Paclitaxel + Trastuzumab + Pertuzumab as Pre-Op for Inflammatory BrCa: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Paclitaxel + Trastuzumab + Pertuzumab as Pre-Op for Inflammatory BrCa (NCT01796197), a na phase 2 study. The primary outcome is Percentages of Participants With Pathologic Complete Response.

2. Clinical Question

The trial is identified as NCT01796197 and is titled “Paclitaxel + Trastuzumab + Pertuzumab as Pre-Op for Inflammatory BrCa.” Its official title describes a Phase II trial of paclitaxel combined with trastuzumab and pertuzumab as preoperative therapy for inflammatory breast cancer. The registry lists breast cancer as the condition.

The clinical question is descriptive rather than comparative. A single-group result can describe the observed response proportion among the defined participants, but it cannot by itself estimate how that result would differ from outcomes under another regimen. The registry record does not report the primary response count, percentage or confidence interval, so the size and precision of the observed response cannot be assessed from the posted results.

3. Trial Design

This is a Phase II, single-group study sponsored by Dana-Farber Cancer Institute. The registry lists an enrollment of 23, with a start date of 2013-08 and primary completion in 2018-06; the study status is completed. Allocation is listed as not applicable, consistent with the single-group model. Masking is listed as none.

The treatment arm is described as receiving paclitaxel, trastuzumab and pertuzumab before surgery. The registry also lists doxorubicin, cyclophosphamide, mastectomy and radiation therapy as interventions. The arm description is truncated, so the complete sequence and details of treatment cannot be established from the registry record. Its brief summary says that trastuzumab is given for a total of 12 months and describes adding pertuzumab to trastuzumab for the same total duration; the complete treatment schedule is not available in the arm description.

A single-group design can document outcomes and safety events among participants receiving the study regimen. Because there is no concurrent control group, it does not provide a randomized, like-for-like comparison with another treatment. Differences from results in other studies would not be controlled by this design and could reflect differences in participants, care or study methods.

The primary outcome is pathologic complete response at 18 weeks. Secondary outcomes listed in the registry include congestive heart failure, disease-free survival, time to treatment failure, overall survival, response and residual disease by intrinsic subtype, predictive accuracy of tumor biopsy RNA sequencing profiles, and residual cancer burden by circulating tumor DNA profile change. The registry lists 10 outcome measures. Details such as analysis methods for these outcomes, follow-up schedules and the full protocol 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: Participants are not being evaluated based on their post-operative treatment option. Two options are provided to the participants in order to best treat them based on the nature of their disease.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Subjects evaluable for response. Participants are not being evaluated based on their post-operative treatment option. Two options are provided to the participants in order to best treat them based on the nature of their disease

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: Participants are not being evaluated based on their post-operative treatment option. Two options are provided to the participants in order to best treat them based on the nature of their disease

6. Primary Endpoint

The registry lists the primary outcome as Percentages of Participants With Pathologic Complete Response, measured over 18 weeks.

The primary endpoint is the percentage of participants with pathologic complete response following preoperative treatment, with a timeframe of 18 weeks. The registry defines pathologic complete response as no invasive carcinoma in either the breast or axillary lymph nodes after preoperative therapy. Participants whose disease is not surgically resectable following that therapy are classified as not having a pathologic complete response.

This endpoint uses a clinically interpretable binary classification: each participant is categorized as having or not having the defined response. The percentage summarizes how common the response was in the endpoint population. The registry specifies that this population consists of participants evaluable for response and says participants are not evaluated according to their postoperative treatment option. It does not report how many participants were evaluable.

Pathologic assessment after preoperative treatment can describe the disease status in tissue at surgery, according to the endpoint definition. The registry’s definition also makes clear that inability to proceed to resection is not treated as a response. These rules affect which outcomes count as events in the calculation and should be considered when interpreting the endpoint.

The registry lists a 90% confidence interval as the endpoint’s dispersion measure, but the primary response estimate and its interval are not reported in the registry record. Without those results, the response proportion and the precision of its estimate cannot be evaluated.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is binary at the participant level: a participant is classified as having or not having pathologic complete response under the registry definition. The reported measure is a percentage of participants. In general, a percentage for a binary outcome summarizes the fraction of the defined analysis population with the event, expressed on a scale readers can interpret directly. The registry does not report the response count or estimate, so no endpoint percentage can be stated.

What does the confidence interval represent?

The registry specifies a 90% confidence interval for the primary endpoint. In general, a confidence interval describes uncertainty around an estimate under the statistical procedure used to construct it. A narrower interval indicates greater precision than a wider interval, while the interval’s location indicates the range of values compatible with the data under that procedure. It is not a guarantee that the true value lies within a particular interval, nor does it replace the estimate itself. Here, neither the estimate nor the interval limits are reported in the registry record, so precision cannot be judged.

Why does the analysis population matter?

The stated primary population is participants evaluable for response, rather than explicitly all enrolled participants. The definition also classifies participants whose disease is not surgically resectable after preoperative treatment as not having a pathologic complete response. These specifications determine who contributes to the endpoint and how particular clinical outcomes are classified. The number evaluable and the handling of any other missing assessments are not reported in the registry record. Without those details, the endpoint denominator cannot be reconstructed from the enrollment figure.

What can a single-group analysis show?

In general, a single-group analysis estimates or describes outcomes among participants receiving the study regimen. It has no concurrent control group with which to estimate a treatment difference. A response percentage, if reported, would describe the study participants under the endpoint definition; it would not by itself show what would have happened to comparable participants under another treatment. The registry lists a single-group model and allocation as not applicable, so the findings should be read as noncomparative.

Masking is listed as none. In general, masking can reduce the influence of knowledge of assigned treatment on assessments or other study processes. The record does not provide details about safeguards or assessment procedures, so no further conclusion about the effect of masking on this endpoint is possible.

How should planning calculations be read?

The sample-size material is described as a planning illustration computed from the observed effect, rather than as the trial’s own design. Its stated assumptions are a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect to detect defined as a stated fraction of the observed effect. For time-to-event outcomes, the stated planning quantity is total events using the Schoenfeld method; for other outcomes, it is participants per arm.

These are hypothetical planning assumptions, not the design of this single-group study. Such calculations can illustrate how a hypothetical future comparison might be planned under chosen assumptions, but they are not evidence that this study had a particular power. They are not observed power, and they do not replace the trial’s actual design rationale. The registry record does not report the trial’s sample-size justification or design assumptions. The numerical planning outputs are not reported in the registry record available for this analysis.

Why can event rates vary?

General statistical context: for binary outcomes, the estimated percentage depends on both the observed event count and the population used as the denominator. A small analysis population can make estimates sensitive to the outcomes of individual participants. Confidence intervals communicate some of that sampling uncertainty, but they do not address every possible source of bias, including missing outcome data or limitations of the study design.

Over-dispersion is a general concern when observed variability exceeds what a chosen statistical model expects. It can lead to uncertainty estimates that are too small if the model does not account for the extra variability. The primary endpoint is a participant-level binary outcome, and the registry does not report an over-dispersion model or other methods for addressing it. It is therefore not possible to say whether such an adjustment was part of the analysis.

The record lists one analysis, but it does not report the statistical procedure used to obtain the endpoint estimate or confidence interval. The method for the posted primary result, any covariate adjustment, and any interim analysis are not reported in the registry record. Interpretation should therefore stay with the stated endpoint definition, listed design and posted counts, without assuming additional analyses or methods.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Treatment Arm")
n      <- c(21)
events <- c(10)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Treatment Arm  21  10  47.6  25.7  70.2  28.3  67.6  28.2  67.8

11. Multiplicity, Missing Data and Analysis Populations

The registry lists multiple outcomes, including the primary pathologic complete response endpoint and secondary outcomes covering safety, survival, subtype-specific response or residual disease, and molecular profiling. When a study evaluates several outcomes or makes multiple statistical comparisons, the chance of at least one apparently notable finding can increase. General approaches to multiplicity include prespecifying a primary comparison, adjusting significance thresholds, or treating secondary findings as exploratory. The registry record does not report whether or how multiplicity was addressed.

The registry lists one analysis, but that fact alone does not explain how outcomes were analyzed or whether multiple testing was considered. The analysis population, statistical tests, confidence interval procedures and any adjustment strategy beyond the primary endpoint description are not reported in the registry record.

For the primary endpoint, the registry identifies participants evaluable for response and specifies that participants whose disease is not surgically resectable after preoperative treatment count as not having pathologic complete response. It does not report the number evaluable, the number with missing assessments, or how missing data other than the stated nonresectability rule were handled. It also does not give enough information to determine whether all enrolled participants were included in any particular analysis population.

The record’s summary of the population says participants are not evaluated based on their postoperative treatment option. It does not provide further detail about whether analyses were prespecified by treatment received, protocol adherence or other population definitions. Those analysis-population details are not reported in the registry record.

These omissions limit reproducibility and make it harder to assess how robust any endpoint estimate would be to alternative missing-data assumptions or analysis choices. They do not establish that such methods were absent from the full study documentation; they mean that they cannot be confirmed from the registry record.

12. Safety Results

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

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: neutrophil count decreased (13.0%), diarrhea (8.7%), febrile neutropenia (4.3%), alkaline phosphatase increased (4.3%).

The serious-event summary lists 23 participants at risk and 6 affected. The other-event summary lists 23 participants at risk and 22 affected. Deaths are listed as 0. These are participant counts in the registry safety record; they should not be confused with the primary pathologic complete response endpoint or with the number of participants evaluable for response.

The registry also lists the most frequent serious adverse event terms as neutrophil count decreased (13.0%), diarrhea (8.7%), febrile neutropenia (4.3%), and alkaline phosphatase increased (4.3%). These percentages are quoted as posted and describe reported event terms. The record does not provide further detail about event timing, severity grading, recurrence, or whether events were judged related to treatment.

Serious adverse events and other adverse events are distinct summaries, and the affected counts should be read within their respective categories. Counts alone do not establish causation. The registry lists multiple drugs and procedures in the study but does not attribute the reported events to any one intervention in the safety summary.

The absence of deaths in the posted count does not mean that no serious adverse events occurred: the record separately reports 6 participants affected by serious events. As with other safety summaries, interpretation depends on the definitions, observation period and completeness of reporting; details beyond the posted figures are not reported in the registry record.

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

The record establishes that this was a completed Phase II, single-group study of preoperative treatment for inflammatory breast cancer. It identifies paclitaxel, trastuzumab and pertuzumab as the central drug combination in the study description, and defines pathologic complete response as the primary endpoint at 18 weeks. It also specifies how participants whose disease is not surgically resectable after preoperative treatment are classified for that endpoint.

What the record does not establish is the primary response result. It does not report the number of participants with pathologic complete response, the response percentage, or the confidence interval. Enrollment of 23 is not a substitute for an endpoint denominator, because the endpoint population is described as evaluable participants and the number evaluable is not stated. The missing result does not show that the treatment did or did not produce a particular outcome.

The design also limits what can be concluded from any response estimate. With no concurrent comparison group, the study cannot directly estimate how outcomes differ from those under another regimen. A single-group result would describe outcomes among the studied participants; it would not, on its own, establish a causal treatment effect.

The safety record reports serious-event and other-event counts, as well as deaths and selected serious-event terms. These are useful descriptions of reported events, but the available details do not establish that an event was caused by a specific intervention. The summary does not provide enough information to characterize timing, duration or treatment attribution.

Thus, the registry record supports a description of the study’s question, design, endpoint definition and some safety reporting. It does not support a conclusion about the magnitude or precision of the primary response, a comparison with another treatment, or treatment causality for the adverse events.

14. Why This Trial Matters Statistically

This study raises a statistical question that is easy to overlook: a clearly defined endpoint is not the same as a reported result. The registry specifies pathologic complete response, its timeframe and a rule for participants whose disease is not surgically resectable. Yet it does not post the response count, percentage or confidence interval. Without those values, readers cannot evaluate either the observed response or its precision.

The single-group structure is also central to interpretation. It allows outcomes and safety events to be described among participants in the study, but it does not provide a randomized comparison. Any estimate from the group would need to be kept distinct from a treatment effect relative to another option.

The analysis population illustrates another important issue. The registry describes participants evaluable for response, while reporting an enrollment of 23. Those are not necessarily the same number, and the record does not state the evaluable count. A sound reading therefore avoids treating the enrollment figure as the endpoint denominator.

Finally, the safety counts show why endpoint categories and denominators matter. The record separately reports serious events, other events and deaths. These categories should not be combined or treated as causal evidence without additional information. The statistical value of a registry summary depends not only on numerical results but also on transparent definitions, denominators and methods.

15. 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 interpreting efficacy is that the registry record does not report the primary pathologic complete response estimate or its 90% confidence interval. It also does not state the number of participants evaluable for response. As a result, neither the observed response proportion nor its precision can be assessed.

The single-group design has no concurrent control group, so it cannot provide a like-for-like comparison with another treatment. The record lists no masking and does not describe assessment safeguards. It also does not provide complete eligibility criteria, the full treatment schedule, or the complete arm description; the treatment details available in the registry are therefore incomplete.

For safety, the registry posts affected counts and selected event terms but does not report further details on event timing, duration, severity grading or attribution to treatment in the available summary. The listed counts do not establish causality.

Statistical methods beyond the specified endpoint and confidence interval type are not reported in the registry record. The record does not state how missing assessments other than the nonresectability rule were handled, whether multiplicity was addressed, or whether interim analyses were conducted. The sample-size rationale for the trial is also not reported. These are limits of what can be determined from the registry record, not proof that the full study documentation contains no additional information.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Paclitaxel + Trastuzumab + Pertuzumab as Pre-Op for Inflammatory BrCa — NCT01796197.
• Registry record last updated 2026-02-05; status last verified 2026-01.
• Results first posted 2021-09-05.
• 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.

19. Record Summary

NCT01796197 is a completed Phase II, single-group study sponsored by Dana-Farber Cancer Institute. The registry lists enrollment of 23, a start date of 2013-08, primary completion in 2018-06, allocation as not applicable, and no masking.

The study examines preoperative paclitaxel, trastuzumab and pertuzumab for inflammatory breast cancer. Its primary endpoint is the percentage of participants with pathologic complete response at 18 weeks, using the registry’s stated definition and evaluable-response population.

The primary result, its confidence interval and the endpoint denominator are not reported in the registry record. Safety counts are posted separately: 6 participants affected by serious events, 22 affected by other events, and 0 deaths. The design supports description of outcomes in the study group, not a direct comparison with a control group.