Adipocytokines in Endometrial Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Adipocytokines in Endometrial Cancer (NCT04697264), a registered phase not stated study. The primary outcome is Correlation Between Circulating Levels of These Markers and Demographic Characteristics..

2. Clinical Question

3. Trial Design

NCT04697264, titled “Adipocytokines in Endometrial Cancer,” is registered as a completed study sponsored by the University of Surrey. The registry gives a start date of 2021-04-12, a primary completion date of 2023-10-31, and total enrollment of 100. Its official title is “Adipocytokines and Their Relationship to Obesity and Endometrial Cancer.”

The design described is based on collecting blood and tissue samples from patients with endometrial cancer and a control population of patients with benign gynaecological conditions. The study intervention is categorized as a diagnostic test and named blood and tissue sample collection. This is not a randomized comparison: allocation is not stated, and the registry explicitly cautions that the arms are not a like-for-like control comparison.

For the cancer population, the record describes blood collection at surgery, on day 1 after surgery, and at follow-up at 3 or 6 months. It lists adiponectin, leptin, tumour necrosis factor alpha, interleukin-6, and insulin-like growth factors 1 and 2 as biomarkers of interest. It also describes collection of adipose tissue after surgery and cancer tissue and lymph nodes after histopathological evaluation. Blood samples from patients undergoing chemotherapy for advanced-stage endometrial cancer are also mentioned. The control population comprises female patients referred to Royal Surrey NHS Foundation Trust for benign conditions, specifically not endometrial cancer.

The registry lists 15 outcome measures and 35 analyses. These counts describe the breadth of registered outcomes and analyses; they do not establish how many were completed, which analyses were prioritized, or what results they produced. Detailed recruitment procedures, allocation methods, and a full statistical analysis 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.

Overall Study

Analysis population for the primary outcome, as defined in the registry: HRT usage counted among menopausal women only.

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 Correlation Between Circulating Levels of These Markers and Demographic Characteristics., measured over Data collected at baseline.

The primary outcome is described as correlation between circulating levels of the study markers and demographic characteristics, using data collected at baseline. The listed characteristics include age, parity, smoking status, menopausal status, medication use, HRT or hormonal contraception, diabetes and hypertension prevalence, prior significant medical history or cancer, and family history of cancer. HRT use is counted among menopausal women only.

A correlation analysis asks whether two measured characteristics vary together and describes the direction and strength of that association under the chosen statistical method. It does not by itself establish that one characteristic causes a change in a biomarker, or that a biomarker causes a clinical outcome. The registry does not identify the particular correlation coefficient, the planned handling of different variable types, or the primary marker-by-characteristic comparisons.

The endpoint can address whether baseline circulating marker levels are associated with demographic and clinical characteristics in the study population. Such associations may be relevant to the study’s stated interest in adipocytokines and obesity in endometrial cancer, but the endpoint is not itself a direct measure of treatment response, cancer progression, or patient benefit. Although the registry describes biomarker changes before and after surgery as secondary outcomes, no primary correlation estimates or uncertainty intervals are reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registered primary question concerns correlation between circulating marker levels and demographic characteristics at baseline. The registry record does not name the correlation statistic, specify a testing procedure, or present the resulting estimates. The concepts below are general explanations of how such analyses are interpreted; they are not claims about the methods used in this study.

What does correlation describe?

In general, correlation summarizes how two variables vary together. A positive association means higher values of one variable tend to occur with higher values of the other; a negative association means higher values of one tend to occur with lower values of the other. The size of a correlation describes the strength of the pattern under the selected measure. Correlation does not establish causation, and a correlation can be affected by other characteristics related to both variables.

The registry lists characteristics that are not all the same kind of measurement. Age and circulating marker levels are quantitative, while characteristics such as smoking status or menopausal status may be categorical. The appropriate summary and test can depend on how variables are measured, their distributions, and the scientific question. The record does not state how these distinctions were handled, whether variables were transformed, or whether adjusted analyses were planned.

How should precision be assessed?

In general, a confidence interval describes a range of values compatible with the data under a specified statistical procedure. A narrow interval indicates greater precision than a wide one, while an interval spanning values with different interpretations may leave the association uncertain. A point estimate without an interval gives limited information about precision. No correlation estimates or confidence intervals for the primary outcome are reported in the registry record, so the precision of any association cannot be evaluated from it.

A p-value, when reported, addresses how compatible the observed data are with a specified null model under the test’s assumptions. It does not measure the size or practical importance of an association. The registry does not report a primary p-value, a significance threshold for the primary outcome, or a description of confirmatory versus exploratory analyses. Statistical significance therefore cannot be assessed from the registry information.

Why do repeated measurements need attention?

The registry describes blood sampling at surgery, on day 1 after surgery, and at follow-up at 3 or 6 months. It also lists secondary outcomes concerning changes in marker levels before and after surgery. General statistical methods for repeated observations need to account for the fact that measurements from the same participant are related rather than independent. Treating them as independent can understate uncertainty. The statistical approach used to handle repeated measurements, and the number of participants contributing at each time point, are not reported in the registry record.

The record also describes biomarkers assessed in blood and tissue. These are different measurement contexts and should not automatically be treated as interchangeable. In general, a comparison of circulating levels with tissue expression asks whether measures from different biological sources are associated. Interpretation depends on the specific measurement definitions, timing, and analysis choices, none of which are fully reported for these outcomes.

What do the planning illustrations mean?

Any sample-size calculations displayed with the registry results are planning illustrations based on an observed effect, not observed power. The stated assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. The planning convention specifies participants per arm for non-time-to-event outcomes and a total number of events for time-to-event outcomes.

In general, a planning calculation asks what sample size would be needed to detect a specified effect under stated assumptions. It does not show the probability that the completed study detected an effect, nor does it demonstrate that a study was adequately powered for every registered outcome. Such calculations depend on the effect size chosen, variability, allocation, and statistical model. The registry record does not report a study-specific design justification or explain whether the planning assumptions were part of the original protocol. The registry’s planning illustration should therefore be distinguished from the original design and from the observed results.

There are 15 registered outcome measures and 35 analyses. In general, when many outcomes or analyses are examined, the chance of at least one apparently notable result can increase if no multiplicity strategy is used. Adjustment methods, outcome prioritization, and distinctions between planned and exploratory analyses are not reported in the registry record. The analysis plan and estimates would be needed to determine how individual results should be interpreted.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 15 outcome measures and 35 analyses. That breadth makes it important to know which outcomes were designated as primary, how multiple comparisons were handled, and whether analyses were prespecified or exploratory. The record identifies the primary outcome as baseline correlation between circulating marker levels and demographic characteristics, and lists multiple secondary biomarker and tissue-expression questions. It does not report a multiplicity adjustment, a testing hierarchy, or a complete statistical analysis plan. Without those details, individual statistical results, if reported elsewhere, would need to be interpreted in the context of the number of analyses considered.

Missing data can affect both estimates and their precision. For a study involving multiple sample-collection times and different sample types, the number of usable observations may vary across outcomes. General approaches include describing the amount and pattern of missingness and explaining how analyses use incomplete records. The registry record does not report missing-data counts, reasons for missing samples, imputation procedures, or sensitivity analyses. It also does not state how participants without measurements at every time point were handled.

The analysis populations are not described in detail. The registry identifies cancer and benign-condition populations and reports total enrollment, but does not state which participants were included in each outcome analysis or whether exclusions were planned. It does not specify an analysis population definition for the baseline correlations, repeated biomarker measurements, tissue assessments, or adverse events. These omissions limit assessment of selection effects and the relationship between the registered enrollment and the data analyzed. They do not establish that data were missing or that exclusions occurred; those details are simply not reported in the registry record.

11. 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 0% reporting threshold.

The adverse-event record lists two groups: patients with endometrial cancer and patients without endometrial cancer who have benign gynaecological issues. For each group, the registry records 50 participants at risk, 0 participants with a serious adverse event, 0 participants with another adverse event, and 0 deaths.

These figures describe what is recorded in the registry, not a randomized safety comparison. The study is a sample-collection study, allocation is not stated, and the registry cautions that the arms are not a like-for-like control comparison. The groups should therefore not be interpreted as treatment and control arms for estimating a treatment-related safety difference.

Zero recorded events does not prove that the underlying risk is zero. It means that the registry reports no events in the listed categories for these groups. The record does not explain event-collection procedures, follow-up completeness for safety, or whether events were actively solicited. Nor does it provide event definitions beyond the serious and other adverse-event categories shown. The figures should be read as registry reporting, not as evidence that the sample-collection procedures or clinical care caused no harm.

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

The study addresses an observational question about circulating adipocytokines and related markers in women with endometrial cancer, alongside a control population with benign gynaecological issues. Its registered primary outcome concerns baseline correlations between marker levels and demographic or clinical characteristics. The record also describes changes in markers over time and biomarker expression in tissue as secondary questions.

The registry record does not report numerical estimates for the primary correlations or the secondary biomarker outcomes. It therefore does not establish whether marker levels were associated with any listed characteristic, how large any association was, or how precisely it was estimated. The completed status and total enrollment do not replace those results.

Even if associations are identified in analyses of this kind, correlation alone cannot determine whether a demographic characteristic changes a biomarker, whether a biomarker affects cancer, or whether either causes a clinical outcome. Other factors may contribute to observed patterns. The non-randomized design and the registry’s warning that the groups are not a like-for-like comparison are especially relevant when interpreting contrasts between the cancer and benign-condition populations.

The registry describes repeated blood collection and tissue assessment, but does not report how these measurements were analyzed or how missing observations were handled. It also does not report the primary correlation estimates, uncertainty intervals, or a full statistical plan. This limits assessment of the strength, precision, and robustness of the findings.

The study’s stated aims can motivate investigation of biomarker relationships in endometrial cancer and obesity. The registry information alone cannot establish that a marker is useful for assessing treatment response, can diagnose or predict disease, or improves clinical outcomes. Those claims would require results and validation evidence beyond the objectives and sample-collection description recorded.

13. Why This Trial Matters Statistically

This study is statistically relevant because it brings together several kinds of measurements: circulating biomarkers, demographic and clinical characteristics, repeated blood samples, and tissue expression. Each supports a different question. Baseline correlations address whether marker levels vary with participant characteristics; repeated measurements address changes over time; tissue comparisons address relationships between circulating markers and tissue expression. Clear definitions and analysis methods matter because these questions are not interchangeable.

The design also illustrates why comparison groups need careful interpretation. The registry includes people with endometrial cancer and a control population referred for benign gynaecological issues, but states that the arms are not a like-for-like control comparison. As an observational study, it can describe associations in these populations, but a contrast between them may reflect other group differences as well as cancer status. It should not be interpreted as a randomized estimate of a treatment effect.

The number of registered outcome measures and analyses raises a further statistical issue: interpretation depends on knowing which analyses were primary, how other outcomes were prioritized, and whether multiple testing was addressed. The registry identifies the primary question but does not report a complete analysis plan or numerical findings. This makes transparent outcome reporting particularly important for readers assessing the evidence.

Finally, the study’s sample collection and biomarker aims should be distinguished from evidence that a marker is clinically useful. Association, change over time, and tissue expression are scientific findings of different kinds; none alone establishes predictive performance or patient benefit. The registry record captures an investigation with these aims, while leaving the estimates and analysis details needed for conclusions unreported.

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.

A central limitation for interpretation is that the registry describes the study’s objectives and sample collection but does not report the numerical results for the primary correlation outcome. No estimates or confidence intervals are available in the registry record to assess association size, direction, or precision. The listed secondary outcomes likewise do not come with reported numerical findings in this record.

The primary outcome spans several circulating markers and a broad set of demographic and clinical characteristics. The registry does not identify the specific marker-by-characteristic analyses, statistical methods, or adjustments that were planned. It also does not report how multiplicity was handled across the 15 outcome measures and 35 analyses. These omissions make it difficult to distinguish confirmatory questions from exploratory analyses.

The cancer and benign-condition groups are not randomized, and the record specifically warns that they are not a like-for-like comparison. Differences between them cannot be attributed to cancer status alone on the basis of this design description. The registry does not report adjustment strategies for potential differences between populations.

Blood collection is described at multiple times, and tissue samples are also part of the study. The record does not report analysis methods for repeated measurements, sample availability by time point, missing-data handling, or analysis-population definitions. It also does not provide details on how biomarkers were measured or how tissue expression was quantified. These specific reporting gaps limit evaluation of the measurement and analysis procedures; they do not establish that a particular problem occurred.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Adipocytokines in Endometrial Cancer — NCT04697264.
• Registry record last updated 2025-03-30; status last verified 2025-03.
• Results first posted 2025-03-30.
• 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

NCT04697264 is a completed study titled “Adipocytokines in Endometrial Cancer,” sponsored by the University of Surrey. The registry gives a start date of 2021-04-12, a primary completion date of 2023-10-31, and enrollment of 100. Its official title concerns adipocytokines and their relationship to obesity and endometrial cancer.

The study describes blood and tissue sample collection from patients with endometrial cancer and a control population referred for benign gynaecological conditions. The primary outcome concerns baseline correlations between circulating marker levels and demographic characteristics. Secondary outcomes include changes in biomarkers over time and marker expression or correlation in tissue.

The registry lists 15 outcome measures and 35 analyses, but does not report primary correlation estimates, confidence intervals, a complete analysis plan, or missing-data procedures. It states that the groups are not a like-for-like control comparison and does not describe random allocation. The adverse-event record lists 0 serious events and 0 deaths in each group. The record’s status and study description establish the intended scope, but not the findings or their precision.