Treatment of Head & Neck Cancer With Chemotherapy and Radiation: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Treatment of Head & Neck Cancer With Chemotherapy and Radiation (NCT00392704), a na phase 2 study. The primary outcome is Two-Year Progression Free Survival (PFS) Probability, the Percentage of Patients Estimated to be Alive Without Worsening of Their Disease Two Years After Beginning Protocol Treatment.

2. Clinical Question

3. Trial Design

This was a phase II clinical study recorded as completed. It used a single-group model, had no masking, and listed allocation as not applicable. The registry reports enrollment of 60 participants. Because there was no separate control group, the design was not a randomized comparison. Its results can describe outcomes observed in the enrolled group, but the record does not support a direct comparison with a concurrent alternative-treatment group.

The official title describes neoadjuvant chemotherapy plus bevacizumab followed by concurrent chemotherapy, bevacizumab, erlotinib and radiation therapy for locally advanced squamous carcinoma of the head and neck. The arm description gives details of initial treatment: paclitaxel 200 mg/m2 and carboplatin area under the curve (AUC) 6.0 on days 1 and 22; 5-FU 200 mg/m2 by continuous infusion on days 1 to 43; and bevacizumab 15 mg/kg on days 1 and 22. The complete treatment schedule, including details of the subsequent concurrent phase, is not reported in the registry record.

The registry lists a start date of 2006-12 and a primary completion date of 2008-08. It also records the study status as completed. The brief summary describes treatment over a period of 4 months. The record does not state whether all enrolled participants completed treatment or follow-up, nor does it provide a participant flow accounting for treatment discontinuation or withdrawal.

The primary outcome was two-year progression-free survival probability, defined in its title as the percentage estimated to be alive without worsening of disease two years after protocol treatment began. Overall survival probability at two years is listed as a secondary outcome. The analysis methods and numerical results for these outcomes 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.

Neoadjuvant Chemotherapy

Combined Modality Therapy

Analysis population for the primary outcome, as defined in the registry: All participants in this study were assessed and included in the progression free survival analysis

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 Two-Year Progression Free Survival (PFS) Probability, the Percentage of Patients Estimated to be Alive Without Worsening of Their Disease Two Years After Beginning Protocol Treatment, measured over 24 months.

The primary endpoint is the estimated percentage of participants who were alive without worsening of their disease at two years after beginning protocol treatment. The registry gives the timeframe as 24 months and says that all participants in the study were assessed and included in the progression-free survival analysis. The outcome title includes both survival and disease progression: a participant must be alive and free from worsening disease to meet the endpoint definition at the stated time.

As a general statistical concept, progression-free survival combines information about how long participants remain alive without disease progression. It can be useful in studies where disease worsening is a clinically important event and where waiting for deaths alone would not capture the full course of outcomes. A time-to-event endpoint can also use information from participants whose follow-up ends before the outcome is observed, but the handling of such observations depends on the analysis method.

The registry record does not report the estimated two-year percentage, its confidence interval, the number of progression or death events, or the method used to estimate the endpoint. Its brief description refers to the percentage estimated to be alive at two years, while the primary endpoint title specifies being alive without worsening of disease. The title provides the fuller endpoint definition; the reported result and calculation details are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry identifies a two-year progression-free survival probability as the primary outcome. This is a time-to-event endpoint: the relevant events are disease worsening or death, according to the endpoint definition. The record describes the endpoint as the percentage estimated to be alive without worsening of disease two years after protocol treatment began. It does not state how progression was defined or assessed, how deaths were handled in relation to progression, or what statistical method was used to calculate the estimate.

What does an estimated time-to-event probability represent?

As a general statistical explanation, a time-to-event probability estimates the proportion of a defined population expected to remain free of the event through a stated time point. It is not necessarily a simple count of participants who have complete follow-up to that point divided by the number enrolled. Some participants may have follow-up that ends before the time point, for example, and an appropriate analysis may account for their observed time without assuming that their later outcome is known. The validity of that approach depends on the analysis method and assumptions about follow-up. Those methods and assumptions are not reported in the registry record.

A confidence interval is commonly used to communicate uncertainty around an estimated probability. In general, a wider interval indicates less precision, while a narrower interval indicates greater precision under the model used. The registry record does not give the primary outcome estimate or a confidence interval, so the result’s precision cannot be assessed. No event count or numbers at risk over follow-up are reported for the primary endpoint.

What can a single-group design estimate?

The study is recorded as a single-group trial with allocation listed as not applicable and no masking. In general, a single-group design can describe outcomes among the people who received the study treatment. It does not, by itself, estimate a treatment difference against a concurrent control group. Differences between the observed course of participants and an external expectation would depend on the source and suitability of that expectation, neither of which is reported in the registry record. The design should therefore be read as a study of outcomes in one treated group, not as a randomized comparative efficacy analysis.

The registry lists enrollment of 60 and says all participants were assessed and included in the progression-free survival analysis. It does not report how many had complete outcome follow-up, how censoring was handled, or whether any participants were excluded from particular analyses. The analysis population statement is useful, but it does not answer those additional questions.

What is reported about statistical testing and planning?

The record lists two outcome measures and no analyses. It does not report a statistical analysis plan, an inferential test for the primary endpoint, a target value for comparison, or a hypothesis-testing result. It also does not report a sample-size justification. Those items are not reported in the registry record, so the study’s original design rationale and planned inferential framework cannot be reconstructed from this information.

The statistical planning assumptions associated with planning illustrations describe a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. The illustrations are planning exercises, not evidence about the study’s original design. The actual trial is single-group, and the observed primary effect is not reported in the registry record. No numerical sample-size result is available in the registry record described for this trial. Any such planning illustration must not be interpreted as observed power or as the trial’s original sample-size justification.

In general, observed power is not a substitute for an effect estimate and its uncertainty. Once data have been collected, the estimate, confidence interval and analysis assumptions are more informative for understanding precision. No recalculated treatment effect is reported for this trial, and there is no sponsor analysis in the registry record against which a recalculation could be compared.

Why does over-dispersion matter?

As a general concept, over-dispersion occurs when the observed variability in data exceeds what a statistical model assumes. If a model does not account for that extra variability, standard errors can be too small and confidence intervals can be too narrow. The primary outcome is a time-to-event probability, and the record does not report a dispersion model or a count-outcome analysis. There is no basis to assert that over-dispersion was present or relevant to the trial’s reported analysis; the method used is not reported in the registry record.

The record also gives no information about interim analyses, adjustment for multiple outcomes, or prespecified subgroup analyses. The absence of these details does not establish that such procedures were or were not used. It means their role in the analysis cannot be evaluated from the registry record.

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("Intervention")
n      <- c(60)
events <- c(50)
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  Intervention  60  50  83.3  71.5  91.7  72.0  90.7  71.9  90.6

11. Multiplicity, Missing Data and Analysis Populations

The record lists two outcome measures: two-year progression-free survival as the primary outcome and two-year overall survival as a secondary outcome. It does not report a multiplicity strategy, such as whether any adjustment was planned when interpreting more than one outcome. The statistical analysis plan and any prespecified hierarchy for testing outcomes are not reported in the registry record. Without those details, the intended handling of multiple statistical questions cannot be assessed.

The registry states that all participants were assessed and included in the progression-free survival analysis. This is the only explicit description of the primary analysis population. The record does not explain how missing outcome information, incomplete follow-up, loss to follow-up, or treatment discontinuation was handled. It also does not give the number of participants with observed status at the two-year time point or describe any imputation or censoring procedures. These details are not reported in the registry record.

In general, missing follow-up can affect a time-to-event estimate if participants with incomplete observation differ in their subsequent outcomes from those who remain under observation. Statistical methods can account for incomplete follow-up under stated assumptions, but the methods and assumptions need to be described to evaluate their suitability. No such description is reported for this trial.

The registry lists two outcome measures and no analyses. It provides no subgroup results, adjusted analyses, or multiplicity-adjusted estimates. The absence of these details prevents assessment of how the posted outcomes, had they been reported, were selected or interpreted across multiple analyses. It does not establish that unreported analyses were conducted; their presence or absence is not reported in the registry record.

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: mucositis/stomatitis (6.7%), dehydration (5.0%), vomiting (5.0%), febrile neutropenia (5.0%), fever (3.3%).

The serious adverse event summary lists 60 participants at risk and 24 affected in the intervention group. For other adverse events, it lists 60 at risk and 59 affected. These counts describe the registry’s safety summary; they do not indicate the number of events experienced by each affected participant. The record does not provide further detail about event duration, severity grading beyond the serious-event classification, or timing in relation to treatment.

The listed serious adverse event terms and percentages are mucositis/stomatitis, 6.7%; dehydration, 5.0%; vomiting, 5.0%; febrile neutropenia, 5.0%; fever, 3.3%; and weakness, 3.3%. The denominator and counting rules for these term-specific percentages are not reported in the registry record. These percentages should therefore be read as the registry’s reported values, not as a basis for independently reconstructing event counts. A participant may also experience more than one type of event, so the percentages should not be added to infer a total.

Deaths are not reported in the registry record. The safety figures do not provide a comparison with another treatment group, since the study was single-group. They describe events recorded for the study group and do not, on their own, establish whether an event was caused by treatment.

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

The registry record establishes that this was a phase II, single-group study of a treatment sequence for locally advanced squamous carcinoma of the head and neck, with enrollment of 60 participants. It identifies two-year progression-free survival probability as the primary endpoint and two-year overall survival probability as a secondary outcome. It also records the study as completed and provides a summary of serious and other adverse event counts and selected serious-event terms.

The record does not report the numerical result for either survival outcome. It gives no confidence interval, event count, or statistical analysis for the primary endpoint. Consequently, the posted information does not show how many participants were estimated to remain alive without disease worsening at two years, or how precisely that quantity was estimated. The absence of these results does not mean that the outcome was either favorable or unfavorable.

Even with a numerical outcome estimate, a single-group study would not provide a randomized estimate of the difference between this treatment and another treatment. General statistical interpretation distinguishes a descriptive outcome in the treated group from a comparative treatment effect. A comparison requires an appropriate reference group and analysis, neither of which is present in this design. The record therefore cannot establish a causal advantage or disadvantage relative to another treatment.

The safety summary reports affected-participant counts and selected event percentages, but does not supply event-level detail, a comparator, or enough information to determine the cause of each event. It should be read as a description of recorded safety events, not as a comparative risk estimate.

Overall, the available information supports a careful description of the study’s design, treatment context, outcome definitions and reported safety summary. It does not support a conclusion about the size, precision, or comparative meaning of the primary outcome. The missing result and analysis information are not reported in the registry record.

14. Why This Trial Matters Statistically

This study illustrates why design and result information need to be read together. The registry describes a multi-component treatment sequence, but the trial itself is single-group. That distinction determines what the design can directly estimate: outcomes within the enrolled group can be described, while a between-treatment contrast cannot be calculated from a missing control arm.

The primary endpoint is a time-to-event probability at a defined follow-up point. Such an endpoint requires more than a percentage label for full statistical interpretation. The estimate, uncertainty interval, event information, follow-up details and analysis method all help readers understand what the value represents and how precise it is. Those result and method details are not reported in the registry record, so the endpoint cannot be quantitatively interpreted from this record.

The trial also demonstrates the difference between an outcome’s definition and its observed result. The record names two-year progression-free survival and states that all participants were included in its analysis, but neither statement supplies the estimated probability. Enrollment and analysis-population descriptions do not substitute for an endpoint estimate.

Finally, planning assumptions should not be mistaken for the actual design. The statistical planning description refers to equal allocation between two arms, whereas the trial is recorded as single-group. The planning illustration is explicitly separate from the trial’s own design and does not provide an observed treatment effect or observed power. Keeping those categories distinct helps prevent a hypothetical sample-size calculation from being treated as evidence about the completed study.

These distinctions matter when interpreting any clinical trial record: design determines the comparisons that are possible, endpoint definitions determine what is being measured, and result details determine whether magnitude and precision can be assessed. For this trial, the record supplies design and outcome labels but not the primary outcome analysis.

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 most important trial-specific limitation for statistical interpretation is that the registry record does not report the primary endpoint estimate or its precision. It also does not report the two-year overall survival result, event counts, or statistical analyses. Without those results, readers cannot assess the magnitude or uncertainty of the outcomes named in the record.

The single-group design has no concurrent control arm. This prevents a direct randomized comparison with another treatment and limits interpretation to outcomes observed among participants in the study group, if those outcomes are reported. The registry does not state a benchmark or comparison target for the primary endpoint.

The record gives an enrollment of 60 and states that all participants were assessed and included in the progression-free survival analysis, but does not report participant flow, completeness of follow-up, or handling of missing outcome information. It also does not describe how disease progression was defined, how outcome events were adjudicated, or how follow-up ending before 24 months was treated in the calculation. These details are not reported in the registry record.

The treatment description is incomplete for reconstructing the full regimen: the official title names a concurrent phase, while the arm description specifies the initial treatment schedule. The complete schedule and the extent to which participants received each component are not reported in the registry record.

The safety summary includes affected-participant counts and selected serious-event percentages, but does not report the denominator or counting rules for each term, event timing, or deaths. In combination, the missing outcome, method, follow-up and safety details restrict quantitative assessment of this study from the registry record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Treatment of Head & Neck Cancer With Chemotherapy and Radiation — NCT00392704.
• Registry record last updated 2013-02-22; status last verified 2013-02.
• Results first posted 2013-02-15.
• 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 records a completed phase II, single-group trial of treatment for locally advanced squamous carcinoma of the head and neck. Enrollment was 60, masking was none, and allocation was listed as not applicable. The record lists a start date of 2006-12 and a primary completion date of 2008-08.

The official title describes neoadjuvant chemotherapy plus bevacizumab followed by concurrent chemotherapy, bevacizumab, erlotinib and radiation therapy. The arm description details an initial regimen including paclitaxel, carboplatin, 5-FU and bevacizumab. The primary outcome was two-year progression-free survival probability; two-year overall survival probability was listed as secondary.

The primary and secondary outcome estimates and their analyses are not reported in the registry record. The safety summary lists 24 of 60 participants affected by serious adverse events and 59 of 60 affected by other adverse events. Selected serious-event terms and percentages are recorded, while deaths are not reported.