Docetaxel Followed by Surgery in Treating Women With Stage II or Stage III Breast Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Docetaxel Followed by Surgery in Treating Women With Stage II or Stage III Breast Cancer (NCT00343512), a non-randomized phase 2 study. The primary outcome is Number Participants to Achieve Pathologic Complete Response.

2. Clinical Question

3. Trial Design

This is a phase 2, non-randomized, single-group study sponsored by Vanderbilt-Ingram Cancer Center. The registry title describes docetaxel followed by surgery for women with stage II or stage III breast cancer, while the official title identifies a pilot study of neoadjuvant dose-dense docetaxel with correlative molecular studies in stage II/III breast cancer. The registry records enrollment of 34 participants.

The stated purpose was to evaluate whether dose-dense scheduling with (peg)filgrastim support might improve clinical and pathologic complete response rates and the safety profile of single-agent neoadjuvant docetaxel. The record also describes evaluating changes in molecular markers after docetaxel. Tissue was to be obtained at the end of four cycles, either by repeat biopsy or definitive surgery. The detailed schedule, criteria for choosing the tissue collection route, and treatment implementation are not reported in the registry record.

The study began in 2004-02, has a listed primary completion date of 2008-03, and is recorded as terminated. The reason for termination and whether it affected planned enrollment, treatment, or follow-up are not reported in the registry record. The record does not describe a randomized allocation, masking, or a control group; masking is listed as none.

Secondary outcomes listed are safety based on the number of patients with each worst-grade toxicity and tumor response measured by ultrasound. The registry lists three outcome measures, but the analysis record lists zero analyses. This means the registry does not contain recorded statistical analyses; it does not establish whether analyses were conducted outside the registry. Details of the protocol, enrollment flow, follow-up completion, and analysis populations 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.

Before assignment: A total of 39 people were consented, one of which was ineligible. Four patients withdrew from the study before beginning treatment.

Overall Study

Reasons for not completing this period:

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.

6. Primary Endpoint

The registry lists the primary outcome as Number Participants to Achieve Pathologic Complete Response, measured over 3 month.

The primary endpoint is the number of participants achieving pathologic complete response after neoadjuvant dose-dense docetaxel. The registry defines pathologic complete response as no residual viable tumor on histologic analysis and gives the timeframe as 3 month. This is a binary outcome at the participant level: a participant either meets the stated histologic definition or does not. The endpoint is expressed as a count of participants, rather than a continuous measurement.

In general, pathologic response is used to describe what is found in tumor tissue after treatment. Histologic assessment can characterize residual viable tumor directly, which makes this endpoint distinct from a clinical assessment based on imaging or examination. The registry separately lists tumor response measured by ultrasound as a secondary outcome. These measures address response in different ways and should not be treated as interchangeable.

The registry record does not report the number achieving pathologic complete response, the number assessed for the endpoint, or a proportion with a confidence interval. It also does not provide details about pathology review, assessment criteria beyond the definition, or handling of participants without an evaluable tissue assessment. As a result, the endpoint is defined, but its observed result and precision cannot be evaluated from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Several statistical ideas help distinguish what this registry record can establish from what remains unknown. The study is single-group and non-randomized, the primary endpoint is a participant count, and the record contains no recorded analysis. The planning assumptions described in the registry are not a substitute for observed results.

What does a single-group design estimate?

In general, a single-group study can describe outcomes observed among the participants receiving the studied intervention. A count or proportion can summarize how often a binary endpoint occurred in that group, provided the outcome count and the relevant denominator are reported. Here, the primary outcome is defined, but neither its count nor its denominator is reported. A response estimate and its precision therefore cannot be assessed from this record.

A randomized comparator can help distinguish treatment effects from other causes of outcome differences by creating groups intended to be comparable. This study has no randomized comparator, and the registry explicitly warns that the arms are not a like-for-like control comparison. A comparison between unlike groups, if one were attempted, could reflect differences in participant characteristics or care as well as treatment. No comparative treatment estimate is reported.

What would an interval communicate?

In general, a confidence interval describes the uncertainty around an estimate under a specified statistical model and its assumptions. For a binary outcome, an interval around a response proportion can show how compatible the observed data are with a range of underlying response frequencies. It does not correct bias from study design, missing outcomes, or an unsuitable comparison. No confidence interval for the primary endpoint is reported in the registry record, so neither its width nor the precision of a response estimate can be described.

What do the planning assumptions mean?

The registry describes planning illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The planning target is expressed as a stated fraction of the observed effect. In general, such calculations illustrate the number of participants per arm that a hypothetical study might need under specified assumptions. They are not observed results, and they are not observed power.

Those assumptions do not describe the recorded design of this trial: the registry describes a single-group study rather than equal allocation between two arms. Further, the primary observed effect needed for the illustration is not reported in the registry record, and no calculated planning values are included in the registry record of the record. The illustrations cannot be read as the trial's enrollment rationale or as evidence that the study had a particular probability of detecting an effect. The registry does not report the original sample-size justification.

Why do outcome and analysis details matter?

For a binary endpoint, the numerator is the number meeting the endpoint definition and the denominator is the number assessed in the relevant population. If some outcomes are missing, the denominator and the interpretation can depend on how those participants are handled. In general, excluding participants without an observed outcome can change the estimated response if missingness is related to prognosis or treatment experience. The primary count, assessed denominator, missing-data approach, and analysis population are not reported in the registry record.

The registry lists three outcome measures and zero recorded analyses. A listed outcome is not equivalent to a reported statistical result. Without an analysis plan, it is not possible to determine which comparisons, adjustments, or inferential procedures were intended or used. The record does not report p-values, confidence intervals, adjusted estimates, interim analyses, or a statistical plan. General statistical principles can explain how these methods work, but they cannot supply the missing trial-specific choices or results.

In general, over-dispersion matters when observed variability exceeds what a statistical model assumes; ignoring it can make uncertainty estimates too optimistic. The registry does not report a model for the primary endpoint or a dispersion estimate, and the outcome is recorded as a participant count. There is no basis in the registry record to claim that over-dispersion was assessed or to select a particular model.

Finally, safety counts require attention to their denominator and definition. The registry gives 32 participants at risk for serious adverse events and 32 at risk for other adverse events, along with affected-participant counts. Those figures do not provide event rates over a specified exposure duration or a controlled comparison. In general, the number of participants with an event differs from the number of events if a participant can experience multiple events. Event-level counts and the rules used to classify events are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists the primary outcome as the number of participants achieving pathologic complete response and names safety by worst-grade toxicity and ultrasound-measured tumor response as secondary outcomes. It records three outcome measures, but zero analyses. The registry record does not report a statistical plan identifying which outcomes or comparisons were prespecified for formal inference, nor does it report how multiple outcomes or multiple tests would be handled.

In general, testing several outcomes can increase the chance of obtaining an apparently unusual result by chance if each test is treated as a separate confirmatory test. Methods for addressing multiplicity depend on the aims and analysis plan. No multiplicity adjustment, testing hierarchy, or distinction between confirmatory and exploratory analyses is reported in the registry record. The record therefore does not support a claim that the reported outcomes were or were not adjusted for multiple testing.

The primary response count, the number assessed, and the analysis population are not reported in the registry record. Missing-data rules, exclusions, withdrawals, and the handling of participants without evaluable pathology are also not reported. These details matter because the denominator and the interpretation of a response estimate depend on who is included and how unobserved outcomes are treated.

The registry does not report interim analyses, stopping rules, or a statistical analysis plan. Its terminated status does not explain whether these methods affected conduct or reporting. The reason for termination is not reported in the registry record. No conclusion about the consequences of missingness, selective reporting, or multiplicity can be drawn without those details.

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.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: infection (18.8%), hemoglobin increased (18.8%), fatigue (12.5%), chest pain (9.4%), diarrhea (6.2%).

The safety summary records 32 participants at risk for serious adverse events, with 9 affected, and 32 participants at risk for other adverse events, with 27 affected. These are participant counts, not counts of all individual events. The registry does not explain why the safety denominator differs from the enrollment of 34, so the difference should not be interpreted as a known exclusion or loss to follow-up.

The listed serious adverse event terms are Infection at 18.8%, hemoglobin increased at 18.8%, Fatigue at 12.5%, Chest Pain at 9.4%, Diarrhea at 6.2%, and Vomiting at 6.2%. These are the percentages as recorded. The registry does not state whether terms overlap within participants, so they should not be added to obtain a total or treated as separate groups of participants.

In general, a safety count is most informative when paired with clear definitions, exposure duration, event timing, severity rules, and attribution. The record's secondary outcome refers to the number of patients with each worst-grade toxicity, but details of the grading procedure and event-level data are not reported in the registry record. With no randomized control group, these counts describe the study's safety reporting and do not establish comparative risk.

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

The registry record establishes that a phase 2, non-randomized, single-group study evaluated neoadjuvant dose-dense docetaxel in women with stage II or stage III breast cancer. It defines the primary outcome as pathologic complete response, meaning no residual viable tumor on histologic analysis, and gives a 3 month timeframe. It also records selected safety counts and secondary outcomes. These details explain what the study set out to assess, but they are not a complete report of its results.

The primary response count is not reported in the registry record. Without that result and its denominator, the observed response frequency and its precision cannot be described. No confidence interval or inferential analysis for the primary outcome is recorded. This absence does not show that the response was high or low; it means that the registry record does not provide the result needed to characterize it.

The single-group design also limits what can be concluded even if a response count is available elsewhere. In general, a response observed after treatment does not by itself show how outcomes would have differed under another treatment or without the studied approach. This record includes no randomized comparator and cautions that arms are not a like-for-like control comparison. It cannot establish a comparative treatment effect from the information recorded.

The adverse-event summary provides counts of participants affected and reported percentages for selected serious adverse event terms. Those summaries are useful descriptions of what the registry records, but event overlap, timing, exposure, and attribution are not specified. They do not establish whether safety is better or worse than with another approach.

The record's terminated status is an important design and reporting context, but the reason for termination is not reported. It should not be used to infer a particular safety concern, recruitment problem, or outcome. Overall, the registry supports a careful description of the study question, design, and reported safety figures. It does not support a quantitative assessment of the primary response or a causal claim about treatment benefit or comparative harm.

13. Why This Trial Matters Statistically

This study illustrates why an outcome definition and an outcome result are different parts of a clinical trial record. The registry defines pathologic complete response in histologic terms and identifies it as the primary endpoint, but it does not report the number achieving that endpoint. Readers can understand what was intended to be measured without being able to estimate the observed response or its uncertainty.

The single-group design also makes the distinction between describing outcomes and estimating treatment effects especially important. A group-level response can be clinically and scientifically informative as a description, but a randomized comparison is generally needed to make a stronger causal comparison between treatment strategies. The registry itself notes that the study is not a randomized comparison and that arms are not a like-for-like control comparison.

Safety reporting presents another statistical lesson: denominators, event definitions, and possible overlap matter. The record gives affected-participant counts and selected serious-event percentages, but does not report the reason the at-risk count differs from enrollment, event timing, or whether listed terms overlap. These limits constrain what the figures can say about event frequency and comparative safety.

Finally, the record distinguishes study conduct from statistical evidence. It identifies enrollment, a terminated status, and a primary completion date, while leaving the termination reason, analysis plan, missing-data rules, and primary result unreported. Planning illustrations based on an observed effect cannot replace the observed outcome itself, and they are not evidence of observed power. The case shows why transparent outcome reporting and explicit analysis details are necessary for readers to judge both magnitude and precision.

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 immediate limitation is that the registry record does not report the primary endpoint result. It defines pathologic complete response but gives neither the number meeting the definition nor the number assessed. A response estimate and its precision cannot be reconstructed from the registry information.

The study is recorded as non-randomized and single-group. There is no randomized comparator against which to evaluate the response or safety counts, and the registry warns that arms are not a like-for-like control comparison. This limits causal and comparative interpretation independently of the missing primary outcome.

The record lists enrollment of 34, while the safety summaries give 32 participants at risk for serious and other adverse events. The reason for this difference is not reported. The registry does not give participant flow, evaluability, reasons for missing outcomes, or the population used for the primary endpoint. The data therefore do not establish whether all enrolled participants contributed to each outcome.

Although the study is marked terminated and has a listed primary completion date of 2008-03, the reason for termination and any impact on planned data collection are not reported. Treatment details, including the exact dose-dense schedule and the specific support regimen, are not reported. The registry also lacks the statistical analysis plan, missing-data methods, interim-analysis details, pathology assessment procedures, and a full account of adverse-event definitions and timing. These omissions limit assessment of conduct, bias, precision, and reproducibility.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Docetaxel Followed by Surgery in Treating Women With Stage II or Stage III Breast Cancer — NCT00343512.
• Registry record last updated 2012-04-27; status last verified 2012-04.
• Results first posted 2010-11-09.
• 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

This registry record describes a phase 2, non-randomized, single-group study sponsored by Vanderbilt-Ingram Cancer Center. It evaluates neoadjuvant dose-dense docetaxel in women with stage II or stage III breast cancer and lists enrollment of 34. The study began in 2004-02, has a primary completion date of 2008-03, and is recorded as terminated.

The primary outcome is the number achieving pathologic complete response, defined as no residual viable tumor on histologic analysis, with a 3 month timeframe. The primary outcome count is not reported in the registry record. Secondary outcomes include safety by worst-grade toxicity and tumor response measured by ultrasound.

The safety summary records 9 of 32 participants affected by serious adverse events and 27 of 32 affected by other adverse events. The registry lists zero analyses. The reason for termination, analysis plan, missing-data methods, and primary response result are not reported in the registry record.