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 Erlotinib Hydrochloride in Reducing Duodenal Polyp Burden in Patients With Familial Adenomatous Polyposis at Risk of Developing Colon Cancer (NCT02961374), a na phase 2 study. The primary outcome is Mean Percent Change in Duodenal Polyp Burden.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02961374 |
| Phase | Phase 2 |
| Condition | Attenuated Familial Adenomatous Polyposis, Familial Adenomatous Polyposis |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 46 |
| Arms in the primary outcome | n/a |
| Lead sponsor | National Cancer Institute (NCI) |
| Results posted | Yes |
2. Clinical Question
Population
Patients with familial adenomatous polyposis or attenuated familial adenomatous polyposis, at risk of developing colon cancer. The registry records 46 patients registered; 42 began protocol treatment and were assessed at baseline and the 6 month timepoint for the primary endpoint.
Intervention
Erlotinib hydrochloride taken by mouth once weekly. Treatment could continue for up to 6 months in the absence of disease progression or unacceptable toxicity.
Comparator
There was no comparison group in this single-group trial. The primary endpoint compares the duodenal polyp burden assessment at baseline with the assessment at 6 months after intervention.
Primary question
What was the mean percent change in duodenal polyp burden from baseline to 6 months after intervention among the patients assessed at both timepoints? The registry record does not report the numerical mean change or its 95% confidence interval.
This is a before-and-after question, not a randomized comparison of erlotinib with another treatment or with no treatment. The endpoint uses the sum of polyp diameters measured by esophagogastroduodenoscopy. It therefore concerns change in the measured diameter burden, rather than simply whether polyps were present. The trial also recorded safety outcomes and other measures of polyp burden and desmoid tumor size. Those additional outcomes do not substitute for the primary endpoint result, which is not reported in the registry record.
3. Trial Design
The registry identifies this as a phase II, single-group trial of erlotinib hydrochloride in patients with familial adenomatous polyposis or attenuated familial adenomatous polyposis. Allocation is listed as not applicable and masking as none. There is no concurrent control arm, so the design cannot directly compare outcomes between treatment groups. The registry lists enrollment of 46 and a completed status.
Patients in the treatment group received erlotinib hydrochloride by mouth once weekly. Treatment was to continue for up to 6 months unless disease progression or unacceptable toxicity occurred. The primary endpoint timeframe is baseline to 6 months post-intervention. For that endpoint, the registry states that 42 patients began protocol treatment and were assessed at both baseline and the 6 month timepoint.
The registry lists the National Cancer Institute as sponsor. The recorded start date is 2017-10-27 and the primary completion date is 2020-02-23. These dates describe the trial record and do not provide information about how outcomes were analyzed.
A single-group before-and-after design describes change over time among treated participants. Without a concurrent comparator, the observed change cannot by itself separate any treatment-associated change from other influences, including natural variation or changes in measurement. The registry record does not report a detailed statistical analysis plan, an interim analysis plan, or the rationale for the enrollment target. It also does not report the numerical primary endpoint result.
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 | Treatment (Erlotinib Hydrochloride) |
|---|---|
| STARTED | 46 |
| COMPLETED | 42 |
| NOT COMPLETED | 4 |
Reasons for not completing this period:
| Reason | Treatment (Erlotinib Hydrochloride) |
|---|---|
| Adverse Event | 4 |
Analysis population for the primary outcome, as defined in the registry: Of the 46 patients registered, 42 patients began protocol treatment and were assessed at both baseline and at the 6 month timepoint.
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 patients that registered for protocol treatment are included in this analysis.
| Characteristic | Unit | Treatment (Erlotinib Hydrochloride) |
|---|---|---|
| Participants analysed | 46 | |
| Age, Continuous | years | 42 (18 to 68) |
| Sex: Female, Male: Female | Participants | 22 |
| Sex: Female, Male: Male | Participants | 24 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 6 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 40 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 |
| Race (NIH/OMB): Asian | Participants | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 |
| Race (NIH/OMB): Black or African American | Participants | 2 |
| Race (NIH/OMB): White | Participants | 43 |
| Race (NIH/OMB): More than one race | Participants | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 1 |
| Region of Enrollment: Puerto Rico | participants | 4 |
| Region of Enrollment: United States | participants | 42 |
6. Primary Endpoint
The registry lists the primary outcome as Mean Percent Change in Duodenal Polyp Burden, measured over Baseline to 6 months post-intervention.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | 95% Confidence Interval |
| Unit | percent change in Duodenal Polyp Burden |
| Endpoint classification | Continuous Endpoint |
The primary endpoint is the mean percent change in duodenal polyp burden from baseline to 6 months post-intervention. Burden is defined using the sum of the diameters of all polyps assessed by esophagogastroduodenoscopy. The calculation compares the follow-up sum with the baseline sum, divides the change by the baseline sum, and expresses it as a percentage.
This endpoint expresses change relative to each participant’s baseline burden, then summarizes those participant-level changes with a mean. A negative percent change corresponds to a lower summed diameter at follow-up than at baseline under the stated formula; a positive percent change corresponds to a higher summed diameter. The registry record does not report the mean or its 95% confidence interval, so the direction, size, and precision of the primary result cannot be described from the record.
Using the sum of diameters gives a continuous measure of polyp burden rather than reducing the assessment to a yes-or-no measure. A mean can describe the group’s average change, but it does not show how changes varied among participants. The registry record does not report the distribution of individual changes or additional details about measurement reliability. Those details would help readers judge how the group mean relates to the range of participant experiences.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The central statistical limitation is that the registry record names the primary endpoint but does not report its numerical estimate. It specifies a mean percent change in duodenal polyp burden and a 95% confidence interval as the dispersion measure, but gives neither the mean nor the interval limits. The posted record therefore does not establish the observed direction or magnitude of change, or how precisely the mean was estimated. No numerical efficacy conclusion can be drawn from the primary endpoint information in this record.
The endpoint is based on paired assessments: baseline and 6 months post-intervention. A within-participant comparison can account for each participant’s baseline value when describing change, but the trial has no concurrent comparison group. Consequently, even if a change estimate were available, it would describe change over time in the treated group and would not, on its own, show what would have happened over the same period without treatment. The registry’s single-group design is not a like-for-like controlled comparison.
The primary endpoint population is also important to interpretation. The record says that 46 patients registered and that 42 began protocol treatment and were assessed at both required timepoints. It does not report the primary numerical result or explain the status or reasons for non-inclusion of other registered patients in that paired assessment population. It does not report details sufficient to determine how missing measurements, if any, were handled in the analysis.
The safety record reports 3 participants with serious adverse events and 46 participants with other adverse events, among 46 at risk in each category. It also lists 0 deaths. These are descriptive safety counts. The registry does not provide a control group for attributing events to treatment, and counts alone do not establish causation. The serious-event terms and their listed percentages should be read as registry summaries, not as a comparison of risk between treatment options.
Any planning illustrations based on an observed effect are distinct from results of the trial’s original design. The registry record describes assumptions for such illustrations but does not report the primary effect estimate needed to assess them. They cannot be treated as observed power or as evidence about the primary outcome. Overall, the record supports a description of the design, endpoint, assessment population, and listed adverse events, but not a numerical judgment about the primary endpoint’s result.
9. Statistical Methods Explained
What does a mean percent change represent?
General statistical explanation: a continuous outcome can take a range of values, rather than belonging only to categories. Here, each participant’s duodenal polyp burden is represented by a sum of polyp diameters. The registry describes calculating percent change by subtracting the baseline sum from the 6-month sum, dividing by the baseline sum, and multiplying by 100. A negative value means that the follow-up sum is lower than the baseline sum; a positive value means it is higher. The primary measure is the mean of the participant-level percent changes.
A group mean compresses individual outcomes into one central summary. It can be useful for describing average change, but it does not convey the spread or shape of individual responses. In particular, the mean alone cannot show whether most participants changed similarly or whether a smaller number of larger changes influenced the average. The registry record does not report the individual-level distribution or the numerical mean.
How should a confidence interval be understood?
General statistical explanation: a confidence interval describes uncertainty around an estimated quantity under the statistical method used. An interval that is narrower indicates greater precision for that estimate under the method’s assumptions; a wider interval indicates less precision. The registry identifies a 95% confidence interval for the primary endpoint, but does not report its limits. Without the estimate and interval, readers cannot evaluate the observed mean’s precision or whether the interval includes no average change.
A confidence interval is not a range containing a specified proportion of individual participants’ changes. It concerns uncertainty about a group-level estimate. It also does not remove limitations arising from the design, measurement, or missing data. In a single-group before-and-after trial, even a precise estimate of average change would not supply the missing concurrent comparison needed to distinguish treatment-associated change from other changes over time.
What does the single-group design allow?
General statistical explanation: a paired before-and-after analysis uses measurements from the same participants at two times. This can describe within-person change and avoids treating baseline and follow-up observations as if they came from unrelated groups. However, without a control group, observed change may reflect factors other than the intervention. The design cannot estimate a treatment-versus-control contrast because no control arm is listed.
The registry lists allocation as not applicable, masking as none, and the model as single group. These design features mean that a randomized, masked comparison should not be inferred. The registry record does not report a detailed statistical analysis plan, including the specific estimator or inferential procedure used for the primary endpoint.
What do the planning assumptions mean?
General statistical explanation: sample-size illustrations answer a planning question about how many participants per arm might be needed under stated assumptions for a future comparison. The registry’s description says those illustrations use 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. It characterizes these as planning illustrations based on the observed effect, not as the trial’s own design. The record does not report numerical illustration results or the primary observed effect needed to assess them.
Such illustrations are not observed power. They do not change the fact that this trial is single group, and they do not create a control arm or turn the trial into a randomized comparison. The registry record does not report the original sample-size justification, so the listed planning assumptions should not be treated as the rationale used to set the trial’s enrollment.
Why can over-dispersion matter in general?
General statistical explanation: over-dispersion means that observed variability is greater than a statistical model expects. When a model understates variability, standard errors and confidence intervals can be too small, making results appear more precise than warranted. This issue is relevant to some count or event outcomes, but the primary endpoint is a continuous mean percent change. The registry record does not report an over-dispersion assessment or a model-based analysis for the primary endpoint, so no such adjustment should be assumed.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists 12 outcome measures and 0 analyses. It names the mean percent change in duodenal polyp burden as the primary outcome and lists additional outcomes concerning adverse events, duodenal polyp number, lower gastrointestinal polyp burden and number, and desmoid tumor size. The record does not report a statistical testing plan for these outcomes or a strategy for controlling multiplicity. It is therefore not possible to determine from the record whether multiple comparisons were planned, how they would be interpreted, or whether any adjustment was used.
The primary endpoint population is described as 42 patients who began protocol treatment and were assessed at baseline and at the 6 month timepoint, out of 46 registered patients. The registry record does not report reasons why other registered patients are not included in that endpoint population. It does not describe imputation, sensitivity analyses, or a rule for handling missing endpoint assessments. Nor does it report enough detail to identify whether the primary analysis population was defined in another way.
These omissions matter because the number and handling of available assessments can affect the interpretation of a mean change. A paired endpoint requires assessments at both timepoints for a participant’s change to be calculated. The record identifies the group assessed at both times, but does not explain the treatment of participants without both assessments or establish whether missingness could affect the result. No assumptions about the missing-data mechanism or analysis population should be inferred.
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 |
|---|---|---|---|
| Treatment (Erlotinib Hydrochloride) | 3 | 46 | 6.5% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Treatment (Erlotinib Hydrochloride) | 0 of 46 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Treatment (Erlotinib Hydrochloride) | 46 of 46 |
Most frequent serious adverse event terms
| Event term | Organ system | Treatment (Erlotinib Hydrochloride) |
|---|---|---|
| Small intestinal obstruction | Gastrointestinal disorders | 1 of 46 |
| Back pain | Musculoskeletal and connective tissue disorders | 1 of 46 |
| Reproductive system and breast -Oth spec | Reproductive system and breast disorders | 1 of 46 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Treatment (Erlotinib Hydrochloride) |
|---|---|---|
| Rash acneiform | Skin and subcutaneous tissue disorders | 25 of 46 |
| Diarrhea | Gastrointestinal disorders | 24 of 46 |
| Nausea | Gastrointestinal disorders | 16 of 46 |
| Fatigue | General disorders | 12 of 46 |
| Headache | Nervous system disorders | 12 of 46 |
| Vomiting | Gastrointestinal disorders | 7 of 46 |
| Dizziness | Nervous system disorders | 7 of 46 |
| Dyspepsia | Gastrointestinal disorders | 6 of 46 |
| Alopecia | Skin and subcutaneous tissue disorders | 5 of 46 |
| Skin and subcut tissue disord - Oth spec | Skin and subcutaneous tissue disorders | 5 of 46 |
Serious events with the highest arm-level rate: small intestinal obstruction (2.2%), back pain (2.2%), reproductive system and breast -oth spec (2.2%).
For the treatment group, the registry lists 46 participants at risk for serious adverse events and 3 affected. It lists 46 participants at risk for other adverse events and 46 affected. The deaths count is 0. These figures are registry-reported counts and describe the recorded safety categories; they do not establish that an event was caused by erlotinib hydrochloride.
The registry’s listed serious adverse event terms are small intestinal obstruction, back pain, and reproductive system and breast -Oth spec, each with a reported percentage of 2.2%. These are the top serious terms identified in the record. The record does not provide further clinical detail about these events in the registry record, so their duration, severity beyond the serious classification, timing, and relationship to treatment should not be inferred.
Safety counts from a single-group study are descriptive. There is no control group in this trial with which to compare event counts or estimate a relative difference. The count of participants with other adverse events should also not be confused with a measure of event severity: the registry separately identifies serious adverse events. These data summarize what the registry reports, rather than establishing comparative safety.
12. What the Result Does, and Does Not, Mean
The registry record defines a clinically relevant measurement question: whether the summed diameters of duodenal polyps changed between baseline and 6 months after intervention among participants assessed at both times. It also documents a phase II, single-group study of weekly erlotinib hydrochloride and records safety outcomes. These design and endpoint details help readers understand what the study set out to measure.
The record does not report the primary mean percent change or its 95% confidence interval. It therefore does not show the observed size or direction of the average change, or the precision of that estimate. No claim that polyp burden increased, decreased, or remained unchanged can be made from the primary endpoint information reported in this record.
Even if the numerical before-and-after change were available, a single-group design would not by itself establish that the intervention caused the change. There is no concurrent comparator, and the record lists no masking. A comparison with baseline is not equivalent to a randomized comparison with another treatment or with no treatment.
The endpoint summarizes a continuous measure of diameter burden. It does not, by itself, establish what happened to every participant, and the mean cannot describe the full distribution of individual changes. Nor does a change in this measure alone establish an effect on outcomes not reported as the primary endpoint. Other listed outcomes include polyp counts, lower gastrointestinal measures, adverse events, and desmoid tumor size, but the record does not report numerical results for these measures in the registry record.
The safety counts provide a separate descriptive account. They should not be interpreted as comparative risk estimates or proof that the intervention caused any event. Taken together, the record establishes the study structure and what was measured, while leaving the primary numerical result and important analysis details unreported.
13. Why This Trial Matters Statistically
This trial is statistically notable for the distinction between a defined endpoint and a reported endpoint result. The registry specifies a mean percent change in duodenal polyp burden, a 95% confidence interval, and a paired assessment timeframe. Yet it does not report the mean or interval limits. A clear definition of what would be measured is not a substitute for the estimate needed to judge the observed result.
The study also illustrates the limits of interpreting a before-and-after change. Pairing baseline and follow-up measurements can characterize change within participants, but a single-group design cannot supply a treatment-versus-control contrast. Readers need to keep the descriptive question—what changed over time in the assessed group—separate from the causal question of what change is attributable to the intervention.
The record also makes the assessment population visible: 42 patients began treatment and were assessed at both baseline and 6 months, among 46 registered. Because reasons for the difference and missing-data methods are not reported, the relationship between the registered population and the paired endpoint population cannot be fully evaluated.
Finally, the registry identifies multiple outcome measures but does not report a multiplicity strategy or detailed statistical analysis plan. These omissions matter when interpreting the strength and scope of any reported findings. In this case, the primary numerical result itself is not reported, so the design and analysis limitations are especially important context rather than a basis for estimating an effect.
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 primary limitation for interpreting efficacy is that the registry record does not report the mean percent change in duodenal polyp burden or its 95% confidence interval. Without those values, the primary endpoint’s direction, magnitude, and precision are unknown from this record.
The trial is single group, with no comparator, and masking is listed as none. Before-and-after assessments can describe change in the treated group, but cannot isolate the intervention’s contribution from other influences over time. The record does not report detailed information about measurement procedures beyond assessment by esophagogastroduodenoscopy and use of summed polyp diameters.
The primary endpoint assessment population comprises 42 patients who began protocol treatment and were assessed at both timepoints, while enrollment is listed as 46. The registry record does not report why the endpoint population differs from the registered population, how any missing measurements were handled, or whether sensitivity analyses were conducted. It also does not report a detailed statistical analysis plan, multiplicity approach, or the trial’s sample-size justification.
The safety information is also limited for comparative interpretation. Although counts and selected serious-event terms are listed, there is no control group, and the record does not establish event attribution. The registry lists 12 outcome measures but reports 0 analyses in the registry record recorded. Numerical results for the other listed outcomes are not reported in the registry record.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Erlotinib Hydrochloride in Reducing Duodenal Polyp Burden in Patients With Familial Adenomatous Polyposis at Risk of Developing Colon Cancer — NCT02961374.
- Registry record last updated 2022-07-26; status last verified 2022-07.
- Results first posted 2021-09-22.
- 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
NCT02961374 is a completed phase II, single-group trial sponsored by the National Cancer Institute. It studied weekly erlotinib hydrochloride in patients with familial adenomatous polyposis or attenuated familial adenomatous polyposis. Treatment could continue for up to 6 months in the absence of disease progression or unacceptable toxicity.
The primary endpoint was mean percent change in duodenal polyp burden from baseline to 6 months post-intervention, assessed by esophagogastroduodenoscopy. The registry reports that 42 patients began treatment and were assessed at both timepoints, among 46 registered patients. It does not report the primary numerical result or confidence interval. Safety listings include 3 participants with serious adverse events, 46 with other adverse events, and 0 deaths.