Photodynamic Therapy Using Porfimer Sodium in Treating Patients With Recurrent Mouth or Throat Dysplasia or Recurrent In Situ Cancer or Stage I Cancer of the Mouth or Throat: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Photodynamic Therapy Using Porfimer Sodium in Treating Patients With Recurrent Mouth or Throat Dysplasia or Recurrent In Situ Cancer or Stage I Cancer of the Mouth or Throat (NCT00530088), a na na study. The primary outcome is Response.

2. Clinical Question

3. Trial Design

This was a single-group study of porfimer sodium followed by photodynamic therapy for recurrent dysplasia, carcinoma in situ, or stage I cancer of the mouth or throat. The registry lists enrollment as 30 and the status as terminated. Its phase field is NA, while the brief purpose describes the study as a phase I trial. The record does not explain that difference or give a reason for termination.

There was no randomized allocation or masking: allocation is listed as NA and masking as NONE. With no concurrent comparator group, the study can describe outcomes among people treated in this study, but it cannot make a like-for-like comparison with another treatment group. Changes over time or differences from other groups cannot be attributed to treatment using this design alone.

The treatment description specifies subcutaneous porfimer sodium followed by photodynamic therapy using laser light delivered through a fiberoptic lens fiber. A single fiber or a diffuser could be used, with the diffuser described for broad areas of dysplasia. The record does not report further details on how treatment choices or delivery were determined.

The listed start is 2001-10 and primary completion is 2010-08. These dates describe the registry record; they do not establish how long any individual participant was followed. The primary outcome timeframe is 2 years, and response was to be evaluated at each follow-up visit. The registry record does not report the schedule of those visits, the actual follow-up completeness, or the number of participants included in an outcome analysis.

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: All treated and eligible 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: All treated and eligible patients

6. Primary Endpoint

The registry lists the primary outcome as Response, measured over 2 years.

The primary endpoint is titled Response and is expressed as a percentage of participants. Its stated population is all treated and eligible patients, and its timeframe is 2 years. The planned assessment uses objective tumor-response categories. Complete response includes complete absence of a visible lesion, with or without a negative biopsy depending on the stated criterion. Partial response includes reduction in lesion size by 50% or more in the maximum size of the initial lesion, or a reduction in lesion grade. Findings below the partial-response criteria are classified as no response; an increase in lesion size or grade is classified as progressive disease.

A response endpoint turns clinical observations into a defined outcome that can be summarized across participants. Specifying criteria helps make the interpretation more consistent than relying on an undefined judgment of improvement. The biopsy and visible-lesion criteria also clarify which findings qualify as complete response under the registry description.

In general, a percentage communicates how frequently an outcome occurred within a defined population. Its interpretation depends on the outcome definitions, the denominator, and whether outcome data are available for the participants included in the analysis. The registry record names the intended population and the 2-year timeframe, but does not report the response percentage, the number in each response category, or the 95% confidence interval. The planned endpoint is therefore described, but its observed result cannot be assessed from the posted outcome information.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the response percentage represent?

The primary outcome is a percentage of participants classified according to tumor response. The outcome description provides rules for assigning the response categories: complete response, partial response, no response, and progressive disease. The intended population is all treated and eligible patients, and the stated timeframe is 2 years. These definitions establish what the endpoint is intended to measure; they do not reveal the observed percentage.

In general, a percentage is interpretable only alongside its denominator and the rules used to decide who is counted as having the outcome. A denominator restricted to participants with an available assessment could differ from the stated population if some participants were not assessed. The registry record does not report the analyzed denominator or the number of missing assessments, so this aspect of the reported response calculation cannot be checked.

What does a confidence interval add?

The registry names a 95% confidence interval as the dispersion measure for the primary endpoint. In general, a confidence interval conveys the statistical uncertainty around an estimate, given the data and the method used to calculate it. A narrower interval indicates greater precision under that method; a wider interval indicates less precision. The interval does not resolve limitations in the study design, and it does not account automatically for biases or missing data.

The registry record does not report the response estimate or its interval, nor does it specify the calculation method. It is therefore not possible to evaluate the interval's width, its assumptions, or how closely the method fits the available data. No recalculated response estimate is presented in the posted results.

How does the design affect interpretation?

This is a single-group study, not a randomized comparison. General statistical interpretation of a single-group outcome focuses on the observed result within the study population. It does not estimate a contrast against a concurrent control group. Because no comparator is recorded, treatment and comparison groups cannot be assessed side by side, and a causal treatment effect cannot be established from a between-group contrast.

Allocation is listed as NA and masking as NONE. The record does not describe a randomized allocation process or masking of outcome assessment. The registry entries do not establish whether other safeguards were used. The study's enrollment is 30, but that figure alone does not show how many participants contributed to the primary endpoint or how precise the endpoint estimate would be.

What do the planning assumptions mean?

The sample-size assumptions describe a planning illustration based on the observed effect, not 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 a stated fraction of the observed effect. The assumptions also distinguish between participant counts per arm for outcomes other than time-to-event outcomes and total event counts for time-to-event outcomes.

These are hypothetical planning conditions. The record describes the actual study as single-group, so the equal-allocation two-arm assumption does not describe its registered design. A planning illustration is not an observed power calculation and does not establish that the study was designed to detect a particular effect. The registry record does not report its own sample-size justification or statistical plan. No numerical planning results are stated in the registry record.

In general, over-dispersion means that variation in observed data is greater than would be expected under a chosen probability model. Allowing for it can affect uncertainty estimates and planning calculations. The registry entries do not say that an over-dispersion adjustment was used in this study, so it should not be assumed to have been part of the analysis.

What analysis details are available?

The record lists two outcome measures and zero analyses. It identifies the primary response endpoint and its intended timeframe, but does not report an analysis method, a statistical model, an adjusted estimate, a test statistic, or a result for that endpoint. The sponsor's own analysis is not reported in the registry record. Thus, there is no posted primary response calculation to independently evaluate or compare with a recalculation.

For a binary endpoint, general methods may estimate a proportion and quantify its uncertainty. The appropriate method can depend on the analysis population, the observed counts, and the statistical plan. Since those outcome counts and the analysis method are not reported, no particular procedure can be attributed to this study. The label 95% confidence interval alone is not enough to identify how it was calculated.

Overall, the registry provides a response definition, a target population, and a timeframe, alongside limited safety counts. It does not provide the primary outcome data or enough analysis detail to reconstruct or assess the primary response analysis.

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("Porfimer Sodium")
n      <- c(29)
events <- c(1)
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  Porfimer Sodium  29  1  3.4  0.1  17.8  0.6  17.2  0.8  17.2

11. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures and zero analyses, but the posted information does not describe how multiple outcomes were handled statistically. A multiplicity adjustment, if any, is not reported in the registry record. The record also does not report whether additional analyses were planned, whether any outcomes were designated secondary, or whether testing was intended to be confirmatory or descriptive beyond the stated primary endpoint.

Missing data are also not described. The primary endpoint population is all treated and eligible patients, but the record does not state how many had an outcome assessment at the 2-year timeframe, whether any assessments were unavailable, or what rules were used for participants without an assessment. It does not report imputation, a missing-data sensitivity analysis, or another method for handling incomplete outcome information. Those methods are not reported in the registry record.

Analysis-population definitions beyond the stated primary population are not reported in the registry record. The record does not give separate counts for treated, eligible, assessed, or analyzed participants. It also does not clarify whether the reported safety population was defined in the same way as the response population.

In general, multiplicity concerns arise when several outcomes or comparisons are examined, because repeated testing can increase the chance of a false-positive finding. Missing-data methods matter because conclusions can depend on who has observed outcomes and how unavailable data are treated. These are general statistical considerations; the registry record does not provide enough analysis detail to determine how either issue was addressed in this study.

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 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: non-cardiac chest pain (3.3%), pain (3.3%), pneumonia aspiration (3.3%).

The registry reports safety information for the Porfimer Sodium group. Serious adverse events were recorded among 30 participants at risk, with 3 affected. Other adverse events were recorded among 30 participants at risk, with 29 affected. These counts describe the posted safety data; the record does not provide event timing, duration, severity grading beyond the serious classification, or details about how events were attributed.

The listed serious adverse-event terms are non-cardiac chest pain, pain, and aspiration pneumonia, each reported as 3.3%. These percentages should be read as the registry's reported figures, not as evidence about cause or treatment attribution. The record does not clarify whether participants could contribute to more than one term, so the terms should not be treated as mutually exclusive or added together.

Deaths are not reported in the registry record. The safety counts do not indicate how the primary response endpoint turned out, and they do not provide a comparison against an untreated or alternative-treatment group. With a single-group design, these figures describe events recorded among participants in the study, without a concurrent control rate for context.

In general, adverse-event summaries depend on the observation period, event definitions, and the population included in safety reporting. Those details are not fully reported in the registry record, so the figures should be interpreted as the recorded counts rather than a complete characterization of safety.

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

The record establishes that a single-group study was conducted to assess porfimer sodium followed by photodynamic therapy in people with recurrent mouth or throat dysplasia, recurrent carcinoma in situ, or stage I cancer of the mouth or throat. It defines a response endpoint based on lesion findings and states a 2-year timeframe. It also provides limited adverse-event counts.

It does not report the primary response percentage or its 95% confidence interval. As a result, the posted results do not quantify the frequency of response or the precision of that estimate. They also do not provide counts in the complete-response, partial-response, no-response, and progressive-disease categories. The endpoint definition cannot be mistaken for an observed result.

The absence of a comparator is another important boundary. In general, an outcome observed in a single group does not show how those participants would have fared under a different treatment or without the study treatment. The record therefore cannot provide a randomized treatment contrast. The safety counts likewise describe the recorded study group and do not establish a comparative safety difference.

The registry status is terminated, but the reason is not reported in the registry record. That status alone does not establish whether termination was related to outcomes, recruitment, resources, or another circumstance. The record also does not provide the statistical plan, sample-size justification, missing-data approach, or detailed analysis population.

The appropriate reading is therefore narrow: the registry describes the intervention, intended population, response criteria, timeframe, and some adverse-event information. It does not provide enough primary outcome data to judge the observed response rate, and its single-group design would limit causal interpretation even if a response estimate were available.

14. Why This Trial Matters Statistically

Statistically, this study illustrates why an outcome definition and an outcome result are different kinds of information. The registry specifies response categories and the intended assessment timeframe, which helps clarify what the primary endpoint was meant to capture. However, without the observed response percentage and its confidence interval, the central effectiveness estimate cannot be evaluated.

The study also demonstrates the interpretive limits of a single-group design. A clearly defined outcome can describe what occurred among treated participants, but without a comparator it cannot directly estimate how outcomes differ from another treatment condition. That distinction remains important even when a study has a specific clinical question and a prespecified endpoint.

The record's safety counts offer a separate example of how denominators and event definitions matter. Serious and other adverse events are reported for participants at risk, while the record does not provide full details on event timing, attribution, or possible overlap among terms. Readers can describe the recorded counts, but should not extend them into an unsupported comparison or causal conclusion.

Finally, the record exposes gaps that matter for statistical appraisal: the response analysis, analysis population, missing-data handling, and statistical plan are not reported. These details help readers distinguish a fully interpretable estimate from an endpoint that is merely defined in a registry. Here, the registry gives useful design and measurement context, while leaving the primary response result unavailable.

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 main limitation for interpreting this specific study is that the registry record does not report the primary response estimate or its 95% confidence interval. The response categories and 2-year timeframe are described, but the observed distribution across those categories is not. Consequently, the primary outcome cannot be quantitatively evaluated from the posted results.

The single-group design provides no concurrent comparator. This prevents a direct within-study comparison of response or adverse events between treatment conditions. The record does not describe random allocation or masking; allocation is listed as NA and masking as NONE. The available information does not establish whether any other methods were used to reduce bias.

Several details needed to assess the endpoint are not reported in the registry record: the number included in the response analysis, outcome availability at the 2-year timeframe, missing-data handling, and the analysis method. Although the stated response population is all treated and eligible patients, the record does not show whether that population was the denominator used in an analysis.

The registry lists two outcome measures and zero analyses, but does not describe a multiplicity approach or provide a complete statistical plan. It also does not provide the study's own sample-size justification. The planning assumptions refer to a hypothetical two-arm illustration, while the registered design is single-group; those assumptions should not be mistaken for the actual trial design.

The study is listed as terminated, and the reason is not reported in the registry record. The start and primary-completion dates do not establish individual follow-up completeness. Safety information is limited to the recorded counts and terms, without fuller event context or a control group.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Photodynamic Therapy Using Porfimer Sodium in Treating Patients With Recurrent Mouth or Throat Dysplasia or Recurrent In Situ Cancer or Stage I Cancer of the Mouth or Throat — NCT00530088.
• Registry record last updated 2014-07-04; status last verified 2014-06.
• Results first posted 2014-07-04.
• 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

This registry record describes a terminated, single-group study of porfimer sodium followed by photodynamic therapy for recurrent mouth or throat dysplasia, recurrent carcinoma in situ, or stage I cancer of the mouth or throat. Enrollment is listed as 30. The registry phase field is NA, although the brief purpose calls the study a phase I trial.

The primary endpoint is response, expressed as a percentage of all treated and eligible patients, with a 2-year timeframe and a stated 95% confidence interval. Response categories are defined by visible lesions, biopsy findings, lesion size, and lesion grade. The observed response percentage and confidence interval are not reported in the registry record.

The record reports serious and other adverse-event counts, including three serious-event terms at 3.3% each. It does not report the reason for termination, the response analysis population, missing-data methods, or the statistical plan. There is no comparator group, so the design does not support a direct treatment-group contrast.