This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Cetuximab, Radiotherapy and Twice Weekly Gemcitabine to Treat Pancreatic Cancer (NCT00225784), a na phase 2 study. The primary outcome is Objective Response of Tumor by RECIST 1.0 Criteria.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00225784 |
| Phase | Phase 2 |
| Condition | Pancreatic Cancer |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 37 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Dartmouth-Hitchcock Medical Center |
| Results posted | Yes |
2. Clinical Question
Population
The study concerned patients with pancreatic adenocarcinoma. The primary outcome population is described as participants who completed treatment. The registry record lists an enrollment of 37, but does not report how many participants completed treatment or how many had an evaluable scan for the primary outcome.
Intervention
The treatment combined weekly cetuximab, twice-weekly gemcitabine and intensity modulated radiotherapy. The registry describes the study as designed to assess the safety and efficacy of this combination. It does not report treatment adherence, dose changes, or the timing and delivery details beyond the stated schedule and radiotherapy description.
Comparator
There was no comparison group in the registry design: the trial is recorded as single-group, with allocation listed as NA. It is therefore not a randomized comparison, and the study does not provide a like-for-like control arm for interpreting outcomes against another treatment.
Primary question
The primary outcome asks how many participants had an objective tumor response under RECIST 1.0, assessed by CT scan one month post-therapy. The record describes complete response, partial response, progressive disease and stable disease criteria. It does not report the observed response count or the result of an analysis, so the primary question cannot be answered from the recorded outcome information.
3. Trial Design
This is a phase II study of cetuximab, gemcitabine and radiotherapy in patients with pancreatic cancer. The registry identifies Dartmouth-Hitchcock Medical Center as the sponsor and records the study as completed. Its listed start is 2005-02 and its listed primary completion is 2010-02. The registry records an enrollment of 37.
The design is single-group, with allocation recorded as NA and masking recorded as none. The treatment arm is described as weekly cetuximab, twice-weekly gemcitabine and intensity modulated radiotherapy. With no control arm, the study can describe outcomes among participants receiving this combination, but it cannot make a randomized comparison with a different treatment or usual care. Differences from outcomes in another study would not be a like-for-like trial comparison.
The primary outcome is the number of participants with an objective tumor response under RECIST 1.0, assessed one month post-therapy. Its population is described as completion of treatment. The registry also lists secondary outcomes concerning adverse events, resectability after therapy, EGFR status and response, disease-free survival, overall survival, and pattern of failure. These outcomes indicate the breadth of questions recorded, but their definitions, analysis details and results are not reported in the registry record.
The registry lists seven outcome measures and no analyses. The number of participants completing treatment, the number assessed for the primary outcome, and the number in each RECIST category are not reported in the registry record. The record also does not report a comparator, an allocation procedure, or a masking procedure beyond the design labels above. Consequently, the design and planned outcome can be described, but the primary outcome findings and any inferential conclusions cannot be reconstructed from the recorded information.
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
| Stage | Cetuximab, Gemcitabine, Radiotherapy |
|---|---|
| STARTED | 37 |
| COMPLETED | 33 |
| NOT COMPLETED | 4 |
Analysis population for the primary outcome, as defined in the registry: Completion of treatment
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.
| Characteristic | Unit | Cetuximab/Gemcitabine/Radiotherapy |
|---|---|---|
| Participants analysed | 37 | |
| Age, Continuous: Between 18 and 65 years | years | 54.7 (39 to 65) |
| Age, Continuous: >=65 years | years | 73.1 (67 to 82) |
| Sex: Female, Male: Female | Participants | 21 |
| Sex: Female, Male: Male | Participants | 16 |
6. Primary Endpoint
The registry lists the primary outcome as Objective Response of Tumor by RECIST 1.0 Criteria, measured over one month post-therapy.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | participants |
| Endpoint classification | Binary Endpoint |
The primary endpoint is the number of participants with an objective tumor response by RECIST 1.0 criteria. It is a count outcome, with participants as the unit, and is assessed by CT scan one month post-therapy. The population is described as participants who completed treatment. RECIST supplies standardized definitions for describing changes in target lesions, allowing response status to be classified using a common measurement framework.
The registry description defines complete response as disappearance of all target lesions. Partial response requires at least a 30% decrease in the sum of the longest diameter of target lesions at baseline. Progressive disease requires at least a 20% increase in that sum, while stable disease means neither the decrease needed for partial response nor the increase needed for progressive disease. These categories distinguish different patterns of tumor change; they do not, by themselves, provide a study result.
For a count endpoint, the response count and the number assessed are needed to understand the observed frequency and its precision. Neither is reported for this primary outcome. The record does not report how the RECIST categories were combined to produce the objective-response count, or whether any participants lacked an evaluable assessment. Thus the endpoint’s measurement approach is described, but its observed value and uncertainty are not reported in the registry record.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry identifies a clinically interpretable primary outcome: an objective tumor response assessed by CT scan one month after therapy using RECIST 1.0. However, it does not report the number of participants who responded, the number assessed, or an estimate of response frequency. No confidence interval, hypothesis test, or primary-outcome analysis is reported in the registry record. The posted information therefore does not establish the observed response level or how precisely it was estimated.
The enrollment entry is 37, but that is not a substitute for the primary-outcome denominator. The outcome population is described as participants who completed treatment, and the record does not give the number who completed treatment or the number with an evaluable scan. Without those details, readers cannot determine how the enrolled group relates to the participants contributing to the primary outcome. Nor can a missing-outcome rate or its possible effect on interpretation be assessed.
The single-group design is important to interpretation. It can describe outcomes observed in the treated group, but there is no concurrent control arm and no randomized comparison. A response observed after the combination cannot, on its own, separate the effects of the individual components or establish what would have happened under another treatment. The record’s allocation label is NA, and the trial is explicitly not a randomized comparison.
The adverse-event information is also descriptive. The record lists 22 participants affected by serious adverse events among 33 at risk in the cetuximab/gemcitabine/radiotherapy group, along with serious-event terms and percentages. These entries describe reported safety observations; they do not provide a treatment-versus-control comparison. The registry does not report a deaths count in the safety fields. Serious-event information should therefore be read as a record of events in this group, not as a comparative estimate of treatment effect.
The registry lists secondary questions about resectability, EGFR status, disease-free survival, overall survival and pattern of failure, in addition to adverse events. It does not report their outcome results or analyses. The record’s completion status does not fill in those missing results. Overall, the posted information supports a description of the design, intervention, outcome definitions and selected safety figures, but not a conclusion about the primary response result, its precision, or comparative efficacy.
9. Statistical Methods Explained
What does a count endpoint mean?
The primary outcome is recorded as a number of participants, rather than as a continuous measurement such as a laboratory value. A count answers how many participants met the outcome definition. To interpret that count as a frequency, a reader also needs to know how many participants were assessed under the definition. The registry describes the primary population as completion of treatment, but does not report the assessed count or response count. No response frequency can therefore be calculated from the registry record.
In general, an estimate based on a count can be accompanied by a confidence interval. A confidence interval expresses the statistical uncertainty associated with an estimate under the chosen method and assumptions. It is not a guarantee that the true value lies within the interval, nor does it account automatically for problems such as missing outcome assessments or bias from study design. No confidence interval for the primary outcome is reported in the registry record.
How should the RECIST definition be read?
RECIST 1.0 provides categories for describing changes in target lesions measured by CT scan. In this record, complete response means that all target lesions disappear; partial response requires at least a 30% decrease in the sum of the longest diameter from baseline; progressive disease requires at least a 20% increase; and stable disease meets neither the partial-response decrease nor the progressive-disease increase. These rules make the outcome definition more reproducible than an undefined judgment of improvement.
The endpoint title refers to objective response, while the description gives the RECIST category definitions. The registry does not report the actual category counts or specify how the categories were combined into the reported objective-response count. That operational detail matters because the endpoint result depends on both the assessment rules and the way categories are translated into the final count.
What can a single-group study estimate?
In general, a single-group study can describe outcomes among participants receiving the study treatment. It lacks a concurrent control group for estimating a between-group contrast. A before-and-after change, if reported, would not by itself establish that treatment caused the change, because time, disease course, other care and selection can also affect observed outcomes. This record is listed as single-group, with allocation NA and no masking. It does not provide a randomized comparison.
Randomization, when used, helps balance measured and unmeasured prognostic factors across treatment groups on average. That design feature is absent from the design recorded. The lack of a comparison group does not make descriptive results meaningless; it limits the claims that can be supported. Since the primary response result itself is not reported, even a descriptive response estimate cannot be assessed from this record.
What do the analysis entries tell readers?
The registry lists seven outcome measures and no analyses. This means the record does not give analysis results for the listed outcomes. It does not establish which statistical tests were planned or used, whether adjustments were made, how missing observations were handled, or whether analysis populations differed by outcome. Those statistical-plan details are not reported in the registry record and should not be inferred from the phase or design labels.
The registry lists secondary outcomes on adverse events, resectability after therapy, EGFR status and response, disease-free survival, overall survival and pattern of failure. Multiple outcomes can raise questions about multiplicity: when many hypotheses are tested, the chance of at least one apparently noteworthy result can increase. Methods such as prespecifying a primary outcome or adjusting for multiple testing can address different aspects of this issue. The registry record does not report a multiplicity strategy or provide analyses to evaluate one.
How should planning calculations be distinguished from trial results?
General sample-size calculations ask how many participants might be needed under specified assumptions to detect a chosen effect with a chosen error rate and power. The planning illustrations associated with this record are described as based on a fraction of the observed effect, a two-sided significance level of 0.05, equal allocation between two arms and a normal approximation. They are planning illustrations, not the trial’s own design, and not observed power. The actual study is single-group, so the equal-allocation assumption in those illustrations is not a description of its treatment design.
Sample-size planning depends on assumptions about the effect, variability or event frequency, statistical test and study design. If the observed effect is not reported, readers cannot evaluate the effect used as the reference for such illustrations from the registry outcome information. A planning calculation also cannot recover missing study results or demonstrate that a study did, or did not, have adequate power. No trial-specific statistical plan or sample-size justification is reported in the registry record.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists a primary outcome and several secondary outcomes, including safety, resectability after therapy, EGFR status and response, disease-free survival, overall survival and pattern of failure. Considering multiple outcomes can create multiplicity concerns when several statistical tests are performed: the chance of at least one apparently notable result can rise as more hypotheses are examined. Common approaches include identifying a primary hypothesis in advance, defining a testing sequence, or applying an adjustment. The registry record does not report a multiplicity strategy, and no analyses are listed.
Missing outcome data are a separate concern. The primary population is described as completion of treatment, but the record does not state how many participants completed treatment, how many had an evaluable CT scan, or how missing assessments were treated. It does not report whether participants without an assessment were excluded, counted in a particular category, or handled through another method. These choices can affect a count endpoint and its interpretation.
The analysis populations for the primary and secondary outcomes are not reported in the registry record. The number enrolled is recorded as 37, but the record does not say whether the primary analysis included everyone enrolled, only treatment completers, or another defined group. Nor does it report whether safety outcomes used a different population. These details should not be inferred from the outcome titles or the trial’s completed status.
The registry contains no analysis entries. It therefore does not provide a statistical analysis plan, missing-data methods, or results with which to judge those choices. These omissions limit assessment of multiplicity, completeness and analysis-population selection; they do not demonstrate that a particular method was or was not used outside what is recorded.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Cetuximab/Gemcitabine/Radiotherapy | 22 | 33 | 66.7% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Cetuximab/Gemcitabine/Radiotherapy | 3 of n/a |
Most frequent serious adverse event terms
| Event term | Organ system | Cetuximab/Gemcitabine/Radiotherapy |
|---|---|---|
| Neutropenia | Blood and lymphatic system disorders | 22 of 33 |
| Nausea/Vomiting | Gastrointestinal disorders | 9 of 33 |
| Gastrointestinal disorder - stent obstruction | Gastrointestinal disorders | 8 of 33 |
| Gastritis/GI Bleed | Gastrointestinal disorders | 5 of 33 |
| Fatigue | General disorders | 4 of 33 |
| CNS Ischemia | Nervous system disorders | 2 of 33 |
| Deep vein thrombosis | Vascular disorders | 2 of 33 |
| Anemia | Investigations | 1 of 33 |
| Hematoma subdural | Nervous system disorders | 1 of 33 |
| Pain - gouty arthritis | Musculoskeletal and connective tissue disorders | 1 of 33 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Cetuximab/Gemcitabine/Radiotherapy |
|---|---|---|
| Anaphylaxtic reaction to erbitux | Immune system disorders | 3 of 37 |
Serious events with the highest arm-level rate: neutropenia (66.7%), nausea/vomiting (27.3%), gastrointestinal disorder - stent obstruction (24.2%), gastritis/gi bleed (15.2%), fatigue (12.1%).
The serious adverse-event entry for the cetuximab/gemcitabine/radiotherapy group records 22 participants affected among 33 at risk. The registry also lists serious-event terms with percentages: neutropenia, 66.7%; nausea/vomiting, 27.3%; gastrointestinal disorder - stent obstruction, 24.2%; gastritis/GI bleed, 15.2%; fatigue, 12.1%; and CNS ischemia, 6.1%. These figures describe the safety information recorded for this group; there is no control group for comparison.
The percentages are event-term entries, not a substitute for the number of participants in each category. The record does not specify in this information whether participants could contribute to more than one term or provide the denominator used for each percentage. In general, adverse-event categories may overlap, so percentages should not be added to create a total. The record’s other-event field lists 3 affected, while the corresponding at-risk field and the deaths field are not reported in the registry record.
These safety data do not by themselves establish that an event was caused by the treatment. They also do not describe comparative risk, since there is no control arm. The registry lists assessment of adverse events as a secondary outcome, but does not provide an analysis or additional event definitions in the available information.
12. What the Result Does, and Does Not, Mean
The record establishes that a phase II, single-group study evaluated a combination of weekly cetuximab, twice-weekly gemcitabine and intensity modulated radiotherapy in patients with pancreatic cancer. It defines the primary question as the number of participants with objective tumor response under RECIST 1.0, assessed one month post-therapy. It also records selected serious adverse-event figures and lists additional secondary outcome topics.
The primary response result is not reported in the registry record. There is no response count, evaluable denominator, estimate of response frequency, confidence interval or analysis result. Consequently, the posted information cannot show how many participants met the primary endpoint or how precise any response estimate would be. A completed status indicates the record’s status; it does not supply the missing outcome findings.
The design also limits what any observed outcome could establish. A single-group study has no randomized control arm to separate outcomes associated with the treatment combination from outcomes that might occur under another treatment or over time. It cannot estimate a randomized between-group treatment effect. The three treatment components are delivered as a combination, so a result from this design would not isolate the contribution of each component.
The safety entries describe events reported in the treated group, not comparative safety estimates. The registry does not report deaths in the safety fields, and the listed percentages do not establish causation. Further details about analysis methods, missing observations, outcome populations and secondary results are not reported in the registry record.
Accordingly, the record is informative about the trial’s stated intervention, design and outcome definitions, but it does not support a conclusion about the primary response result or the treatment’s comparative effects. Those are limits of the information recorded, not evidence that an unreported result was favorable or unfavorable.
13. Why This Trial Matters Statistically
This trial illustrates why a clearly named clinical endpoint is only one part of statistical interpretation. The registry defines objective response using RECIST 1.0 and identifies the assessment timing as one month post-therapy. That makes the intended measurement interpretable. But a definition cannot replace the observed count, the number assessed, or an estimate of uncertainty. Without those outcome results, readers cannot judge the response frequency or its precision.
It also demonstrates the distinction between descriptive and comparative evidence. A single-group design can document outcomes and safety observations in participants receiving a combination regimen. It cannot provide the same control of confounding as a randomized comparison, and it does not estimate a randomized contrast against another treatment. This distinction remains important even when the clinical question is relevant and the outcome criteria are standardized.
The listed safety information reinforces the need to read denominators and event definitions carefully. Affected participants, participants at risk, and percentages attached to event terms answer different questions. They should not be combined or treated as a comparative risk estimate when the record supplies no control arm and does not provide every denominator or definition.
Finally, this record shows how registry completeness affects statistical appraisal. It lists multiple secondary outcomes but no analyses, and does not report the primary response result, missing-data handling, analysis populations, or multiplicity approach. These gaps prevent readers from assessing the statistical methods applied to the outcomes. A trial record can communicate its design and planned measurements while still leaving the evidence needed for an outcome-level interpretation unavailable.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The principal limitation for interpreting the primary endpoint is that its result is not reported. The registry gives the RECIST 1.0 criteria and the assessment time, but not the response count, assessed denominator, RECIST category counts, or an estimate with uncertainty. It also does not explain how the categories were combined to define the objective-response count. Therefore the primary endpoint cannot be quantitatively interpreted from the record.
The study is single-group, has no masking, and is not a randomized comparison. There is no like-for-like control group in the record, so it cannot support a randomized comparison of outcomes. Because the intervention combines cetuximab, gemcitabine and radiotherapy, the design as recorded also does not separate the effects of its components.
The enrollment entry does not resolve uncertainty about the outcome population. The primary population is described as completion of treatment, but the number completing treatment and the number assessed are not reported in the registry record. Missing-data handling and analysis-population definitions are also not reported. Readers cannot assess how exclusions, incomplete treatment or unavailable scans might relate to the primary estimate.
The record lists secondary outcomes but no analyses. Results for those outcomes, the statistical analysis plan, sample-size justification, and any multiplicity strategy are not reported in the registry record. The safety information includes serious-event counts and term percentages, but the available fields do not give all denominators or establish causation; no deaths count is reported. These limitations constrain the conclusions that can be drawn from the registry information and should not be filled by assumptions.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Cetuximab, Radiotherapy and Twice Weekly Gemcitabine to Treat Pancreatic Cancer — NCT00225784.
- Registry record last updated 2014-07-16; status last verified 2011-10.
- Results first posted 2013-04-18.
- 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.
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18. Record Summary
The registry record describes a completed phase II, single-group study sponsored by Dartmouth-Hitchcock Medical Center. It records enrollment of 37 and a treatment regimen of weekly cetuximab, twice-weekly gemcitabine and intensity modulated radiotherapy for pancreatic cancer. The primary outcome is the number of participants with objective tumor response by RECIST 1.0, assessed by CT scan one month post-therapy among participants completing treatment.
The record lists seven outcome measures and no analyses. It does not report the primary response count, assessed denominator, confidence interval, or analysis result. Secondary outcomes concern adverse events, resectability, EGFR status and response, disease-free survival, overall survival and pattern of failure. Serious adverse-event information is recorded for the treatment group, but there is no comparator. Missing-data methods, analysis populations and a statistical plan are not reported in the registry record.