To give a preliminary report of clinical and treatment factors associated with toxicity in men receiving high-dose radiation therapy (RT) on a phase 3 dose-escalation trial.
The trial was initiated ...with 3-dimensional conformal RT (3D-CRT) and amended after 1 year to allow intensity modulated RT (IMRT). Patients treated with 3D-CRT received 55.8 Gy to a planning target volume that included the prostate and seminal vesicles, then 23.4 Gy to prostate only. The IMRT patients were treated to the prostate and proximal seminal vesicles to 79.2 Gy. Common Toxicity Criteria, version 2.0, and Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer late morbidity scores were used for acute and late effects.
Of 763 patients randomized to the 79.2-Gy arm of Radiation Therapy Oncology Group 0126 protocol, 748 were eligible and evaluable: 491 and 257 were treated with 3D-CRT and IMRT, respectively. For both bladder and rectum, the volumes receiving 65, 70, and 75 Gy were significantly lower with IMRT (all P<.0001). For grade (G) 2+ acute gastrointestinal/genitourinary (GI/GU) toxicity, both univariate and multivariate analyses showed a statistically significant decrease in G2+ acute collective GI/GU toxicity for IMRT. There were no significant differences with 3D-CRT or IMRT for acute or late G2+ or 3+ GU toxicities. Univariate analysis showed a statistically significant decrease in late G2+ GI toxicity for IMRT (P=.039). On multivariate analysis, IMRT showed a 26% reduction in G2+ late GI toxicity (P=.099). Acute G2+ toxicity was associated with late G3+ toxicity (P=.005). With dose-volume histogram data in the multivariate analysis, RT modality was not significant, whereas white race (P=.001) and rectal V70 ≥15% were associated with G2+ rectal toxicity (P=.034).
Intensity modulated RT is associated with a significant reduction in acute G2+ GI/GU toxicity. There is a trend for a clinically meaningful reduction in late G2+ GI toxicity with IMRT. The occurrence of acute GI toxicity and large (>15%) volumes of rectum >70 Gy are associated with late rectal toxicity.
Purpose Men with localized prostate cancer often are treated with external radiotherapy (RT) over 8 to 9 weeks. Hypofractionated RT is given over a shorter time with larger doses per treatment than ...standard RT. We hypothesized that hypofractionation versus conventional fractionation is similar in efficacy without increased toxicity. Patients and Methods We conducted a multicenter randomized noninferiority trial in intermediate-risk prostate cancer (T1 to 2a, Gleason score ≤ 6, and prostate-specific antigen PSA 10.1 to 20 ng/mL; T2b to 2c, Gleason ≤ 6, and PSA ≤ 20 ng/mL; or T1 to 2, Gleason = 7, and PSA ≤ 20 ng/mL). Patients were allocated to conventional RT of 78 Gy in 39 fractions over 8 weeks or to hypofractionated RT of 60 Gy in 20 fractions over 4 weeks. Androgen deprivation was not permitted with therapy. The primary outcome was biochemical-clinical failure (BCF) defined by any of the following: PSA failure (nadir + 2), hormonal intervention, clinical local or distant failure, or death as a result of prostate cancer. The noninferiority margin was 7.5% (hazard ratio, < 1.32). Results Median follow-up was 6.0 years. One hundred nine of 608 patients in the hypofractionated arm versus 117 of 598 in the standard arm experienced BCF. Most of the events were PSA failures. The 5-year BCF disease-free survival was 85% in both arms (hazard ratio short v standard, 0.96; 90% CI, 0.77 to 1.2). Ten deaths as a result of prostate cancer occurred in the short arm and 12 in the standard arm. No significant differences were detected between arms for grade ≥ 3 late genitourinary and GI toxicity. Conclusion The hypofractionated RT regimen used in this trial was not inferior to conventional RT and was not associated with increased late toxicity. Hypofractionated RT is more convenient for patients and should be considered for intermediate-risk prostate cancer.
Trial RTOG 9202 was a phase 3 randomized trial designed to determine the optimal duration of androgen deprivation therapy (ADT) when combined with definitive radiation therapy (RT) in the treatment ...of locally advanced nonmetastatic adenocarcinoma of the prostate. Long-term follow-up results of this study now available are relevant to the management of this disease.
Men (N=1554) with adenocarcinoma of the prostate (cT2c-T4, N0-Nx) with a prostate-specific antigen (PSA) <150 ng/mL and no evidence of distant metastasis were randomized (June 1992 to April 1995) to short-term ADT (STAD: 4 months of flutamide 250 mg 3 times per day and goserelin 3.6 mg per month) and definitive RT versus long-term ADT (LTAD: STAD with definitive RT plus an additional 24 months of monthly goserelin).
Among 1520 protocol-eligible and evaluable patients, the median follow-up time for this analysis was 19.6 years. In analysis adjusted for prognostic covariates, LTAD improved disease-free survival (29% relative reduction in failure rate, P<.0001), local progression (46% relative reduction, P=.02), distant metastases (36% relative reduction, P<.0001), disease-specific survival (30% relative reduction, P=.003), and overall survival (12% relative reduction, P=.03). Other-cause mortality (non-prostate cancer) did not differ (5% relative reduction, P=.48).
LTAD and RT is superior to STAD and RT for the treatment of locally advanced nonmetastatic adenocarcinoma of the prostate and should be considered the standard of care.
Abstract
Background
A total of 10%–20% of patients develop long-term toxicity following radiotherapy for prostate cancer. Identification of common genetic variants associated with susceptibility to ...radiotoxicity might improve risk prediction and inform functional mechanistic studies.
Methods
We conducted an individual patient data meta-analysis of six genome-wide association studies (n = 3871) in men of European ancestry who underwent radiotherapy for prostate cancer. Radiotoxicities (increased urinary frequency, decreased urinary stream, hematuria, rectal bleeding) were graded prospectively. We used grouped relative risk models to test associations with approximately 6 million genotyped or imputed variants (time to first grade 2 or higher toxicity event). Variants with two-sided Pmeta less than 5 × 10−8 were considered statistically significant. Bayesian false discovery probability provided an additional measure of confidence. Statistically significant variants were evaluated in three Japanese cohorts (n = 962). All statistical tests were two-sided.
Results
Meta-analysis of the European ancestry cohorts identified three genomic signals: single nucleotide polymorphism rs17055178 with rectal bleeding (Pmeta = 6.2 × 10−10), rs10969913 with decreased urinary stream (Pmeta = 2.9 × 10−10), and rs11122573 with hematuria (Pmeta = 1.8 × 10−8). Fine-scale mapping of these three regions was used to identify another independent signal (rs147121532) associated with hematuria (Pconditional = 4.7 × 10−6). Credible causal variants at these four signals lie in gene-regulatory regions, some modulating expression of nearby genes. Previously identified variants showed consistent associations (rs17599026 with increased urinary frequency, rs7720298 with decreased urinary stream, rs1801516 with overall toxicity) in new cohorts. rs10969913 and rs17599026 had similar effects in the photon-treated Japanese cohorts.
Conclusions
This study increases the understanding of the architecture of common genetic variants affecting radiotoxicity, points to novel radio-pathogenic mechanisms, and develops risk models for testing in clinical studies. Further multinational radiogenomics studies in larger cohorts are worthwhile.
Radiation therapy is a key modality in the treatment of cancer. Substantial progress has been made in unraveling the molecular events which underpin the responses of malignant and surrounding normal ...tissues to ionizing radiation. An understanding of the genes involved in processes such as DNA double-strand break repair, DNA damage response, cell-cycle control, apoptosis, cellular antioxidant defenses, and cytokine production, has evolved toward examination of how genetic variants, most often, single nucleotide polymorphisms (SNPs), may influence interindividual radioresponse. Experimental approaches, such as candidate SNP-association studies, genome-wide association studies, and massively parallel sequencing are being proposed to address these questions. We present a focused review of the evidence supporting an association between SNPs in DNA repair genes and radioresponse in normal tissues and tumors. Although preliminary results indicate possible associations, there are methodological weaknesses in many of the studies, and independent validation of SNPs as biomarkers of radioresponse in much larger cohorts will likely require research cooperation through international consortia.
To update the incidence of late toxicity of RTOG 9406, a three-dimensional conformal radiation therapy (3DCRT) dose escalation trial for prostate cancer.
A total of 1,084 men were registered to this ...Phase I/II trial of 3DCRT (eligible patients, 1,055). The dose for level I was 68.4 Gy; 73.8 Gy for level II; 79.2 Gy for level III; 74 Gy for level IV; and 78 Gy for level V. Patients in levels I to III received 1.8 Gy/fraction, and those in levels IV to V received 2.0 Gy/fraction. Disease group I patients were treated at the prostate only, group 2 patients were treated at the prostate and at the seminal vesicles with a prostate boost, and group 3 patients were treated at the prostate and seminal vesicles. The median follow-up period for surviving patients was 6.1 y (level V) to 12.1 y (level I).
The incidence rates of RTOG grade 3 or less gastrointestinal or genitourinary toxicity were 3%, 4%, 6%, 7%, and 9% in group 1 and 6%, 2%, 6%, 9%, and 12% in group 2 at dose levels of I, II, III, IV, and V, respectively. In group 1, level V patients had a higher probability of grade 2 late or greater gastrointestinal or genitourinary toxicity than those in levels I, II, and III (hazard ratio HR = 1.93, p = 0.0101; HR = 2.29, p = 0.0007; HR = 2.52, p = 0.0002, respectively). In group 2, dose level V patients had a higher probability of grade 2 or greater late gastrointestinal or genitourinary toxicity than those in dose levels II, III, and IV (HR = 2.61, p = 0.0002; HR = 2.22, p = 0.0051; HR = 1.60, p = 0.0276, respectively).
Tolerance to high-dose 3DCRT remains excellent. There is significantly more grade 2 or greater toxicity with a dose of 78 Gy at 2 Gy/fraction than with 68.4 Gy to 79.2 Gy at 1.8 Gy/fraction and with 74 Gy at 2 Gy/fraction.
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.
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.
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).
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.
We used a novel method (omega score) to analyse the effects of short-term androgen deprivation therapy (ADT) for prostate cancer according to the relative risk of competing events. Among patients ...with low-risk or favourable intermediate-risk disease, those with higher omega scores selectively benefitted from ADT.
Previous studies indicate that the benefit of short-term androgen deprivation therapy (ADT) with radiotherapy (RT) for prostate cancer depends on competing risks.
To determine whether a quantitative method to stratify patients by risk for competing events (omega score) could identify subgroups that selectively benefit from ADT.
An ancillary analysis of NRG/RTOG 9408 phase 3 trial (NCT00002597) involving 1945 prostate cancer patients was conducted.
Short-term ADT.
We applied generalised competing event regression models incorporating age, performance status, comorbidity, T category, Gleason score (GS), and prostate-specific antigen (PSA), to stratify patients according to relative hazards for primary cancer-related events (distant metastasis or prostate cancer death) versus competing noncancer mortality. We tested interactions between ADT and subgroups defined by standard risk criteria versus relative risk (RR) using the omega score.
T2b, higher GS, and higher PSA were associated with an increased RR for cancer-related versus competing mortality events (a higher omega score); increased age and comorbidity were associated with a decreased omega score. Of 996 patients with low-risk/favourable intermediate-risk (FIR) disease, 286 (28.7%) had a high omega score (≥0.314). Of 768 patients with unfavourable intermediate-risk disease, 175 (22.8%) had a low omega score. The overall discordance in risk classification was 26.1%. Both standard criteria and omega score identified significant interactions for the effect of ADT on cancer-related events and late mortality in low- versus high-risk subgroups. Within the low-risk/FIR subgroup, a higher omega score identified patients in whom ADT significantly reduced cancer events and improved event-free survival. Limitations are the need for external/prospective validation and lower RT doses than contemporary standards.
Stratification based on competing event risk is useful for identifying prostate cancer patients who selectively benefit from ADT.
We analysed the effectiveness of androgen deprivation therapy (ADT) for localised prostate cancer among patients, defined by the relative risk (RR) for cancer versus noncancer events. Among patients with traditional low-risk/favourable intermediate-risk disease, those with a higher RR benefitted from short-term ADT.
Shoulder pain and disability are well recognized complications associated with surgery for head and neck cancer. This study was designed to examine the effects of progressive resistance exercise ...training (PRET) on upper extremity pain and dysfunction in postsurgical head and neck cancer survivors.
Fifty-two head and neck cancer survivors were assigned randomly to PRET (n = 27) or a standardized therapeutic exercise protocol (TP) (n = 25) for 12 weeks. The primary endpoint was change in patient-rated shoulder pain and disability from baseline to postintervention. Secondary endpoints were upper extremity strength and endurance, range of motion, fatigue, and quality of life.
Follow-up assessment for the primary outcome was 92%, and adherence to the supervised PRET and TP programs were 95% and 87%, respectively. On the basis of intention-to-treat analyses, PRET was superior to TP for improving shoulder pain and disability (-9.6; 95% confidence interval 95% CI, -16.4 to -4.5; P = .001), upper extremity strength (+10.8 kg; 95% CI, 5.4-16.2 kg; P < .001), and upper extremity endurance (+194 repetitions x kg; 95% CI, 10-378 repetitions x kg; P = .039). Changes in neck dissection impairment, fatigue, and quality of life favored the PRET group but did not reach statistical significance.
The PRET program significantly reduced shoulder pain and disability and improved upper extremity muscular strength and endurance in head and neck cancer survivors who had shoulder dysfunction because of spinal accessory nerve damage. Clinicians should consider the addition of PRET in the rehabilitation of postsurgical head and neck cancer survivors.
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