Lapatinib and Radiation for Stage III-IV Head and Neck Cancer Patients Who Cannot Tolerate Concurrent Chemotherapy: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Lapatinib and Radiation for Stage III-IV Head and Neck Cancer Patients Who Cannot Tolerate Concurrent Chemotherapy (NCT00490061), a na phase 2 study. The primary outcome is Progression Free Survival.

2. Clinical Question

The study also proposed to evaluate time-to-progression, 2-year locoregional control, overall survival, and late toxicity, with particular attention to mucosal and dermatologic toxicity. The listed secondary outcome is overall survival. These aims describe what the study intended to assess; they do not establish that each outcome was reported.

The central statistical issue is that the registry record gives the endpoint definition and its intended time point but no observed primary outcome estimate. It therefore does not allow a reader to assess the 2-year progression-free survival rate, its precision, or how the observed data compare with any target. The single-group design also means that the study cannot directly estimate a treatment contrast against a concurrent control group.

3. Trial Design

This was a phase II, single-group study of lapatinib with radiotherapy for people with stage III-IV head and neck cancer who could not tolerate concurrent chemotherapy. The registry record lists enrollment of 17 participants, allocation as not applicable, and no masking. It gives the status as terminated. The recorded start is 2007-07 and primary completion is 2013-01.

The intervention group is described as receiving radiotherapy and lapatinib. The regimen description states that lapatinib was administered orally once daily at 1500mg/d for seven days before and throughout radiotherapy. Radiotherapy was described as intensity-modulated radiotherapy. DCE-MRI was part of the intervention description, including imaging around lapatinib loading and radiotherapy. The registry record also lists a G.E. Healthcare 1.5T MR system as an intervention device.

Because there was no separate control arm, the study is not a randomized comparison. Its design can describe outcomes among enrolled participants, but it does not by itself isolate the effect of lapatinib from radiotherapy, participant characteristics, or other influences on outcomes. The registry record does not report a comparator regimen or a planned between-group contrast.

The primary outcome was progression-free survival at 2 years after study enrollment, expressed as a percentage of participants, with a 95% confidence interval specified as the dispersion measure. The primary outcome description defines progression-free survival from treatment start to documented tumor progression or death from any cause, whichever occurs first. The listed secondary outcome is overall survival. Although the study summary also describes other intended assessments, their numerical results are not reported in the registry record.

The record gives no reason for termination, recruitment flow, or details about how many participants completed follow-up. These omissions limit interpretation of the enrolled group and the extent to which the intended follow-up was achieved.

4. Participant Flow and Accounting

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

Before assignment: \# of subjects were screened.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: 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 Progression Free Survival, measured over 2 year PFS: PFS at 2 yrs after study enrollment.

The primary endpoint is progression-free survival at 2 years after study enrollment, reported as a percentage of participants. Progression-free survival combines two events that matter to the endpoint definition: documented tumor progression and death from any cause. The event is the first of these to occur, and the time origin is starting treatment.

Progression is defined using RECIST V1.0. The description specifies at least a 20% increase in the sum of the longest diameters of target lesions, relative to the smallest recorded sum since treatment began, or the appearance of one or more new lesions. This makes the outcome depend on documented disease assessments as well as the occurrence and timing of death.

A fixed-time survival percentage provides an estimate of the proportion of the specified population who remain free of progression or death at the chosen time point. It is useful for presenting a clinically interpretable milestone, while the time-to-event definition preserves the ordering and timing of events used to classify participants. The registry record specifies a 95% confidence interval to convey uncertainty around the percentage, but the numerical estimate and interval are not reported in the registry record.

The endpoint should not be confused with overall survival, which considers death rather than progression or death, or with time-to-progression, which is named as an objective in the study summary but is not the primary endpoint listed in the registry record. None of these distinctions supplies an outcome estimate when the result itself is absent.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a single-group design estimate?

In a single-group study, the observed participants receive the study intervention, and outcomes are described within that group. Such a design may estimate an outcome rate or characterize events during follow-up, but it does not create a randomized control group for estimating a treatment contrast. General statistical principle: a comparison with an external benchmark or historical experience can be affected by differences in eligibility, care, measurement, and follow-up, so it is not equivalent to a concurrent randomized comparison.

For this study, the registry record identifies one group receiving radiotherapy and lapatinib and records allocation as not applicable. It does not report a randomized allocation scheme or a like-for-like control group. Interpretation should therefore focus on the outcomes actually observed in the enrolled group, if reported, rather than treating the design as a comparative test.

How should the primary endpoint be understood?

Progression-free survival is a time-to-event outcome. Each participant's time begins at treatment start, and the event is the first documented tumor progression or death from any cause. The endpoint description defines progression by RECIST V1.0 as at least a 20% increase in the sum of the longest diameters of target lesions, using the smallest sum recorded since treatment began as reference, or one or more new lesions.

The primary measure is a percentage at the 2-year time point, rather than a reported median time or hazard ratio. General statistical principle: a time-to-event percentage describes the estimated proportion without the defined event at a particular time, while a confidence interval indicates the uncertainty around that estimate. A confidence interval is not a guarantee that the true value lies within its limits; it is a measure of statistical uncertainty under the method used. The registry record specifies a 95% confidence interval, but neither its limits nor the endpoint estimate are reported in the registry record.

Time-to-event outcomes can account for differing follow-up durations when analyzed with appropriate methods. However, the registry record does not report the estimator, censoring rules, or details of the analysis. It is therefore not possible to determine how incomplete follow-up was handled or whether the reported endpoint, if any, incorporated censoring.

What does a confidence interval add?

General statistical explanation: an estimate alone does not show how much uncertainty surrounds it. A confidence interval presents a range of values compatible with the data and the specified statistical procedure. A wider interval generally reflects less precision, which may result from limited information, variability, or both. In a small study, estimates can be particularly uncertain, but the actual precision cannot be assessed without the numerical estimate and interval. Enrollment of 17 does not, on its own, reveal how many endpoint events occurred or how much follow-up was available.

Why do event counts and denominators matter?

A percentage is meaningful only with its denominator and outcome definition. The primary endpoint is specified as a percentage of participants and the population is all enrolled participants. The record does not state the number of participants contributing evaluable primary outcome data or give a primary endpoint event count. The safety summaries separately identify 16 participants at risk for serious adverse events and 16 at risk for other adverse events. Those denominators should not be assumed to be the analysis population for progression-free survival.

General statistical principle: when outcomes are missing, an analysis may depend on whether missingness relates to prognosis or event status. Different handling choices can produce different estimates. The registry record does not report a missing-data method, censoring approach, or sensitivity analysis, so the influence of unavailable assessments cannot be evaluated.

How should planning illustrations be read?

The planning assumptions describe illustrations based on an observed effect, rather than the trial's own design. They specify a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is described as a stated fraction of the observed effect. The record also distinguishes illustrations for time-to-event outcomes, which use a total event count, from other outcomes, which use participants per arm.

These assumptions do not mean that the trial itself had two arms. The study is recorded as single-group, and no observed primary effect is reported in the registry record. Planning illustrations are not observed power and do not establish that a study was adequately sized. The record does not report the original sample-size justification or its own prospective design assumptions.

What can be inferred from the safety summaries?

General statistical principle: safety event summaries can count affected participants, events, or event terms, and these are not interchangeable. A participant may experience more than one event, and one event may be represented by a term in a coded list. The record gives counts of participants affected for serious and other adverse events, alongside serious-event terms and percentages. It does not explain the coding rules, overlap among terms, severity grading beyond the serious classification, or causal attribution. Therefore, the entries should be read as registry-reported safety information rather than as a complete account of each participant's event history.

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("Radiotherapy (Radiation) and Lapatinib")
n      <- c(16)
events <- c(9)
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  Radiotherapy (Radiation) and Lapatinib  16  9  56.2  29.9  80.2  33.2  76.9  32.9  77.0

11. Multiplicity, Missing Data and Analysis Populations

The study summary names several objectives: time-to-progression, 2-year locoregional control, progression-free survival, overall survival, and late toxicity, with mucosal and dermatologic toxicity singled out for evaluation. The registry record lists progression-free survival as the primary outcome and overall survival as a secondary outcome. It reports two outcome measures but no analysis results.

When a study examines multiple outcomes or multiple comparisons, general statistical principle: the chance of obtaining at least one apparently notable result can increase if no adjustment or prespecified hierarchy is used. The registry record does not report a multiplicity strategy, an outcome hierarchy beyond naming the primary outcome, or whether any adjustment was planned. An interim analysis plan is also not reported in the registry record.

The primary outcome population is described as all enrolled participants, and the recorded enrollment is 17. The record does not report the number with evaluable 2-year follow-up, endpoint event counts, participant disposition, reasons for missing assessments, or how missing data and censoring were handled. It is therefore not possible to establish whether all enrolled participants contributed to the primary estimate or how incomplete follow-up may have affected it.

The safety summaries use 16 participants at risk for serious adverse events and 16 at risk for other adverse events. The relationship between these denominators and the enrolled population is not explained; no reason for the difference is reported. No assumption should be made about the status or follow-up of participants outside those safety denominators.

The analysis populations, including any distinction between enrolled, treated, or evaluable participants, are not further described in the registry record. The statistical analysis plan, missing-data procedures, and sensitivity analyses are also not reported. As a result, the primary endpoint's analytic population and robustness to missing observations cannot be independently assessed.

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: edema, larynx (6.2%), thrombosis/thrombus/embolism (6.2%), hemolysis (6.2%), alt increased (6.2%), lymphopenia (6.2%).

The adverse-event summary separates serious events from other events. For serious adverse events, 16 participants were listed as at risk and 6 as affected. For other adverse events, 16 were listed as at risk and 8 as affected. The registry record does not explain why these denominators are lower than the enrollment of 17, and the death count in the adverse-event summary is not reported in the registry record.

The serious-event terms listed with 6.2% each are edema, larynx; thrombosis/thrombus/embolism; hemolysis; ALT increased; lymphopenia; and hyponatermia. These term-level entries should not be treated as a count of distinct participants without further information. A participant may have had more than one event or term, and the registry record does not state the extent of overlap or give event-level details.

General statistical principle: an adverse-event summary describes events recorded during the study; it does not by itself establish that an intervention caused them. The record does not report attribution, grading details beyond the serious classification, timing, duration, or resolution. The listed percentages and affected-participant counts should therefore be read as descriptive safety information, not as a comparative risk estimate. There is no separate control group in this study against which to compare event rates.

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

The record establishes that a phase II, single-group study enrolled 17 participants to receive lapatinib with radiotherapy, and that progression-free survival at 2 years was designated as the primary outcome. It also defines the endpoint and specifies a 95% confidence interval as the intended measure of precision. These design details clarify what the study set out to assess.

The registry record does not report the primary endpoint estimate, its confidence interval, the number of progression or death events, or the outcome follow-up available. The record therefore does not establish the observed 2-year progression-free survival percentage or how precisely it was estimated. The absence of a numerical result in the registry record is not itself evidence of a particular outcome.

The study's single-group design also limits what a result could mean. If an outcome estimate were available, it would describe participants treated under the study regimen. Without a concurrent comparator, it would not directly show how outcomes differ from those under another treatment approach, nor would it isolate the contribution of lapatinib from radiotherapy or other factors.

The safety summary reports participants affected by serious and other adverse events and lists serious-event terms. It does not provide detailed event timing, attribution, or overlap among terms. Those safety data can be described, but they do not support a causal or comparative interpretation on their own.

The record labels the study terminated, but the reason is not reported in the registry record. It also does not report recruitment flow, missing-data handling, or an analysis plan. These gaps constrain assessment of study conduct and completeness. The most defensible reading is therefore descriptive: the record documents a planned endpoint and a small enrolled single-group cohort, while leaving the primary numerical outcome and several analysis details unreported.

14. Why This Trial Matters Statistically

This trial illustrates an important distinction between a research question and an interpretable numerical result. The registry record states a specific primary endpoint, a time point, a population, and an event definition. Those details are essential for judging what an estimate would mean, but they do not replace the estimate itself. Without the reported 2-year progression-free survival percentage and its confidence interval, the outcome's magnitude and precision cannot be evaluated.

The design also matters statistically. A single-group study can describe outcomes within the enrolled cohort, but does not provide a randomized comparator for estimating a treatment contrast. This limits causal interpretation even if outcome data are available. Readers should distinguish a within-group outcome rate from evidence that one regimen changes outcomes relative to another.

The recorded enrollment of 17 makes transparent reporting of event counts, follow-up, and uncertainty especially important. General statistical principle: small bodies of data can yield imprecise estimates, and a confidence interval helps display that uncertainty. In this record, the confidence interval is specified as the planned dispersion measure, but its numerical limits are not reported.

The safety summary also demonstrates why denominators and definitions matter. Serious and other adverse events have separate at-risk and affected counts, while the record does not explain the relationship of those denominators to enrollment or describe overlap among event terms. A clear account of who was assessed and how events were categorized is needed for meaningful interpretation.

Finally, the terminated status and absence of reported analysis details show why registry status alone cannot explain study completion or outcome availability. The reason for termination, missing-data procedures, and analysis populations are not reported. Statistically, these omissions make it important to separate documented design information from conclusions that would require outcome and conduct details.

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 central limitation is that the registry record does not report a numerical result for the primary endpoint. Although 2-year progression-free survival and a 95% confidence interval are specified, neither the estimate nor its interval is available in the record. Event counts and follow-up details are also not reported, preventing assessment of precision or completeness.

The study is single-group, with allocation recorded as not applicable and no masking. The record does not describe a concurrent comparator. Any reported outcomes would therefore be descriptive for the treated cohort, rather than a direct randomized estimate of differences between treatment strategies.

The enrollment was 17, and the record does not explain recruitment flow, participant disposition, or the relation between enrollment and the safety denominators of 16. The reason for termination is not reported in the registry record. These omissions prevent assessment of whether the planned population and follow-up were fully achieved.

The registry record does not report the statistical analysis plan, how censoring or missing assessments were handled, the analysis populations, or sensitivity analyses. It also does not state whether multiplicity was addressed across the several objectives described in the study summary. The intended endpoint is defined, but its implementation and analysis cannot be independently evaluated from the available record.

Safety information is limited to affected-participant counts and listed event terms. Attribution, grading details, timing, duration, and overlap among terms are not described. The death count in the adverse-event summary is not reported in the registry record. Together, these limitations require cautious, descriptive interpretation and preclude stronger comparative conclusions.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Lapatinib and Radiation for Stage III-IV Head and Neck Cancer Patients Who Cannot Tolerate Concurrent Chemotherapy — NCT00490061.
• Registry record last updated 2017-03-06; status last verified 2017-01.
• Results first posted 2017-03-06.
• 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 record describes a terminated phase II, single-group study of lapatinib with radiotherapy for people with stage III-IV head and neck cancer who could not tolerate concurrent chemotherapy. It records enrollment of 17 participants, no masking, and allocation as not applicable. The recorded start is 2007-07 and primary completion is 2013-01.

The primary outcome is 2-year progression-free survival as a percentage of participants, with a 95% confidence interval specified. The endpoint is defined as time from treatment start to first documented progression or death from any cause. Its numerical result is not reported in the registry record. The listed secondary outcome is overall survival.

The safety summary lists 16 participants at risk and 6 affected for serious adverse events, and 16 at risk and 8 affected for other adverse events. A reason for termination, primary outcome estimate, analysis details, and missing-data procedures are not reported in the registry record.