, it was used in NRG Oncology/RTOG 1203 to compare intensity modulated RT (IMRT) to standard RT. This paper reports on the expanded validation of EPIC for use in women receiving pelvic RT.

METHODS

In addition to the EPIC bowel domain, urinary toxicity (EPIC urinary domain), patient reported bowel toxicities (PRO-CTCAE) and quality of life (Functional Assessment of Cancer Therapy (FACT)) were completed before, during and after treatment. Sensitivity, reliability and concurrent validity were assessed.

RESULTS

Mean bowel and urinary scores among 278 women enrolled were significantly worse during treatment and differed between groups. Acceptable to good reliability for bowel and urinary domain scores were obtained at all time points with the exception of one at baseline. Correlations between function and bother scores within the bowel and urinary domains were consistently stronger than those across domains. Correlations between bowel domain scores and PRO-CTCAE during treatment were stronger than those with the FACT.

CONCLUSION

Correlations within and among the instruments indicate EPIC bowel and urinary domains are measuring conceptually discrete components of health. These EPIC domains are valid, reliable and sensitive instruments to measure PRO among women undergoing pelvic radiation.

Patient-Reported Toxicity During Pelvic Intensity-Modulated Radiation Therapy: NRG Oncology-RTOG 1203

Purpose NRG Oncology/RTOG 1203 was designed to compare patient-reported acute toxicity and health-related quality of life during treatment with standard pelvic radiation or intensity-modulated radiation therapy (IMRT) in women with cervical and endometrial cancer. Methods Patients were randomly assigned to standard four-field radiation therapy (RT) or IMRT radiation treatment. The primary end point was change in patient-reported acute GI toxicity from baseline to the end of RT, measured with the bowel domain of the Expanded Prostate Cancer Index Composite (EPIC). Secondary end points included change in patient-reported urinary toxicity, change in GI toxicity measured with the Patient-Reported Outcome Common Terminology Criteria for Adverse Events, and quality of life measured with the Trial Outcome Index. Results From 2012 to 2015, 289 patients were enrolled, of whom 278 were eligible. Between baseline and end of RT, the mean EPIC bowel score declined 23.6 points in the standard RT group and 18.6 points in the IMRT group ( P = .048), the mean EPIC urinary score declined 10.4 points in the standard RT group and 5.6 points in the IMRT group ( P = .03), and the mean Trial Outcome Index score declined 12.8 points in the standard RT group and 8.8 points in the IMRT group ( P = .06). At the end of RT, 51.9% of women who received standard RT and 33.7% who received IMRT reported frequent or almost constant diarrhea ( P = .01), and more patients who received standard RT were taking antidiarrheal medications four or more times daily (20.4% v 7.8%; P = .04). Conclusion Pelvic IMRT was associated with significantly less GI and urinary toxicity than standard RT from the patient's perspective.

Predictors of Radiation Therapy-Related Gastrointestinal Toxicity From Anal Cancer Dose-Painted Intensity Modulated Radiation Therapy: Secondary Analysis of NRG Oncology RTOG 0529

PURPOSE

NRG Oncology RTOG 0529 assessed the feasibility of dose-painted intensity modulated radiation therapy (DP-IMRT) to reduce the acute morbidity of chemoradiation with 5-fluorouracil (5FU) and mitomycin-C (MMC) for T2-4N0-3M0 anal cancer. This secondary analysis was performed to identify patient and treatment factors associated with acute and late gastrointestinal (GI) adverse events (AEs).

METHODS AND MATERIALS

NRG Oncology RTOG 0529 treatment plans were reviewed to extract dose-volume data for tightly contoured small bowel, loosely contoured anterior pelvic contents (APC), and uninvolved colon outside the target volume (UC). Univariate logistic regression was performed to evaluate association between volumes of each structure receiving doses ≥5 to 60 Gy (V5-V60) in 5-Gy increments between patients with and without grade ≥2 acute and late GI AEs, and grade ≥3 acute GI AEs. Additional patient and treatment factors were evaluated in multivariate logistic regression (acute AEs) or Cox proportional hazards models (late AEs).

RESULTS

Among 52 evaluable patients, grade ≥2 acute, grade ≥2 late, and grade ≥3 acute GI AEs were observed in 35, 17, and 10 patients, respectively. Trends (P<.05) toward statistically significant associations were observed between grade ≥2 acute GI AEs and small bowel dose (V20-V40), grade ≥2 late GI AEs and APC dose (V60), grade ≥3 acute GI AEs and APC dose (V5-V25), increasing age, tumor size >4 cm, and worse Zubrod performance status. Small bowel volumes of 186.0 cc, 155.0 cc, 41.0 cc, and 30.4 cc receiving doses greater than 25, 30, 35, and 40 Gy, respectively, correlated with increased risk of acute grade ≥2 GI AEs.

CONCLUSIONS

Acute and late GI AEs from 5FU/MMC chemoradiation using DP-IMRT correlate with radiation dose to the small bowel and APC. Such associations will be incorporated in the dose-volume normal tissue constraint design for future NRG oncology anal cancer studies.