Efficacy And Safety Of Sunitinib In Women With Advanced Breast Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Efficacy And Safety Of Sunitinib In Women With Advanced Breast Cancer (NCT00471276), a non-randomized phase 2 study. The primary outcome is Number of Participants With Objective Response.

2. Clinical Question

The clinical question is whether objective responses were observed among participants enrolled in this phase II study of sunitinib for advanced breast cancer. The endpoint concerns tumor response, not a comparison of treatment against another therapy or against no treatment. Because the study used a single group, the registry record cannot establish what would have happened to a comparable group of participants without sunitinib or under another treatment.

The endpoint description sets out response criteria and assessment timing: baseline, Week 9, and every 8 weeks up to Month 34. A confirmed complete response required disappearance of all target lesions. A confirmed partial response required at least a 30% decrease in the sum of the longest dimensions of target lesions, using the baseline sum as the reference. These definitions clarify what counted as a response, but the record does not report how many participants met either definition.

The registry also lists secondary outcomes including clinical benefit, progression-free survival, duration of response, overall survival, and quality-of-life measures. Their inclusion indicates a broader set of planned outcome topics; it does not, by itself, provide the results for those outcomes. Those results are not reported in the registry record included for this analysis.

3. Trial Design

This was a phase II study of sunitinib malate as a single agent for women with advanced breast cancer. The registry describes the design as non-randomized, with no masking and a single-group model. Enrollment was 83. The study status is completed; the recorded start was 2007-08 and primary completion was 2010-06.

Participants were assigned to the sunitinib group in the registry description. The brief summary says treatment was once daily until disease progression. The record does not provide additional details about dose, treatment modifications, adherence, or the actual duration of treatment for individual participants. Such details are not reported in the registry record.

The absence of randomization and a control group shapes the interpretation. The study can describe outcomes recorded among participants in the sunitinib group, but it cannot make a randomized comparison with another treatment. Differences between the observed outcome and an external expectation would not, by themselves, identify an effect caused by treatment, because there is no concurrent randomized control group to support that contrast.

The primary endpoint was the number of participants with objective response, based on confirmed complete or partial response according to RECIST. The specified assessment schedule was baseline, Week 9, and every 8 weeks up to Month 34. The primary endpoint population was the intent-to-treat population, defined in the record as all enrolled participants. The actual primary endpoint count is not reported in the registry record.

The registry lists 20 outcome measures and 2 analyses. It also names secondary outcomes that include clinical benefit, objective response of superficial lesions, progression-free survival, duration of response, overall survival, objective response in a subgroup for whom sunitinib was at least a third-line therapy, and changes in quality-of-life scores. The registry record does not provide the numerical results or analysis details for those outcomes. In particular, it does not report the protocol, sample-size justification, interim analyses, or the full statistical analysis plan.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Intent to Treat (ITT) population: all enrolled participants

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 of Participants With Objective Response, measured over Baseline, Week 9, and every 8 weeks up to Month 34.

The primary endpoint is a count: the number of participants with an objective response. The registry defines response as a confirmed complete response or confirmed partial response according to RECIST. A complete response meant disappearance of all target lesions. A partial response meant at least a 30% decrease in the sum of the longest dimensions of target lesions, with the baseline sum serving as the reference.

Response criteria make the endpoint operational: they specify which observed changes qualify rather than leaving response to an undefined judgment. Confirmation is part of the stated endpoint definition. The assessment schedule was baseline, Week 9, and every 8 weeks up to Month 34, allowing response status to be assessed over the stated follow-up schedule.

As a general statistical point, an objective-response count describes how many participants met a defined response criterion in the analyzed population. It is not the same as a time-to-event measure such as progression-free survival, nor does it by itself describe response duration. The registry lists those outcomes separately as secondary outcomes.

The endpoint was defined for the intent-to-treat population, which the record describes as all enrolled participants. However, the response count and any uncertainty measure for it are not reported in the registry record. Without those results, the primary endpoint definition can be explained, but the observed response result and its precision cannot be assessed.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary endpoint is a binary participant outcome: a participant either met the stated objective-response definition or did not. The registry reports the endpoint as a number of participants rather than as a continuous measurement. In general, a binary endpoint can be described by a count and, when the necessary denominator and analysis are available, by an estimated response proportion. The registry record does not report the primary response count or an uncertainty interval, so no such estimate can be interpreted.

What does a confidence interval convey?

As a general statistical explanation, a confidence interval expresses uncertainty around an estimate under a specified statistical procedure. It gives a range of values that are compatible with the data and method at the stated confidence level. A narrower interval generally indicates greater precision, while a wider interval indicates less precision. The registry record does not report a confidence interval for the primary response endpoint, so its precision cannot be evaluated from the available record.

What is the importance of the study design?

This study is recorded as non-randomized and single-group, with no masking. Randomization can help create comparable groups for estimating a treatment contrast. A single-group study does not provide that randomized contrast. Its outcome can be described for the enrolled participants, but differences from outcomes in other populations or studies may reflect differences in participants, care, assessment, or other factors, not necessarily treatment. This is a general limitation of interpretation, not a claim about what occurred in this study.

No masking was recorded. In general, masking can reduce the risk that knowledge of treatment assignment influences some assessments or decisions. The potential relevance depends on the outcome and study procedures. The record does not explain how response assessments were conducted beyond their RECIST definition and schedule, so the specific effect of masking on assessment in this study cannot be evaluated.

How should the response criteria be read?

The registry uses RECIST criteria and requires a confirmed complete or partial response. Complete response is defined as disappearance of all target lesions. Partial response is defined as at least a 30% decrease in the sum of the longest dimensions of target lesions relative to the baseline sum. These rules set the classification threshold. They do not show the number of participants who satisfied it. The assessment schedule was baseline, Week 9, and every 8 weeks up to Month 34; the record does not report the completeness of assessments at those times.

What can the planning illustrations tell readers?

The registry's planning assumptions describe an illustration based on an observed effect, using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. The effect to detect is defined as a stated fraction of the observed effect. For time-to-event outcomes, the stated planning approach uses the total number of events; for other outcomes, it gives participants per arm. These are planning conventions, not results from the actual single-group study.

In general, planning calculations ask what sample size or event count would be needed under specified assumptions to detect a target effect at a chosen power. Such calculations depend on the assumed effect and other design inputs. Here, the stated assumptions are for a hypothetical two-arm illustration and should not be confused with the actual non-randomized, single-group design. The trial's own design rationale and sample-size justification are not reported in the registry record. Any illustrated sample size is a planning value, not an observed result or observed power.

Why does over-dispersion matter?

As a general explanation, over-dispersion occurs when count data vary more than a statistical model assumes. If it is ignored, uncertainty estimates can be too small and inferential conclusions can be misleading. This concept is most relevant to count outcomes modeled as rates or event totals, rather than to a simple participant-level yes-or-no endpoint alone. The registry record does not report a model for the primary endpoint or a test for over-dispersion, so it is not possible to say whether this issue affected the study's analyses.

More broadly, the record lists 20 outcome measures and 2 analyses but does not report the full statistical analysis plan, any multiplicity procedure, or the detailed methods used for each outcome. A complete methodological assessment would require those details, as well as outcome estimates and uncertainty measures. Where those details are absent, the appropriate interpretation is that they are not reported in the registry record, rather than inferring the methods used.

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("Sunitinib")
n      <- c(83)
events <- c(7)
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  Sunitinib  83  7  8.4  3.5  16.6  4.1  16.4  4.2  16.4

11. Multiplicity, Missing Data and Analysis Populations

The registry lists 20 outcome measures and 2 analyses. It names one primary endpoint and several secondary outcomes, including clinical benefit, response of superficial lesions, progression-free survival, duration of response, overall survival, a subgroup response outcome, and quality-of-life changes. When many outcomes or analyses are considered, the chance of at least one apparently notable result can increase. As a general statistical matter, multiplicity procedures may be used to control the interpretation of multiple tests or estimates.

The registry record does not report whether a multiplicity adjustment was planned or used, how the 2 analyses relate to the outcomes, or which outcomes were included in each analysis. It also does not report interim analyses or a full statistical analysis plan. Those details are not reported in the registry record and should not be inferred from the outcome list alone.

The primary population is identified as the intent-to-treat population, defined as all enrolled participants. The record does not describe the analysis populations for secondary outcomes, whether all enrolled participants contributed data to each endpoint, or how missing observations were handled. It does not report the number of missing assessments, withdrawals, or participants with incomplete follow-up. These omissions matter because response and time-to-event outcomes can be affected by how incomplete observations are treated.

The primary endpoint result is also not reported. Consequently, neither a multiplicity-adjusted interpretation nor an assessment of missing-data sensitivity can be made from this record. The endpoint definition and population are documented, but the results and associated analysis details needed to evaluate robustness are not.

12. 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: dehydration (3.6%), nausea (2.4%), vomiting (2.4%), confusional state (2.4%), pulmonary embolism (2.4%).

The registry lists the sunitinib group with 83 participants at risk for serious adverse events and 13 affected. It separately lists 83 at risk and 83 affected for other adverse events. These entries are counts as recorded; they should not be treated as evidence of a comparison between treatments, because this was a single-group, non-randomized study. The record does not provide a control group.

The serious adverse-event terms with listed percentages are dehydration, 3.6%; nausea, 2.4%; vomiting, 2.4%; confusional state, 2.4%; pulmonary embolism, 2.4%; and hypertension, 2.4%. The registry presents these as serious-event terms and percentages. They should be read descriptively, not as estimates of comparative risk or proof that sunitinib caused the events.

The record does not report a death count. It also does not give the event-level detail needed to determine whether participants experienced more than one event, how events were attributed, or how long participants were followed for safety. These details are not reported in the registry record. The listed figures therefore describe the registry entries but do not support broader conclusions about comparative safety or causation.

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

The study record documents a phase II evaluation of single-agent sunitinib in women with advanced breast cancer. It specifies a single-group, non-randomized design, no masking, enrollment of 83, and an objective-response endpoint based on confirmed RECIST response. It also identifies the assessment schedule and lists a range of secondary outcome topics. These registry entries describe the study question and its structure.

The record does not report the primary objective-response count or an uncertainty measure. As a result, the posted information does not establish how many participants met the response definition or how precisely any response estimate was measured. No conclusion about the magnitude or reliability of an objective-response result can be drawn from the endpoint definition or enrollment alone.

Even a reported response count in a single-group study would describe outcomes among the enrolled participants, not establish a treatment effect relative to a concurrent randomized comparator. The non-randomized design cannot rule out alternative explanations for observed outcomes. The absence of masking is also part of the design context, although the record does not provide enough detail to assess its effect on endpoint assessment.

The listed secondary outcomes do not substitute for their missing results. The registry record does not report estimates for progression-free survival, duration of response, overall survival, clinical benefit, or quality-of-life changes. It also does not report the statistical analysis plan, missing-data procedures, or a multiplicity approach. Those are meaningful limits on interpretation, rather than evidence that the outcomes were favorable or unfavorable.

Safety entries are descriptive and lack a randomized comparison. They do not by themselves establish causation. Overall, the record describes the design and intended measurements, but the absence of the primary efficacy result and other analysis details prevents a full assessment of efficacy, precision, and robustness.

14. Why This Trial Matters Statistically

This trial is statistically informative as an example of how design determines the claims an outcome can support. The single-group structure allows outcomes to be described among enrolled participants, while the lack of randomization means it cannot provide a randomized treatment contrast. That distinction is essential when interpreting any response count from a study without a concurrent comparator.

The record also illustrates the difference between a clearly defined endpoint and a reported endpoint result. It specifies what counted as an objective response, including confirmation, RECIST criteria, and an assessment schedule. Yet the objective-response count and its precision are not reported in the registry record. A precise definition is necessary for consistent measurement, but it cannot replace the observed data needed to assess the result.

Its outcome list spans response, time-to-event outcomes, and quality-of-life measures. These outcomes answer different questions and require different summaries and analysis approaches. Listing them does not show which results were observed or how the analyses accounted for multiple outcomes. The record's 20 outcome measures and 2 analyses make the unreported analysis plan and multiplicity procedures particularly relevant to interpretation, without implying that any specific procedure was or was not used.

Finally, the stated planning illustration is distinct from the actual trial design. It assumes equal allocation between two arms, while the study itself is recorded as single-group and non-randomized. Recognizing that distinction prevents hypothetical planning quantities from being mistaken for observed evidence or for the study's own design rationale. The record is useful for understanding the intended question and documented design, while its missing results limit what can be concluded about the outcomes.

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 principal trial-specific limitation in the registry record is the absence of the primary objective-response count and any uncertainty estimate. The endpoint is defined, but the observed result cannot be assessed. The record also does not provide numerical results for the listed secondary outcomes, including progression-free survival, duration of response, overall survival, clinical benefit, or quality-of-life measures.

The single-group, non-randomized design has no concurrent randomized control group. This limits causal interpretation and prevents a like-for-like treatment comparison. No masking was recorded. The registry describes response criteria and assessment timing, but it does not explain the response review process or report whether all scheduled assessments were completed.

The record defines the primary population as all enrolled participants, but it does not report missing-data handling, completeness of follow-up, withdrawals, or endpoint-specific analysis populations. The sample-size justification, detailed statistical plan, interim analyses, and multiplicity procedures are not reported in the registry record. Their absence prevents assessment of whether the reported analyses—if any—followed prespecified methods.

The safety information is also limited. It gives group counts and selected serious-event terms with percentages, but does not report deaths or sufficient event-level detail to evaluate duration, recurrence, attribution, or comparative risk. These limitations do not show that outcomes were absent; they identify what the registry record does not report.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Efficacy And Safety Of Sunitinib In Women With Advanced Breast Cancer — NCT00471276.
• Registry record last updated 2011-07-25; status last verified 2011-07.
• Results first posted 2011-07-22.
• 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

The registry describes a completed phase II study of sunitinib as a single agent for women with advanced breast cancer. The design was non-randomized, unmasked, and single-group, with enrollment of 83. The recorded start was 2007-08 and primary completion was 2010-06.

The primary endpoint was the number of participants with confirmed objective response according to RECIST, in an intent-to-treat population defined as all enrolled participants. Assessments were scheduled at baseline, Week 9, and every 8 weeks up to Month 34. The primary endpoint result is not reported in the registry record.

The record lists 20 outcome measures and 2 analyses, as well as secondary efficacy and quality-of-life outcomes. It also reports descriptive adverse-event entries. The detailed statistical plan, missing-data methods, multiplicity procedures, and sample-size justification are not reported in the registry record.