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 64Cu DOTA-Trastuzumab PET/CT in Studying Patients With Gastric Cancer (NCT01939275), a na na study. The primary outcome is Number of HER2 Negative, Positive, or Equivocal Participants With Either Negative or Positive Tumor Readings.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT01939275 |
| Phase | NA |
| Condition | Adenocarcinoma of the Gastroesophageal Junction, Diffuse Adenocarcinoma of the Stomach, Intestinal Adenocarcinoma of the Stomach |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 8 |
| Arms in the primary outcome | n/a |
| Lead sponsor | City of Hope Medical Center |
| Results posted | Yes |
2. Clinical Question
Population
The registry describes patients with gastric cancer, including adenocarcinoma of the stomach and gastroesophageal junction. The listed conditions span recurrent disease and stages IA through IV, as well as diffuse, intestinal, and mixed stomach adenocarcinoma. Enrollment was 8. The record does not report how participants were distributed among these diagnoses or stages.
Intervention
Participants received copper Cu 64-DOTA-trastuzumab intravenously on day 1, followed by PET/CT on day 2 or 3. The study also lists laboratory biomarker analysis and computed tomography among its interventions. The clinical purpose was to study tumor characteristics using a radiolabeled imaging procedure.
Comparator
There was no separate control or comparator group. The study is recorded as a single-group design, with allocation listed as not applicable and masking as none. The imaging readings were considered in relation to tumor HER2 status, but this is not a treatment-arm comparison.
Primary question
The primary endpoint concerns the number of participants classified as HER2-negative, HER2-positive, or equivocal who had either negative or positive tumor readings on 64Cu-DOTA-trastuzumab PET imaging. In practical terms, the study asks how the imaging interpretation relates to the recorded HER2 status. The registry record does not report the category counts or an analysis of agreement between imaging and HER2 status, so the size or direction of any relationship cannot be described from the posted results.
3. Trial Design
This was a completed pilot clinical trial with a single diagnostic group and an enrollment of 8. The study was not a randomized comparison: allocation is listed as not applicable, and there is no separate control arm. Masking is listed as none. The study phase is recorded as not applicable. These design features make the trial a small imaging investigation rather than a comparison of treatments.
Participants received copper Cu 64-DOTA-trastuzumab intravenously on day 1 and underwent PET/CT on day 2 or 3. The registry also lists laboratory biomarker analysis and computed tomography. The imaging procedure was intended to characterize tumors in patients with gastric cancer. The listed eligible conditions include stomach and gastroesophageal junction adenocarcinoma, recurrent gastric cancer, and several stages of disease; the record does not state how the enrolled participants were divided across these categories.
Two radiologists read the scans. One radiologist read the first scan, while a second nuclear radiologist read the remaining seven. The second radiologist was blinded to tumor HER2 status and tumor location until radiolabeled uptake had been measured. The record does not describe a common reading process in which both radiologists independently assessed all scans, nor does it report a reader-agreement analysis.
The primary outcome timeframe is up to 1 year. The registry marks the trial completed, but its record does not report the primary endpoint’s participant counts or statistical analysis results. The trial’s protocol details, including a statistical analysis plan and a sample-size justification, are not reported 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.
Overall Study
| Stage | Diagnostic (Copper Cu 64-DOTA-trastuzumab PET Scan) |
|---|---|
| STARTED | 8 |
| COMPLETED | 8 |
| NOT COMPLETED | 0 |
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 | Diagnostic (Copper Cu 64-DOTA-trastuzumab PET Scan) |
|---|---|---|
| Participants analysed | 8 | |
| Age, Continuous | years | 64 (50 to 73) |
| Sex: Female, Male: Female | Participants | 3 |
| Sex: Female, Male: Male | Participants | 5 |
| Race/Ethnicity, Customized: Asian | Participants | 6 |
| Race/Ethnicity, Customized: Hispanic | Participants | 2 |
| Region of Enrollment: United States | participants | 8 |
6. Primary Endpoint
The registry lists the primary outcome as Number of HER2 Negative, Positive, or Equivocal Participants With Either Negative or Positive Tumor Readings, measured over Up to 1 year.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is a participant count organized around HER2 status and the tumor’s PET imaging interpretation. The listed HER2 categories are negative, positive, and equivocal. The imaging description says a tumor that appeared “hot” relative to adjacent tissue was reported by the radiologist as negative, positive, equivocal, or unknown. The outcome title focuses on participants with either negative or positive tumor readings, while the endpoint description gives the broader set of possible reading categories.
This type of endpoint is used to describe how often an imaging classification occurs in the study group and how it relates to a tumor characteristic such as HER2 status. In a diagnostic imaging study, that information can help characterize the pattern of readings observed; it is not, by itself, proof of diagnostic accuracy or clinical benefit. Accuracy would require a clearly defined reference standard and appropriate comparisons, with results reported for the relevant categories.
The endpoint is specified for a timeframe of up to 1 year. However, the registry record does not report the number of participants in each HER2 category, the imaging-reading counts, or a measure of agreement or diagnostic performance. The posted endpoint description therefore identifies what was intended to be counted, but does not permit interpretation of the observed category distribution.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a small, single-group imaging study with enrollment of 8. Its primary endpoint concerns the relationship between tumor HER2 status and 64Cu-DOTA-trastuzumab PET imaging readings. The endpoint is clinically framed as a count of participants across HER2 status categories who had either negative or positive tumor readings. However, the registry record does not provide the number of participants in those categories or report statistical analyses of the imaging results.
That omission limits interpretation more than the small enrollment alone. Without the observed counts, it is not possible to describe which reading categories occurred, whether readings differed by HER2 status, or how precisely any such pattern was estimated. No effect estimate, confidence interval, hypothesis test, or analysis result is reported in the registry record. The record’s description of the outcome should therefore not be mistaken for a report of its findings.
In general, a confidence interval communicates the range of values compatible with an estimate under the assumptions of the analysis. In a small diagnostic study, category counts can be especially important because a small change in classification may substantially alter the apparent pattern. But no confidence intervals or category estimates are reported for this endpoint, so the precision of the imaging findings cannot be assessed from the registry record.
The study has no randomized treatment comparator and cannot estimate a treatment contrast. Its design can support descriptive reporting of readings in the enrolled group, but a claim about comparative diagnostic performance would require appropriate reference information and reported results. The endpoint description mentions HER2 status, but the registry record does not provide the status and scan-reading cross-classification or explain a statistical comparison between them.
There are safety counts: the record lists 0 serious adverse events among 8 participants at risk, 8 participants with other adverse events among 8 at risk, and 0 deaths. These figures are descriptive registry counts. The record does not supply the event terms for the other adverse events or enough detail to determine their nature, timing, severity, or relationship to study procedures. They should not be treated as a comparative safety estimate.
The study is marked completed, but completion does not fill the gap in the reported endpoint results. The most defensible statistical conclusion is that the registry describes the intended imaging assessment and reports limited safety counts, while the primary outcome’s observed distribution and inferential results are not reported in the registry record.
9. Statistical Methods Explained
The central statistical feature of this study is its single-group diagnostic design. Participants underwent the same general imaging procedure, and the primary outcome was framed as a count of imaging readings considered alongside HER2 status. There is no randomized arm comparison. The registry lists no allocation and no masking, so analyses intended to compare treatment groups would not apply to this design.
What does a participant count tell the reader?
For a binary outcome, a count tells how many participants meet a specified definition. A proportion places that count in relation to the number assessed. These are descriptive summaries: they show what was observed in the study group, rather than establishing that the same pattern will occur in other patients. The primary outcome is described as a number of participants, but the registry record does not report the category counts. It is therefore not possible to reconstruct proportions or compare categories from the posted results.
The endpoint also involves multiple labels. HER2 status is described as negative, positive, or equivocal. The imaging reading could be negative, positive, equivocal, or unknown, while the outcome title specifies either negative or positive tumor readings. For a diagnostic question, it is important to know how the categories were cross-classified and how unknown or equivocal readings were handled. Those details and the resulting counts are not reported in the registry record.
How should uncertainty be understood?
In general, an estimate from a study is subject to sampling uncertainty because the enrolled participants are only a subset of the wider population of interest. A confidence interval is a way to express that uncertainty around an estimate, under the statistical model used. For a count or proportion, its width depends on the observed data and the method used. No interval estimates are reported for the primary endpoint, so the statistical precision of its results cannot be evaluated.
In general, a p-value addresses how compatible observed data are with a specified null hypothesis under stated assumptions; it does not measure the size or clinical importance of a finding. A hypothesis test also requires a defined comparison and analysis plan. No hypothesis test or p-value for the primary endpoint is reported in the registry record, and the absence of a reported test should not be read as evidence for or against a relationship between imaging and HER2 status.
What does the reader allocation imply?
The record says one radiologist read the first scan and another nuclear radiologist read the remaining seven. The second radiologist was blinded to HER2 status and tumor location until radiolabeled uptake was measured. Blinding to this information can help reduce the risk that knowledge of the reference information influences the uptake assessment. However, because the readers did not both assess every scan according to the reported description, their individual readings cannot be compared across the entire study group. The registry record does not report reader agreement, repeat readings, adjudication, or a reproducibility analysis.
How do the planning assumptions differ from the trial analysis?
General sample-size planning illustrations use assumptions to estimate how many participants might be required under a hypothetical design and effect. The planning assumptions described for this record use a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of an observed effect. Those are planning assumptions, not evidence that the trial itself used a two-arm design. The actual study is recorded as single group. The registry record does not report the trial’s own sample-size justification, and a planning illustration is not observed power or an analysis of the enrolled participants.
For count outcomes, over-dispersion is a general concern when variability exceeds what a simple model assumes. It matters when choosing a model for repeated or clustered counts, for example, because underestimated variability can make uncertainty appear too small. The registry does not describe a count model or report repeated count data for this endpoint, so over-dispersion cannot be assessed as an issue in the reported analysis.
Overall, the registry gives enough information to describe the design, endpoint concept, and reader assignment, but not enough to reproduce a statistical analysis. The statistical analysis plan, model choices, missing-data rules, and endpoint estimates are not reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists one primary outcome measure. That does not establish that only one outcome or analysis was planned: the protocol-level analysis plan and any prespecified hierarchy of outcomes are not reported in the registry record. No adjustment for multiple comparisons, multiplicity strategy, or interim analysis plan is reported. Without those details, it is not possible to determine whether the recorded outcome was the only planned analysis or how any additional analyses were intended to be interpreted.
Missing-data handling is also not described. The registry record does not state whether all enrolled participants contributed an evaluable scan, how a scan that could not be interpreted would be handled, or whether unknown and equivocal readings were treated as outcome categories or as missing. Although the endpoint description includes “unknown” as a possible imaging reading, the record does not give the number of such readings or a rule for including them in analysis.
The record does not define an analysis population, such as all enrolled participants or only those with an evaluable scan. It does not report exclusions from the primary analysis, deviations from the imaging schedule, or the number of participants with complete data. Consequently, the endpoint denominator and the effect of any missing observations cannot be determined. These omissions are particularly relevant for a small study, because each participant’s classification can meaningfully affect a descriptive summary. The registry record does not report sensitivity analyses for missing or uncertain readings.
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 |
|---|---|---|---|
| Diagnostic (Copper Cu 64-DOTA-trastuzumab PET Scan) | 0 | 8 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Diagnostic (Copper Cu 64-DOTA-trastuzumab PET Scan) | 0 of 8 |
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 |
|---|---|
| Diagnostic (Copper Cu 64-DOTA-trastuzumab PET Scan) | 8 of 8 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Diagnostic (Copper Cu 64-DOTA-trastuzumab PET Scan) |
|---|---|---|
| Anemia | Blood and lymphatic system disorders | 3 of 8 |
| Hypoalbuminemia | Metabolism and nutrition disorders | 3 of 8 |
| Hyponatremia | Metabolism and nutrition disorders | 3 of 8 |
| Hypophosphatemia | Metabolism and nutrition disorders | 3 of 8 |
| Blood bilirubin increased | Investigations | 2 of 8 |
| Hypocalcemia | Metabolism and nutrition disorders | 2 of 8 |
| Sinus tachycardia | Cardiac disorders | 1 of 8 |
| Abdominal distension | Gastrointestinal disorders | 1 of 8 |
| Abdominal pain | Gastrointestinal disorders | 1 of 8 |
| Diarrhea | Gastrointestinal disorders | 1 of 8 |
The registry safety counts list 0 serious adverse events among 8 participants at risk. The record also lists 8 participants with other adverse events among 8 at risk, and 0 deaths. These are counts of affected participants, not a comparison between treatment groups, because the study has a single diagnostic group.
No serious adverse event terms are listed. The registry record does not provide the terms or descriptions for the other adverse events, so their nature and clinical significance cannot be assessed from these figures. It also does not report details about timing, severity, duration, or attribution to the imaging agent or procedure. The fact that other adverse events were recorded does not, by itself, establish their cause.
These counts are descriptive and should be interpreted in light of the small enrolled group and the lack of a comparator. They do not establish that an event cannot occur, nor do they support a comparative risk estimate. The registry record reports zero deaths, but does not provide further detail about how deaths were assessed or classified.
12. What the Result Does, and Does Not, Mean
The result record supports a limited description of what the study set out to assess: tumor readings from 64Cu-DOTA-trastuzumab PET imaging in relation to HER2 status among patients with gastric cancer. It also reports safety counts for the single diagnostic group. The registry does not report the actual primary endpoint category totals, so the observed pattern of imaging readings cannot be summarized or quantified.
It therefore does not establish how often scans were positive or negative, whether those readings aligned with HER2 status, or how reliably readers classified tumors. Those conclusions would require the participant-level classification counts or suitable summary estimates, along with information about evaluability and the intended reference standard. None of those results is reported in the registry record.
Even if category counts were available, a small single-group pilot would primarily describe findings in the enrolled participants. General statistical reasoning cautions against treating such descriptive results as a definitive estimate for a broader patient population. A confidence interval, if reported, would help convey uncertainty, but no interval is reported for the primary endpoint.
The study also does not compare imaging with an alternative diagnostic approach or compare treatments. It cannot, from this design, estimate a treatment effect. The registry’s general statement that diagnostic procedures may help characterize tumors is a study rationale, not a result demonstrating diagnostic benefit.
The safety counts should likewise be read narrowly: zero serious adverse events and zero deaths were recorded, while other adverse events were recorded in all 8 participants at risk. Details that would explain the other adverse events are not reported. These observations do not establish a comparative safety profile.
In short, the registry record documents a completed pilot imaging study and names its intended endpoint, but the posted endpoint results are insufficient to determine what the imaging assessment found. The absence of reported endpoint estimates is not evidence that the imaging did or did not correspond to tumor HER2 status.
13. Why This Trial Matters Statistically
This trial is statistically instructive because it separates a clearly stated diagnostic question from the evidence needed to answer it. The endpoint identifies a relationship of interest between HER2 status and PET imaging readings. To interpret that relationship, readers need the count of participants in each relevant classification, the number with evaluable scans, and a clear account of how equivocal or unknown readings were handled. Those results are not reported in the registry record.
The study also illustrates the distinction between a pilot investigation and a comparative trial. Its single-group design is appropriate for describing an imaging procedure in an enrolled group, but it does not supply a randomized comparator for estimating differences between groups. Statistical claims must match the design: without a control arm, a treatment contrast is not available.
Reader assignment is another important design consideration. One radiologist read the first scan and a second reader read the remaining seven. The second reader was blinded to HER2 status and tumor location until uptake was measured. This detail is relevant to potential reading bias, but it does not provide a measure of reproducibility. Because the readers did not both read every scan as described, a direct across-reader agreement assessment is not reported.
Finally, the record distinguishes neither an analysis population nor the handling of uncertain readings. In diagnostic studies, transparent reporting of these choices helps readers understand what the estimates represent. Here the outcome definition is available, but the counts and analysis details needed to judge its precision and meaning are not reported. The statistical importance of the trial therefore lies as much in these reporting requirements as in the imaging question itself.
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 primary limitation for statistical interpretation is that the registry record does not report the observed primary endpoint counts or analysis results. The intended outcome is described, but the imaging classifications by HER2 status are unavailable. This prevents assessment of the endpoint’s distribution, precision, or relationship to HER2 status.
Enrollment was 8, so any descriptive findings would apply directly to a small group. The record does not report how many participants had each listed cancer type, stage, or HER2 category. The range of conditions listed does not show that every type or stage was represented among those enrolled.
The trial had no comparator group and was not randomized. It therefore cannot estimate differences against another imaging procedure, diagnostic strategy, or treatment. Masking is listed as none, although the second nuclear radiologist was blinded to HER2 status and tumor location until uptake was measured. The first scan was read by a different radiologist from the one who read the remaining seven, and the registry does not report a reader-agreement or reproducibility analysis.
The record does not report an analysis population, missing-data rules, handling of equivocal or unknown scans, or the statistical analysis plan. It also does not report a sample-size justification. The primary endpoint timeframe is up to 1 year, but the record does not describe the timing of each participant’s assessment beyond the planned scan on day 2 or 3. Finally, the other adverse event terms and their severity or attribution are not reported, limiting interpretation of the safety counts.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: 64Cu DOTA-Trastuzumab PET/CT in Studying Patients With Gastric Cancer — NCT01939275.
- Registry record last updated 2025-02-28; status last verified 2025-02.
- Results first posted 2019-10-08.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
The registry describes a completed pilot, single-group diagnostic imaging study sponsored by City of Hope Medical Center, with enrollment of 8. Participants received copper Cu 64-DOTA-trastuzumab intravenously on day 1 and underwent PET/CT on day 2 or 3. The primary outcome concerns participant counts by tumor HER2 status and imaging reading, with a timeframe of up to 1 year.
Two radiologists read the scans: one read the first scan, and a second nuclear radiologist read the remaining seven. The second reader was blinded to HER2 status and tumor location until uptake was measured. The registry reports 0 serious adverse events, 8 participants with other adverse events, and 0 deaths.
The primary endpoint’s observed counts and statistical analysis results are not reported in the registry record. The record also does not report the statistical plan, analysis population, missing-data handling, or sample-size justification. As a result, the posted information describes the study question and design but does not establish the observed imaging findings.