Pilot, Neoadjuvant Gemcitabine and Abraxane Chemotherapy Followed by Surgery, Adenocarcinoma of the Pancreas: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Pilot, Neoadjuvant Gemcitabine and Abraxane Chemotherapy Followed by Surgery, Adenocarcinoma of the Pancreas (NCT01783054), a na early/phase 1 study. The primary outcome is Tumor Response.

2. Clinical Question

3. Trial Design

This was an early-phase, single-group pilot study of neoadjuvant gemcitabine and Abraxane followed by surgery for patients with localized, resectable pancreatic adenocarcinoma. The registry classifies the study as early phase 1 and lists 2 participants as enrolled. Allocation is recorded as not applicable, and masking as none. These details describe a small, unmasked study without a separate control group; they do not establish a comparative treatment effect.

The treatment description specifies gemcitabine and Abraxane on days 1, 8 and 15 of each cycle, for 2 cycles over 12 weeks. Surgery was planned 4-8 weeks after chemotherapy. Surgery and genetic expression are also listed among the interventions. The record does not provide enough detail to explain the genetic-expression procedures or their timing.

The study start is listed as 2012-07, with primary completion in 2015-10. Its status is terminated. The registry does not report why it was terminated or provide a detailed account of the conduct of the study. Although the record identifies several secondary outcomes, it does not document the primary tumor-response result. It also lists 0 analyses. Thus, the design and intended endpoint can be described, but the posted record does not permit an assessment of the planned response estimate or a comparison between treatment strategies.

Because there was only one group, outcomes cannot be contrasted with outcomes under a control condition. General statistical interpretation of an uncontrolled study must therefore focus on what was measured in the enrolled group and on the uncertainty and completeness of those observations. Here, the central primary outcome is explicitly recorded as not documented after early termination.

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

Analysis population for the primary outcome, as defined in the registry: The study terminated early and the data for this outcome measure was not documented.

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 Tumor Response, measured over at time of surgery.

The primary endpoint was tumor response assessed in the resection specimen at the time of surgery. The study intended to estimate the rate of good histopathologic response after neoadjuvant chemotherapy. The record defines a good response as a grade III or IV histopathologic appearance, equivalent to <10% viable tumor.

In general, a specimen-based endpoint can describe the observed tissue appearance after treatment among participants who undergo surgery and have a specimen assessed. It is different from an endpoint based only on imaging or symptoms: it uses histopathologic assessment of the resected tumor. The endpoint definition gives a threshold for classifying response, but the registry record does not report how assessments were conducted, whether assessors were blinded, or how specimens without an evaluable result would be handled.

The endpoint is intended to summarize the proportion meeting the response definition; it does not by itself establish what would have happened without the chemotherapy. A comparator group would be needed for a direct controlled comparison. More fundamentally, the registry states that the study terminated early and the data for this outcome were not documented. No response rate, participant-level outcome, or uncertainty estimate is available in the registry record. The endpoint can therefore be explained as planned, but its result cannot be interpreted from the posted record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods matter because they define what a result estimates, how uncertainty is represented, and which observations contribute to the analysis. For this study, the registry record identifies the design and intended endpoint but does not report the primary outcome data or an analysis of that outcome. Statistical concepts can clarify what would ordinarily be needed to interpret such a result, but they cannot fill in missing study findings.

What does the single-group design estimate?

In general, a single-group study can describe outcomes among the participants enrolled and assessed under its procedures. For a binary endpoint such as meeting a response definition, an analysis might report the number meeting the definition and the number evaluated, along with a proportion and an uncertainty interval. This describes the observed group. Without a control group, it does not directly estimate the difference between treatment and control, and it does not eliminate alternative explanations for the observed outcome.

For this study, the planned binary classification was a good histopathologic response, defined as grade III or IV and equivalent to <10% viable tumor in the resection specimen. The registry does not provide the count meeting that definition, the number with an evaluable specimen, or a response estimate. There is therefore no observed response statistic to interpret. Enrollment alone cannot be substituted for the number with an assessed primary outcome.

Why does precision matter?

In general, a point estimate gives a central summary, while a confidence interval conveys the range of values reasonably compatible with the data under the statistical model. Wider intervals indicate less precision. In a very small study, estimates of proportions can be especially uncertain, and even complete outcome ascertainment would not make a small sample equivalent to a large one. A confidence interval is not reported for the primary endpoint in this record, because the endpoint data are not documented.

The number enrolled is 2. That count is important context for the scale of the study, but it should not be turned into a calculated percentage, an estimate of precision, or an assumed endpoint denominator. The record does not state how many enrolled participants reached surgery or had a specimen assessed. Those missing details prevent reconstruction of an endpoint analysis.

What can a p-value establish?

In general, a p-value describes how compatible data are with a specified statistical model under a null hypothesis. It is not the probability that a treatment works, and it does not measure the size or clinical importance of an effect. A p-value would not overcome the limitations of a single-group design, nor would it replace an effect estimate and its uncertainty. The registry reports 0 analyses and does not report a p-value for the primary endpoint.

The planning assumptions in the record describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. Those are planning assumptions for illustrations, not evidence that the pilot itself used a two-arm design. The actual study is recorded as single-group with allocation not applicable. The record does not report the trial's own sample-size justification or a statistical analysis plan.

How should planning illustrations be read?

In general, sample-size calculations show how many participants or events might be needed under stated assumptions to detect a specified effect with a chosen probability of detection. Such calculations are planning tools, not observed power. A planning illustration based on a fraction of an observed effect is conditional on that effect estimate and the other assumptions being used; it does not describe what the trial actually achieved.

The record describes illustrations using equal allocation between two arms and a normal approximation. It specifies that time-to-event calculations use a total event count, while other calculations use participants per arm. These conventions do not turn this single-group pilot into a comparative study. Because the primary response data are not documented, the registry record does not allow readers to verify an observed primary-outcome effect for that endpoint. Any planning values should therefore be understood as hypothetical calculations under their stated assumptions, not as evidence about this study's outcome or power.

Why can over-dispersion matter?

In general, over-dispersion occurs when observed variability is greater than a statistical model assumes. If a model understates variability, standard errors may be too small and confidence intervals too narrow; tests may then appear more decisive than the data justify. This issue is relevant when selecting models for outcomes with extra variability, but the registry does not report a model for the primary endpoint or enough data to evaluate over-dispersion. It would be inappropriate to claim that it occurred in this study.

For a single-group binary response, the key descriptive information would ordinarily include the observed response count, the number assessed, and an uncertainty estimate using a method appropriate to the data. For time-to-event outcomes, interpretation would also depend on follow-up, censoring, and event information. The registry names recurrence and overall survival as secondary outcomes but does not report their results or these supporting details.

Overall, statistical methods can explain how a complete analysis might be interpreted, but they cannot recover undocumented results. The registry record supports description of the intended endpoint, study structure, and enrollment; it does not support a numerical estimate of tumor response, an inferential conclusion, or a reconstruction of the analysis plan.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 6 outcome measures and names four secondary outcomes: R0 resection status, median time to recurrence, median overall survival, and adverse events. It identifies tumor response as the primary outcome. The record does not describe the remaining outcome measures in the information available for this analysis, or explain how the outcomes were prioritized beyond the primary designation.

When a study evaluates multiple outcomes, the chance of at least one apparently unusual finding can increase if many statistical tests are performed. General approaches include prespecifying a primary outcome, controlling error across tests, or treating secondary findings as exploratory. The registry record does not report a multiplicity adjustment, a testing hierarchy, or an analysis plan. It also reports 0 analyses, so there are no posted outcome tests to assess for multiplicity.

Missing-data procedures are not reported in the registry record. The primary outcome data are explicitly described as not documented after early termination. The record does not specify whether any participants had an evaluable resection specimen, how missing observations would be classified, or whether any imputation or sensitivity analysis was planned. Analysis populations, such as an intention-to-treat or evaluable-participant population, are also not reported.

These omissions matter because the denominator and handling of unavailable assessments can affect an estimated response rate. The enrollment count does not establish the endpoint denominator. Without the analysis population and missing-data rules, even a reported estimate would require careful interpretation; here, no primary estimate is reported at all.

11. 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: cholangitis (50.0%), biliary stent drainage (50.0%), renal insuffiency (50.0%), fever (50.0%).

The registry lists one group titled “Chemotherapy, Surgery.” For this group, 2 participants are recorded as at risk and 2 as affected for serious adverse events. The same counts are recorded for other adverse events. These entries describe the registry's participant-level fields; they do not provide a controlled comparison or show how risk would differ under another treatment.

Four serious-event terms are listed: cholangitis, biliary stent drainage, renal insuffiency, and fever. Each is reported at 50.0%. These percentages should be read as the registry presents them, not as an estimate of comparative risk. The record does not give enough detail to determine timing, duration, recurrence, severity gradation, relatedness to treatment, or whether terms could overlap within a participant. Deaths are not reported in the registry record.

With only 2 enrolled participants and no comparator, these safety entries are descriptive and highly limited in scope. They do not establish how often such events would occur in a broader population, whether an event was caused by treatment, or how the event profile compares with another approach. The registry record also does not explain the circumstances of early termination or connect termination to safety findings. The listed adverse events should therefore be interpreted as reported observations, not as a causal or comparative safety conclusion.

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

This record describes a pilot study of neoadjuvant gemcitabine and Abraxane followed by surgery in patients with localized, resectable pancreatic adenocarcinoma. It identifies an intended primary endpoint based on histopathologic response in the resection specimen and defines a good response as grade III or IV, equivalent to <10% viable tumor. It also records 2 participants enrolled and a terminated study.

The record does not document the primary response data. As a result, it does not establish how many participants met the response definition, what response rate was observed, or how precise any estimate would be. It also does not report results for the listed secondary outcomes of resection status, recurrence, and overall survival. The adverse-event fields contain descriptive entries, but these are not controlled comparisons and do not establish treatment causality.

The absence of a reported tumor-response result does not show that the treatment did or did not produce a response. It means that the primary question cannot be answered from the registry record. Similarly, early termination by itself does not explain why the study stopped; the reason is not reported in the registry record.

General interpretation of a pilot study should distinguish feasibility or descriptive aims from evidence of comparative effect. This record does not provide a control group, a reported endpoint analysis, or a statistical plan that would support an estimate of treatment benefit relative to another strategy. Even a complete single-group response result would describe outcomes in that group rather than establish what would have occurred under a comparator.

The most supportable reading is therefore narrow: the intended design and endpoint are documented, but the primary outcome is not. The record can inform readers about the study's structure and the limits of its reported findings, not about the efficacy of the regimen or a comparative treatment effect.

13. Why This Trial Matters Statistically

This trial is statistically informative as an example of the difference between a registered research question and an interpretable outcome result. The record specifies a primary tumor-response endpoint, including a histopathologic definition, but reports that the study terminated early and that the endpoint data were not documented. A clearly defined endpoint is necessary for interpretation, but it cannot substitute for observed outcome data.

The single-group design also shapes what any results could establish. In general, a study without a comparator can describe outcomes in its participants, but it cannot estimate a direct contrast with another treatment. That distinction is important when readers encounter a treatment sequence and a clinically meaningful endpoint: the intervention and endpoint alone do not create a causal comparison.

The enrollment of 2 makes the scale of the pilot clear, while the missing endpoint information prevents even a descriptive response estimate. The record's safety entries offer a separate example of why reported percentages need context. With no comparator and limited participant information, event listings cannot establish comparative risk or causation.

Finally, the record distinguishes planning assumptions from the design actually registered. Planning illustrations based on equal allocation between two arms do not alter the single-group design, and they should not be interpreted as observed power. Overall, the study highlights the importance of reporting participant flow, analysis populations, outcome data, and uncertainty alongside a prespecified endpoint. Without these elements, readers can identify what investigators intended to study, but cannot determine the primary result or its precision.

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 this trial is that its primary outcome data are not documented. The registry states that the study terminated early, but does not report the observed histopathologic response, the number of participants with a resection specimen, or the number evaluated for the endpoint. Consequently, neither a response estimate nor its precision can be assessed.

The recorded enrollment is 2, and the study has no separate comparator group. Its single-group structure limits causal and comparative interpretation even if descriptive outcomes are available. The registry does not report participant characteristics, treatment completion, withdrawals, protocol deviations, or follow-up completeness. The reason for termination is also not reported in the registry record.

Methods needed to evaluate the endpoint are not described in detail. The record does not report how histopathologic assessments were performed, how assessors were selected or blinded, or how unevaluable specimens and missing observations were to be handled. The analysis population and statistical analysis plan are not reported, and the registry lists 0 analyses.

Although several secondary outcomes are named, their results are not reported in the information available for this analysis. Safety fields list adverse events but do not describe event timing, relatedness, or context, and deaths are not reported in the registry record. The genetic-expression intervention is named without a description of its role. These limitations restrict interpretation to the registered aims, design, enrollment, and listed safety entries; they do not permit conclusions about efficacy or comparative safety.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Pilot, Neoadjuvant Gemcitabine and Abraxane Chemotherapy Followed by Surgery, Adenocarcinoma of the Pancreas — NCT01783054.
• Registry record last updated 2016-03-08; status last verified 2015-10.
• Results first posted 2015-11-09.
• 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.

18. Record Summary

The registry record describes an early-phase, single-group pilot study of neoadjuvant gemcitabine and Abraxane followed by surgery for localized, resectable pancreatic adenocarcinoma. It lists 2 participants enrolled, no masking, and a terminated status. The treatment description specifies 2 cycles over 12 weeks, with chemotherapy on days 1, 8 and 15 of each cycle and surgery 4-8 weeks after chemotherapy.

The primary outcome was good histopathologic tumor response at surgery, defined as grade III or IV and equivalent to <10% viable tumor. The record states that the study terminated early and the primary outcome data were not documented. It lists R0 resection status, recurrence, overall survival, and adverse events as secondary outcomes, but does not report results for the first three in the information available for this analysis. Safety fields list 2 participants at risk and affected for both serious and other adverse events. No comparative treatment effect or primary response estimate can be determined from the registry record.