Bevacizumab in Treating Patients With Persistent or Recurrent Ovarian Epithelial Cancer or Primary Peritoneal Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Bevacizumab in Treating Patients With Persistent or Recurrent Ovarian Epithelial Cancer or Primary Peritoneal Cancer (NCT00022659), a na phase 2 study. The primary outcome is Number of Participants and Degree of Toxicity of Bevacizumab in This Cohort of Patients as Assessed by CTC..

2. Clinical Question

The trial’s stated purpose was to evaluate bevacizumab in patients with persistent or recurrent ovarian epithelial cancer or primary peritoneal cancer. Its primary endpoint, however, is specifically framed around toxicity: a participant count and the degree of toxicity. That distinction matters when interpreting the record. The study objective mentions whether bevacizumab works, but the primary endpoint description does not report a tumor-response measure or an estimate of treatment benefit.

Because the design is single-group, the registry record does not offer a concurrent control group for judging what would have happened without bevacizumab. The treatment schedule and the enrolled clinical population describe the setting in which toxicity and the listed secondary outcomes were to be assessed. They do not, by themselves, establish a causal treatment effect.

The endpoint was assessed every cycle while on treatment, 30 days after the last cycle of treatment, and up to 5 years. The result values for the primary endpoint and the secondary outcomes are not reported in the registry record. Consequently, the question that can be addressed from the posted information is about the study’s design and recorded safety counts, rather than the magnitude or precision of an efficacy effect.

3. Trial Design

This was a phase II, single-group study sponsored by the National Cancer Institute (NCI). The registry lists enrollment of 64 and a completed status. The recorded start was 2002-04, and primary completion was 2010-03. Allocation is listed as NA and masking as none. These characteristics describe a nonrandomized treatment cohort, not a like-for-like comparison between treatment and control groups.

Participants received bevacizumab intravenously over 30–90 minutes on day 1. Courses were scheduled to repeat every 21 days unless disease progression or unacceptable toxicity occurred. Laboratory biomarker analysis is also listed. The record does not provide further details about the biomarker procedures or how they were incorporated into an analysis.

The primary outcome is described as the number of participants and degree of toxicity assessed by CTC. The population for this outcome is identified as eligible and evaluable patients. Assessment was planned every cycle during treatment, 30 days after the last cycle, and up to 5 years. Overall survival and duration of progression-free survival are listed as secondary outcomes. Although the registry lists five outcome measures, their individual result values are not reported in the registry record.

The registry’s adverse-event record separately lists 62 participants at risk for serious events, with 26 affected, and 62 at risk in the other adverse-event category, with 62 affected. These entries should not be treated as the result for the primary endpoint: the primary endpoint’s result value is not reported in the registry record, and the adverse-event entries have their own categories and denominators.

The design information does not state the protocol’s sample-size justification, planned interim analyses, or detailed statistical analysis plan. Those details are not reported in the registry record. Nor does the registry record present a control-group estimate against which the observed cohort can be compared.

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: Eligible and treated patients.

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: Eligible and treated patients.

6. Primary Endpoint

The registry lists the primary outcome as Number of Participants and Degree of Toxicity of Bevacizumab in This Cohort of Patients as Assessed by CTC., measured over Assessed every cycle while on treatment, 30 days after the last cycle of treatment, up to 5 years..

The primary endpoint is titled as the number of participants and degree of toxicity of bevacizumab in the cohort, assessed by CTC. Its unit is participants, and its stated population is eligible and evaluable patients. The assessment schedule is every cycle while on treatment, 30 days after the last cycle of treatment, and up to 5 years. The actual primary endpoint result is not reported in the registry record.

A participant count is a descriptive way to report how many people in the defined analysis population experienced an event or toxicity category. The degree component can distinguish severity, which is relevant because a simple count alone does not communicate how serious an event was. These are general statistical considerations; the registry record does not specify the detailed grading rules used or provide the endpoint’s observed category counts.

Collecting toxicity information repeatedly during treatment and after treatment can capture events at different points in the observation period. Interpretation still depends on clear definitions of the event, its severity, the population included, and the amount of follow-up available. Those details are not all reported in the registry record.

The title and description make toxicity the focus of the primary endpoint. Overall survival and duration of progression-free survival are listed separately as secondary outcomes. The registry record does not report results for those outcomes, so they cannot be used to quantify treatment benefit or compare outcomes across treatment strategies.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a participant count represent?

A participant count records how many people in a specified analysis population experienced an event or met an endpoint definition. It is descriptive unless accompanied by a defined comparison and an analysis that estimates uncertainty. The primary endpoint in this study is framed as a count of participants and degree of toxicity, but its result values are not reported in the registry record. The adverse-event entries are separate posted safety information and should not be mistaken for the missing primary endpoint result.

Counts need context. The population at risk, the event definition, observation period, and handling of people with incomplete follow-up all affect interpretation. A count without its denominator is difficult to contextualize; a percentage without a clearly defined denominator and time window can also be hard to interpret. The registry lists 62 at risk in each adverse-event category, but it does not report detailed event-level follow-up or explain every denominator convention in the posted record.

Why does a single-group design matter?

In a single-group study, outcomes are observed among participants receiving the study intervention, without a concurrent control group in the described design. The resulting data can describe what was recorded in that cohort. They do not provide a randomized contrast that controls for differences between treatment groups. General statistical reasoning therefore cautions against interpreting an event count as a causal estimate of what bevacizumab changed.

Randomization can help balance measured and unmeasured prognostic factors between groups on average. It is not listed for this study: allocation is NA, masking is none, and the model is single-group. The registry explicitly notes that this is not a randomized comparison and that arms are not a like-for-like control comparison. Any external comparison would depend on assumptions about differences in population, care, outcome definitions, and follow-up; such a comparison is not reported in the registry record.

What do precision and statistical significance usually describe?

In general, an estimate describes the observed magnitude of a quantity, while a confidence interval communicates its statistical precision. A narrow interval indicates less uncertainty under the analysis assumptions than a wide interval. A p-value, in general, measures how incompatible the observed data are with a specified null model, conditional on the model and assumptions. Neither a confidence interval nor a p-value can replace assessment of study design, outcome definitions, and the relevance of the comparison.

The registry record reports no analyses and no primary endpoint estimate, confidence interval, or p-value. Thus, there is no reported inferential result to interpret for the primary outcome. Absence of a registered analysis is not proof that no analysis was conducted elsewhere; it means that an analysis result is not available in this registry record.

How should planning calculations be understood?

Sample-size calculations are planning illustrations, not observations from the trial. The listed planning assumptions describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect defined as a fraction of the observed effect. For time-to-event calculations, the assumption is expressed as a total number of events; other calculations are expressed as participants per arm. These assumptions do not describe the actual single-group study design and should not be mistaken for its protocol or observed results.

A planning calculation asks what sample size could be needed to detect a specified effect under stated assumptions. It is not observed power, and it does not show that the study had a particular probability of detecting an effect after the data were collected. The registry record does not report the trial’s own sample-size justification. Any planning illustration based on an observed effect is conditional on that effect and its assumptions, rather than evidence that the trial was designed around that target.

Why can over-dispersion matter?

As a general statistical concept, over-dispersion occurs when observed variability is greater than a model expects. If an analysis assumes less variability than the data contain, uncertainty can be understated and inferential results can appear more precise than warranted. The appropriate response depends on the outcome type and model, and may involve a model that better represents the variability. The registry record does not describe a model for the toxicity endpoint or report evidence about over-dispersion, so this is a general consideration, not a claim about this trial’s analysis.

What can be inferred from the listed outcome types?

The primary outcome is a toxicity count and degree, while overall survival and duration of progression-free survival are secondary outcomes. Different outcome types require different definitions and analytic approaches. Event counts depend on the population and observation window; time-to-event outcomes depend on event definitions, censoring, and follow-up. The registry does not report the detailed analysis methods, censoring rules, or estimates for the secondary outcomes. Those methods and results are not reported in the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists five outcome measures and identifies toxicity as the primary endpoint, with overall survival and duration of progression-free survival among the secondary outcomes. It reports an analysis count of 0. No adjustment for multiple comparisons, hierarchy among secondary outcomes, or prespecified testing sequence is described. Such details are not reported in the registry record.

Multiplicity is a general concern when several outcomes or analyses are tested. The more hypotheses considered, the greater the chance that at least one result may appear noteworthy by chance if each is assessed without accounting for the overall testing strategy. The implications depend on which outcomes were prespecified, the number of analyses conducted, and how results are interpreted. The registry’s outcome list alone does not establish what testing strategy, if any, was used.

Missing-data methods are also not reported in the registry record. The record does not describe the extent or reasons for missing endpoint observations, how incomplete follow-up was handled, or whether any imputation was used. It also does not give enough detail to assess whether eligible and evaluable participants differed from those who were not evaluable. These omissions matter because missing observations can affect both the observed event count and the population to which an estimate applies.

The record identifies the primary endpoint population as eligible and evaluable patients, while the adverse-event entries give their own at-risk counts. The relationship between those populations is not further explained. The registry record does not report a full analysis-population definition or a flow of participants through assessment and follow-up. Consequently, the missingness, denominator choices, and multiplicity implications cannot be resolved from the posted information.

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 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: neutropenia (3.2%), thrombosis embolism (3.2%), constipation (3.2%), nausea (3.2%), gi other (3.2%).

The adverse-event record lists a bevacizumab group with 62 participants at risk for serious events and 26 affected. It separately lists 62 at risk and 62 affected in the other adverse-event category. The registry record does not provide further explanation of the category labels in this entry, so the two sets of counts should be read as separately reported safety data rather than merged.

The top serious adverse terms listed are neutropenia, thrombosis embolism, constipation, nausea, gastrointestinal other, and dyspnea. Each is reported at 3.2%. These term-specific percentages are registry entries; the record does not provide additional detail about event severity, timing, recurrence, or whether participants could contribute to multiple terms. They should not be summed or treated as mutually exclusive categories.

Counts and percentages describe observed reports within the recorded safety population. They do not establish that bevacizumab caused an event, and the single-group design does not provide a randomized safety comparison. Interpretation also depends on how events were defined, collected, and followed. Those detailed methods are not reported in the registry record.

The primary toxicity endpoint’s result is not reported in the registry record. The safety entries therefore provide selected adverse-event information, not a complete substitute for the primary outcome or for a comprehensive comparative safety analysis.

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

The record establishes that this was a completed phase II, single-group study of bevacizumab in patients with persistent or recurrent ovarian epithelial cancer or primary peritoneal cancer. It documents the treatment schedule, a toxicity-focused primary endpoint, secondary survival outcomes, and selected adverse-event counts. The registry reports enrollment of 64 and lists adverse-event populations and terms.

Those details do not amount to a reported estimate of treatment efficacy. The primary endpoint result is not reported in the registry record, and results for overall survival and duration of progression-free survival are also not reported. The record gives no treatment-effect estimate, confidence interval, or p-value. It therefore does not support a numerical conclusion about the magnitude or precision of an outcome effect.

The study’s design also does not supply a randomized control comparison. In general, outcomes in a treated cohort cannot by themselves distinguish treatment effects from other explanations, including patient characteristics, disease course, or other aspects of care. This limitation concerns what the design can establish; it does not determine whether the treatment had an effect.

The posted safety figures describe recorded events in the specified safety categories. They should be interpreted with attention to their at-risk populations and the limited event detail in the record. The serious adverse terms are each listed at 3.2%, but this information does not establish causality or provide a complete accounting of risk over time.

Overall, the registry record is informative about the study’s structure and selected safety reporting, but insufficient for estimating an efficacy effect or assessing its statistical precision. The absence of posted analyses or endpoint results is a limitation of the available registry information, not a finding that the outcomes were absent or that no analysis was ever conducted.

13. Why This Trial Matters Statistically

This study is statistically instructive because its title and stated objective refer to treatment evaluation, while the registered primary endpoint is a count and degree of toxicity. Distinguishing the study’s broad objective from its specified primary outcome prevents readers from treating a toxicity endpoint as an efficacy result. The registry also lists survival outcomes as secondary measures, but does not report their results.

The single-group design illustrates an important distinction between describing outcomes and estimating comparative effects. A cohort can provide descriptive information about participants who received a treatment, but a concurrent randomized comparison is needed to make a stronger direct comparison while reducing the influence of differences between groups. Allocation is listed as NA, masking as none, and the design as single-group, so the record should not be read as a controlled treatment contrast.

The safety entries also show why denominators and endpoint definitions matter. Serious-event and other-event categories have separate at-risk populations and affected counts. The terms and percentages provide selected detail, but do not replace a full report of the primary endpoint or an analysis of uncertainty. Statistical interpretation depends on knowing who was assessed and how events were classified.

Finally, the record lists five outcome measures but no analyses. That makes the distinction between an outcome being registered and a result being reported particularly important. Without posted estimates and their uncertainty, readers cannot judge precision, statistical evidence, or the relative importance of outcomes. The trial remains useful as an example of how design, endpoint choice, and reporting completeness shape the conclusions that can be drawn from a clinical study record.

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 the registry does not report the primary endpoint result. Although the endpoint is defined as the number of participants and degree of toxicity assessed by CTC, no result value or detailed breakdown is present. The secondary outcomes, overall survival and duration of progression-free survival, also have no reported results in the registry record.

The single-group design lacks a concurrent comparator, and the registry identifies no randomized allocation. As a result, the posted information cannot support a like-for-like comparison or isolate a causal effect. The record’s own caution that arms are not a control comparison is consistent with this design limitation.

The primary endpoint is described for eligible and evaluable patients, while the safety record gives 62 at risk in each of two adverse-event categories. The registry does not explain in detail how these analysis populations relate to the enrollment of 64, how evaluability was determined, or whether all participants had comparable observation. Missing-data methods and participant flow are not reported in the registry record.

Additional limitations include the absence of a detailed statistical analysis plan, sample-size justification, registered analysis results, and information about multiplicity handling. Detailed definitions and collection methods for adverse events, censoring rules for time-to-event outcomes, and the handling of incomplete follow-up are not reported in the registry record. These gaps limit assessment of both the reliability and generalizability of any outcome estimates, even where selected safety counts are available.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Bevacizumab in Treating Patients With Persistent or Recurrent Ovarian Epithelial Cancer or Primary Peritoneal Cancer — NCT00022659.
• Registry record last updated 2019-07-24; status last verified 2019-07.
• Results first posted 2015-05-12.
• 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

NCT00022659 is a completed phase II, single-group study sponsored by the National Cancer Institute (NCI), with enrollment listed as 64. The recorded start was 2002-04 and primary completion was 2010-03. Participants received bevacizumab intravenously on day 1, with courses repeating every 21 days unless disease progression or unacceptable toxicity occurred. Masking is listed as none, and allocation as NA.

The primary endpoint concerns the number of participants and degree of toxicity assessed by CTC, in eligible and evaluable patients. Overall survival and duration of progression-free survival are listed as secondary outcomes. The record lists five outcome measures and an analysis count of 0, but primary and secondary outcome results are not reported in the registry record.

Safety entries list 62 at risk and 26 affected for serious events, and 62 at risk and 62 affected in the other category. Six top serious adverse terms are each reported at 3.2%. These descriptive entries do not constitute a randomized comparison or a complete estimate of treatment effect.