This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for External Beam Radiation Therapy (EBRT) With or Without Hormonal Therapy in Prostate Cancer (NCT00388804), a randomized phase 3 study. The primary outcome is Prostate Specific Antigen (PSA) Failures.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00388804 |
| Phase | Phase 3 |
| Condition | Prostate Cancer |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 39 |
| Arms in the primary outcome | 2 |
| Lead sponsor | M.D. Anderson Cancer Center |
| Results posted | Yes |
2. Clinical Question
Population
Men with prostate cancer traditionally considered at intermediate risk for PSA failure after conventional local therapy were the intended population. The registry record reports enrollment of 39 participants and says one person was not treated and was excluded from the primary analysis. Further eligibility details are not reported in the registry record.
Intervention
The intervention was radiation therapy with short-course hormone therapy. The listed hormone medicines include bicalutamide or flutamide, together with leuprolide or goserelin. The registry describes radiation over 8 1/2 weeks. It lists dose-escalation IMRT, 3D-CRT, or proton therapy in the study objective, but does not identify which radiation technique each participant received.
Comparator
The comparison group received radiation therapy without hormone therapy. Its arm description specifies 42 treatments over 8 1/2 weeks, 5 days per week with 2 days rest in between. The registry does not report the radiation technique used for each participant.
Primary question
The primary question was whether adding short-course androgen suppression to radiation would improve PSA outcome compared with radiation alone. PSA failure was defined as a rising PSA without evidence of local or distant recurrence. The posted primary outcome is the number of participants with PSA failure from 3 months up to 2 years.
This is a question about a biomarker-based outcome, not a direct comparison of symptoms or survival. The registry also names local control, freedom from distant metastasis, overall survival, quality of life, testosterone, hemoglobin, and pretreatment biomarkers as secondary objectives. No secondary results are posted in the registry record. The primary outcome therefore addresses only the recorded PSA-failure measure; it cannot answer those other questions.
3. Trial Design
The registry describes a randomized, phase 3, parallel-group trial with no masking. It lists M.D. Anderson Cancer Center as the sponsor. The recorded enrollment is 39, and the trial status is terminated. The reason for termination is not reported in the registry record. The record identifies two groups: RT Group 1 and RT Group 2 + Hormone Therapy.
RT Group 1 received radiation therapy over 8 1/2 weeks, with 42 treatments, 5 days per week and 2 days rest in between. The other group received radiation over the same stated period with hormone therapy. Listed medicines are bicalutamide or flutamide during the first 21-30 days, plus leuprolide or goserelin. The arm description contains incomplete dosing information for goserelin, so its full schedule is not reported in the registry record. The record does not state how the hormone regimens were selected or whether every listed radiation technique was used.
The primary outcome analysis includes 17 participants in RT Group 1 and 21 in RT Group 2 + Hormone Therapy. The registry says one person was not treated and therefore excluded from that analysis. It does not report further details about the allocation process, concealment, eligibility criteria, adherence, or reasons for exclusion. The record’s primary outcome timeframe is 3 months up to 2 years, with PSA assessment at three-month intervals during the initial two years and every 6 months thereafter. The primary outcome description does not provide later follow-up results. No analysis methods or secondary results are posted in the registry record.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Before assignment: Of the 39 enrolled participants, one participant was excluded from the trial before assignment to groups.
Overall Study
| Stage | RT Group 1 | RT Group 2 + Hormone Therapy |
|---|---|---|
| STARTED | 17 | 21 |
| COMPLETED | 17 | 21 |
| NOT COMPLETED | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: One person was not treated and therefore excluded from the analysis.
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | RT Group 1 | RT Group 2 + Hormone Therapy | Total |
|---|---|---|---|---|
| Participants analysed | 17 | 21 | 38 | |
| Age Continuous | years | 66.3 (53 to 78) | 64.5 (48 to 73) | 65.3 (48 to 78) |
| Sex: Female, Male: Female | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Male | Participants | 17 | 21 | 38 |
| Region of Enrollment: United States | participants | 17 | 21 | 38 |
6. Primary Endpoint
The registry lists the primary outcome as Prostate Specific Antigen (PSA) Failures, measured over 3 months up to 2 years.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants with prostate-specific antigen (PSA) failure. The registry defines failure as a rising PSA without evidence of local or distant recurrence. PSA was to be measured at baseline and after radiation at three-month intervals during the initial two years, then every 6 months thereafter. The posted outcome timeframe is 3 months up to 2 years.
In general, an endpoint is a prespecified measure used to address a trial’s central research question. PSA is a laboratory marker, so this endpoint records a biochemical outcome rather than directly measuring symptoms, quality of life, distant metastasis, or survival. The registry’s primary objective was to assess whether short-course androgen suppression alongside radiation could improve PSA outcome relative to radiation alone. It separately lists local control, freedom from distant metastasis, overall survival, and quality-of-life measures as secondary objectives.
The posted result is a count of participants with an event in each group. It records zero PSA failures among 17 participants in RT Group 1 and zero among 21 participants in RT Group 2 + Hormone Therapy. These counts describe the recorded endpoint during the stated timeframe. They do not establish what happened after that timeframe, and the registry record does not report follow-up completeness or additional primary-outcome results.
7. Results Posted in the Registry
- RT Group 2 + Hormone Therapy: 0.0% (0/21) versus 0.0% (0/17) on control; risk difference 0.0 percentage points (95% CI 0.0 to 0.0); unadjusted two-proportion z-test p = n/a.
Risk difference: RT Group 2 + Hormone Therapy
95% CI: 0.0 to 0.0 percentage points
Recalculated from the posted summary statistics
8. Statistical Interpretation
The posted primary outcome records zero PSA failures among 17 analyzed participants receiving radiation alone and zero among 21 analyzed participants receiving radiation plus hormone therapy. The reported risk difference for the combination group relative to the radiation-only group is 0.0, with a confidence interval from 0.0 to 0.0. These are the registry’s posted values; they describe no observed separation between the groups for this endpoint in the analyzed participants.
This result should be read as a description of the recorded observations, not as proof that the treatments have identical effects or that PSA failure cannot occur. When neither group has a recorded event, the observed difference is zero, but a small trial with no observed events has limited information for distinguishing among possible underlying event risks. The registry record does not give an analysis method explaining how the reported interval was obtained, and it does not post a hypothesis-test result. A separate inferential p-value is therefore not reported in the registry record.
The analysis excludes one person who was not treated. The record does not say which group that person was assigned to, why treatment was not received, or how that person’s outcome was handled beyond exclusion. The listed outcome denominators total the analyzed participants, not the full enrollment. Without additional participant-level follow-up information, the posted counts cannot show whether all included participants had complete assessment through the stated period.
The trial is marked terminated, but the reason for termination is not reported in the registry record. The record also reports no posted analyses and no secondary outcomes. As a result, the primary result cannot be supplemented with registry results about survival, recurrence beyond PSA failure, quality of life, or other listed objectives. The posted data support a narrow conclusion: no PSA failures were recorded in either analyzed group within the stated primary-outcome timeframe. They do not establish a comparative treatment benefit, equivalence, or the longer-term course of outcomes.
9. Statistical Methods Explained
The reported primary measure is a binary outcome: each participant either met the registry’s definition of PSA failure during the stated timeframe or did not. For a binary endpoint, the event count and the number assessed in each group are central to interpretation. Here, the registry records zero events in each group, with 17 analyzed in RT Group 1 and 21 in RT Group 2 + Hormone Therapy. The result is not a continuous PSA measurement, and the posted outcome does not give individual PSA values or the timing of any measurements for individual participants.
What does the risk difference represent?
A risk difference compares the event proportions in two groups by subtracting one group’s proportion from the other’s. In general, it is expressed on the same scale as the underlying event proportions. The registry reports a risk difference of 0.0 for RT Group 2 + Hormone Therapy relative to RT Group 1. With no recorded events in either group, the two observed proportions are both zero, and the recorded difference is also zero. This is an unadjusted comparison in the posted summary; the registry record does not describe covariate adjustment or a model used for this outcome.
A zero observed difference does not mean the underlying event risks are known to be equal. It means that the observed counts produced no difference in this sample. General statistical reasoning distinguishes an estimate from the range of values that could remain compatible with the data. That distinction matters especially when there are no observed events and the analyzed groups are small. The posted confidence interval is also 0.0 to 0.0, but the record does not explain the calculation method or how uncertainty was handled in the setting of zero events.
What does randomization contribute?
In general, random allocation is intended to make comparison groups similar on average with respect to factors present before assignment. It does not guarantee balance in every trial, and it cannot correct every problem that may arise after assignment, such as incomplete outcome assessment or treatment not received. This registry identifies the study as randomized but does not report the sequence-generation or allocation-concealment procedures. It also states that masking was none. The record does not describe whether outcome assessors were masked.
How should the analysis population be understood?
The primary outcome population excludes one person who was not treated. The record does not report whether that person was assigned to a group, the reason treatment was not received, or whether an outcome was available. Excluding participants after randomization can affect the comparability intended by random assignment, depending on circumstances. The registry does not report an intention-to-treat analysis or another explicit analysis-population definition. It is therefore most precise to describe the posted result as an analysis of the reported treated population, with one untreated person excluded, rather than to label it using an analysis strategy that is not stated.
What can be said about planning calculations?
The registry record does not report the trial’s sample-size justification or its planned statistical analysis. Any planning illustrations associated with the observed effect are hypothetical calculations, not evidence about the trial’s original design or observed power. In general, such illustrations depend on assumptions about the effect to detect, significance level, allocation, and statistical approximation. The stated assumptions for the illustration use a two-sided significance level of 0.05, equal allocation, and a normal approximation, with the effect set as a fraction of the observed effect. Because the observed risk difference is 0.0, these illustrations should not be treated as a reconstruction of the trial’s protocol or evidence that the trial was adequately sized.
The registry reports one outcome measure and zero posted analyses. It does not report whether interim analyses were planned or performed, how missing outcome data were handled, or how any planned comparisons were to be interpreted. These details matter because they define how results are selected, analyzed, and reported. General statistical explanations can clarify the meaning of the posted estimate, but they cannot fill in methods that are not reported in the registry record.
10. Confidence Intervals and Precision
A confidence interval is, in general, a range produced by a statistical method to represent uncertainty around an estimate. Its interpretation depends on the method used and the assumptions behind that method. The registry reports a risk-difference estimate of 0.0 and an interval from 0.0 to 0.0 for the comparison of RT Group 2 + Hormone Therapy with RT Group 1. The interval is therefore reported with no width, but the registry record does not identify the calculation method or explain how it handled zero events in both groups.
That numerical interval should not be read as proof of perfect precision or as evidence that all clinically meaningful differences have been ruled out. The underlying event counts are zero in both groups, and the analyzed groups include 17 and 21 participants. No observed events means the data provide no event-based separation between groups in this sample. The displayed estimate and interval alone do not establish that the true event risks are identical.
Precision also depends on whether outcome assessments were complete and whether follow-up was comparable. The registry describes PSA monitoring at three-month intervals during the initial two years and every 6 months thereafter, while the primary outcome timeframe is 3 months up to 2 years. It does not report completeness of follow-up, participant-level missingness, or results after the stated timeframe. The precision of longer-term comparisons cannot be assessed from the posted primary outcome.
No separate p-value is reported in the registry record. The record does not give enough information to reconstruct an alternative interval or test without adding assumptions. The appropriate reading is therefore to report the estimate and interval as posted, note the absence of events in both analyzed groups, and acknowledge that the registry does not describe the method or broader uncertainty sufficiently to support stronger claims.
11. Multiplicity, Missing Data and Analysis Populations
The registry lists several secondary objectives in addition to the primary PSA-failure endpoint. They include local control, freedom from distant metastasis, overall survival, health-related quality of life, prognostic value of pretreatment testosterone, changes in hemoglobin, and pretreatment biomarkers. No secondary results are posted in the registry record. It does not report whether these objectives were tested, how many comparisons were planned, or whether any multiplicity strategy was specified.
In general, multiplicity arises when several outcomes or comparisons are assessed. If many statistical tests are conducted, the chance of finding an apparently notable result by chance can increase. A prespecified plan can help readers understand which findings are primary, how secondary findings are treated, and whether adjustments are used. The registry identifies PSA failure as the primary endpoint, but does not report a statistical analysis plan or any approach to multiplicity. No conclusion about adjustment or the interpretation of unreported secondary analyses can be drawn.
For missing data, the record states that one person was not treated and was excluded from the primary analysis. It does not report the assigned group, the reason for non-treatment, or whether an outcome was available for that person. It also does not describe missing PSA measurements among analyzed participants, loss to follow-up, or imputation methods. The fact that an analyzed count is reported does not establish that outcome data were complete for every participant throughout the timeframe.
The registry does not report an explicit intention-to-treat analysis, per-protocol analysis, or other formal analysis-population definition. This limits assessment of how randomization was preserved in the analysis and how exclusions may have affected the comparison. These omissions do not change the posted counts, but they limit interpretation of how those counts relate to the full randomized population and to the trial’s broader set of objectives.
12. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| RT Group 1 | 0 | 17 | 0.0% |
| RT Group 2 + Hormone Therapy | 0 | 21 | 0.0% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| RT Group 1 | 4 of 17 |
| RT Group 2 + Hormone Therapy | 1 of 21 |
Most frequent non-serious adverse event terms
| Event term | Organ system | RT Group 1 | RT Group 2 + Hormone Therapy |
|---|---|---|---|
| Urinary frequency | Renal and urinary disorders | 2 of 17 | 1 of 21 |
| Urinary incontinence | Renal and urinary disorders | 1 of 17 | 0 of 21 |
| Dysuria | Renal and urinary disorders | 1 of 17 | 0 of 21 |
| Diarrhea | Gastrointestinal disorders | 1 of 17 | 0 of 21 |
| Alanine transaminase (ALT) | Metabolism and nutrition disorders | 1 of 17 | 0 of 21 |
| Aspartate transaminase (AST) | Metabolism and nutrition disorders | 1 of 17 | 0 of 21 |
The registry reports zero participants with serious adverse events in RT Group 1, among 17 at risk, and zero in RT Group 2 + Hormone Therapy, among 21 at risk. No serious adverse-event terms are listed. These are participant counts in the posted safety data; they do not establish that no events occurred outside the registry’s recorded categories or reporting period.
For other adverse events, the record reports 4 affected participants among 17 at risk in RT Group 1 and 1 among 21 at risk in RT Group 2 + Hormone Therapy. These counts are distinct from the serious adverse-event counts. The registry record does not provide event descriptions, severity, timing, or the number of total events experienced by each participant. It also does not explain the collection period or how adverse events were attributed to treatment.
Deaths are not reported in the registry record. The small group counts and lack of detail mean that these posted safety figures should be read descriptively, rather than as a comprehensive comparison of safety between groups. They do not establish that either regimen is safer or less safe.
13. What the Result Does, and Does Not, Mean
The registry’s primary result is straightforward at the level of observed counts: no PSA failures were recorded in either analyzed group during the stated timeframe. The reported risk difference is 0.0, with a confidence interval from 0.0 to 0.0. This describes the posted data for 17 participants receiving radiation alone and 21 receiving radiation with hormone therapy, after one untreated person was excluded.
The result does not show that the groups have identical underlying outcomes. A trial with no events in either group may produce no observed difference while still leaving uncertainty about what would be observed in a larger group or over longer follow-up. The registry does not report a method for the interval, a separate hypothesis-test result, or follow-up completeness. It therefore does not support a conclusion of equivalence or a definitive conclusion about comparative effects.
The endpoint is PSA failure, defined as a rising PSA without evidence of local or distant recurrence. It is not the same as overall survival, local control, distant metastasis, symptoms, or quality of life. Although the registry names these outcomes among its secondary objectives, it posts no secondary results. No inference about those outcomes follows from the primary endpoint counts.
The record also does not state why the trial was terminated, whether the planned enrollment was achieved, or what statistical analysis was intended. Those gaps leave open important questions about the trial’s conduct and interpretation. The result is best understood as a limited descriptive finding in the analyzed sample and timeframe, rather than a general statement about all people with intermediate-risk prostate cancer or all radiation and hormone regimens.
14. Why This Trial Matters Statistically
This trial is statistically informative as an example of how a zero-event result can be easy to state but difficult to interpret. Both groups have zero recorded PSA failures, so the observed comparison is centered at no difference. At the same time, the analyzed groups are small, and the registry does not explain the method behind the confidence interval reported as 0.0 to 0.0. A point estimate and its reported interval must be read alongside the event counts and the method that generated them.
The record also illustrates why the analysis population matters. One person was not treated and was excluded from the primary analysis, but the registry does not identify the assigned group or explain the circumstances. Readers cannot fully assess how this exclusion relates to randomization or the full enrolled population. Stating the analyzed denominators is useful, but a clear account of exclusions and missing outcomes is also important.
There is a further distinction between a planned clinical question and the information actually posted. The registry describes multiple secondary objectives, yet reports no secondary results and no analyses. It marks the trial terminated without reporting why. Those omissions restrict the scope of interpretation, regardless of how clearly the primary count is presented.
For biostatisticians and clinical researchers, the record underscores the value of transparent reporting of analysis plans, interval methods, follow-up completeness, and participant disposition. Such detail helps readers distinguish a result that is simply uninformative about differences from one that provides precise evidence of similarity. The posted data support a descriptive comparison for the specified PSA endpoint, while leaving those broader statistical questions unresolved.
15. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
Several limitations follow directly from the registry record. The trial is marked terminated, but the reason is not reported. The record does not explain whether enrollment ended as planned or whether the termination affected follow-up or outcome collection. The listed enrollment is 39, while the primary analysis includes 17 and 21 participants; one person was not treated and excluded. The registry does not identify that person’s assigned group or provide a fuller account of participant disposition.
The primary endpoint timeframe is 3 months up to 2 years, and the registry describes PSA measurement schedules. It does not report the number of participants with complete follow-up, missing PSA assessments, or results beyond the stated timeframe. The confidence interval is reported as 0.0 to 0.0, but the method used to calculate it is not described. No separate hypothesis-test result or statistical analysis plan is posted.
Although the study objective mentions dose-escalation IMRT, 3D-CRT, or proton therapy, the record does not report which technique participants received. The description of the hormone intervention is incomplete for goserelin, and the full regimen-selection process is not reported. The registry also provides no secondary outcome results, despite listing several secondary objectives. These limitations constrain assessment of treatment exposure, outcome completeness, and the broader clinical questions raised by the trial.
16. Related Tutorials
17. Related Statistical Calculators
18. Sources
- ClinicalTrials.gov: External Beam Radiation Therapy (EBRT) With or Without Hormonal Therapy in Prostate Cancer — NCT00388804.
- Registry record last updated 2012-08-08; status last verified 2012-06.
- Results first posted 2012-08-08.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
Continue through the Clinical Biostats statistical pathway
Use this trial's endpoint as a starting point for deeper study of effect measures, confidence intervals, and sample-size planning.
19. Record Summary
NCT00388804 is a randomized, phase 3, parallel-group trial with no masking, sponsored by M.D. Anderson Cancer Center. Its status is terminated. The trial compared radiation therapy alone with radiation therapy plus short-course hormone therapy in people with prostate cancer described as intermediate risk.
The primary endpoint was PSA failure, defined as a rising PSA without evidence of local or distant recurrence, during 3 months up to 2 years. The posted result is zero failures among 17 participants in the radiation-only group and zero among 21 in the combination group. The reported risk difference is 0.0, with a confidence interval from 0.0 to 0.0. One person was not treated and was excluded from the primary analysis.
The registry does not report the reason for termination, a statistical analysis plan, a confidence-interval method, or secondary results. The posted counts describe the primary endpoint in the analyzed participants; they do not establish equivalence or address unreported outcomes.