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 Use of Trastuzumab to Induce Increased ER Expression in ER-negative/Low, Her-2/Neu Positive Breast Cancer (NCT00726180), a na phase 1, phase 2 study. The primary outcome is Standard Immunohistochemistry and Allred Scores Were to be Used to Measure the Estrogen Receptor (ER) Response Rate in Patients With ER-negative/Low, and Human Epidermal Growth Factor Receptor 2 (HER2)/Neu-positive Breast Cancer..
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00726180 |
| Phase | Phase 1, Phase 2 |
| Condition | Breast Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 1 |
| Arms in the primary outcome | n/a |
| Lead sponsor | University of Michigan Rogel Cancer Center |
| Results posted | Yes |
2. Clinical Question
Population
Patients with breast cancer described as ER-negative or ER-low and HER2/Neu-positive. The registry record reports that only one patient enrolled; it does not provide further participant characteristics.
Intervention
Trastuzumab, listed as a drug intervention. The record does not describe a dose or treatment schedule.
Comparator
No comparator group is described. The study is listed as a single-group trial, and allocation is recorded as NA; there is no like-for-like control comparison.
Primary question
Whether an estrogen receptor response could be measured in this population, using standard immunohistochemistry and Allred scores over a timeframe of 90 days.
The clinical rationale in the registry summary is that increasing ER expression in ER-negative tumors might make hormonal therapy a possible option. That rationale motivates the study question; it is not evidence that ER expression changed in enrolled patients or that any treatment outcome improved.
The primary outcome is described as an ER response rate, but the registry record does not provide a response definition, a threshold for a positive response, or an observed response estimate. It states that only 1 patient enrolled and that no data was obtained. Accordingly, the record cannot establish whether the proposed measurement was feasible, how often an ER response occurred, or how variable a response might be in the intended population.
3. Trial Design
The registry classifies the study as Phase 1 and Phase 2, with a single-group model and no masking. Allocation is listed as NA. These entries describe the recorded design; they do not establish the details of a treatment protocol that are not present in the registry record.
The listed intervention is trastuzumab (Herceptin®). The treatment-arm description is blank, and no dose, schedule, treatment duration, or other co-interventions are reported in the registry record. The planned primary-outcome timeframe is 90 days. The primary completion date is 2010-06, and the study start is recorded as 2008-07. The overall status is terminated. The reason for termination is not reported in the registry record.
Enrollment was 1. The primary-outcome description states that only 1 patient was enrolled and that no data was obtained. Thus, although the registry identifies a primary outcome and its timeframe, it does not supply an analyzable outcome result. The record lists one treatment arm and no comparator, so it cannot support a treatment-versus-control estimate.
The registry does not report a target enrollment or explain how enrollment was selected. It also does not report a sample-size justification, a recruitment plan, or whether any changes to the study design occurred. The presence of Phase 1 and Phase 2 labels alone does not specify the sequence or purpose of any phases beyond those registry classifications.
Because the study is single-group and only one patient enrolled, it is important to distinguish the intended research question from evidence that could answer it. The intended question concerns ER response after trastuzumab in a specific tumor subgroup. The recorded enrollment and absence of outcome data mean that the registry record does not report an observed response to interpret.
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 | Treatment Arm |
|---|---|
| STARTED | 1 |
| COMPLETED | 1 |
| NOT COMPLETED | 0 |
Analysis population for the primary outcome, as defined in the registry: Only 1 patient was enrolled to this study, so no data was obtained.
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 | Treatment Arm |
|---|---|---|
| Participants analysed | 1 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 1 |
| Age, Categorical: >=65 years | Participants | 0 |
| Age Continuous | years | 32 |
| Sex: Female, Male: Female | Participants | 1 |
| Sex: Female, Male: Male | Participants | 0 |
| Region of Enrollment: United States | participants | 1 |
6. Primary Endpoint
The registry lists the primary outcome as Standard Immunohistochemistry and Allred Scores Were to be Used to Measure the Estrogen Receptor (ER) Response Rate in Patients With ER-negative/Low, and Human Epidermal Growth Factor Receptor 2 (HER2)/Neu-positive Breast Cancer., measured over 90 days.
| Element | Registry entry |
|---|---|
| Result type | N/A |
| Measure of spread | not applicable |
| Unit | not stated |
| Endpoint classification | not reduced to a single comparison |
The primary outcome is described as the ER response rate, measured using standard immunohistochemistry and Allred scores in patients with ER-negative/low, HER2/Neu-positive breast cancer. The planned timeframe is 90 days. Immunohistochemistry is a laboratory method for assessing the presence and level of a marker in tissue. An Allred score is a scoring approach for describing ER staining. In general, a response-rate endpoint converts an outcome into a count or proportion meeting a prespecified response definition.
Measuring ER expression is relevant to the study’s stated rationale because the registry summary proposes that increasing ER expression could make hormonal therapies a possible option. That is a reason to investigate the marker; it does not make a change in the marker equivalent to a clinical benefit. The record does not define what degree of change would count as a response, whether a baseline and follow-up specimen were both required, or how scores would be combined into a response rate. These details are not reported in the registry record.
Most importantly, the primary-outcome description says that only 1 patient enrolled and no data was obtained. There is therefore no reported ER measurement, response classification, or response-rate estimate to interpret. The endpoint’s intended measurement and timeframe can be described, but its observed value cannot.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record describes a study intended to assess ER response after trastuzumab in ER-negative/low, HER2/Neu-positive breast cancer. It identifies standard immunohistochemistry and Allred scores as the measurement approach and gives a 90-day timeframe. These are descriptions of the planned outcome, not reported outcome findings.
The record reports enrollment of 1 and explicitly states that no primary-outcome data was obtained. It reports no ER scores, response classifications, response rate, confidence interval, or statistical test for the primary outcome. As a result, the posted results do not quantify an effect, and there is no estimate of its precision. The absence of an outcome estimate must not be read as evidence of no change or no response; the registry says that the data were not obtained.
The design is single-group, with no comparator. Even if an outcome measurement had been recorded, a single-group result would describe observations in that group and would not by itself provide a like-for-like comparison with an untreated or alternative-treatment group. In the actual record, the lack of outcome data means even a within-group response description is unavailable.
The adverse-event entries list 1 person at risk for serious events and 0 affected, and 1 at risk for other listed events and 0 affected. These are counts in a very small enrolled group, not a precise estimate of event frequency in a broader population. Deaths are not reported in the registry record, and no top serious-event terms are listed. The counts should be read as recorded entries, not as proof that an event could not occur.
The study status is terminated, but the reason is not reported in the registry record. The record also does not report an analysis plan, an explanation for the lack of outcome data, or an account of whether any data were collected but unavailable for analysis. Those gaps limit interpretation of both the intended outcome and the study’s completion.
Any sample-size figures presented as planning illustrations are not observed power and do not change the interpretation of this study. The stated illustration assumptions include a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. They are not a report of this single-group study’s design or a registry-record justification for its enrollment. With no observed primary-outcome data reported, such planning quantities cannot be treated as evidence about the study’s treatment effect.
Overall, the record documents a clinical question and a planned measurement approach, but it does not report results that answer that question. Conclusions about ER response, the size or precision of any treatment effect, or comparative effects are not supported by the posted outcome information.
9. Statistical Methods Explained
What does an outcome estimate mean?
General: A statistical estimate is a numerical summary of observed data. For a response-rate outcome, the estimate would ordinarily describe how many observed participants met a defined response criterion relative to the number assessed. Its interpretation depends on a clear response definition, complete and suitable measurements, and a stated analysis population. The registry record names an ER response rate but reports no outcome data, so there is no estimate to interpret for this study.
General: A confidence interval describes a range of values compatible with the data under the assumptions of the statistical method. It conveys uncertainty in an estimate; it is not a guarantee that the true value lies in the interval. A useful interval requires an estimate and data. Neither a primary-outcome estimate nor a confidence interval is reported in the registry record.
What does the single-group design allow?
The registry classifies the model as single-group and allocation as NA. No comparator group is described. In general, a single-group study can describe measurements collected in the treated group, but it cannot provide a direct randomized contrast with a control group when no such group exists. Observed changes may also be difficult to attribute to an intervention without a suitable comparison, depending on the question and design. In this record, no ER outcome measurement is reported, so there is no within-group change to describe either.
The masking entry is NONE. This records the study as unmasked; it does not establish which people involved in treatment, measurement, or assessment knew the treatment assignment. Further details about masking procedures are not reported in the registry record. In general, knowledge of treatment can influence some assessments or decisions, though the relevance depends on how the outcome is collected. The record identifies immunohistochemistry and Allred scoring but does not state whether tissue assessment was blinded to other information.
Why is the endpoint definition important?
The stated primary outcome is an ER response rate assessed with standard immunohistochemistry and Allred scores. In general, a response-rate analysis needs an operational definition of response, including how baseline and follow-up values are compared and what score change qualifies. It also needs rules for participants without a usable measurement. The registry record does not report these details. Without them, readers cannot determine how a response would have been classified or reproduced from individual measurements.
The planned timeframe is 90 days. A timeframe clarifies when an outcome is intended to be assessed, but it does not by itself describe when treatment began, how the assessment window was applied, or how measurements outside that window were handled. Those procedures are not reported in the registry record. The primary-outcome description says that no data was obtained, so it is not possible to assess whether the planned timing was achieved.
How should planning illustrations be read?
The sample-size assumptions describe planning illustrations, not the actual design or enrollment justification for this trial. They specify a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect expressed as a stated fraction of the observed effect. The assumptions also distinguish participants per arm for non-time-to-event outcomes from total events for time-to-event outcomes. These are methodological assumptions for planning calculations, not evidence that this single-group trial used a two-arm design.
General statistical principle: a sample-size calculation depends on a target effect and assumptions about variability, significance level, power, allocation, and the analysis. Changing those assumptions changes the resulting planning requirement. A planning illustration is not observed power: it does not show that the enrolled study had a particular probability of detecting an effect. It is also not the same as an observed result or a protocol-based sample-size justification. The registry record does not report its own sample-size justification.
The illustrations refer to fractions of an observed effect, but the registry record reports no primary-outcome data or observed ER effect. Consequently, the planning figures should be read only according to their stated illustrative assumptions and not as a description of an observed effect from this study. They do not supply missing outcome results or establish that the intended study question was answered.
What can the adverse-event counts tell us?
In general, an adverse-event count describes observed events within a defined group and observation period. Interpreting an event rate also requires knowing the population at risk, how events were collected, the event definitions, and the duration of observation. The registry lists one person at risk for serious events and zero affected, and one person at risk for other events and zero affected. It does not give a detailed collection method or observation period for these entries. The counts therefore describe only what is recorded, and they cannot establish a precise underlying risk.
General statistical principle: small amounts of information lead to substantial uncertainty, even when the recorded event count is zero. A zero count does not mean the true event risk is zero. No confidence interval or inferential analysis for adverse events is reported. Deaths are not reported in the registry record, and no top serious-event terms are listed; these are reporting details rather than a basis for inferring unreported outcomes.
What analyses are reported?
The registry record lists zero analyses. It does not report a statistical analysis plan, model, test, estimate, or adjustment method for the primary outcome. This should not be replaced with assumptions about what the investigators might have planned. No analyses can be reconstructed from the registry’s primary-outcome description because the record says that no outcome data was obtained. Any methods as general explain concepts, not methods confirmed as used in this study.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists one primary outcome measure and zero analyses. It does not report a multiplicity procedure, such as a strategy for adjusting interpretation across multiple outcomes or tests. It would be inappropriate to infer whether such a procedure was planned or needed beyond what the record states. The registry record also does not provide a statistical analysis plan describing outcome hierarchy, repeated assessments, or additional exploratory analyses.
The primary-outcome description states that only 1 patient enrolled and no data was obtained. This is the central limitation for missingness and analysis-population interpretation: there is no reported primary-outcome dataset from which to determine who had an observed ER assessment or how missing observations were handled. The record does not say whether a specimen was unavailable, an assessment was not performed, or data were collected but not entered. Those reasons are not reported in the registry record.
The analysis population is not reported in the registry record. No definitions are given for an enrolled, treated, evaluable, or other analysis group. With only 1 patient enrolled and no outcome data obtained, the record does not support an account of exclusions, adherence, or analysis-set membership beyond the enrollment statement.
In general, missing-data methods depend on why measurements are absent and on the intended estimand. A method cannot recover an outcome value without assumptions, and those assumptions should be stated. No imputation method, sensitivity analysis, or missing-data assumption is reported. The absence of such information is distinct from evidence that a particular missing-data method was not used: the registry record simply does not report one.
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 |
|---|---|---|---|
| Treatment Arm | 0 | 1 | 0.0% |
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 |
|---|---|
| Treatment Arm | 0 of 1 |
The adverse-event group is labeled Treatment Arm. The registry lists 1 person at risk for serious adverse events and 0 affected. It also lists 1 at risk for other adverse events and 0 affected. These entries are counts, not estimates of event probability with a stated precision. With only one enrolled patient, they provide very limited information about safety in a wider patient population.
A zero recorded count should not be interpreted as proof that the intervention cannot be associated with an event. In general, event counts depend on the observation period, definitions, and how events are sought and recorded. Those collection details are not reported in the registry record. The record also lists no top serious-event terms. Deaths are not reported in the registry record; the death entry has no reported value.
The serious and other event counts should be kept separate from the primary ER outcome. The safety entries do not provide an ER response measurement, and the absence of primary-outcome data does not alter how the adverse-event counts are recorded. No comparative safety inference is possible because no comparator group is described. These entries are best read as the registry’s recorded counts for this very small enrolled group, with substantial limits on what they can establish.
12. What the Result Does, and Does Not, Mean
The record documents a study of trastuzumab in ER-negative/low, HER2/Neu-positive breast cancer, with the aim of measuring ER response using immunohistochemistry and Allred scores over 90 days. It also records that the study was single-group, had no masking, enrolled 1 patient, and was terminated. These registry entries describe the study and its intended question, but they do not constitute evidence of an ER response.
The primary-outcome description says that no data was obtained. Therefore, the posted results do not establish whether ER expression changed, whether a response occurred, or how large any change might have been. They do not provide a confidence interval or other measure of precision. Missing outcome data must not be interpreted as a finding of no response; it means that the record does not report an observed outcome.
The study has no comparator group in the registry description. It cannot provide a direct comparison between trastuzumab and another treatment or a control. In general, a single-group observation can answer descriptive questions when measurements are available, but attributing a change to an intervention is a different and more demanding question. Here, even a descriptive ER response result is unavailable.
The registry summary offers a rationale: increasing ER expression could potentially make hormonal therapies a therapeutic option. That statement describes the motivation for investigating the question. It is not a reported result, and the record does not show that the proposed change occurred or that it affected treatment choices, prognosis, or any other clinical outcome.
The recorded adverse-event entries show zero affected among one person at risk in each of the serious and other event categories. Such counts do not establish the absence of risk in a broader population. The reason for termination, the details of outcome-data collection, the analysis population, and the statistical plan are not reported in the registry record. The firm statistical conclusion is therefore limited: the registry identifies an intended outcome and reports enrollment, but it contains no primary-outcome data with which to estimate ER response.
13. Why This Trial Matters Statistically
This trial matters statistically because it illustrates the difference between a well-defined research motivation and an answerable empirical result. The registry describes a biological question about ER expression in ER-negative/low, HER2/Neu-positive breast cancer and identifies a measurement approach. But an endpoint description is not an endpoint result. Without outcome data, there is no response estimate to evaluate, regardless of how relevant the research question may be.
The record also shows why design labels and enrollment need context. A single-group study can be useful for describing measurements in a treated group, but it does not create a like-for-like control comparison. Enrollment was 1, and the primary-outcome description states that no data was obtained. This leaves the intended response question unanswered in the registry record and makes precision impossible to assess.
Statistical interpretation depends not only on the chosen endpoint but also on the operational definition, analysis population, missing-data approach, and analysis plan. The registry does not report these details. Their absence does not establish what investigators did or did not do beyond the recorded statements; it limits what a reader can evaluate from this record.
Finally, the record underscores the distinction between planning illustrations and study evidence. Sample-size illustrations based on assumptions are not observed power, actual enrollment justification, or treatment-effect results. They cannot compensate for missing primary-outcome data. Clear reporting of outcomes and analysis methods is essential for allowing readers to distinguish an unanswered question from a finding of no effect.
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 most direct limitation is that only 1 patient enrolled and the primary-outcome description states that no data was obtained. There is consequently no reported ER measurement, response classification, or response-rate estimate. The record cannot show whether the planned assessment was completed or whether the endpoint could be evaluated in the enrolled patient.
The study is single-group and has no like-for-like control comparison. Allocation is recorded as NA, and no comparator arm is described. This limits the kinds of comparisons the design could support, even if outcome data were available. In this record, the lack of primary-outcome data is an additional and more immediate barrier to interpretation.
The registry does not report a response threshold, score-change rule, specimen timing details, analysis population, or missing-data method. It also does not report treatment dose or schedule, a statistical analysis plan, or the reason for termination. These details are not reported in the registry record and should not be inferred from the study title or phase labels.
The adverse-event counts are based on one person at risk in each listed category and do not provide a precise characterization of safety. No comparator is available for a comparative safety assessment. Deaths are not reported in the registry record, and the list of top serious-event terms is empty. The record does not provide details on adverse-event ascertainment or duration of follow-up.
These limitations concern what can be concluded from the registry record; they do not explain why enrollment was limited or why outcome data were absent. The reason for termination and the reason no primary-outcome data were obtained are not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Use of Trastuzumab to Induce Increased ER Expression in ER-negative/Low, Her-2/Neu Positive Breast Cancer — NCT00726180.
- Registry record last updated 2013-10-15; status last verified 2013-08.
- Results first posted 2013-10-15.
- 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 Phase 1 and Phase 2, single-group, unmasked study of trastuzumab in ER-negative/low, HER2/Neu-positive breast cancer. The primary outcome was an ER response rate measured using standard immunohistochemistry and Allred scores, with a timeframe of 90 days.
The study started in 2008-07, had a primary completion date of 2010-06, and is listed as terminated. Enrollment was 1. The primary-outcome description states that no data was obtained. No comparator group, primary-outcome estimate, or statistical analysis is reported.
The adverse-event record lists zero affected for serious events among one at risk and zero affected for other events among one at risk. Deaths are not reported in the registry record. The reason for termination, sample-size justification, statistical plan, analysis population, and missing-data procedures are not reported in the registry record. The available information therefore describes the intended study question and recorded enrollment, but does not provide an observed ER response result.