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 Trial of ADT and SBRT Versus SBRT for Intermediate Prostate Cancer (NCT03056638), a randomized phase 3 study. The primary outcome is Number of Patients With a Positive Biopsy.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT03056638 |
| Phase | Phase 3 |
| Condition | Prostate Cancer |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 56 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Memorial Sloan Kettering Cancer Center |
| Results posted | Yes |
2. Clinical Question
Population
People with intermediate-risk prostate cancer. The registry record lists prostate cancer as the condition and describes the primary outcome population as intermediate-risk prostate cancer patients. It also says data for that population were not collected.
Intervention
Degarelix, a short course of androgen deprivation therapy, given monthly for 6 months, together with stereotactic body radiation therapy (SBRT), specified as 8 Gy x 5.
Comparator
SBRT alone, also specified as 8 Gy x 5. The registry record describes the study as randomized and parallel, with no masking.
Primary question
Whether the 2-year biopsy positivity rate differs between treatment with SBRT plus short-course androgen deprivation therapy and treatment with SBRT alone. The record lists the number of patients with a positive biopsy as the primary outcome, but reports that the outcome data were not collected.
This is a question about a tissue-sampling outcome after treatment, rather than a question about symptoms, survival, or a broader measure of disease control. A positive biopsy means that cancer is identified in the sampled tissue; a negative biopsy means it was not identified in the tissue examined. As a general statistical point, a biopsy result is an observed measure that depends on the sampled tissue and the assessment process. It should not be treated as a complete measure of every aspect of a person’s health or cancer status.
The registry record does not report a comparison of biopsy positivity between the randomized groups. It therefore cannot show the direction or size of any difference, or how precisely such a difference was estimated. The clinical question is clear from the registered endpoint and treatment arms, but the outcome results needed to answer it are not reported in the registry record.
3. Trial Design
This was a phase III randomized trial with a parallel-group design. The registry describes the study as unmasked, meaning masking was not used according to the record. It lists Memorial Sloan Kettering Cancer Center as the sponsor. The recorded enrollment is 56.
The intervention arm combined Degarelix with SBRT. The arm description specifies Degarelix monthly for 6 months and SBRT 8 Gy x 5. The comparison arm received SBRT 8 Gy x 5 without the listed Degarelix intervention. The registry’s brief summary characterizes the study as comparing stereotactic radiation with a short course of Degarelix against stereotactic radiation alone.
The study start date is 2017-03-28, and the primary completion date is 2023-08-16. Its status is terminated. The reason for termination is not reported in the registry record. The allocation procedure, randomization ratio, and details of how the random sequence was generated or concealed are not reported in the registry record. The record also does not describe whether treatment adherence, crossover, or protocol deviations were assessed.
The design establishes the intended basis for a randomized comparison, but it does not by itself provide evidence about the primary outcome. The registry lists the 2-year number of patients with a positive biopsy as the primary outcome and explicitly states that data for the outcome population were not collected. No primary outcome analysis is listed. As a result, the randomized design and treatment descriptions can be characterized, but the intended efficacy comparison cannot be interpreted from the registry results.
Random assignment is generally used to make treatment groups comparable at the point of allocation, on average, with respect to both measured and unmeasured characteristics. That general rationale does not establish that the groups in this trial were balanced, particularly because baseline characteristics and outcome data are not reported in the record. The absence of masking is also relevant context for interpreting the design, but the record does not describe how outcome assessment was conducted.
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.
Overall Study
| Stage | Degarelix in Conjunction With Stereotactic Body Radiosurgery | Stereotactic Body Radiosurgery (SBRT) |
|---|---|---|
| STARTED | 27 | 29 |
| COMPLETED | 26 | 29 |
| NOT COMPLETED | 1 | 0 |
Reasons for not completing this period:
| Reason | Degarelix in Conjunction With Stereotactic Body Radiosurgery | Stereotactic Body Radiosurgery (SBRT) |
|---|---|---|
| Death | 1 | 0 |
Analysis population for the primary outcome, as defined in the registry: N/A - data were not collected
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 | Degarelix in Conjunction With Stereotactic Body Radiosurgery | Stereotactic Body Radiosurgery (SBRT) | Total |
|---|---|---|---|---|
| Participants analysed | 27 | 29 | 56 | |
| Age, Continuous | years | 68 (54 to 79) | 70 (55 to 79) | 68 (54 to 79) |
| Sex: Female, Male: Female | Participants | 0 | 0 | 0 |
| Sex: Female, Male: Male | Participants | 27 | 29 | 56 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 1 | 1 | 2 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 24 | 26 | 50 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 2 | 2 | 4 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Asian | Participants | 1 | 2 | 3 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Black or African American | Participants | 6 | 6 | 12 |
| Race (NIH/OMB): White | Participants | 19 | 19 | 38 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 1 | 2 | 3 |
| Region of Enrollment: United States | Participants | 27 | 29 | 56 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Patients With a Positive Biopsy, measured over 2 years.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The registered primary endpoint is the number of patients with a positive biopsy at 2 years. Its description states that the trial was intended to compare the 2-year biopsy positivity rate for intermediate-risk prostate cancer patients treated with SBRT plus short-course androgen deprivation therapy against SBRT alone. The registry lists the outcome population as “N/A - data were not collected.”
A biopsy provides a tissue-based assessment. In general, a positive result records cancer identified in sampled tissue, while a negative result records that cancer was not identified in the tissue examined. Such an endpoint can be used to assess whether cancer is detected in prostate tissue at a specified follow-up time. It is a particular clinical measure and should not be conflated with other outcomes, such as survival, symptoms, or treatment-related harms.
The planned time point matters because biopsy findings can depend on when tissue is sampled. The record specifies 2 years, but does not report the biopsy procedures, assessment criteria, handling of missing or unevaluable samples, or the number of participants assessed. These details are not reported in the registry record.
Because the endpoint data were not collected, no positivity rate, between-group effect estimate, or confidence interval is available from the record. The primary endpoint is therefore identifiable as a planned measure, but its observed values and comparative results are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a randomized comparison of Degarelix plus SBRT against SBRT alone, with biopsy positivity at 2 years as the primary outcome. However, it states that outcome data were not collected for the primary outcome population. It lists no outcome analyses. Consequently, there is no reported estimate of the difference between treatment groups for biopsy positivity, and there is no uncertainty interval or statistical test for that comparison in the record.
This absence of an estimate is not evidence that the groups had the same biopsy outcome. It also does not establish that one regimen had a better or worse outcome. Without observed outcome data, the direction, magnitude, and precision of a comparative effect cannot be assessed. The statistical conclusion is limited: the registry describes the question and intended endpoint but does not report results that answer the question.
The status is terminated, but the reason for termination is not reported in the registry record. Termination alone does not reveal whether the study stopped because of recruitment, operational, safety, funding, administrative, or other considerations. None of those explanations should be inferred from the status field. Nor does the record state whether the study ended before or after any planned analysis milestones.
The safety information is separate from the missing primary outcome. The record reports serious adverse event counts, other adverse event counts, and deaths for the treatment groups. These observations describe recorded safety events in the registry, but do not substitute for the planned biopsy comparison. They also do not, by themselves, establish whether an event was caused by treatment or whether the groups differed in underlying risk.
General statistical interpretation depends on both an estimated effect and its uncertainty. An effect estimate describes the observed contrast between groups; a confidence interval indicates a range of values compatible with the data under the model and assumptions used. Neither is reported for the primary outcome. A p-value is also not reported, and should not be inferred from the enrollment or adverse-event counts.
The registry includes a planning-illustration assumption statement: two-sided significance level 0.05, equal allocation between arms, and a normal approximation, with the effect to detect expressed as a fraction of the observed effect. These are described as assumptions for planning illustrations, not as the trial’s documented design justification. The registry does not report a sample-size justification or an observed primary outcome effect. A planning calculation cannot replace missing outcome data or be read as evidence about the treatment comparison.
9. Statistical Methods Explained
The statistical information in the registry record is limited. It identifies a randomized, parallel-group phase III design and a primary endpoint, but lists no outcome analyses. The primary outcome population is marked as data not collected. The methods explanation below distinguishes what the record states from general statistical principles; the latter describe how such a comparison is often understood and do not establish which analysis was conducted in this trial.
What does randomization contribute?
In general, randomization assigns participants to treatment groups by chance. Its purpose is to reduce systematic differences between groups at allocation, including differences in factors that are measured and factors that are not measured. It does not guarantee identical groups, especially in a trial with limited enrollment. Group comparability is assessed using baseline information, which is not reported in the registry record.
The record says the study was randomized but does not report the sequence-generation method, allocation concealment, randomization ratio, or stratification factors. Those details can matter when evaluating how randomization was implemented. The recorded enrollment is 56, but enrollment alone does not disclose how many participants were assigned to each group, received each treatment, completed follow-up, or contributed an outcome.
How would a binary endpoint be compared?
In general, biopsy positivity is a binary outcome: each assessed participant is classified as positive or not positive under the study’s assessment rules. A comparison could describe the outcome in each arm and estimate a contrast between those arm-level results. The choice of contrast and statistical method depends on the protocol, data structure, and analysis plan. The registry record does not report a primary outcome analysis, the biopsy results, group denominators, or the analysis method, so none can be attributed to this trial.
An effect estimate would quantify the observed between-group contrast, while a confidence interval would communicate its statistical uncertainty. A wider interval generally indicates less precision, and a narrower interval generally indicates greater precision, subject to the model and assumptions. A confidence interval is not a guarantee that the true effect lies within its limits; it is interpreted through the statistical procedure that produced it. No primary outcome estimate or interval is reported in the registry record.
A significance test addresses compatibility between observed data and a specified null hypothesis under a statistical model. A p-value is not a measure of the size or clinical importance of an effect. It also does not provide the probability that the null hypothesis is true. Because there is no reported primary outcome analysis, there is no registered p-value for that endpoint to interpret.
What do the planning assumptions mean?
The registry describes planning illustrations based on a two-sided significance level of 0.05, equal allocation, and a normal approximation. It says the effect targeted in those illustrations is a stated fraction of the observed effect. These are assumptions for planning calculations, not a reported account of the trial’s own sample-size justification. No justification for the enrollment target is reported in the registry record.
In general, a sample-size calculation depends on assumptions about the effect to detect, outcome variability or event frequency, significance level, allocation, and desired power. Changing those assumptions changes the planning result. Where a planning illustration uses a fraction of an observed effect, that illustration is a hypothetical design scenario based on that chosen fraction. It is not an observed treatment effect, and its calculated power is not the trial’s observed power. The record does not provide a primary outcome effect estimate, so the planning statement cannot be used to infer how the treatment groups actually compared.
For a two-arm illustration, participants per arm refers to a planning quantity under the stated allocation assumption. It is not the same as the number enrolled or the number analyzed in this trial. The registry’s planning note also distinguishes participant-based calculations from time-to-event calculations, which use a total number of events. The listed primary endpoint is biopsy positivity, not a time-to-event endpoint. No specific sample-size illustration results are included in the registry record.
Why can variation matter?
General statistical methods must account for the type and variability of the outcome. For a binary outcome, observed proportions can vary because of chance, and the amount of information depends on the number of participants with observed outcomes in each group. Missing outcome measurements reduce the information available and may introduce bias if missingness is related to prognosis or treatment. Since the registry says the primary outcome data were not collected, the amount and pattern of missingness cannot be evaluated.
Over-dispersion is a general issue for count outcomes when observed variability exceeds what a simple model assumes. It can make standard errors too small if not accommodated. This endpoint is described as biopsy positivity, not a count of repeated events, and the registry does not report an analysis model. Therefore, over-dispersion is not a documented issue for the primary analysis in this record; it is a general modeling consideration rather than a trial-specific finding.
What can be concluded from the statistical record?
The record supports a description of the study design, treatment arms, intended endpoint, and status. It does not support a quantitative assessment of the primary treatment contrast. No adjustment variables, subgroup analyses, interim analyses, stopping boundaries, or prespecified statistical model are reported in the registry record. Without these details and, most importantly, without primary outcome data, the trial’s comparative efficacy result and its precision cannot be reconstructed from the registry entry.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists the number of patients with a positive biopsy at 2 years as the primary outcome and reports that data for the outcome population were not collected. It lists one outcome measure and no analyses. These entries do not provide an analysis population or a result for the primary endpoint.
Multiplicity arises when several outcomes, time points, treatment comparisons, or subgroup tests are considered. In general, repeated testing can increase the chance of obtaining a nominally significant finding by chance unless the analysis plan addresses that issue. The registry record does not report a multiplicity adjustment, hierarchy among outcomes, or a plan for interpreting multiple tests. The presence of one listed primary outcome does not establish that no other analyses were planned or conducted; those details are not reported in the registry record.
The record does not describe missing-data handling, the number of participants with an available biopsy result, reasons for missingness, or any imputation or sensitivity analysis. It also does not identify an intention-to-treat, per-protocol, or other primary analysis population. Because primary outcome data were not collected, it is not possible to assess whether missingness differed between randomized groups or whether any particular analysis population was used.
Interim analyses and any associated statistical boundaries are not reported in the registry record. The termination status does not establish that an interim analysis occurred or explain the decision to stop. The reason for termination is also not reported in the registry record.
11. 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 |
|---|---|---|---|
| Degarelix in Conjunction With Stereotactic Body Radiosurgery | 1 | 27 | 3.7% |
| Stereotactic Body Radiosurgery (SBRT) | 0 | 29 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Degarelix in Conjunction With Stereotactic Body Radiosurgery | 1 of 27 |
| Stereotactic Body Radiosurgery (SBRT) | 0 of 29 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Degarelix in Conjunction With Stereotactic Body Radiosurgery | 2 of 27 |
| Stereotactic Body Radiosurgery (SBRT) | 0 of 29 |
Most frequent serious adverse event terms
| Event term | Organ system | Degarelix in Conjunction With Stereotactic Body Radiosurgery | Stereotactic Body Radiosurgery (SBRT) |
|---|---|---|---|
| Cardiac disorders - Other, specify | Cardiac disorders | 1 of 27 | 0 of 29 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Degarelix in Conjunction With Stereotactic Body Radiosurgery | Stereotactic Body Radiosurgery (SBRT) |
|---|---|---|---|
| Hyperglycemia | Metabolism and nutrition disorders | 1 of 27 | 0 of 29 |
| Lymphocyte count decreased | Investigations | 1 of 27 | 0 of 29 |
Serious events with the highest arm-level rate: cardiac disorders - other, specify (3.7%).
The registry reports serious adverse events and other adverse events separately for the two treatment groups. In the Degarelix-plus-SBRT group, 27 were listed as at risk for serious events and 1 as affected; 27 were listed as at risk for other events and 2 as affected. In the SBRT group, 29 were listed as at risk for serious events and 0 as affected; 29 were listed as at risk for other events and 0 as affected. The record lists deaths as 1 in the Degarelix-plus-SBRT group and 0 in the SBRT group.
These are registry counts, not a comparative safety analysis. The record does not report event timing, exposure duration, event-level details, statistical comparisons, or whether deaths or adverse events were judged related to treatment. The at-risk counts should not be interpreted as outcome data for the primary biopsy endpoint.
The registry lists “Cardiac disorders - Other, specify” among the top serious terms, with 3.7%. It does not provide further attribution for that term in the information recorded. A percentage attached to a term is not, by itself, evidence of a treatment effect or a comparison between arms. Small event counts can also yield imprecise comparisons; no confidence interval or formal safety comparison is reported in the registry record.
12. What the Result Does, and Does Not, Mean
The result available from the registry is principally a description of a trial that was intended to compare short-course Degarelix plus SBRT with SBRT alone. It was randomized, phase III, parallel-group, and unmasked. Its primary question concerned biopsy positivity at 2 years. The registry states that the primary outcome data were not collected and lists no analyses.
Accordingly, the record does not establish whether biopsy positivity was more frequent in either group, whether the groups were similar, or how large any difference may have been. No effect estimate, confidence interval, or primary-outcome p-value is reported. The absence of these results is not evidence of no effect; it means the treatment contrast cannot be evaluated from the primary endpoint information in the registry record.
The record’s safety counts provide limited descriptive information, but do not answer the primary question. They should not be treated as a complete account of all possible harms, nor as proof that an event was caused by a treatment. The record does not report event attribution, timing, or a statistical comparison of safety outcomes.
More generally, a trial’s design and a trial’s results are different kinds of evidence. Randomization describes how a comparison was intended to be made. To interpret the comparison, readers also need the observed outcomes, the number assessed in each group, the analysis population, and an estimate of uncertainty. Those primary endpoint details are not reported in the registry record.
The terminated status also needs careful interpretation. It records the study’s status, but the reason for termination is not reported in the registry record. No explanation for the termination, and no conclusion about its consequences for the intended analysis, should be inferred from status alone.
13. Why This Trial Matters Statistically
This trial is statistically notable because its registered question has a direct randomized comparison but no reported primary outcome data. The design makes clear what contrast the investigators intended to study: adding a short course of Degarelix to SBRT compared with SBRT alone. The primary endpoint also specifies a follow-up time and a tissue-based outcome. Yet the registry record says the outcome data were not collected.
This distinction matters for readers evaluating clinical trial evidence. A detailed design can clarify the target question, but it cannot substitute for an estimate of the result. Without group outcome values and an uncertainty measure, the registry cannot show whether the observed data support a difference, nor whether any estimated difference would be precise. Statistical interpretation must stop short of a treatment-effect conclusion.
The record also illustrates why enrollment figures and planning assumptions do not answer an efficacy question. Enrollment is not an outcome, and planning calculations are not observed treatment effects. A planning illustration based on an assumed effect and allocation can describe a hypothetical design scenario; it cannot establish what happened to participants in the trial or the precision of an unreported comparison.
Finally, the safety counts and the primary endpoint address different questions. Safety counts are relevant descriptive information, but they do not recover the missing biopsy results. Keeping these evidence types distinct helps prevent a registry entry with incomplete outcome reporting from being read as either a positive or a negative efficacy finding.
14. 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.
The main limitation for interpreting the intended comparison is explicit: the registry says primary outcome data were not collected. It therefore does not report biopsy results, group denominators for that endpoint, an effect estimate, a confidence interval, or a statistical test. The number of participants enrolled does not resolve this gap.
The status is terminated, but the reason is not reported in the registry record. Without that information, it is not possible to characterize the circumstances of termination or determine whether it affected follow-up, data collection, or analysis. The record also does not report baseline characteristics, participant flow, adherence, crossover, protocol deviations, or the number completing follow-up.
Several features of the methods are not described: the randomization procedure, allocation concealment, analysis population, statistical model, handling of missing data, and any multiplicity approach. Masking is listed as none, but the registry does not explain how biopsies were assessed or whether outcome assessors were masked. The biopsy assessment criteria and handling of unevaluable samples are not reported in the registry record.
The safety record gives counts but not event timing, severity details beyond the serious-versus-other classification, causal attribution, or comparative uncertainty. The listed serious term is not accompanied by further contextual detail. These limitations mean that the safety entries should be read descriptively and separately from the missing primary endpoint.
These are limitations of what the registry record reports; they do not establish that additional information does not exist elsewhere. No other source or publication is identified in the registry information summarized for this trial.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Trial of ADT and SBRT Versus SBRT for Intermediate Prostate Cancer — NCT03056638.
- Registry record last updated 2024-08-28; status last verified 2024-08.
- Results first posted 2024-08-28.
- 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.
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18. Record Summary
NCT03056638 is a randomized, phase III, parallel-group, unmasked trial comparing Degarelix monthly for 6 months plus SBRT 8 Gy x 5 with SBRT 8 Gy x 5 alone for intermediate-risk prostate cancer. The registry records enrollment of 56, a start date of 2017-03-28, a primary completion date of 2023-08-16, and a status of terminated.
The primary endpoint was the number of patients with a positive biopsy at 2 years. The registry states that the primary outcome population data were not collected and lists no analyses. It therefore reports no comparative primary outcome estimate. Serious and other adverse-event counts and deaths are recorded by group, but no comparative safety analysis or event attribution is reported. The reason for termination and several details of the statistical plan are not reported in the registry record.