Levonorgestrel-Releasing Intrauterine System in Treating Patients With Complex Atypical Hyperplasia or Grade I Endometrial Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Levonorgestrel-Releasing Intrauterine System in Treating Patients With Complex Atypical Hyperplasia or Grade I Endometrial Cancer (NCT00788671), a na phase 2 study. The primary outcome is Response Rate at 12 Month.

2. Clinical Question

3. Trial Design

This is a phase II, single-group study sponsored by M.D. Anderson Cancer Center. The registry lists enrollment of 69 and identifies placement of a levonorgestrel-releasing intrauterine system as the treatment. It also lists laboratory biomarker analysis and a quality-of-life assessment. The secondary outcome named in the registry is the Short Form-36 (SF-36) quality-of-life score.

The study has no randomized comparator: allocation is listed as not applicable, and the design is single group. Masking is listed as none. Consequently, the study is structured to describe outcomes among participants receiving the intervention, rather than to estimate a randomized difference between treatment groups. The registry record does not report a separate control condition or an allocation procedure.

The recorded start date is 2008-11-03, and the primary completion date is 2016-06-10. The registry status is active, not recruiting. These registry entries describe the study record and do not establish that all planned follow-up or reporting is complete. The record does not report further operational details such as recruitment procedures, eligibility criteria, or the planned follow-up schedule beyond the primary outcome timeframe.

The primary outcome is response rate at 12 months, with the timeframe also stated as at one year. Response is defined as complete or partial response based on endometrial biopsy. Although the record names three outcome measures, it does not report an analysis count or the results for the primary endpoint. The analysis population and the statistical plan 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.

Before assignment: 69 participants enrolled, 12 participants did not participate on study (9) upgraded pathology, (2) screen failure and (1) withdrew.

Overall Study

Reasons for not completing this period:

5. Baseline Characteristics

The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.

6. Primary Endpoint

The registry lists the primary outcome as Response Rate at 12 Month, measured over At 1 year.

The primary endpoint is the response rate at 12 months, described as a percentage of participants. The registry defines response as complete response or partial response based on an endometrial biopsy, with the outcome timeframe stated as at one year. Thus, the endpoint is a binary classification at the participant level: each participant is either counted as meeting the response definition or not, according to the biopsy-based assessment.

A response proportion is used to describe how frequently a specified outcome occurs in a study population. In this study, it gives a summary of the fraction of participants classified as responders under the registry definition. It is not, by itself, a comparison with what would have happened without the intervention. Because this is a single-group study, the endpoint can describe outcomes in the treated group but cannot establish a randomized treatment contrast.

The registry specifies a 90% confidence interval as the measure of dispersion for the endpoint. A confidence interval expresses uncertainty around an estimated response proportion; a narrower interval indicates greater precision under the method used. The observed response proportion, interval limits, and method used to calculate that interval are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is binary at the participant level: the registry definition classifies complete or partial response on biopsy as response. A response rate is a proportion, meaning that the count meeting the definition is considered in relation to the participants assessed under the analysis. The actual count, denominator, and estimate are not reported in the registry record, so no response proportion can be interpreted from the listed endpoint description alone.

What does the confidence interval describe?

The endpoint specifies a 90% confidence interval. In general, a confidence interval describes statistical uncertainty around an estimate. It is not a guarantee that the true value lies within the particular interval, nor does it describe the range of individual participant outcomes. Its width depends on the amount and pattern of data and on the calculation method. The registry record does not report the interval limits or the method used to calculate the interval, so its precision cannot be evaluated.

For a binary outcome, methods for estimating a confidence interval can differ, especially when the number of participants or the number of responses is limited. Different methods may produce different limits. The choice of method, any continuity adjustment, and any other interval details are not reported in the registry record. No particular method should therefore be attributed to this study based only on the endpoint description.

Why does the single-group design matter?

A single-group study estimates outcomes in the participants who received the study intervention. It does not directly estimate a contrast against an untreated group or another therapy. Random allocation in a comparative study can help balance measured and unmeasured participant characteristics across groups; that feature is absent from this registered design. The response proportion may be described, but attributing the observed responses to the intervention requires caution because the study has no concurrent comparator.

Masking is listed as none. In general, masking can reduce the potential for knowledge of treatment assignment to influence assessment or participant-reported outcomes. In a single-group study with no masking, assessment procedures can be particularly important. The registry record does not report details about biopsy review, assessor masking, or quality-control procedures, so the extent to which these issues were addressed is not known.

How should planning calculations be read?

Any sample-size illustrations associated with this record are planning illustrations, not observed power. The stated assumptions for those illustrations are a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect described as a fraction of the observed effect. Those assumptions describe a hypothetical planning exercise; they are not reported as the design of this single-group study. The record does not report the trial's own sample-size justification, so the planning assumptions should not be treated as the protocol's rationale.

In general, power is a design-stage probability calculated under specified assumptions. It does not measure whether an observed result is reliable, and retrospective observed-power calculations do not replace estimates and confidence intervals. A planning sample size is not an observed study outcome. For time-to-event illustrations, the stated convention is a total event count using the Schoenfeld approach; other illustrations use participants per arm. Those conventions do not change the fact that the registered study has a single group and no randomized arm comparison.

The registry identifies the endpoint, timeframe, and confidence-interval level but does not report the analysis method, analysis population, adjustment strategy, or handling of missing assessments. Thus, the statistical interpretation is limited to the general meaning of the endpoint and design; it cannot establish how the investigators conducted the analysis.

10. Exact Estimates for Each Arm

No two-arm comparison is shown for this trial, but each arm's result can still be summarized with exact interval estimates computed from the posted counts. The Clopper-Pearson interval is exact and conservative; the Wilson interval is a common closer-to-nominal alternative; the Bayesian credible interval uses a uniform Beta(1, 1) prior. For small groups the three can differ noticeably.

R code and output

arm    <- c("Treatment")
n      <- c(47)
events <- c(39)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Treatment  47  39  83.0  69.2  92.4  69.9  91.1  69.8  91.1

11. Multiplicity, Missing Data and Analysis Populations

The registry lists three outcome measures and names quality of life measured with the Short Form-36 (SF-36) survey as a secondary outcome. The primary endpoint is the biopsy-based response rate at 12 months. Multiple outcomes can raise multiplicity questions when several statistical tests or estimates are used to support conclusions. Whether the investigators designated a hierarchy, adjusted for multiple comparisons, or treated secondary outcomes as exploratory is not reported in the registry record. The record lists zero analyses, so it does not provide analysis-level results or details.

Missing data can affect a response proportion if some participants do not have an evaluable biopsy at the specified timeframe. The registry record does not report how many participants had a one-year assessment, how missing biopsies were classified, or whether any imputation or sensitivity analysis was planned or performed. It also does not report the analysis population, such as whether the primary analysis included all enrolled participants or only those with an evaluable assessment. These details matter because the denominator and treatment of missing outcomes influence the interpretation of a proportion.

The enrollment is listed as 69, while the treatment safety summary lists 57 at risk. The registry record does not explain the relationship between these counts, and the safety count should not be assumed to define the endpoint population. No conclusion about attrition, completeness of follow-up, or the effect of missing information can be drawn from these counts alone. The statistical plan and missing-data procedures are not reported in the registry record.

12. Safety Results

The registry reports serious adverse events as affected participants divided by participants at risk.

Deaths

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 1% reporting threshold.

Most frequent non-serious adverse event terms

The treatment-group safety summary lists 57 participants at risk for serious adverse events and 0 participants affected. It lists 57 at risk for other adverse events and 26 affected. The record also lists 2 deaths. These are descriptive counts in the registry safety summary; they do not by themselves establish whether an event was caused by the intervention.

The registry lists no serious adverse event terms among the top serious terms. This means the record does not provide named serious-event terms in that list; it should not be interpreted as a complete account of every possible event category or as proof that no events of any kind occurred. The listed count of 0 affected applies to the serious-adverse-event category as recorded.

The safety summary does not report the event definitions, observation period, severity details for other adverse events, or whether the deaths were related to treatment. It also does not explain the difference between the safety count of 57 at risk and the enrollment of 69. The two deaths therefore should be reported as registry-listed deaths, without attributing their cause or relationship to the intervention.

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

The record establishes that investigators registered a phase II, single-group study of a levonorgestrel-releasing intrauterine system in patients with complex atypical hyperplasia or grade I endometrial cancer. It defines a primary endpoint based on complete or partial response on endometrial biopsy at one year and specifies a 90% confidence interval. These details make the intended outcome and timeframe clear.

The record does not report the observed response count, response percentage, or confidence-interval limits. It therefore does not establish how many participants met the response definition or how precisely a response proportion was estimated. The endpoint definition describes what was to be measured; it is not evidence that the outcome occurred at any particular rate.

Because the study is single group and has no randomized comparator, the registered design cannot isolate an intervention effect through a between-group comparison. Even if a response estimate were available, the design would describe outcomes in the treated participants rather than show what would have occurred in a comparable control group. The absence of masking is also recorded, while details about endpoint assessment procedures are not reported.

The safety summary reports 0 serious adverse events among 57 participants at risk, 26 affected by other adverse events among 57 at risk, and 2 deaths. These figures are descriptive and do not identify treatment causality. The registry does not report the reasons for the safety denominator, the observation period for these counts, or the relationship of the deaths to treatment.

Accordingly, the record supports a careful account of the study design, endpoint definition, and listed safety counts. It does not support a conclusion about the magnitude of the response outcome, the precision of that outcome, or a causal treatment effect. Statistical interpretation requires both an estimate and the context of how it was obtained; the endpoint results and much of that analysis context are not reported in the registry record.

14. Why This Trial Matters Statistically

This study illustrates the distinction between a registered outcome and a reported result. The registry clearly names a response-rate endpoint, defines response using complete or partial biopsy response, and sets the timeframe at one year. Those elements describe what the study set out to measure. Without the observed estimate and confidence interval, however, readers cannot judge the outcome's magnitude or precision.

The single-group structure also makes the estimand important. A response proportion in treated participants answers a descriptive question about outcomes in that group. It does not estimate a randomized difference from a comparator. Statistical reporting should make that distinction explicit so a within-group result is not mistaken for a comparative treatment effect.

The record also shows why denominators and analysis populations matter. Enrollment is 69, whereas the safety summary lists 57 participants at risk. The record does not explain those counts or identify the primary endpoint denominator. Without knowing who had an evaluable biopsy and how missing assessments were handled, the response proportion cannot be interpreted fully even if it were reported.

Finally, the specified 90% confidence interval signals that uncertainty was intended to accompany the primary estimate, but the interval itself and its method are absent from the registry record. The statistical lesson is that an endpoint label, a planned confidence interval, and an enrollment figure do not substitute for transparent reporting of the estimate, denominator, analysis method, and missing-data handling. Those pieces are needed to understand what the evidence describes and where its limits lie.

15. Limitations

• The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
• Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.

The most direct limitation for interpreting this record is that it does not report the primary response result. The observed response proportion, number meeting the response definition, and 90% confidence interval are absent. The registry therefore does not permit evaluation of the primary outcome's magnitude or statistical precision.

The design is single group, with no randomized comparator, and masking is listed as none. A descriptive response rate cannot separate intervention-associated outcomes from other explanations, and the record does not report procedures that might reduce bias in biopsy assessment. The exact eligibility criteria and participant characteristics are also not reported in the registry record, limiting assessment of whom the enrolled group represents.

Enrollment is listed as 69, while the safety summary lists 57 participants at risk. The relationship between these counts is not explained. The number with an evaluable one-year biopsy, the analysis population, and the handling of missing endpoint data are not reported. This prevents assessment of endpoint completeness or the influence of missing information.

The record names three outcome measures but does not report the statistical plan, multiplicity approach, sample-size justification, or analysis details. It also lists 2 deaths without reporting their relationship to treatment, and does not describe the adverse-event observation period or event definitions. These omissions constrain both efficacy and safety interpretation. They do not establish that a particular analysis or procedure was absent; those details are simply not reported in the registry record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Levonorgestrel-Releasing Intrauterine System in Treating Patients With Complex Atypical Hyperplasia or Grade I Endometrial Cancer — NCT00788671.
• Registry record last updated 2026-10-27; status last verified 2026-10.
• Results first posted 2022-04-28.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

This phase II study, sponsored by M.D. Anderson Cancer Center, evaluates placement of a levonorgestrel-releasing intrauterine system in patients with complex atypical hyperplasia or grade I endometrial cancer. It is registered as a single-group study with no masking and enrollment of 69. The registry dates are 2008-11-03 for study start and 2016-06-10 for primary completion; status is active, not recruiting.

The primary outcome is response rate at 12 months, defined as complete or partial response based on endometrial biopsy, with a 90% confidence interval specified. The observed response result and interval are not reported in the registry record. The safety summary lists 0 serious adverse events among 57 at risk, 26 affected by other adverse events among 57 at risk, and 2 deaths. The record does not report treatment relatedness for the deaths or the statistical and missing-data methods used for the primary analysis.