Bevacizumab, Docetaxel, and Radiation Therapy in Treating Patients With Stage III or Stage IV Head and Neck Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Bevacizumab, Docetaxel, and Radiation Therapy in Treating Patients With Stage III or Stage IV Head and Neck Cancer (NCT00281840), a na phase 2 study. The primary outcome is Time to Progression.

2. Clinical Question

The registry describes a Phase II study of a combined treatment approach for locally advanced squamous cell cancer of the head and neck. Its rationale notes that bevacizumab may affect tumor growth by blocking blood flow to a tumor, that docetaxel is chemotherapy, and that radiation therapy uses high-energy x-rays to kill tumor cells. The study evaluates the combination rather than isolating the contribution of any one component.

The principal question is descriptive in this design: how long participants remain free of progression after treatment begins, as measured by the study’s time-to-progression endpoint. The registry also lists response rate as a secondary outcome. It does not report a comparison against another treatment, usual care, or an untreated group. Consequently, the record cannot establish whether an outcome differs from what would have occurred under another approach.

The record identifies 30 participants as the enrollment and specifies that the primary endpoint concerns participants who received at least one treatment on study. It does not report the number included in the endpoint analysis, an estimate of time to progression, or a confidence interval. Those missing results mean the stated clinical question cannot be answered from the posted registry results alone.

3. Trial Design

This is a Phase II, single-group study sponsored by Case Comprehensive Cancer Center. The registry lists the study status as completed, with a start date of 2005-09 and a primary completion date of 2012-04. Enrollment is 30. The population is described as patients with stage III or stage IV head and neck cancer, and the official title identifies locally advanced squamous cell cancer of the head and neck.

The listed arm is bevacizumab with docetaxel and radiation therapy. The registry also lists conventional surgery among the interventions, but the arm description does not explain its use or indicate a separate surgery group. The specific treatment schedule, doses, sequencing, eligibility details, and rules for modifying or stopping treatment are not reported in the registry record.

Allocation is recorded as not applicable, masking is none, and the model is single group. There is therefore no randomized comparison within the study, and the record does not support a like-for-like comparison between treatment arms. Because participants receive a combination, outcomes cannot be attributed separately to bevacizumab, docetaxel, radiation therapy, or any role for surgery.

The primary outcome is time to progression, described as a mean with a 95% confidence interval and a timeframe of 5 yrs after treatment. The endpoint description says that time is measured from the date of treatment and that participants who remain progression free are censored at the date of their last follow-up information. Response rate is listed as a secondary outcome. The registry lists two outcome measures, but it records zero analyses. Numerical outcome estimates and analysis details are not reported in the registry record.

The record does not report a protocol-based sample-size justification, a prespecified statistical analysis plan, interim analyses, or details about how the Phase II study was intended to guide subsequent research. None should be inferred from the phase designation or enrollment alone.

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: Patients who received at least one treatment on study

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 Time to Progression, measured over 5 yrs after treatment.

Time to progression measures the interval from the date of treatment until disease progression. Unlike a simple count of whether progression occurred, a time-to-event endpoint incorporates when progression is observed. The registry’s endpoint description specifies that participants who remain progression free are censored at the date of their last follow-up information. Censoring indicates that the event time is not observed during the available follow-up; it does not mean that progression never occurred.

The endpoint is summarized in the registry as a mean with a 95% confidence interval, with a timeframe of 5 yrs after treatment. In general, time-to-event outcomes are useful when participants have different lengths of follow-up or when some have not experienced the event by the end of observation. Their interpretation depends on clear event definitions, follow-up procedures, and appropriate handling of censoring. The registry description supplies the basic time origin and censoring rule, but additional implementation details are not reported in the registry record.

A confidence interval expresses uncertainty around an estimate under the statistical method used. It does not, by itself, show the treatment’s causal effect or compare outcomes with another treatment. Here, the registry record does not report the mean time to progression or its confidence interval, so the magnitude and precision of the primary endpoint cannot be assessed from the posted results. The record also does not state the number of progression events or the number of participants with complete follow-up.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical interpretation begins with the design. This study is recorded as a single-group Phase II study, with allocation not applicable and no masking. A single-group design observes outcomes in participants receiving the study treatment, rather than comparing outcomes between randomized groups. It can provide descriptive information about the treated participants, but a comparison with another treatment requires information from outside the study and assumptions that may not be verifiable from the registry record.

What does time to progression summarize?

Time to progression is a time-to-event outcome. The event is disease progression, and the registry says the time origin is the date of treatment. Participants without observed progression are censored at their last follow-up information. Censoring is common when observation ends before an event is recorded. In general, an analysis must account for the fact that the exact event time is unknown for censored participants. The registry does not report the number of events, the number censored, the follow-up distribution, or the analysis method used.

The record describes the primary endpoint as a mean with a 95% confidence interval. A mean is a measure of the average on the stated time scale, while a confidence interval conveys uncertainty around an estimate under its statistical assumptions. For time-to-event data, the method used to estimate a mean and its interval matters, especially when some event times are censored. Those method details and the actual estimate are not reported in the registry record. It is therefore not possible to check how the stated summary was calculated or to assess its precision.

What can a confidence interval tell readers?

In general, a confidence interval gives a range of values compatible with the data under the model and procedure used. A narrower interval indicates greater precision than a wider interval, considered in context. It does not guarantee that the study is free of bias, establish a causal effect, or show how results would compare with a different treatment. Since no interval is posted for time to progression, its precision cannot be evaluated.

Why does the absence of a comparator matter?

A treatment effect is a contrast between outcomes under different treatment conditions. This study has no randomized comparison arm, so the record does not provide that contrast. Descriptive results, if reported, would characterize the enrolled and treated group. Comparing them informally with results from a different study can be misleading because populations, treatment delivery, outcome definitions, and follow-up may not match. Randomization is not the only way to study treatment effects, but no alternative comparative design or adjustment strategy is described in this registry record.

The treatment is a combination of bevacizumab, docetaxel, and radiation therapy. In general, a combination study cannot isolate the contribution of each component without a design or analysis that separates their effects. No such component-specific comparison is reported. Conventional surgery appears in the intervention listing, but its relationship to the described treatment arm is not explained.

How should the adverse-event summaries be read?

The registry distinguishes serious adverse events from other adverse events and gives the numbers at risk and affected for each group. The serious-event group has 30 at risk and 12 affected; the other-event group has 30 at risk and 30 affected. These are descriptive counts for the study group, not treatment-versus-control comparisons. The listed serious-event terms have percentages, but the record does not provide term-specific counts or clarify all details of event collection, attribution, or duration. A reported event does not by itself establish that the study treatment caused it.

What does over-dispersion mean in general?

For count outcomes, a simple statistical model may assume that the variability in counts follows a particular relationship to their average. Over-dispersion means the observed variability is greater than that assumption allows. If present and ignored, uncertainty estimates can be too small, making intervals appear more precise than warranted. This is a general statistical consideration; the registry record does not report a count-based primary analysis, an over-dispersion assessment, or an adjustment for it.

What can be inferred from the analysis record?

The registry lists two outcome measures and zero analyses. It provides an endpoint definition and some adverse-event summaries but no numerical primary or secondary outcome result. The statistical plan, model specifications, covariates, handling of missing outcome data beyond the stated censoring description, and any sensitivity analyses are not reported in the registry record. These omissions prevent a fuller assessment of analysis choices and robustness.

Any sample-size illustration should be treated as a planning exercise, not as evidence about the observed study’s power. In general, a planning calculation depends on assumptions about the effect to detect, variability or event patterns, allocation, and the chosen error rate. The registry record does not report a trial-specific sample-size justification or the assumptions used to plan enrollment. A calculation based on an observed effect, if used for illustration, is not observed power and does not show that the study was adequately powered for its clinical question.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures: time to progression as the primary endpoint and response rate as a secondary outcome. It records zero analyses and does not report numerical results for either measure. A multiplicity strategy—how statistical interpretation is adjusted when several outcomes or comparisons are considered—is not reported in the registry record. The record also does not describe a hierarchy of endpoints, a prespecified testing order, or whether any formal hypothesis tests were planned.

Missing data require separate consideration. For the primary endpoint, the registry explicitly says participants who remain progression free are censored at the date of their last follow-up information. That is a time-to-event censoring rule, not a complete account of missing-data handling. The number of censored participants, reasons for loss to follow-up, and any sensitivity analyses are not reported in the registry record. The record does not explain how missing response assessments or other incomplete outcome information were handled.

The primary endpoint population is described as participants who received at least one treatment on study. The registry does not state how many participants met this definition for analysis or whether a different analysis population was used for any outcome. It does not report an intention-to-treat population, per-protocol population, exclusions, or the number of participants with evaluable outcome data. Accordingly, the enrollment of 30 should not be assumed to equal the analysis population for each outcome.

The analysis plan, interim analyses, and any procedures for controlling false-positive findings are not reported in the registry record. Without those details and without posted outcome analyses, readers cannot determine how multiplicity or incomplete data influenced the reported results.

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 without neutropenia (10.0%), pneumonitis/pulmonary infiltrates (10.0%), dehydration (6.7%), hypotension (3.3%), thrombosis/embolism (3.3%).

The registry records 30 participants at risk for serious adverse events, of whom 12 are listed as affected. For other adverse events, it records 30 participants at risk and 30 affected. These counts describe the study group; without a comparator arm, they do not establish how event occurrence differs from another treatment or from no treatment.

The listed serious adverse-event terms include infection without neutropenia and pneumonitis/pulmonary infiltrates, each reported as 10.0%; dehydration is reported as 6.7%; and hypotension, thrombosis/embolism, and wound-infection are each reported as 3.3%. These percentages are the registry’s posted values. The record does not give term-specific counts, so they should not be converted into counts or treated as a complete account of event burden. It also does not report the number of deaths.

Serious adverse events and other adverse events are separate summaries and should not be combined. The registry does not provide enough detail to determine event duration, recurrence, severity grades beyond the serious classification, timing, or attribution to a particular component of the treatment combination. In general, adverse events observed during a study are not necessarily caused by the study treatment. These figures are descriptive safety information, not a comparative estimate of treatment-related risk.

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

The registry establishes that a Phase II, single-group study enrolled 30 participants and evaluated a treatment arm described as bevacizumab with docetaxel and radiation therapy. It defines time to progression as the primary endpoint, specifies a time origin and censoring rule, and lists response rate as a secondary outcome. It also records descriptive adverse-event summaries. These registry entries characterize the study and the information posted about it.

The record does not report the primary endpoint estimate, its 95% confidence interval, or a response-rate result. It therefore does not show the observed duration to progression or the precision of that outcome estimate. Nor does it supply a comparative result against another treatment. The absence of a comparator is fundamental: outcomes in one treated group cannot, by themselves, identify what difference the treatment caused.

The study evaluates a combination. The record does not support attributing any outcome separately to bevacizumab, docetaxel, or radiation therapy. Although conventional surgery is listed as an intervention, its role is not explained in the arm description. The treatment schedule and details of exposure are also not reported in the registry record.

The serious and other adverse-event counts provide some descriptive safety information. They do not establish that an event was caused by treatment, and there is no concurrent group against which to compare event occurrence. The registry’s term-level percentages add context but do not replace missing details such as term-specific counts, event timing, or attribution.

In general, results from a Phase II study may inform further research, but the record does not state the intended decision threshold or how the findings were to guide subsequent study. It also does not report the rationale for the enrollment target or a statistical analysis plan. The appropriate conclusion is limited to what is posted: the study design and endpoint definitions are recorded, some adverse-event summaries are available, and numerical efficacy analyses are not reported in the registry record. That is not evidence of benefit or lack of benefit; it is a limit on what can be concluded from these registry results.

13. Why This Trial Matters Statistically

This study illustrates why design and reporting details matter as much as an endpoint label. Time to progression is a time-to-event measure, and its interpretation depends on the definition of progression, time origin, follow-up, and handling of participants without an observed event. The registry specifies the date of treatment as the time origin and describes censoring at last follow-up for participants who remain progression free. Those details help define the intended measure, even though the estimate and analysis are not posted.

The single-group design also makes the inferential boundary clear. The study can be described as evaluating a treatment combination in an enrolled group, but it has no randomized control arm. It therefore does not produce a within-study contrast that would separate treatment effects from other explanations for observed outcomes. In a combination regimen, component effects are likewise not isolated by the design described in the registry.

Reporting the analysis population and uncertainty is essential for interpreting a clinical endpoint. The registry names the population for the primary endpoint, but does not state how many participants were included in the analysis or report a mean and confidence interval. As a result, readers cannot assess either the observed outcome or its precision. The record’s completed status does not fill that gap: status indicates completion, not that numerical results are available in the registry.

The safety summaries show another statistical distinction. Counts and percentages can describe events in a study group, but without comparison data they do not estimate relative risk. Definitions, denominators, event attribution, and follow-up all affect interpretation. Here, the registry provides at-risk and affected counts for broad safety categories and selected serious-event percentages, while several details remain unreported.

These features make the record useful as an example of how to distinguish a planned question from an interpretable result. A clear endpoint definition and an enrollment figure do not substitute for outcome estimates, uncertainty, and analysis methods. Nor should a planning calculation be confused with observed evidence or observed power. The statistical value of the record lies in identifying the design and reporting limits that shape any conclusions drawn from it.

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 the absence of numerical efficacy results. Although time to progression is identified as the primary endpoint and response rate as a secondary outcome, neither outcome’s result is reported in the registry record. The primary mean and 95% confidence interval are absent, as are the numbers of progression events and censored participants. This prevents assessment of the endpoint magnitude and precision.

The single-group design has no concurrent comparator. It cannot provide a randomized treatment contrast, and any comparison with a different study would be indirect. The combined treatment also prevents attribution of observed outcomes to individual components. The registry lists conventional surgery but does not explain its role or whether it was part of the described arm.

Several design and analysis details are not reported in the registry record: eligibility criteria, treatment schedule and doses, follow-up procedures, progression assessment procedures, statistical model, covariate adjustment, analysis populations, and handling of missing data beyond the stated censoring description. The record does not report a sample-size justification, interim analyses, or a statistical analysis plan. It is therefore not possible to assess whether analyses followed prespecified methods or how enrollment was determined.

Safety interpretation is also limited. The record gives broad counts for participants affected by serious and other adverse events and selected percentages for serious-event terms, but not term-specific counts, event timing, duration, attribution, or detailed severity. A death count is not reported in the registry record. No control group is available to contextualize the event summaries.

Finally, the record’s completed status and stated primary completion date do not resolve the absence of posted analyses. These limitations concern what can be interpreted from the registry record and do not establish whether additional results or analyses exist elsewhere.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Bevacizumab, Docetaxel, and Radiation Therapy in Treating Patients With Stage III or Stage IV Head and Neck Cancer — NCT00281840.
• Registry record last updated 2015-06-09; status last verified 2015-05.
• Results first posted 2015-06-09.
• 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

NCT00281840 is a completed Phase II, single-group study sponsored by Case Comprehensive Cancer Center. The registry lists 30 enrolled participants and a treatment arm of bevacizumab with docetaxel and radiation therapy for stage III or stage IV head and neck cancer. Allocation is not applicable, and masking is none.

The primary endpoint is time to progression, summarized as a mean with a 95% confidence interval over the stated timeframe of 5 yrs after treatment. Participants who remain progression free are censored at their last follow-up information. Response rate is listed as a secondary outcome. The registry records two outcome measures and zero analyses.

The registry reports serious adverse events among 12 of 30 participants at risk and other adverse events among 30 of 30 at risk. It lists selected serious-event terms with percentages but does not report deaths. Numerical efficacy results, the analysis plan, and several design and follow-up details are not reported in the registry record.