Chemoradiation in Locally Advanced Pancreatic Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Chemoradiation in Locally Advanced Pancreatic Cancer (NCT00262951), a na phase 2 study. The primary outcome is Number of Patients in Whom Tumor Was Resectable.

2. Clinical Question

The study asked whether a treatment program combining chemotherapy, radiation therapy, and interferon alfa before possible surgery could make locally advanced pancreatic adenocarcinoma resectable. The registry’s stated purpose was to study this approach in patients whose cancer could not be removed surgically at the outset. The planned treatment program also included tumor resection when considered possible, and the registry lists chemotherapy and surgery among the interventions.

The primary question was framed around the number of patients in whom the tumor was resectable. The registry describes assessment using CT scans after each course, with evaluation of local tumor growth or regression and metastatic disease. If imaging suggested that resection might be possible, surgery would be recommended. Overall survival was listed as a secondary outcome, but no result for that outcome is reported in the registry record.

This was a single-group study, not a randomized comparison. Its design therefore addresses whether resectability was observed among patients treated in the study, rather than estimating a randomized treatment effect against a concurrent control group. The registry record does not give a reported resectability count or an analysis comparing outcomes with another group. As a result, the central clinical question is identifiable from the registered endpoint and description, but the posted record does not provide the numerical outcome needed to answer it.

3. Trial Design

This was a phase II pilot study with a single-group model and no masking. The registry lists allocation as not applicable, consistent with there being no randomized arms. Enrollment was 23. The registered group is described as pancreatic adenocarcinoma patients treated with a chemotherapy regimen and radiation, and/or surgery. The listed interventions include recombinant interferon alfa, cisplatin, fluorouracil, radiation therapy, and tumor resection.

The study began in 2005-01, had primary completion in 2011-04, and is listed as terminated. The registry record does not explain the reason for termination, so the status alone does not establish why the study ended or whether all planned assessments were completed. The phase II pilot designation identifies the study’s registered phase and pilot character; details of the intended progression to any later study are not reported in the registry record.

The primary outcome was the number of patients in whom the tumor was resectable, with a timeframe of up to 5 years or until disease progression. The description says CT imaging was to assess the tumor after each course and to evaluate metastatic disease. Overall survival was listed as a secondary outcome. The registry lists 2 outcome measures, but does not provide a reported analysis for either one in the record.

Because the study has one group and no concurrent control, outcomes can be described for enrolled participants but cannot by themselves provide a randomized comparison. The registry record does not report the planned sample-size justification, detailed treatment schedules, or statistical analysis plan. It also does not describe a masking procedure; masking is listed as none.

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:

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 Number of Patients in Whom Tumor Was Resectable, measured over Up to 5 Years or Until Disease Progression.

The primary endpoint is the number of patients whose tumor was judged resectable. The registry describes resectability as an imaging-based assessment of whether surgery could be recommended after treatment. CT scans of the chest, abdomen, and pelvis were planned to assess metastatic disease; if no metastatic disease was present, attention would focus on local tumor growth or regression and its implications for resection. The described assessment was to occur after each course, with surgery recommended if the tumor appeared potentially resectable.

Resectability is used as a clinically relevant intermediate outcome in this study because the stated treatment rationale was to try to shrink a tumor that could not initially be removed, so surgery might become possible. This explains the endpoint’s role in the study question; it does not establish that the treatment achieved that goal. The registered timeframe is up to 5 years or until disease progression.

The registry record does not report the observed number of patients whose tumors were resectable, how many underwent surgery, or the criteria used to classify resectability beyond the description of imaging and surgical recommendation. It also does not report an endpoint estimate or uncertainty interval. The endpoint definition is therefore available, but its numerical result cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods help distinguish a clearly defined outcome from an adequately reported result. In this study, the registered primary outcome is a count: the number of patients in whom the tumor was considered resectable. The registry record describes how that judgment was to be informed by imaging and clinical consideration of surgery. It does not report the observed count or a statistical analysis of the endpoint.

What does a count endpoint tell the reader?

A count records how many participants met a defined outcome. For a count to be interpretable, readers need to know the number assessed, the outcome definition, and how participants with incomplete or unevaluable assessments were handled. The registry gives an enrollment of 23 and describes the planned resectability assessment, but it does not report how many participants had an assessment, the number classified as resectable, or how missing assessments were handled. Enrollment should not be mistaken for the number with an evaluable endpoint.

General: a count can be presented alone or alongside a proportion and an uncertainty interval. An interval communicates how much statistical uncertainty surrounds an estimate under the assumptions of the method used. Such estimates are not reported for the primary endpoint in this registry record, so no precision assessment can be made from it.

Why does the study design matter?

The registered model is single group, allocation is not applicable, and masking is listed as none. General: a randomized control group helps distinguish differences associated with assigned treatments from differences that could arise from participant characteristics, disease course, or other influences. A single-group study does not create that randomized contrast. Its results can describe outcomes among enrolled participants, but the design alone does not identify what would have happened to comparable participants under a different treatment.

The absence of masking is also relevant to outcomes involving judgment. The endpoint uses the concept of resectability, with imaging and a decision about whether surgery is recommended. The record describes the assessment process but does not report whether a blinded independent review was used or specify additional adjudication procedures. That information is not reported in the registry record. This does not establish that assessments were biased; it means the record does not let readers evaluate safeguards against assessment knowledge influencing a judgment.

What can be said about statistical testing?

The registry lists 2 outcome measures and 0 analyses. It does not report a test statistic, p-value, confidence interval, adjusted estimate, or model for the primary endpoint. It also does not report an analysis plan explaining how the primary outcome would be analyzed. The absence of an analysis in the registry record means there is no inferential result to interpret; it does not show that no analysis was conducted outside the record.

General: a p-value, when reported, addresses how compatible the observed data are with a specified null model and its assumptions. It does not by itself measure the size or clinical importance of an outcome, and it does not replace an estimate with an uncertainty interval. Neither a p-value nor an estimate is reported for the primary endpoint.

How should the timing description be read?

The endpoint timeframe is up to 5 years or until disease progression, and the description states that CT assessment would follow each course. This is a planned assessment schedule, not evidence that every participant completed every assessment. The registry record does not state the number or timing of assessments actually performed, the handling of disease progression in the endpoint analysis, or whether any assessment schedule changed.

Overall survival is listed as a secondary outcome. General: time-to-event analysis accounts for the time until an event and may also account for participants whose event has not been observed by the end of follow-up. Interpreting such an analysis generally requires information about follow-up, censoring, event counts, and the model or estimator. Those details and an overall-survival result are not reported in the registry record, so no survival curve, hazard estimate, or survival comparison can be evaluated from it.

What role does sample-size planning play?

A sample-size calculation is a planning exercise based on a chosen outcome, target effect, variability or event assumptions, and statistical criteria. It is not a description of the outcomes actually observed. The registry record does not report the study’s sample-size justification or assumptions. No conclusion about the original design target or the adequacy of enrollment can therefore be drawn from the enrollment figure alone.

General: a study’s ability to detect a prespecified effect is sometimes described during planning, but observed data do not acquire more or less credibility simply because a study was small or large. The observed estimate and its uncertainty are central to interpretation. Since the primary estimate and its uncertainty are not reported, the statistical precision of the resectability result cannot be assessed.

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("Pancreatic Adenocarcinoma Patients")
n      <- c(23)
events <- c(7)
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  Pancreatic Adenocarcinoma Patients  23  7  30.4  13.2  52.9  15.6  50.9  15.6  51.1

11. Multiplicity, Missing Data and Analysis Populations

Multiplicity concerns the interpretation of several statistical tests or outcomes, especially when a study makes multiple claims based on separate tests. The registry lists 2 outcome measures: resectability as the primary outcome and overall survival as a secondary outcome. It does not report inferential analyses for either measure, nor does it describe a strategy for handling multiple comparisons. Whether any multiplicity adjustment was planned or used is not reported in the registry record. With no reported tests or estimates, there is no multiplicity-adjusted result to interpret.

Missing-data methods are also not described. The record does not state whether any participants lacked a resectability assessment, how disease progression affected endpoint availability, or how incomplete follow-up was handled for overall survival. Enrollment of 23 does not establish that all participants contributed data to every outcome. The numbers analyzed for the primary or secondary outcomes are not reported in the registry record.

The analysis population is not specified. The registry does not say whether an analysis included all enrolled participants, only those who began treatment, only those with an endpoint assessment, or another defined group. It also does not report exclusions or reasons for any exclusions. These omissions prevent readers from tracing how enrollment relates to the population underlying any outcome estimate.

These are reporting gaps, not evidence that particular methods were or were not used. The registry record does not give the statistical analysis plan, missing-data procedures, or outcome-specific denominators. Consequently, the main available information is the registered outcome definition and study structure, rather than a complete account of analysis choices.

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: dehydration (21.7%), nausea (13.0%), vomiting (13.0%), fever (in the absence of neutropenia) (8.7%), anorexia (8.7%).

The registry lists 23 participants at risk for serious adverse events and 12 affected. In a separate adverse-event field, it lists 23 at risk and 23 affected. These are the recorded participant counts; they do not by themselves describe the number of distinct events, their duration, or whether participants experienced more than one event. The registry record does not provide those details.

The listed serious adverse-event terms and percentages are dehydration, 21.7%; nausea, 13.0%; vomiting, 13.0%; fever in the absence of neutropenia, 8.7%; anorexia, 8.7%; and colitis, 8.7%. These are the entries recorded for the study. The record does not specify how the terms were selected for the displayed list, provide event-level narratives, or explain whether a participant could be included under more than one term. The percentages should therefore be read as registry-reported figures, not as a complete account of every safety event.

The record also does not provide timing, severity grades, duration, resolution, or attribution of events to a specific intervention. It does not explain whether all participants received each listed intervention. The listed safety counts are descriptive and do not establish a comparison with another treatment group, because the trial was single group and had no registered comparator.

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

The registry record establishes that a phase II pilot study enrolled 23 participants in a single group and named resectability as its primary outcome. It describes an imaging-based assessment intended to guide whether surgery could be recommended, and it lists overall survival as a secondary outcome. It also reports selected adverse-event counts and serious-event terms.

The record does not report the primary resectability result, an overall-survival result, or statistical analyses of either outcome. It therefore cannot show how many participants were judged resectable, how precisely that outcome was estimated, or how survival was observed. A protocol description is not a substitute for an outcome estimate. The absence of an outcome in the registry record should not be interpreted as a zero result.

The single-group design means that even a reported outcome count would describe experience in the enrolled group rather than a randomized contrast against a comparator. The record does not establish what would have occurred in a comparable group treated differently. Nor does it report enough detail to assess outcome completeness, analysis populations, missing data, or the statistical plan.

The adverse-event figures can be read as descriptive registry entries for the enrolled group. They do not show comparative safety, establish causation, or provide a complete clinical account of each event. The registry status is terminated, but the reason for termination is not reported in the registry record.

Accordingly, the record is informative about the intended question, study structure, enrollment, and some safety reporting, but does not contain the efficacy results needed to answer the primary question statistically. It neither demonstrates benefit nor establishes lack of benefit. The available information supports a description of what was registered and reported, not a conclusion about treatment effectiveness.

14. Why This Trial Matters Statistically

This trial illustrates why registry information must be separated into design details and outcome evidence. Its primary endpoint is clearly named as the number of patients whose tumor was resectable, and the record gives a description of imaging and surgical assessment. Yet the numerical result for that endpoint is not reported. A well-described outcome plan does not tell readers what happened to participants.

The single-group structure is another important statistical feature. Without a concurrent randomized comparator, the design does not estimate a treatment contrast in the way a controlled comparison would. This remains true even if a count or proportion were available. Study design determines which questions can be answered, while reporting determines whether readers can evaluate the observed result.

The record also demonstrates the importance of analysis transparency. It lists a secondary survival outcome and adverse-event information, but does not report analyses for the outcome measures or explain analysis populations, missing-data handling, or multiplicity. Those details help readers judge the relationship between enrolled participants, outcome assessments, and statistical conclusions.

Finally, the status of terminated and the presence of safety entries can invite interpretation beyond what the record says. The reason for termination is not reported, and the event data do not supply a comparative safety assessment. A careful statistical reading keeps these distinct details within their limits. The study matters as an example of how endpoint definitions, design, and completeness of results jointly shape what can be learned from a clinical-trial record.

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 immediate limitation for interpreting this study is that the registry record does not report the primary endpoint result. The planned outcome was the number of patients in whom the tumor was resectable, but no such count, estimate, or uncertainty interval is available. Overall survival is listed as a secondary outcome, without a reported result or analysis.

The study was single group, with allocation listed as not applicable and no masking. There is no registered control group for a like-for-like comparison. Therefore, the design does not provide a randomized treatment contrast. The registry record also does not report whether resectability judgments were independently reviewed or whether assessors were blinded to treatment or clinical information.

Enrollment was 23, but the number contributing to each outcome is not reported. The record does not describe missing assessments, exclusions, actual follow-up, or the analysis population. The timeframe for the primary endpoint extends up to 5 years or until disease progression, but the record does not state how many participants were followed for that duration or how progression affected analysis.

The record lists the study as terminated but does not report the reason. It does not provide the sample-size justification, statistical analysis plan, outcome-specific results, or multiplicity and missing-data procedures. The treatment description also does not provide the detailed regimen schedule or indicate which participants received each intervention. These limitations restrict interpretation to the registered design and available descriptive entries; they do not establish why information is absent or what unreported analyses may have found.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Chemoradiation in Locally Advanced Pancreatic Cancer — NCT00262951.
• Registry record last updated 2017-12-28; status last verified 2017-12.
• Results first posted 2012-02-03.
• 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 phase II pilot study of multi-agent neoadjuvant chemoradiation in locally advanced pancreatic adenocarcinoma. It used a single-group model, had no masking, and enrolled 23 participants. The study began in 2005-01, reached primary completion in 2011-04, and is listed as terminated.

The primary outcome was the number of patients in whom the tumor was resectable, assessed using CT imaging and consideration of surgery. Overall survival was listed as a secondary outcome. The record does not report results or analyses for these outcomes. It reports adverse-event counts and selected serious-event terms, but does not give fuller event-level or comparative safety information. The reason for termination, analysis populations, missing-data procedures, and statistical analysis plan are not reported in the registry record.