Gemcitabine and Cisplatin for Advanced or Recurrent Endometrial Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Gemcitabine and Cisplatin for Advanced or Recurrent Endometrial Cancer (NCT00388154), a na phase 2 study. The primary outcome is Participant Responses.

2. Clinical Question

3. Trial Design

This was a phase II, single-group study of gemcitabine and cisplatin in advanced or recurrent endometrial cancer. The registry lists M.D. Anderson Cancer Center as the sponsor, enrollment of 21, and study status as COMPLETED. The recorded start was 2004-08, and primary completion was 2013-11.

Because the study had one group, the design can describe outcomes among participants treated with the combination but cannot estimate a randomized contrast against another treatment. Allocation is recorded as NA and masking as NONE. A separate control arm, random assignment, and a masked comparison are not reported in the registry record. The study’s phase designation and objectives describe its stated purpose, not a guarantee that an effect was demonstrated.

The combination schedule was gemcitabine 900 mg/m^2 intravenously over 1 hour on Day 1 and Day 8, with cisplatin 30 mg/m^2 intravenously over 1 hour on Day 1 and Day 8. The primary objective was to estimate antitumor activity. The secondary objective was to determine the nature and degree of toxicity.

For response evaluation, the registry says participants who received one or more course(s) of chemotherapy and survived at least 4 weeks were considered evaluable; one participant was not evaluable. The registry also describes response confirmation by imaging after a 4-week+ interval following a 3 week (21 day) therapy course. Further details about enrollment criteria, treatment discontinuation, follow-up, and the analysis population are not reported in the registry record.

4. Participant Flow and Accounting

The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Participants who received one or more course(s) of chemotherapy and survived at least 4 weeks were considered evaluable for response; One participant was not evaluable.

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: One participant of the 21 enrolled was not evaluable for response or toxicity after transitioning to comfort care without completing the first treatment cycle.

6. Primary Endpoint

The registry lists the primary outcome as Participant Responses, measured over Responses required confirmation by imaging after 4-week+ interval following 3 week (21 day) therapy course..

The primary outcome is titled Participant Responses and is recorded in participants. It uses RECIST response categories: complete response, partial response, progressive disease, and stable disease. A complete response requires disappearance of target and nontarget lesions, no new lesions, and confirmation by two disease assessments 4 weeks apart. A partial response requires a 30% decrease in the sum of longest diameters of measurable target lesions, no progression of nontarget lesions or development of new lesions, and confirmation by two assessments 4 weeks apart. For a solitary pelvic mass measurable by physical examination but not radiography, the stated partial-response threshold is a 50% decrease in longest diameter.

Progressive disease is defined by a 20% increase in the sum of target-lesion diameters from the smallest sum at any assessment, or new lesions within 9 weeks of study entry, with the additional nontarget-lesion and pleural-effusion qualifications in the registry definition. Stable disease means the condition meets none of the other listed categories. The registry states that responses required imaging confirmation after the specified interval.

Response categories offer a standardized way to describe tumor change. For a study whose primary objective is antitumor activity, such categories can translate imaging assessments into outcomes that can be counted. The registry record does not report the number of participants in each response category, an overall response estimate, or uncertainty around such an estimate.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a single-group design estimate?

In a single-group study, outcome summaries describe participants who received the study treatment. A response count or proportion would characterize the observed cohort under the study’s eligibility, treatment, follow-up, and outcome-assessment procedures. It does not directly estimate what would have happened to the same participants under another treatment. That comparison requires a counterfactual, and this design has no randomized comparator arm to provide one.

Here, the registry describes a phase II study, allocation NA, masking NONE, and a SINGLE GROUP model. The objective was to estimate antitumor activity, with toxicity as a secondary objective. Those design labels do not supply an efficacy estimate. A numerical response result and its uncertainty are not reported in the registry record.

How should a binary response outcome be understood?

The response categories are mutually defined clinical-imaging classifications in the registry description. A response summary could count participants meeting the complete-response or partial-response definition, while other categories classify different observed states. The registry record does not state an overall response calculation or provide the category counts, so no response proportion can be interpreted from this record.

In general, a confidence interval expresses uncertainty around an estimated quantity, such as a response proportion. A wider interval indicates less precision, while a narrower interval indicates greater precision under the method used. The interval is not a guarantee that the true value lies within it, and it does not address design limitations such as lack of a comparator. No confidence interval for response is reported in the registry record.

For binary outcomes, general statistical methods often model the chance of an event and account for the number of observations contributing to the estimate. The precision depends on the observed data and the assumptions of the method. Over-dispersion is a general concern when observed variability exceeds what a chosen model assumes; it can make standard uncertainty estimates too small if not addressed. The registry record does not report a model, an over-dispersion assessment, or an uncertainty calculation for response.

What does the response definition contribute?

RECIST supplies operational criteria for classifying change in lesions. The registry specifies disappearance of target and nontarget lesions and absence of new lesions for complete response, with confirmation by two assessments 4 weeks apart. For partial response, it specifies a 30% reduction in the sum of longest diameters of measurable target lesions, along with no progression of nontarget lesions or new lesions, again confirmed by two assessments 4 weeks apart. A special threshold of 50% decrease in longest diameter applies when a solitary pelvic mass is measurable by physical examination but not radiography.

The registry defines progressive disease using a 20% increase in the sum of target-lesion diameters relative to the smallest sum at any assessment, or appearance of new lesions within 9 weeks of study entry, along with stated qualifications for nontarget lesions and pleural effusions. Stable disease is the category that does not meet the other definitions. These criteria standardize the classification, but they do not substitute for reporting the observed counts or the measurement process in individual participants.

What can the safety summaries support?

Safety figures use participants at risk and participants affected. The record lists 20 at risk for serious adverse events and 18 affected; for other adverse events it lists 20 at risk and 20 affected. A percentage attached to a serious adverse-event term describes the frequency reported for that term in the treatment group, as recorded. These summaries do not provide event-level timing, duration, severity grades, recurrent-event counts, or a comparative estimate. Such details are not reported in the registry record.

General safety analyses may distinguish the proportion of participants with at least one event from the total number of events. They may also classify seriousness, severity, relatedness, and timing separately. Those distinctions matter because one participant can experience more than one event, and an event’s seriousness is not the same concept as its severity. The registry record’s participant counts and term percentages should be read only at the level specified; details beyond them are not reported.

What do planning calculations mean?

General sample-size calculations describe how many participants might be needed under stated assumptions to detect an effect with a specified level of statistical power. The planning illustration described for this study uses a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect defined as a stated fraction of the observed effect. It is a planning illustration based on the observed effect, not the trial’s own design. The study itself is single-group, so the equal-allocation two-arm assumption does not describe its design.

Such calculations are not observed power and do not establish that an effect exists. They depend on assumptions about the target effect, outcome variability, allocation, and analysis method. A calculation using a fraction of an observed effect asks about planning for a smaller or larger target relative to that effect; it does not repair limitations in the original design. The registry record does not report the trial’s own sample-size justification or protocol assumptions. Specific participant requirements from any planning calculation are not reported in the registry record.

The posted registry record lists no analyses and supplies no response estimate to assess. Consequently, there is no sponsor-reported estimate to compare with a recalculated value, and no recalculated efficacy estimate is reported in the registry record. Statistical interpretation should therefore focus on the design and definitions that are available, while treating the primary numerical outcome as unreported.

10. Multiplicity, Missing Data and Analysis Populations

The registry names a primary objective of estimating antitumor activity and a secondary objective of determining the nature and degree of toxicity. It does not report a statistical analysis plan describing how these objectives were to be tested or summarized. The number and hierarchy of statistical hypotheses, any adjustment for multiple comparisons, and any interim analyses are not reported in the registry record. Without those details, the potential effects of multiplicity on statistical error rates cannot be assessed.

The primary outcome definition sets out RECIST categories and the response-evaluability criterion. One participant was not evaluable for response. The record does not explain why that participant was not evaluable, how missing response information was handled, or whether participants were analyzed in an intention-to-treat or another analysis population. The handling of withdrawals, incomplete imaging, and other missing data is not reported in the registry record.

The response criterion required confirmation by two disease assessments 4 weeks apart. The registry also describes imaging confirmation after a 4-week+ interval following a 3 week (21 day) therapy course. It does not report the completeness or timing of assessments for individual participants. The analysis denominator used for a numerical response estimate is therefore not available beyond the stated evaluability description.

These omissions do not demonstrate that the investigators failed to plan or conduct analyses. They mean the registry record does not provide the information needed to determine the multiplicity strategy, missing-data assumptions, or exact analysis population. No adjustment method, imputation method, or sensitivity analysis is reported in the registry record.

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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: neutropenia (25.0%), thrombocytopenia (25.0%), hypokalemia (20.0%), fatigue (20.0%), hyperglycemia (15.0%).

The registry lists 20 participants at risk for serious adverse events, of whom 18 were affected. For other adverse events, 20 were at risk and 20 were affected. These are participant counts, not a count of all individual events, and they should be interpreted according to the categories used in the record.

The listed serious adverse-event terms and percentages are Neutropenia, 25.0%; Thrombocytopenia, 25.0%; Hypokalemia, 20.0%; Fatigue, 20.0%; Hyperglycemia, 15.0%; and Renal Insufficiency, 10.0%. The registry presents these as serious terms. It does not provide event-level details such as timing, duration, severity grade, or whether a participant experienced more than one listed term. The number of deaths is not reported in the registry record.

These safety summaries describe reports in the gemcitabine-plus-cisplatin group. They do not establish that treatment caused each event, and without a comparison group they do not quantify relative safety. The figures should not be read as a complete account of all possible adverse events; only the recorded summaries are available in the registry record.

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

The study record makes clear what investigators intended to examine: response to gemcitabine plus cisplatin in advanced or recurrent endometrial cancer, and the nature and degree of toxicity in the cohort. It also gives a response-classification framework and a treatment schedule. These details help define what the study was designed to describe.

However, the registry record does not report numerical counts for the primary response categories, a response proportion, or an effect estimate with a confidence interval. It therefore does not show how many participants met the response definitions or how precisely any response rate was estimated. The primary objective cannot be judged from the posted record alone.

The safety summaries show that 18 of 20 participants at risk were recorded as affected by serious adverse events and that 20 of 20 were affected by other adverse events. Several serious-event terms and their percentages are also listed. These are descriptive observations in one treatment group; they do not establish causal attribution or a relative risk compared with another regimen.

The single-group design is important to interpretation. It can describe the study cohort, but it does not include a randomized control group for estimating a treatment contrast. The completed status means the study is recorded as completed; it does not itself indicate what the outcomes were. Likewise, a phase II designation describes the study phase, not the direction or size of any result.

In general, an unreported result should not be treated as either evidence of benefit or evidence of no benefit. The appropriate conclusion from this registry record is narrower: design, objectives, definitions, and selected safety figures are available, while the numerical efficacy outcome and its statistical uncertainty are not reported in the registry record.

13. Why This Trial Matters Statistically

This trial is statistically informative as an example of the difference between a study objective and a reported result. The registry states a clear primary aim—estimating antitumor activity—and gives a structured response definition. Yet it does not report the numerical response categories or an estimate of response. A carefully specified endpoint is essential for interpretation, but endpoint definitions alone do not answer the efficacy question.

The single-group structure also illustrates the distinction between describing an outcome and estimating a comparative treatment effect. Results from a treated cohort can characterize what was recorded among those participants. Without a concurrent randomized comparator, the design cannot isolate the effect of treatment from other explanations for outcomes. This limitation is separate from whether the endpoint is measured consistently.

The record also makes the analysis population important. It states that participants receiving one or more course(s) of chemotherapy and surviving at least 4 weeks were considered evaluable, and that one participant was not evaluable. Without a reported analysis denominator or missing-data approach, readers cannot determine how that non-evaluable participant influenced any response summary.

Finally, the safety reporting demonstrates why denominators and event categories matter. The registry distinguishes participants at risk from participants affected, and lists serious-event terms with percentages. Those summaries can describe reported experience, but do not supply all details needed for causal or comparative safety interpretation. Taken together, the study highlights how design, endpoint definitions, analysis populations, and completeness of reporting jointly determine what statistical conclusions are supportable.

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 most direct limitation of interpretation is that the registry record does not report the numerical primary response result. Counts by RECIST category, an overall response estimate, and uncertainty around an estimate are not reported. The absence prevents readers from evaluating the stated antitumor-activity objective from this record.

The single-group design provides no randomized comparison. Allocation is recorded as NA, masking as NONE, and the model as SINGLE GROUP. Consequently, descriptive outcomes in the treatment group cannot be interpreted as a randomized treatment contrast. The record does not report a comparator group or comparative effect estimate.

One participant was not evaluable for response. Although the registry specifies a response-evaluability rule, it does not report why this participant was not evaluable, the response denominator used in an analysis, or how missing response information was handled. The complete analysis population, follow-up completeness, and assessment-level data are not reported in the registry record.

Statistical details are also limited. The registry lists no analyses. The statistical analysis plan, sample-size justification, interim-analysis approach, multiplicity procedures, and methods for confidence intervals or hypothesis tests are not reported in the registry record. The planning illustration described for sample-size calculations is not the study’s own design, and should not be interpreted as observed power.

Safety interpretation has additional constraints. Counts and listed serious-event percentages are available, but event-level timing, severity grading, relatedness, recurrence, and the number of deaths are not reported in the registry record. These limitations restrict both efficacy and safety conclusions to the information explicitly recorded.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Gemcitabine and Cisplatin for Advanced or Recurrent Endometrial Cancer — NCT00388154.
• Registry record last updated 2014-11-13; status last verified 2014-11.
• Results first posted 2014-11-13.
• 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

NCT00388154 is a completed phase II, single-group study sponsored by M.D. Anderson Cancer Center. It enrolled 21 participants with advanced or recurrent endometrial cancer and evaluated gemcitabine plus cisplatin. The recorded study start was 2004-08 and primary completion was 2013-11.

The primary objective was to estimate antitumor activity using RECIST response criteria; the secondary objective was to determine toxicity. One participant was not evaluable for response. The registry record does not report numerical response results, a response estimate, or statistical analyses. Safety summaries list 20 participants at risk and 18 affected by serious adverse events, and 20 at risk and 20 affected by other adverse events. These are descriptive figures from the treatment group, with no randomized comparator.