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 S0032, Combination Chemotherapy Plus Hormone Therapy in Treating Patients With Metastatic Prostate Cancer (NCT00028769), a na phase 2 study. The primary outcome is Progression-free Survival.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00028769 |
| Phase | Phase 2 |
| Condition | Prostate Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 41 |
| Arms in the primary outcome | n/a |
| Lead sponsor | SWOG Cancer Research Network |
| Results posted | Yes |
2. Clinical Question
Population
Patients with high-risk metastatic adenocarcinoma of the prostate were eligible for the study. The primary analysis population is described as all eligible patients who started treatment. The number meeting that definition is not reported in the registry record.
Intervention
The study evaluated chemotherapy with hormone therapy. The named drugs were estramustine, etoposide and paclitaxel, together with hormone therapy selected from leuprolide, bicalutamide, nilutamide, goserelin and flutamide.
Comparator
There was no separate comparison group: the registry describes a single-group study and gives allocation as NA. The study therefore does not provide a randomized, like-for-like control comparison.
Primary question
The primary endpoint was progression-free survival, measured from registration to the first documentation of progression. The study asked how long this outcome lasted among eligible patients who started the treatment combination. The registry record does not report the observed median or its 95% confidence interval.
The registry describes a phase II evaluation, not a randomized comparison of treatment strategies. Its stated purpose was to study combination chemotherapy plus hormone therapy in metastatic prostate cancer. The information recorded identifies the treatment approach and the endpoint, but the posted results do not establish how progression-free survival compared with another treatment or with a control group.
3. Trial Design
This was a completed phase II study with a single-group model. The registry lists enrollment as 41 and allocation as NA; it does not describe random assignment. Masking is listed as none. These features mean the recorded design is an evaluation within one treatment group, rather than a blinded comparison between treatment arms.
The regimen combined hormone therapy with estramustine, etoposide and paclitaxel. The registry lists bicalutamide, flutamide, goserelin, leuprolide and nilutamide among the hormone drugs. It does not describe how choices among these hormone therapies were made, or provide further treatment-delivery details beyond the arm description.
The registry lists the study start as 2001-12 and primary completion as 2010-06. The status is completed. These dates describe the record’s study timeline; they do not supply a result for the primary endpoint.
Progression-free survival is the primary outcome. The outcome description specifies assessment over 0-5 years, with assessments every 3 months after chemotherapy if there had been no progression, and continued assessments every 3 months after chemotherapy until progression. The analysis population is defined as all eligible patients who started treatment. The number of enrolled participants who were eligible and started treatment is not reported in the registry record.
The registry also identifies a secondary outcome concerning patients with Grade 3 through Grade 5 adverse events related to study drug. It lists three outcome measures, but does not give a result for that secondary outcome in the registry record for this analysis. The registry names SWOG Cancer Research Network as sponsor.
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 | CAD + Chemo |
|---|---|
| STARTED | 41 |
| Eligible | 36 |
| Eligible and Began Protocol Therapy | 35 |
| COMPLETED | 0 |
| NOT COMPLETED | 41 |
Reasons for not completing this period:
| Reason | CAD + Chemo |
|---|---|
| Adverse Event | 2 |
| Refusal Unrelated to Adverse Events | 1 |
| Progression or Death | 31 |
| Other - Not Protocol Specified | 1 |
| Ineligible | 5 |
| Not Analyzable | 1 |
Analysis population for the primary outcome, as defined in the registry: All eligible patients who started treatment were included in 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 | CAD + Chemo |
|---|---|---|
| Participants analysed | 35 | |
| Age Continuous | years | 60 (45 to 79) |
| Sex: Female, Male: Female | Participants | 0 |
| Sex: Female, Male: Male | Participants | 35 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 3 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 32 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 9 |
| Race (NIH/OMB): White | Participants | 26 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Southwestern Oncology Group Performance Status: 0 | participants | 20 |
| Southwestern Oncology Group Performance Status: 1 | participants | 15 |
| Bone Pain Grade (CTC version 2.0): Missing | participants | 2 |
| Bone Pain Grade (CTC version 2.0): <2 | participants | 26 |
| Bone Pain Grade (CTC version 2.0): >=2 | participants | 7 |
| Previous Prostatectomy: Yes | participants | 6 |
| Previous Prostatectomy: No/Unknown | participants | 29 |
| Gleason Score: Missing | participants | 1 |
| Gleason Score: 6 | participants | 2 |
| Gleason Score: 7 | participants | 12 |
| Gleason Score: 8 | participants | 6 |
| Gleason Score: 9-10 | participants | 14 |
6. Primary Endpoint
The registry lists the primary outcome as Progression-free Survival, measured over 0-5 years (assessed every 3 months if no progression when the chemotherapy had been finished. Once off chemotherapy, assessed every 3 months until progression).
| Element | Registry entry |
|---|---|
| Result type | Median |
| Measure of spread | 95% Confidence Interval |
| Unit | months |
| Endpoint classification | Time-to-Event Analysis |
Progression-free survival measures the time from registration until the first documented progression. The registry defines progression using prostate-specific antigen (PSA) findings, clinical criteria or symptomatic deterioration. It describes PSA progression as a 25% increase greater than baseline. If PSA had decreased during the study, progression was defined as a 25% increase from the nadir PSA level, with an absolute value of >=5 ng/mL. Clinical progression included a new lesion at any site or death without documented progression. Symptomatic deterioration meant a global decline in health status requiring treatment discontinuation without objective evidence of progression.
As a general statistical concept, a time-to-event endpoint incorporates both whether an event occurs and how long it takes to occur. It can retain information from participants whose event has not been observed by the end of their follow-up, although the registry record does not report the number of such participants or the censoring method used in this analysis.
The registry specifies the median and a 95% confidence interval as the summary and measure of uncertainty for the primary outcome. In general, a median time-to-event estimate describes the point at which the estimated event-free proportion reaches its midpoint. A confidence interval expresses uncertainty around an estimate; its width helps indicate how precisely the result is estimated. The median and interval themselves are not reported in the registry record, so their magnitude and precision cannot be assessed.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central interpretive limitation is that the registry record identifies progression-free survival as the primary endpoint but does not report its numerical result. The observed median and 95% confidence interval are not reported in the registry record. Consequently, the posted information does not show the estimated duration of progression-free survival or how precisely it was estimated. A numerical treatment effect cannot be described from the available record.
The design also limits what the study can establish. It is listed as a single-group phase II study with allocation NA and no masking. There is no separate control group in the record, so the outcome cannot be interpreted as a randomized estimate of the difference between this combination and another treatment. Changes over time in a single group cannot, by themselves, distinguish treatment effects from other influences on outcomes.
The record’s primary analysis population is all eligible patients who started treatment. Enrollment is listed as 41, but the number of eligible participants who started treatment is not reported in the registry record. The enrolled count should not be treated as the analysis denominator without that information.
Progression was defined using PSA, clinical findings and symptomatic deterioration. That definition gives the endpoint several routes to an event, but the record does not report how many progressions were identified by each route. It also does not report participant-level follow-up, censoring, or the number of observed progression events. Those omissions prevent a fuller assessment of how the time-to-event estimate was formed.
The available safety information lists 35 at risk and 6 affected in the serious-event category, and 35 at risk and 35 affected in the other-event category. The registry does not explain the meaning of the category label “other” in the record details used. It lists serious-event terms with percentages, including cardiac ischemia/infarction and thrombosis/embolism, each at 5.7%. These entries describe recorded safety counts and terms; they do not establish comparative risk because there is no control group.
There are no posted hazard ratios or other sponsor-reported comparative estimates in the registry record. No p-value for the primary outcome is reported. A finding of statistical significance, or lack of significance, cannot be inferred from the endpoint name, the study phase, or the safety counts. The record supports a description of the design and listed measures, but not a quantitative conclusion about progression-free survival.
9. Statistical Methods Explained
The main statistical feature is the time-to-event nature of progression-free survival. Each participant’s outcome is expressed as elapsed time from registration to the first qualifying progression event. Time-to-event methods are useful when participants can have different lengths of follow-up, and when some have not had an observed event by the end of observation. In general, methods for this kind of data account for incomplete event observation rather than treating every participant without a recorded event as if the event could never occur. The registry does not report the censoring details or estimator used for this outcome.
What does the median describe?
In general, the median time-to-event is the time at which an estimated event-free curve reaches its midpoint. It is a summary of the event-time distribution, rather than an average of all observed times. Its interpretation depends on the event definition and the analysis of follow-up. The registry specifies a median for progression-free survival, but the numerical median is not reported in the registry record. It is therefore not possible to state when the midpoint was reached.
What does a confidence interval add?
The primary endpoint’s dispersion is specified as a 95% confidence interval. In general, a confidence interval describes the statistical uncertainty around an estimate under the method’s assumptions. It is not a guarantee that an individual participant’s outcome will fall within the interval, and it does not show the range of all participant outcomes. A narrower interval generally indicates greater precision than a wider interval, but precision cannot be evaluated without the endpoints of the reported interval. Those endpoints are not reported in the registry record.
How should the single-group design affect interpretation?
In general, a single-group study can describe outcomes observed among participants receiving a regimen, but it does not create a randomized counterfactual comparison. Random allocation can help balance known and unknown factors between groups; this study is listed as having allocation NA and a single-group model. Accordingly, its record does not support a randomized estimate of the regimen’s effect relative to a comparator. The sample-size assumptions describe a planning illustration based on an observed effect, with two-sided significance level 0.05, equal allocation between two arms and a normal approximation. These are assumptions for an illustration, not evidence that this single-group study used those design features.
What can a hazard ratio tell a reader?
As a general concept, a hazard ratio compares event rates over follow-up between groups, subject to the model and assumptions used. It is not the same as a ratio of median survival times. A hazard ratio requires a comparison, and the registry describes no separate randomized group. A sponsor-reported hazard ratio is not reported in the registry record. No hazard-ratio interpretation or comparative estimate can therefore be made from the posted results.
How should the sample-size illustrations be read?
In general, sample-size planning asks how many participants or events might be needed to detect a chosen effect under specified assumptions. The registry’s planning description uses a stated fraction of the observed effect, and distinguishes time-to-event illustrations, which use total events, from other illustrations, which use participants per arm. Such calculations are hypothetical planning illustrations, not observed outcomes, and they do not establish the study’s actual power. The registry does not report its own sample-size justification or statistical plan. The illustrations should not be interpreted as a retrospective measure of the probability that this trial detected an effect.
No p-value or numerical primary endpoint estimate is reported in the registry record. General statistical principles cannot fill in those missing results. In particular, the endpoint definition and the fact that the study is completed do not reveal the observed median, its confidence interval, or a treatment effect.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists three outcome measures, with progression-free survival identified as the primary endpoint and a secondary outcome concerning Grade 3 through Grade 5 adverse events related to study drug. It does not report a multiplicity adjustment or explain how statistical testing across outcomes was handled. Without a stated analysis plan, it is not possible to determine whether or how the chance of false-positive findings across multiple tests was addressed.
Missing-data procedures are not reported in the registry record. The primary endpoint description gives a follow-up schedule and defines progression, but does not describe how missing assessments, withdrawal, or incomplete follow-up were handled. The number of participants censored and the reasons for censoring are also not reported. As a general matter, incomplete follow-up can affect time-to-event estimates, and interpretation depends on how participants leave observation and on the assumptions used by the analysis.
The primary analysis population is specified as all eligible patients who started treatment. The registry lists enrollment as 41, but does not report how many participants were eligible and started treatment. It does not state whether other analysis populations were used, or how exclusions after enrollment were handled. The record also does not report an intention-to-treat analysis population; with a single-group design, the stated population definition is the information available.
The statistical analysis plan, interim analyses, and sample-size justification are not reported in the registry record. The planning illustration described for sample-size calculations is not a substitute for those details and does not establish the analysis methods used for the posted outcomes.
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 |
|---|---|---|---|
| CAD + Chemo | 6 | 35 | 17.1% |
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 |
|---|---|
| CAD + Chemo | 35 of 35 |
Most frequent serious adverse event terms
| Event term | Organ system | CAD + Chemo |
|---|---|---|
| Cardiac ischemia/infarction | Cardiac disorders | 2 of 35 |
| Thrombosis/embolism | Vascular disorders | 2 of 35 |
| Flu-like symptoms-other | General disorders | 1 of 35 |
| Infection with 3-4 neutropenia | Infections and infestations | 1 of 35 |
| Abnormal troponin I (cTnI) | Investigations | 1 of 35 |
| Leukopenia | Investigations | 1 of 35 |
| Second primary | Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 1 of 35 |
Most frequent non-serious adverse event terms
| Event term | Organ system | CAD + Chemo |
|---|---|---|
| Fatigue/malaise/lethargy | General disorders | 30 of 35 |
| Leukopenia | Investigations | 21 of 35 |
| Nausea | Gastrointestinal disorders | 20 of 35 |
| Anemia | Blood and lymphatic system disorders | 18 of 35 |
| Alopecia | Skin and subcutaneous tissue disorders | 18 of 35 |
| Pain-other | General disorders | 15 of 35 |
| Neutropenia/granulocytopenia | Investigations | 13 of 35 |
| Edema | General disorders | 12 of 35 |
| SGOT (AST) increase | Investigations | 11 of 35 |
| Hyperglycemia | Metabolism and nutrition disorders | 10 of 35 |
Serious events with the highest arm-level rate: cardiac ischemia/infarction (5.7%), thrombosis/embolism (5.7%), flu-like symptoms-other (2.9%), infection with 3-4 neutropenia (2.9%), abnormal troponin i (ctni) (2.9%).
The registry lists 35 at risk and 6 affected for the serious-event category labeled “CAD + Chemo.” It also lists 35 at risk and 35 affected in the other-event category. The record details used for this analysis do not explain the “other” label, so the categories should not be assumed to have a particular definition or relationship to one another. These are counts recorded for the listed group, not a comparison between treatment arms.
The listed serious-event terms include cardiac ischemia/infarction at 5.7% and thrombosis/embolism at 5.7%. Flu-like symptoms-other, infection with 3-4 neutropenia, abnormal troponin I (cTnI) and leukopenia are each listed at 2.9%. The registry does not report additional context about how these term percentages were calculated, or whether categories overlap. They should therefore be read as listed safety summaries, not added together or treated as mutually exclusive.
The secondary outcome is described as the number of patients with Grade 3 through Grade 5 adverse events related to study drug, but its result is not reported in the registry record. The listed serious-event counts and terms do not by themselves show comparative safety, establish causation, or provide a full account of adverse events.
12. What the Result Does, and Does Not, Mean
The registry record documents a phase II study of chemotherapy combined with hormone therapy in patients with metastatic prostate cancer. It identifies a single-group design, the treatment components, a progression-free survival endpoint, and selected safety information. These registry entries describe what was studied and what outcomes were listed; they do not provide a numerical estimate of the primary endpoint.
The median progression-free survival and its 95% confidence interval are not reported in the registry record. Nor does the record include a sponsor-reported hazard ratio or a randomized comparator. As a result, the posted information cannot quantify the duration of progression-free survival, its precision, or a difference in outcome between treatment strategies.
In general, a single-group outcome can be useful for describing observed experience in the group studied. It does not alone show what would have happened to the same participants under a different treatment. The lack of a control group matters especially when interpreting whether an observed outcome is attributable to the regimen rather than to other factors.
The registry’s serious-event counts and listed terms provide limited safety information, but do not represent a comparative safety analysis. The secondary outcome concerning Grade 3 through Grade 5 adverse events related to study drug has no reported result in the record details. The safety entries should not be read as a complete account of either benefits or harms.
These limitations do not establish that the regimen is effective or ineffective, safe or unsafe. They mean that the posted record, as described, does not contain the results needed to make those statistical judgments. The conclusions should remain limited to the study design, endpoint definition, and safety counts that are actually recorded.
13. Why This Trial Matters Statistically
This study is statistically instructive because its primary outcome is time-to-event, while its design is single-group. Those features illustrate why an endpoint definition and an analysis result are both needed for interpretation. The registry defines progression using PSA, clinical progression or symptomatic deterioration, and specifies a median with a 95% confidence interval. Yet the numerical estimate and interval are not reported in the registry record. Knowing what was measured does not reveal the observed result.
The single-group structure also clarifies the difference between describing an outcome and estimating a comparative treatment effect. A treatment group’s time-to-event experience may be summarized, but without a concurrent comparator there is no randomized contrast in this record. The design therefore does not answer how the outcome compares with another treatment under the same study conditions.
The record also distinguishes a defined analysis population from enrollment. The primary endpoint population includes all eligible patients who started treatment, while enrollment is listed as 41. The number satisfying the analysis-population definition is not reported. This is a reminder that a registered enrollment figure does not automatically identify the denominator for every outcome.
Finally, the safety information shows why category definitions and denominators matter. The record lists at-risk and affected counts alongside adverse-event terms and percentages, but gives limited context for interpreting the “other” category and no comparative arm. Careful reading avoids treating separate entries as directly comparable or combining them into an unsupported total. These statistical considerations are relevant to understanding what a registry entry can and cannot establish.
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 registry record does not report the primary endpoint’s median or 95% confidence interval, despite specifying both as the intended summary. It also does not report a sponsor-reported hazard ratio, a p-value, or another numerical comparative estimate. The central efficacy result therefore cannot be assessed from the recorded details.
The study is described as single-group, with allocation listed as NA and masking as none. There is no randomized control group in the record, limiting causal and comparative interpretation. The registry does not describe the process by which hormone therapy choices were made or provide further details about treatment delivery.
Although enrollment is listed as 41, the number of eligible patients who started treatment—the stated primary analysis population—is not reported. The record also does not state the number of progression events, the amount of follow-up for each participant, how many were censored, or the reasons for incomplete observation. Those omissions limit assessment of the time-to-event analysis.
The statistical analysis plan, sample-size justification, interim analyses, multiplicity handling and missing-data methods are not reported in the registry record. The secondary outcome concerning Grade 3 through Grade 5 adverse events related to study drug has no result listed in the registry entries. Safety details are limited to the stated counts and terms, with no control group for comparison and no further explanation of the “other” category. These gaps restrict interpretation without changing what the record explicitly reports.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: S0032, Combination Chemotherapy Plus Hormone Therapy in Treating Patients With Metastatic Prostate Cancer — NCT00028769.
- Registry record last updated 2013-07-16; status last verified 2013-06.
- Results first posted 2013-07-16.
- 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
The registry describes a completed phase II, single-group study of chemotherapy plus hormone therapy for metastatic prostate cancer. Enrollment is listed as 41; allocation is NA and masking is none. The regimen included estramustine, etoposide and paclitaxel with hormone therapy. SWOG Cancer Research Network is listed as sponsor.
The primary endpoint was progression-free survival, measured from registration to first documented progression and summarized as a median with a 95% confidence interval. The analysis population was all eligible patients who started treatment. The numerical median, confidence interval and eligible-starter count are not reported in the registry record. Listed safety information includes 35 at risk and 6 affected in the serious-event category, along with event terms and percentages. The record does not provide a randomized comparison or a numerical primary efficacy result.