Role of Dutasteride in Patients Undergoing 3D Mapping Biopsy in Early Stage Prostate Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Role of Dutasteride in Patients Undergoing 3D Mapping Biopsy in Early Stage Prostate Cancer (NCT00985738), a randomized phase 2 study. The primary outcome is To Determine the Effect of Short-term Intake of Daily Dutasteride Prostate Cancer Volume, Distribution Within the Gland and Gleason Score Sum in Patients in Comparison to Placebo After Adjusting for Changes in Prostate Gland Volume..

2. Clinical Question

The intended assessment relied on mapping biopsy and comparison with the initial trans-rectal biopsy in the treatment and control groups. The primary outcome was specified with a timeframe of 24 Months. The record describes several outcome components rather than a single numerical contrast, and no endpoint results or analysis are reported.

The clinical question therefore remains unanswered by the posted endpoint record. The available information describes the intended comparison and the trial’s design, but it does not show whether dutasteride changed any of the biopsy measures relative to placebo. The stated termination and absence of endpoint data are central to interpreting the trial.

3. Trial Design

This was a phase 2, randomized, double-blind, parallel-group, placebo-controlled trial sponsored by the University of Colorado, Denver. The registry reports enrollment of 16 and lists the study status as terminated. Its recorded start was 2009-09, and primary completion was recorded as 2013-01. The record does not explain why the trial was terminated.

Participants were assigned to dutasteride or placebo. The dutasteride description specifies a dose of 0.5 mg given every day for 3 months. The placebo group was to receive placebo for 3 months instead of the intervention drug. The record identifies double masking but does not state which individuals or roles were masked, so the extent of masking beyond that designation is not reported in the registry record.

The primary outcome was intended to address changes in prostate gland volume, distribution within the gland, and Gleason score sum. The description refers to mapping biopsy compared with initial trans-rectal biopsy in the treatment and control groups. The outcome timeframe is listed as 24 Months, but the endpoint was not reached.

Randomization and masking describe design features, not evidence that the planned comparison was completed. The registry explicitly states that the study was terminated, study endpoints were not reached, and no data were collected. It does not report the randomization procedure, allocation concealment, reasons for termination, or whether any protocol changes occurred. No analysis is listed 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: Subjects who qualified for the study based on the eligibility criteria were randomized to a placebo or treatment arm. After approximately 90 days (± 10 days), patients returned to undergo 3D mapping biopsy as part of their management of prostate cancer and received the tests/procedures outlined in the study calendar.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: "The study was terminated. Study end points were not reached. No data were 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.

Population: A one sided test of proportions with an alpha level of 0.025 was performed for a conservative Fisher's exact method. It was estimated that an 80% power in a test of proportions with 100 men in each arm would detect a 17% difference in proportion of men with increased tumor volume (upstaging) between the treatment arm and the control arm.

6. Primary Endpoint

The registry lists the primary outcome as To Determine the Effect of Short-term Intake of Daily Dutasteride Prostate Cancer Volume, Distribution Within the Gland and Gleason Score Sum in Patients in Comparison to Placebo After Adjusting for Changes in Prostate Gland Volume., measured over 24 Months.

The primary endpoint was intended to assess the effect of dutasteride on prostate cancer volume, cancer distribution within the gland, and Gleason score sum, relative to placebo and after adjustment for changes in prostate gland volume. The record describes assessment using mapping biopsy in relation to the initial trans-rectal biopsy in both study groups. The stated timeframe is 24 Months.

These measures address different aspects of disease findings: volume concerns the amount of cancer identified, distribution concerns its location within the gland, and Gleason score sum represents a score derived from biopsy findings. In general, measuring multiple aspects can give a broader description than relying on a single characteristic. Adjustment for changes in gland volume was part of the stated endpoint question, but the registry does not report the adjustment method or the exact statistical definition of each measure.

The registry states that study endpoints were not reached and no data were collected. Consequently, it reports no endpoint estimates, group comparisons, confidence intervals, or test results. The recorded outcome cannot establish whether the groups differed on any of these measures.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

There is no reported primary endpoint analysis to interpret. The registry describes a randomized, double-blind, parallel-group comparison, but it also states that the study was terminated, endpoints were not reached, and no data were collected. The following concepts explain what the planned statistical comparison would ordinarily involve; they do not describe analyses that this trial is known to have performed.

What does randomization contribute?

In general, random assignment is intended to make treatment groups comparable with respect to factors that could affect outcomes, including factors that are not measured. It supports interpreting a between-group contrast as an effect of assignment, provided the trial is conducted and analyzed as planned. Randomization does not guarantee that groups will be identical, and it does not eliminate problems caused by incomplete outcome data or deviations from the planned process. The registry does not report the randomization procedure or allocation-concealment details.

What does double masking mean?

The record labels the trial double-masked. In general, masking is intended to limit expectations from influencing care, outcome assessment, or reporting. The registry does not specify which people were masked, how masking was maintained, or whether it was assessed. The designation therefore describes the recorded design, but it does not provide enough detail to evaluate its implementation.

How would the endpoint comparison be framed?

The primary question involves dutasteride versus placebo and includes cancer volume, gland distribution, and Gleason score sum. The description also refers to changes from the initial trans-rectal biopsy to mapping biopsy and to adjustment for changes in prostate gland volume. In general, an analysis needs a defined outcome, a defined comparison, and a specification of how repeated or related measurements are handled. The registry does not report those statistical details, and its primary outcome is not reduced to one comparison because it has several components or time points.

An adjusted estimate would compare groups while accounting for specified covariates or changes. Adjustment can be useful when it is prespecified and appropriate to the question, but the estimate depends on the model and variables used. Here, the record states that adjustment for changes in prostate gland volume was part of the intended question, but it does not report the model, covariates, assumptions, or an adjusted result. No model can be inferred from the endpoint wording alone.

What would uncertainty measures tell a reader?

In general, a confidence interval gives a range of values compatible with an estimate under the model and sampling assumptions. Its width reflects precision: a wider interval indicates greater uncertainty than a narrower interval. A p-value addresses the compatibility of data with a specified null hypothesis under an analysis model; it is not a measure of clinical importance or the probability that a treatment works. The registry reports no primary endpoint estimate, confidence interval, or p-value, so these aspects of the planned comparison cannot be assessed.

When an outcome contains multiple components or comparisons, multiplicity is a concern in general. Repeated testing can increase the chance of finding an apparently notable result even when no underlying effect exists. A statistical plan may specify a primary contrast, adjustment procedure, or interpretation hierarchy. No multiplicity approach is reported in the registry record. Given that no endpoint data were collected, there are no reported primary outcome tests to interpret in any case.

What is over-dispersion, and is it relevant?

In general, over-dispersion occurs when outcome variability is greater than assumed by a statistical model. If it is ignored, standard errors may be too small and uncertainty may be understated. The choice of model depends on the outcome scale and data structure. The registry does not report endpoint data, a fitted model, or evidence of over-dispersion; this concept therefore cannot be assessed as a trial-specific feature.

The record includes a description of planning illustrations based on an observed effect, with assumptions including a two-sided significance level of 0.05, equal allocation, and a normal approximation. These are described as illustrations rather than the trial’s own design justification. Since no primary endpoint data were collected, the registry does not provide an observed endpoint effect from which such illustrations could be interpreted. No trial-specific sample-size justification or statistical analysis plan is reported.

These statistical concepts clarify what would be needed to evaluate a completed comparison, but they cannot supply the missing results. The registry does not report a completed endpoint analysis, and no treatment-effect calculation should be inferred from design descriptions or safety counts.

10. Multiplicity, Missing Data and Analysis Populations

The primary outcome includes several components: prostate cancer volume, distribution within the gland, and Gleason score sum. The description also refers to changes identified by mapping biopsy relative to the initial trans-rectal biopsy, with a timeframe of 24 Months. The registry does not reduce this outcome to one comparison. It does not state which component would be primary within the endpoint, how related tests would be handled, or whether any multiplicity adjustment was planned. These details are not reported in the registry record.

The registry says that study endpoints were not reached and no data were collected. It provides no missing-data method, imputation strategy, or description of how participants with unavailable measurements would have been handled. It does not report an analysis population such as intention-to-treat or per-protocol, nor does it state how participants were to be included in an endpoint analysis.

In general, multiplicity procedures address the increased chance of misleading findings when several outcomes or contrasts are tested. Missing-data methods address how incomplete outcome measurements affect estimates and uncertainty. An analysis population defines which participants are included and under what assignment or adherence rules. These choices can materially affect interpretation, but none can be reconstructed from the trial’s design description alone.

The enrollment field reports 16, but that figure does not identify the population used for an outcome analysis. No such analysis is reported. The registry record also does not explain the study’s termination or whether any planned analyses were attempted before termination.

11. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 5% reporting threshold.

The registry lists safety counts separately for dutasteride and placebo. For each group, the serious adverse-event fields report 8 at risk and 0 affected; the other adverse-event fields also report 8 at risk and 0 affected. These figures describe the posted counts, not a comparative estimate of safety. No event terms are listed among the top serious terms.

The deaths fields are null. A null entry should not be read as a reported count of zero; the registry record does not provide a death count for either group. The adverse-event timeframe, collection procedures, definitions, and completeness are not described in the available record, so the counts cannot be interpreted beyond what is explicitly listed.

In general, a count of zero affected participants in a registry field does not prove that an event is impossible or that risk is absent. It also does not establish that the groups have equivalent safety profiles. The posted safety information should be kept distinct from the unreported primary biopsy outcomes and from any broader conclusion about treatment effects.

12. What the Result Does, and Does Not, Mean

This record documents a planned randomized, double-blind comparison of dutasteride and placebo in patients with prostate cancer undergoing mapping biopsy. It specifies the intervention regimen, describes the intended biopsy-based outcome, and records that the trial was terminated. The registry states that endpoints were not reached and no data were collected. Those details describe an incomplete evidence record, not a positive or negative primary endpoint result.

The record does not show whether dutasteride changed cancer volume, distribution within the gland, or Gleason score sum compared with placebo. It reports no effect estimate or uncertainty measure for those outcomes. The absence of a result cannot be interpreted as evidence that there was no difference, nor can it support a claim that there was a difference. The clinical question remains unanswered by the posted endpoint information.

The safety fields list zero affected participants for serious and other adverse events in each group, with 8 at risk in each group for each field. The deaths entries are null rather than reported zero counts. These registry entries are limited information and do not resolve the primary question or establish an overall comparative safety conclusion.

Randomization, masking, and placebo control are design features that can strengthen a completed comparison when carried out as intended. They do not overcome the absence of endpoint data. The registry does not explain the reason for termination, the analysis plan, the handling of missing data, or the intended analysis populations. Conclusions about those matters would go beyond the reported information.

13. Why This Trial Matters Statistically

This trial is statistically important as an example of the difference between a carefully described research question and an analyzable result. The registry specifies randomization, double masking, a placebo comparator, and biopsy-based outcomes. Yet it also reports termination, endpoints not reached, and no data collected. A design can indicate how investigators intended to answer a question, but only outcome data and a reported analysis can quantify the comparison.

The primary outcome is not a simple single measurement. It spans cancer volume, distribution within the gland, and Gleason score sum, while also referring to comparisons between mapping biopsy and initial trans-rectal biopsy and adjustment for gland-volume changes. Such a structure makes prespecification important: readers need to know which contrast answers the main question and how related outcomes are interpreted. Those statistical details are not reported.

The case also illustrates why missing results should not be mistaken for a null finding. Without an endpoint estimate and a measure of uncertainty, there is no basis for evaluating either the direction or precision of a treatment-group difference. The record’s safety entries do not fill that gap because they concern different outcomes.

Finally, registered design labels alone do not establish whether planned methods were implemented or whether the resulting analysis would be reliable. The record does not report the reason for termination or a completed statistical analysis. Keeping these limits explicit helps distinguish what the registry documents from what remains unknown.

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 trial-specific limitation is that the registry states the study was terminated, its endpoints were not reached, and no data were collected. As a result, the intended primary comparison has no reported outcome estimate. The record does not explain why termination occurred, whether the study stopped before or after any assessments, or whether any protocol changes affected the planned endpoint.

Although enrollment is reported as 16, the record does not give participant flow, group-specific endpoint completion, or an analysis population. The safety fields list 8 at risk in each group, but they do not establish who contributed to the intended biopsy analysis. The number enrolled should not be treated as the number with evaluable primary outcomes.

The primary outcome has several components and references more than one biopsy assessment. The registry does not specify the exact statistical definitions, a hierarchy among components, the adjustment model, multiplicity handling, or a method for missing data. It does not report the analysis plan, interim analyses, or sample-size justification. These items are not reported in the registry record.

The record labels the study double-masked but does not identify who was masked or describe how masking was maintained. It also does not report the randomization method or allocation concealment. These omissions limit evaluation of the trial’s implementation, independently of the absence of endpoint results.

The safety information is also limited: the deaths fields are null, and the available record does not describe adverse-event ascertainment or its timeframe. The listed safety counts should therefore be interpreted narrowly. None of these limitations can be resolved by assuming methods or results that are not recorded.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Role of Dutasteride in Patients Undergoing 3D Mapping Biopsy in Early Stage Prostate Cancer — NCT00985738.
• Registry record last updated 2016-05-17; status last verified 2016-03.
• Results first posted 2016-04-18.
• 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.

18. Record Summary

The registry describes a phase 2 randomized, double-blind, parallel-group, placebo-controlled trial sponsored by the University of Colorado, Denver. It reports enrollment of 16, a recorded start of 2009-09, primary completion of 2013-01, and terminated status.

The intervention was dutasteride at 0.5 mg daily for 3 months; the comparator was placebo for 3 months. The primary outcome concerned prostate cancer volume, distribution within the gland, and Gleason score sum, with a stated timeframe of 24 Months and adjustment for changes in prostate gland volume.

The registry states that study endpoints were not reached and no data were collected. It lists no primary analyses. Safety fields report 0 serious and 0 other adverse events affected in each group, with 8 at risk for each field; deaths are null. The reason for termination and the statistical analysis plan are not reported in the registry record.