Transurethral Ultrasonic Imaging For Detection and Classification of Prostate Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Transurethral Ultrasonic Imaging For Detection and Classification of Prostate Cancer (NCT02307552), a na na study. The primary outcome is Measure Novel Transurethral Ultrasound Signatures to Detect Prostate Cancer.

2. Clinical Question

This is therefore a question about diagnostic identification, not a comparison of treatments. In a completed diagnostic-accuracy study, scan classifications would ordinarily be assessed against a reference standard, here described as histopathology after robotic prostatectomy. Such an evaluation would need usable paired scan and reference-standard information to characterize how often the imaging identifies cancer and how often it does not. The registry record contains no collected endpoint data from which to assess those properties.

The study summary also describes a hypothesis that tissue-density variations might produce image signatures that help identify prostate cancer. That is the proposed rationale, not an observed finding from this study. The registry record does not establish whether the device can locate cancer, whether its images improve on other imaging, or whether its use could reduce the need for biopsy. Those questions remain unanswered by the posted results.

3. Trial Design

This was a single-group device study sponsored by the University of California, Irvine. The intervention was UreScan, and the study concerned prostate cancer. The registry record lists enrollment of 1, a start date of 2013-06, primary completion of 2014-04, and a status of terminated. Phase is listed as NA.

All patients were intended to receive a prostate scan with the UreScan machine. The arm description says that scans would be evaluated for accuracy in detecting cancer loci against histopathological reviews of the prostate after robotic prostatectomy. The design therefore describes an imaging procedure and a planned comparison with a tissue-based reference, rather than separate treatment arms. Allocation is listed as NA, masking as none, and the model as single group.

There is no like-for-like control group in this record. The comparison with histopathology is part of the proposed diagnostic assessment; it should not be read as a randomized comparison between imaging strategies or treatments. The registry record does not report a detailed recruitment pathway, eligibility criteria, image-reading procedures, or how scan results and reference assessments were to be paired.

The registry states that the study was discontinued due to lack of feasibility and negative results, and that data were not collected. It does not explain the operational details behind the feasibility concern or define what negative results refers to. Since no primary outcome data were collected, the planned single-group diagnostic assessment cannot be reconstructed from the posted results. The record also does not report a protocol sample-size justification or a prespecified statistical analysis plan.

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

Analysis population for the primary outcome, as defined in the registry: Data were not collected because the study was discontinued due to lack of feasibility and negative results.

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: 1

6. Primary Endpoint

The registry lists the primary outcome as Measure Novel Transurethral Ultrasound Signatures to Detect Prostate Cancer, measured over one year.

The primary outcome is titled Measure Novel Transurethral Ultrasound Signatures to Detect Prostate Cancer. Its timeframe is one year. The accompanying description states that the primary objective was to determine whether transurethral ultrasound could be used to identify prostate cancer, with the aim of avoiding prostate needle biopsies for diagnosis.

For a diagnostic imaging question, the endpoint is intended to capture whether the scan can identify cancer. The arm description gives the planned reference: histopathological review of the prostate after robotic prostatectomy. In general, comparing an imaging classification with a reference assessment can help determine how well the imaging identifies disease in the tissue being examined. It is important to distinguish this diagnostic question from whether a treatment changes health outcomes; this endpoint does not describe a treatment-effect comparison.

The registry record states that data were not collected because the study was discontinued due to lack of feasibility and negative results. It provides no observed endpoint value, scan classification, histopathology result, or accuracy estimate. Consequently, the endpoint's purpose can be described, but its performance cannot be assessed from the posted results. The record also does not report a more detailed operational definition of a positive scan or the exact method for matching scan findings to tissue findings.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record identifies a single-group device study with no masking and no randomized allocation. It describes an intended diagnostic assessment: UreScan scans were to be evaluated against histopathological reviews after robotic prostatectomy. It does not report a completed statistical analysis, and the primary outcome description says data were not collected. The discussion below explains relevant statistical ideas in general; it does not assert that these methods were used in this study.

What does a diagnostic comparison require?

In general, diagnostic accuracy is evaluated by comparing the test under study with a reference standard. Here, the described test is transurethral ultrasonic imaging and the planned reference is histopathological review of the prostate after robotic prostatectomy. To make that comparison, evaluators need results from both assessments for the relevant participants or tissue locations, along with rules for deciding when findings correspond. The registry record does not report those paired data or the detailed matching rules.

Different summaries answer different questions. Some describe how often the test detects disease when the reference indicates disease; others describe how often it classifies non-diseased findings as negative. Overall agreement can also be reported, but agreement alone may obscure the kinds of errors that matter for a diagnostic question. These are general concepts only. No such summary is reported for this study, and the absence of collected data means these quantities cannot be derived from the posted outcome record.

What would a confidence interval mean?

In general, a confidence interval expresses the uncertainty around an estimate under a specified statistical model and sampling process. A narrow interval indicates greater precision under those assumptions, while a wide interval indicates less precision. For diagnostic measures, intervals are especially useful because an estimate based on limited observations may be highly uncertain. A point estimate without an interval can make that uncertainty difficult to see. This study has no posted endpoint estimate or confidence interval to interpret.

Confidence intervals do not repair design limitations or establish that a diagnostic test is useful in every setting. Their interpretation depends on what observations were included, how the reference standard was applied, and how the estimate was calculated. The registry record does not report a statistical plan, an analysis population, or an estimation method for the primary outcome.

Why do analysis populations matter?

In general, a statistical analysis should make clear which participants or observations are included and why. A diagnostic analysis may need to define whether it uses all enrolled participants, only those with both test and reference results, or a subset meeting other criteria. These choices affect what population the results describe and can introduce bias if observations are excluded in ways related to test results or disease status. The registry record does not report an analysis population. It states that data were not collected, so there is no reported endpoint analysis population to evaluate.

Missing data also require context. In general, missing test results, missing reference assessments, or incomplete pairing can affect estimates. Their consequences depend on why information is missing and on the analysis approach. Here, the record gives a broader statement that data were not collected after discontinuation; it does not describe individual missing observations, a missing-data strategy, or imputation. It would not be appropriate to infer a particular missingness mechanism.

What does the sample-size illustration show?

The accompanying sample-size section is a planning illustration, not an account of the study's actual design or evidence of achieved power. Its stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the assumed effect is a stated fraction of the observed effect. Those are assumptions for an illustration. They do not match the registry's description of a single-group study, and the record does not report that this was the trial's planning method.

In general, a sample-size calculation estimates how many observations a planned design would need under specified assumptions. It depends on the target effect, variability, significance threshold, power target, and analysis method. Changing an assumption changes the resulting planning estimate. A planning calculation does not show that a study actually enrolled that number, collected usable outcomes, or had a particular probability of detecting a result. It is not observed power. No protocol sample-size justification is reported in the registry record.

What can be said about statistical testing?

The registry record lists 0 analyses and does not provide an inferential result for the primary endpoint. It does not report a statistical test, model, point estimate, confidence interval, or p-value for diagnostic performance. In general, a p-value summarizes how compatible data are with a specified null model under the assumptions of a test; it is not a measure of clinical importance, and it does not quantify the probability that a hypothesis is true. There is no posted primary-outcome p-value to interpret.

For this record, the most accurate statistical account is descriptive: a single-group diagnostic study was planned, enrollment is listed as 1, the study was terminated, and the primary outcome data were not collected. The absence of an estimate is not the same as a precise estimate of no effect or no diagnostic ability. It means that the registry record does not contain outcome data on which to base such an estimate.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists one primary outcome measure and 0 analyses. It does not report a statistical analysis plan, an inferential analysis, or any p-values. It also does not describe whether other outcomes were prespecified or whether any formal adjustment for multiple testing was planned. The multiplicity approach is therefore not reported in the registry record.

In general, multiplicity arises when several outcomes, comparisons, subgroups, or analysis choices are examined. Repeated testing can increase the chance of finding an apparently notable result by chance, depending on the analysis strategy. Prespecifying the main question and explaining any adjustment helps readers understand how results should be interpreted. These are general considerations; the record does not show that multiple statistical tests were performed.

For missing data, the primary outcome description says data were not collected because the study was discontinued due to lack of feasibility and negative results. This is different from a completed outcome analysis in which some observations are missing and others are available. The registry record does not report a missing-data plan, reasons for missing individual observations, imputation, or a sensitivity analysis. It is therefore not possible to assess how missing values were handled in an endpoint analysis.

The record does not specify an analysis population, such as which participants would be included in a diagnostic comparison or how incomplete test-reference pairs would be treated. Although enrollment is listed as 1, the record does not say whether that participant contributed a scan, histopathology result, or paired outcome data. The stated absence of collected primary data precludes interpreting any analysis population as an observed set of endpoint results.

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 0% reporting threshold.

The adverse-event record lists All Patients with 1 at risk for serious events and 0 affected by serious events. It also lists 1 at risk for other events and 0 affected by other events. Deaths are not reported in the registry record. These are the posted safety figures; they should be read alongside the study's small listed enrollment and the fact that primary outcome data were not collected.

A zero count in a registry table means that no affected participants are recorded in that category for the listed group. It does not establish that a device has no risk, particularly when the record contains only 1 participant at risk. A small observed count provides little information about how often an event might occur in a broader population. This is a general limitation of interpreting safety counts, not a claim about what would have happened in a larger study.

The registry record does not provide serious adverse-event terms, event narratives, or additional detail on safety follow-up. It lists no serious-event terms. The death count is null rather than a reported zero, so it should not be interpreted as a confirmed zero deaths. The record's safety figures also do not establish how completely adverse events were collected after discontinuation.

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

The result of this registry record is primarily an account of an unfinished diagnostic investigation. It describes a plan to assess UreScan transurethral ultrasonic imaging for identifying prostate cancer, with histopathological review after robotic prostatectomy as the planned reference. It records enrollment of 1 and a terminated status. Most importantly for interpretation, it states that primary outcome data were not collected because the study was discontinued for lack of feasibility and negative results.

What this does mean is that the posted record does not contain an analyzable diagnostic outcome. It offers no estimate of how accurately the scan identified cancer loci, no measure of uncertainty around such an estimate, and no completed comparison with the histopathological reference. The phrase negative results appears in the discontinuation explanation, but the record does not define it or provide numerical results behind it. It cannot be used as a substitute for an outcome analysis.

What this does not mean is that the device has been shown to perform well or poorly. Without collected endpoint data and a reported analysis, the record cannot establish either conclusion. It also cannot show that imaging can avoid prostate needle biopsies, which is described as an intended objective. The study summary's hypothesis about image signatures and its mention of preliminary findings are rationale and background, not a reported result from this study.

Nor is this a comparison of UreScan with another imaging approach or treatment. The registry describes a single group, with no masking and no randomized allocation. The planned histopathology assessment is a reference for diagnostic evaluation, not a control treatment arm. These design details define the kind of question the study aimed to address, but the absence of outcome data prevents answering it from the posted record.

The accompanying tables, plots, and sample-size section should be read in that context. General statistical displays cannot replace missing clinical observations. Planning illustrations do not show observed power, do not indicate that the planned study was adequately sized, and are not a clinical finding. The record supports a limited conclusion: the diagnostic question was posed, the study was terminated, and the primary endpoint was not measured in collected data.

13. Why This Trial Matters Statistically

This study matters statistically because it illustrates the difference between a planned endpoint and an observed result. A registry can state a clinically relevant diagnostic objective and describe a proposed reference assessment, yet still lack the data needed to estimate performance. Here, the primary question was whether transurethral ultrasound could identify prostate cancer, but the record says outcome data were not collected after discontinuation.

For diagnostic research, the distinction between a test and a reference standard is essential. The arm description proposes comparing UreScan findings with histopathological reviews after robotic prostatectomy. That comparison could, in principle, support estimates of diagnostic performance if the scan and tissue results were collected and aligned. Without those observations, there is no basis for calculating accuracy or describing precision. The record therefore demonstrates why a design description alone is not an evidence estimate.

The enrollment figure also needs context. Enrollment of 1 is not equivalent to a completed dataset with interpretable paired diagnostic results. The record does not state that the participant contributed usable scan and histopathology data, and its primary outcome description says data were not collected. Reporting the status and endpoint-data limitation together prevents readers from treating enrollment as proof of an evaluable study.

Finally, the record distinguishes study findings from planning calculations. A sample-size illustration can help explain how assumptions influence a future design, but it is not evidence that a trial achieved a target power or detected an effect. This is especially important where the illustration's stated equal-allocation, two-arm assumption differs from the registry's single-group design. The statistical lesson is to read outcome availability, design, and planning assumptions separately rather than letting one stand in for another.

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 is explicit: the registry record says data were not collected for the primary outcome because the study was discontinued due to lack of feasibility and negative results. It does not provide diagnostic findings, an estimate of performance, or an interval describing uncertainty. The phrase negative results is not defined, so its meaning cannot be determined from the posted record.

Enrollment is listed as 1, but the record does not say whether this participant underwent a scan, had the planned robotic prostatectomy, or contributed paired scan and histopathology findings. The endpoint timeframe is one year, but the record does not explain the timing or completeness of any assessment. It also does not provide eligibility criteria, recruitment details, or the operational rules for identifying and matching cancer loci.

The study is listed as single group, with allocation NA and masking none. No like-for-like control comparison is reported. The registry does not describe who interpreted scans, whether image interpretation was independent of histopathology, or how disagreements would be resolved. These details are not reported in the registry record and should not be assumed.

The record lists 0 analyses and does not report a statistical analysis plan, an analysis population, a missing-data strategy, a multiplicity approach, or a sample-size justification. The sample-size material accompanying the page is described as a planning illustration, not the trial's own design. Its assumptions include equal allocation between two arms, unlike the registry's single-group design.

Safety reporting is also limited: the adverse-event table lists 1 at risk and 0 affected in the serious and other event categories, while deaths are not reported in the registry record. The record does not provide event narratives or further follow-up detail. Taken together, these gaps limit both diagnostic and safety interpretation.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Transurethral Ultrasonic Imaging For Detection and Classification of Prostate Cancer — NCT02307552.
• Registry record last updated 2017-07-27; status last verified 2017-06.
• Results first posted 2017-06-27.
• 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 record describes a single-group device study of UreScan transurethral ultrasonic imaging for identifying prostate cancer. It lists the University of California, Irvine as sponsor, enrollment of 1, a start date of 2013-06, primary completion of 2014-04, and status as terminated. Masking is listed as none and allocation as NA.

The primary objective was to determine whether transurethral ultrasound could identify prostate cancer, with histopathological review after robotic prostatectomy described as the planned reference. The primary outcome timeframe is one year. The record states that data were not collected because the study was discontinued due to lack of feasibility and negative results. It lists 0 analyses and does not report diagnostic performance estimates or a statistical analysis plan.

The adverse-event table records 1 at risk and 0 affected in both serious and other event categories. Deaths are not reported in the registry record. The posted information documents the study's intended question and termination, but does not provide collected primary outcome evidence with which to answer that question.