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 Fibrin Melanoma Axillary Node Study in Patients With Melanoma (NCT00504582), a randomized na study. The primary outcome is Drain Duration.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00504582 |
| Phase | NA |
| Condition | Melanoma |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 121 |
| Arms in the primary outcome | 3 |
| Lead sponsor | M.D. Anderson Cancer Center |
| Results posted | Yes |
2. Clinical Question
Population
Patients with melanoma undergoing axillary node dissection. The registry record lists an enrollment of 121. Primary drain-duration data were not collected for the questionnaire-only arm.
Intervention
Fibrin sealant, described as Tisseel applied externally to the dissected axillary area after node dissection.
Comparator
No fibrin sealant. The registry record identifies this as the control arm.
Primary question
Can applying fibrin sealant to axillary soft tissues after node dissection result in earlier drain removal? Drain duration was measured as the number of days the drain remained in place, from surgery until removal, up to 40 days.
The study’s primary objective focused on drain removal timing. The registry record also describes secondary objectives concerning postoperative morbidity, patient valuation of outcomes using a willingness-to-pay model, and whether VEGF-D, VEGF-C, or VEGFR-3 measures correlate with nodal tumor burden or lymphedema. These objectives provide context for the trial’s broader interests, but the posted results include drain duration and the number of participants with infection. The registry record does not report results for the other described objectives.
The primary endpoint is clinically interpretable as elapsed time with a surgical drain in place. However, the posted primary data are descriptive summaries by arm, and the registry record does not report an inferential comparison between those arms. The results therefore describe the observed drain durations without establishing whether the observed difference is distinguishable from chance variation.
3. Trial Design
The registry record describes a randomized, parallel-arm trial with no masking. It lists an enrollment of 121 and identifies M.D. Anderson Cancer Center as the sponsor. The study status is completed. The recorded start date is 2002-05-15, and the primary completion date is 2020-04-09.
The intervention arm received fibrin sealant applied externally to the dissected axillary area. The comparator was no fibrin sealant. A questionnaire-only arm is also listed, but primary drain-duration data were not collected for that arm. The primary outcome summaries include 44 participants in the treatment arm and 45 in the control arm. The posted infection outcome includes 46 participants in the treatment arm and 45 in the control arm. The registry record does not explain the differing arm counts across these outcomes, so they should be read as the denominators reported for each outcome rather than assumed to represent identical analysis populations.
Random allocation is intended to create groups that are comparable on average, while a parallel design assigns each participant to one arm for the comparison. The registry record does not report the randomization procedure, allocation concealment, or any stratification factors. With no masking, participants and study personnel were not masked to assignment according to the registry record. Further details of how this was implemented are not reported in the registry record.
The record lists a total enrollment of 121, but the posted outcome denominators do not account for every enrolled participant. The reason is not reported in the registry record. The record also does not report a detailed analysis population definition, such as whether analyses followed all randomized participants or only those with available outcome data. These omissions limit reconstruction of how the randomized groups relate to the posted summaries.
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: There were 121 total patients associated with this study. 92 patients were evaluable for the treatment study. 9 patients were inevaluable due to withdrew consent, surgery cancelled, patient elected to proceed with biopsy not surgery, not coming to MD Anderson, diagnosed with merkle cell carcinoma and sarcoma. There were 20 patients with melanoma who have undergone axillary dissection within prior six months as part of their surgical treatment who only completed the questionnaire.
Overall Study
| Stage | Treatment Arm | Control Arm | Questionnaire Only |
|---|---|---|---|
| STARTED | 47 | 45 | 20 |
| COMPLETED | 46 | 45 | 20 |
| NOT COMPLETED | 1 | 0 | 0 |
Reasons for not completing this period:
| Reason | Treatment Arm | Control Arm | Questionnaire Only |
|---|---|---|---|
| Lost to Follow-up | 1 | 0 | 0 |
Analysis population for the primary outcome, as defined in the registry: Data not collected for Questionnaire Only Arm.
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: Baseline characteristics not taken for the questionnaire only arm.
| Characteristic | Unit | Treatment Arm | Control Arm | Questionnaire Only | Total |
|---|---|---|---|---|---|
| Participants analysed | 47 | 45 | 0 | 92 | |
| Age, Categorical: <=18 years | Participants | 0 | 0 | — | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 36 | 37 | — | 73 |
| Age, Categorical: >=65 years | Participants | 11 | 8 | — | 19 |
| Sex: Female, Male: Female | Participants | 12 | 8 | — | 20 |
| Sex: Female, Male: Male | Participants | 35 | 37 | — | 72 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 1 | 1 | — | 2 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 46 | 44 | — | 90 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | — | 0 |
| Race (NIH/OMB): American Indian or Alaska Native | Participants | 0 | 0 | — | 0 |
| Race (NIH/OMB): Asian | Participants | 0 | 0 | — | 0 |
| Race (NIH/OMB): Native Hawaiian or Other Pacific Islander | Participants | 0 | 0 | — | 0 |
| Race (NIH/OMB): Black or African American | Participants | 0 | 1 | — | 1 |
| Race (NIH/OMB): White | Participants | 47 | 44 | — | 91 |
| Race (NIH/OMB): More than one race | Participants | 0 | 0 | — | 0 |
| Race (NIH/OMB): Unknown or Not Reported | Participants | 0 | 0 | — | 0 |
| Region of Enrollment: United States | participants | 47 | 45 | — | 92 |
6. Primary Endpoint
The registry lists the primary outcome as Drain Duration, measured over from surgery until drain removed, up to 40 days.
| Element | Registry entry |
|---|---|
| Result type | Mean |
| Measure of spread | Full Range |
| Unit | days |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is drain duration, defined as the number of days the drain was in place from surgery until removal, up to 40 days. The record summarizes this endpoint using a mean and a full range for each arm. Drain duration directly reflects the time until a postoperative drain is removed, making it a straightforward measure for the stated objective of assessing whether sealant use can result in earlier removal.
The treatment arm had a mean drain duration of 23 days, with a full range from 7 to 40 days. The control arm had a mean of 21 days, with a full range from 5 to 36 days. The questionnaire-only arm has no primary endpoint data. These summaries describe the recorded values in the two arms, but they do not by themselves quantify the precision of an arm-to-arm comparison.
A mean conveys the average duration, while a full range shows the lowest and highest recorded values. A range is sensitive to the most extreme observations and does not show how values are distributed between those extremes. The registry record does not report a standard deviation, confidence interval, or statistical test for the primary endpoint. It also does not report an inferential comparison or a more detailed description of the endpoint’s analysis. As a result, the posted summaries support a descriptive account, not a conclusion about the statistical uncertainty of the difference between arms.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The posted primary endpoint summaries show a mean drain duration of 23 days in the treatment arm and 21 days in the control arm. The full ranges were 7 to 40 days and 5 to 36 days, respectively. These descriptive values do not show earlier average drain removal in the treatment arm, but they are not a statistical test of the treatment effect. The registry record does not report a confidence interval, standard error, or p-value for the primary comparison. Consequently, the precision of an arm-to-arm difference in drain duration cannot be assessed from the posted primary summaries alone.
The infection outcome is reported as 12 participants in the treatment arm and 8 in the control arm, with denominators of 46 and 45. The posted risk estimates are 0.261 for treatment and 0.178 for control. The estimated risk difference is 0.083, with a 95% confidence interval from -0.086 to 0.252. This interval includes no difference and is also compatible with differences in either direction. The unadjusted p-value is 0.339. The risk ratio is 1.467, with a confidence interval from 0.663 to 3.248; the odds ratio is 1.632, with a confidence interval from 0.595 to 4.475. Both intervals include their respective no-association values.
These infection estimates are imprecise: the confidence interval for the risk difference extends from a negative value to a positive value, and the ratio intervals cover values on both sides of no association. The estimates therefore do not resolve whether infection frequency differed between the arms. They should not be interpreted as establishing an effect or the absence of an effect.
The primary drain-duration result and the infection result answer different questions. Drain duration was the stated primary endpoint, whereas infection was a posted secondary outcome. The infection comparison cannot replace the missing inferential analysis of the primary endpoint. Also, the registry record does not report whether the secondary analysis was prespecified in a statistical analysis plan or whether it was adjusted for the number of outcomes examined. Its p-value is explicitly unadjusted, so it should be treated as a secondary, exploratory result rather than as a standalone confirmatory finding.
The results are limited to the outcomes and summaries posted in the registry record. The record does not report results for the other described secondary objectives, nor does it provide enough information to determine how missing outcome data or analysis populations were handled. No interpretation of these data establishes that a treatment works or does not work; the posted evidence describes observed summaries and the uncertainty around the reported infection comparison.
9. Statistical Methods Explained
The registry record identifies drain duration as the primary outcome and reports a mean and full range for each of the two arms with primary data. It does not report the statistical method used to compare the primary endpoint. The arm summaries are therefore best read descriptively. A mean gives the arithmetic average of observed durations, while the range identifies the minimum and maximum values. Neither quantity alone describes the full distribution or the precision of a between-arm estimate.
For a stronger comparison of a continuous outcome such as duration, analysts commonly report an estimated difference between arm means together with a confidence interval and a test result. A confidence interval communicates the range of effect sizes compatible with the data under the method’s assumptions. The registry record does not report such a comparison for drain duration, nor does it report variability measures such as standard deviations. It is therefore not possible to recover the uncertainty of the primary comparison from the posted means and ranges without making assumptions that are not in the record.
What does the infection risk difference represent?
The infection outcome is binary: each participant is counted as having or not having an infection during the stated follow-up. The posted risks are 0.261 in the treatment arm and 0.178 in the control arm. The estimated risk difference is 0.083, with a confidence interval from -0.086 to 0.252. A risk difference expresses the contrast on the absolute-risk scale; its no-difference value is zero. The reported interval includes zero, so the data do not isolate a single direction of difference.
The risk ratio and odds ratio express the same outcome on relative scales. The posted risk ratio is 1.467, with a confidence interval from 0.663 to 3.248. The odds ratio is 1.632, with a confidence interval from 0.595 to 4.475. A ratio of one represents no relative difference. Each reported interval includes one, and each spans a broad range of possible associations. These estimates are different ways to describe the infection comparison; they do not provide independent replications of the result.
How should the p-value be read?
The unadjusted p-value for infection is 0.339. In general, a p-value describes how unusual the observed data, or data more extreme, would be under a specified null model and its assumptions. It does not measure the probability that the null hypothesis is true, and it does not measure the size or clinical importance of an effect. The registry record does not report a multiplicity adjustment for this comparison. The p-value should therefore be interpreted with the confidence interval, the outcome’s secondary status, and the absence of reported analyses for other stated objectives in mind.
Why do uncertainty intervals matter?
A point estimate is one summary of the observed contrast; an interval indicates how much uncertainty remains around it. In general, wide intervals can reflect limited information, substantial variation, or both. For the infection outcome, the posted interval permits materially different directions and magnitudes of association. For drain duration, no interval is reported, so its comparative precision cannot be assessed. Neither the reported infection intervals nor the primary descriptive summaries establish that the intervention caused a particular outcome.
What does the planning illustration mean?
The registry record includes a planning illustration based on the observed infection effect, using a two-sided significance level of 0.05, equal allocation, and a normal approximation. It presents participants per arm for 80% and 90% power under planning scenarios for 100%, 75%, and 50% of the observed effect. The corresponding participant counts are 389 and 520 for planning for 100% of the observed effect; 667 and 893 for planning for 75% of the observed effect; and 1,447 and 1,936 for planning for 50% of the observed effect.
These are planning illustrations, not observed trial results and not estimates of the trial’s observed power. They are conditional on the stated assumptions and on effect sizes drawn from the observed estimate, which itself is uncertain. They do not establish that these sample sizes were the trial’s original targets. The trial’s own sample-size justification and design assumptions are not reported in the registry record.
More generally, power is a design-stage probability of detecting a specified effect under a specified model and assumptions. It is not a measure of whether a completed study has demonstrated an effect. Retrospective calculations framed as observed power do not add information beyond the observed estimate and its uncertainty. The planning counts are most useful as illustrations of how required sample size can change when the target effect differs, rather than as evidence about the trial’s result.
The registry record reports no primary comparison and no reported analyses for the stated secondary objectives beyond the posted infection comparison. It does not report adjustment methods, model details, missing-data methods, or a statistical analysis plan. Those details matter because methods can affect uncertainty estimates and because results are interpretable only in relation to the analyses actually specified and conducted. When such details are absent, conclusions should stay close to the posted summaries rather than filling in unreported analytical choices.
10. Multiplicity, Missing Data and Analysis Populations
The registry record does not report a statistical analysis plan, a multiplicity strategy, or whether any outcomes were designated as confirmatory beyond identifying drain duration as the primary outcome. The posted infection p-value is unadjusted. With more than one outcome or analysis, unadjusted testing can increase the chance of at least one result appearing unusual by chance. General methods for addressing multiplicity include adjusting the testing threshold or controlling an error rate across a defined family of tests, but whether any such approach was used is not reported in the registry record.
The record describes secondary objectives beyond infection, including postoperative morbidity, patient valuation, and vascular growth-factor measures. Their results and analyses are not reported in the registry record. Without the complete set of planned and conducted comparisons, the scope of multiplicity cannot be assessed. The infection result should therefore be treated as an unadjusted secondary finding and not as if it were the sole analysis undertaken.
Missing data and analysis populations also require caution. The registry record lists enrollment of 121, but the primary endpoint summaries include 44 treatment participants and 45 control participants, while the infection summaries include 46 and 45. The questionnaire-only arm has no primary drain-duration data and is listed with no participants in the posted outcome summaries. The reasons for the outcome-specific denominators and the handling of participants without outcome data are not reported in the registry record.
The record does not identify whether the primary or secondary analyses used an intention-to-treat population, a per-protocol population, or another analysis set. It does not report a missing-data method, imputation, sensitivity analysis, or participant flow explaining how randomized participants contributed to each endpoint. These details affect how confidently the posted arm summaries can be linked to the full randomized population. In their absence, the reported denominators should be retained as the outcome-specific counts, without assuming why they differ or how unobserved outcomes may have affected the results.
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 Arm | 2 | 47 | 4.3% |
| Control Arm | 1 | 45 | 2.2% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Treatment Arm | 0 of 47 |
| Control Arm | 0 of 45 |
| Questionnaire Only | 0 of 0 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Treatment Arm | 0 of 47 |
| Control Arm | 0 of 45 |
| Questionnaire Only | 0 of 0 |
Most frequent serious adverse event terms
| Event term | Organ system | Treatment Arm | Control Arm | Questionnaire Only |
|---|---|---|---|---|
| Infection | Infections and infestations | 2 of 47 | 1 of 45 | 0 of 0 |
Serious events with the highest arm-level rate: infection (4.3%).
The registry record lists infection as the leading serious adverse event term, at 4.3%. The group-specific serious adverse event counts are 2 of 47 in the treatment arm and 1 of 45 in the control arm. The listed counts for other serious adverse events are 0 in each of those arms, and deaths are listed as 0 in each. The questionnaire-only group has zero participants at risk in the posted adverse-event summary.
These are descriptive safety counts, not a statistical comparison. The registry record does not report confidence intervals or a significance test for the serious adverse event figures. The adverse-event denominators also differ from the outcome-specific denominators for the primary drain-duration and infection summaries; the reason is not reported in the registry record. The infection term in the serious adverse event listing should not be conflated with the separate secondary outcome counting participants with infection: they appear in different registry summaries and use different posted denominators.
Small counts can provide limited precision about uncommon events. In general, zero reported events does not establish that the underlying risk is zero, and a difference in observed counts does not by itself establish a treatment-related difference. The posted serious-event information is best read as the counts recorded in each group, without drawing a causal conclusion or treating the summaries as a complete safety analysis.
12. What the Result Does, and Does Not, Mean
The primary results establish what the registry record reports descriptively: mean drain duration was 23 days in the treatment arm and 21 days in the control arm, with overlapping full ranges. They do not establish the statistical precision of that contrast, because no primary confidence interval, test, or variability estimate is reported. The observed means alone cannot show whether an arm difference is more than would be expected from sampling variation.
For infection, the posted estimates indicate uncertainty rather than a settled comparison. The risk-difference interval extends from -0.086 to 0.252, and the unadjusted p-value is 0.339. The ratio intervals also include their no-association values. The result does not demonstrate that infection frequency differed, but it also does not establish that the groups were equivalent. Demonstrating equivalence or ruling out an important difference would require a defined margin and an analysis designed to address that question; those are not reported in the registry record.
The findings do not prove that fibrin sealant changes drain duration, infection, or any other outcome. They also do not prove that it has no effect. The record’s available primary results are descriptive, and the secondary infection estimate is imprecise. The trial’s other described objectives do not have results reported in the registry record, so no conclusion about those questions follows from the posted outcomes.
The planning counts do not change this interpretation. They are illustrations under stated assumptions based on fractions of the observed infection effect; they are not observed trial power and do not establish whether the actual study was adequately planned for its primary question. The trial’s sample-size justification is not reported in the registry record.
Overall, the posted information supports a narrow reading: reported arm summaries and safety counts, plus an uncertain secondary infection comparison. It does not support a definitive claim about treatment benefit, lack of benefit, safety equivalence, or the broader secondary objectives. Any stronger interpretation would require analyses and design information not reported in the registry record.
13. Why This Trial Matters Statistically
This trial illustrates an important distinction between an observed difference and a statistically characterized treatment effect. The primary outcome is expressed in an accessible unit, days with a drain in place, and the registry record provides means and ranges. Yet without a reported comparison interval or test, readers cannot assess how precisely the arm contrast is estimated. A clinically direct endpoint does not eliminate the need to report uncertainty.
It also shows why outcome-specific denominators matter. The primary and infection summaries have different arm counts, and the total enrollment is 121. Without participant flow or analysis-population details, readers cannot determine how those counts arose. Transparent accounting of randomized participants and missing outcomes is essential for judging how closely results reflect the randomized groups.
The infection result demonstrates the value of considering confidence intervals alongside p-values. Its point estimates are accompanied by intervals that cover a range of possible directions and magnitudes. The unadjusted p-value alone would not communicate that uncertainty or distinguish a lack of clear evidence from evidence of no meaningful difference. Secondary results also need context about the number of outcomes and the analysis plan.
Finally, the registry record distinguishes neither a reported design-stage sample-size justification nor a reported primary inferential analysis. The planning illustration is not a substitute for either. For clinical researchers and statisticians, the central lesson is that a completed randomized trial can have descriptive results posted while key components needed for a full statistical interpretation remain unreported. Clear reporting of estimands, analysis populations, uncertainty, missing-data handling, and multiplicity helps readers understand what a trial can—and cannot—establish.
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.
Several limitations specific to this record constrain interpretation. Most importantly, the primary endpoint has only arm-level means and full ranges. The registry record does not report a primary effect estimate, confidence interval, test, standard deviations, or analysis method. The stated primary question about earlier drain removal therefore cannot be evaluated with a reported inferential comparison.
The record lists an enrollment of 121, but the endpoint-specific denominators are smaller and differ between drain duration and infection. It does not explain the differences, report participant flow, or describe how missing outcomes were handled. Primary drain-duration data were not collected for the questionnaire-only arm. These omissions make it difficult to assess how the analyzed participants relate to the randomized population.
The design information is also incomplete. Randomization and parallel assignment are reported, but the randomization procedure, allocation concealment, and analysis populations are not. The study was unmasked; further details about who knew assignment and how outcome assessment was conducted are not reported in the registry record. The sample-size justification, statistical analysis plan, and interim-analysis approach are not reported in the registry record.
The secondary evidence is limited to the posted infection comparison. Its confidence intervals are broad and its p-value is unadjusted. The record does not report multiplicity handling or results for the other described secondary objectives. Serious adverse event summaries are counts without a comparative uncertainty analysis, and the record does not explain the relationship between their denominators and those used for the efficacy outcomes.
These are limitations of what can be learned from the registry record; they do not establish that omitted analyses were not conducted. Their absence from the record means the reported findings should be interpreted narrowly and without assumptions about unreported procedures.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Fibrin Melanoma Axillary Node Study in Patients With Melanoma — NCT00504582.
- Registry record last updated 2023-05-09; status last verified 2023-04.
- Results first posted 2021-10-26.
- 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
NCT00504582 is a completed randomized, parallel-arm, unmasked study sponsored by M.D. Anderson Cancer Center. It enrolled 121 patients with melanoma and evaluated fibrin sealant applied to the dissected axillary area after node dissection against no fibrin sealant. The primary outcome was drain duration, measured in days from surgery until removal, up to 40 days.
The posted primary summaries report means of 23 days in the treatment arm and 21 days in the control arm, with full ranges of 7 to 40 days and 5 to 36 days. No inferential primary comparison is reported in the registry record. The posted secondary infection comparison has an estimated risk difference of 0.083, with a confidence interval from -0.086 to 0.252 and an unadjusted p-value of 0.339. The registry record also lists serious adverse event counts and a planning illustration based on the observed infection effect.
Missing-data handling, analysis populations, multiplicity methods, the trial’s sample-size justification, and results for the other described secondary objectives are not reported in the registry record. The available results are therefore descriptive for the primary outcome and uncertain for the secondary infection comparison.