Topical Keratin in Treating Radiation Dermatitis in Patients With Breast Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Topical Keratin in Treating Radiation Dermatitis in Patients With Breast Cancer (NCT03374995), a randomized na study. The primary outcome is Incidence of Early Adverse Skin Reactions (EASRs).

2. Clinical Question

The clinical question is whether the recorded frequency and severity categories of radiation-related skin reactions differ between participants assigned topical keratin and participants receiving standard care. The registry describes a pilot study, so its stated focus is on studying the intervention in this setting. However, the record does not include primary endpoint counts by arm or a reported comparison. It therefore does not establish what the observed difference between groups was, or how precisely any difference was estimated. The analysis is limited to the question and outcome definitions in the registry record; it cannot establish whether either approach changed skin reactions.

3. Trial Design

This is a randomized pilot clinical trial with a parallel-group design. The registry record lists 25 participants enrolled and identifies Wake Forest University Health Sciences as the sponsor. The trial status is completed. The record lists no masking, so it is described as an unmasked study. The method used to generate the random allocation sequence, any concealment procedures, and the roles of participants or study staff in allocation are not reported in the registry record.

One group received topical keratin at least BID until the end of radiation therapy, approximately 3-6 weeks. The other received standard of care as directed by the radiation oncologist over the same stated period. The registry also lists best practice and quality-of-life assessment among the interventions. The detailed procedures, measures, and results for those entries are not reported in the registry record.

The primary outcome is incidence of early adverse skin reactions, assessed up to 4 weeks post-RT. Its description says participants would report at a total of 7 visits any experience with Grade I or Grade II acute radiation dermatitis using the RTOG grading system. The Modified ONS Criteria for Radiation-Induced Acute Skin Toxicity would be used for classification. The record lists 4 outcome measures, but does not report how all were analyzed or how the visit-level observations were combined.

The registry record does not report the planned sample-size justification, a detailed statistical analysis plan, or an analysis population. Although enrollment is listed as 25, the adverse-event entries give risk denominators of 13 and 11 for the two groups. Why those denominators differ from the enrollment figure is 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:

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 Incidence of Early Adverse Skin Reactions (EASRs), measured over Up to 4 weeks post-RT.

The primary endpoint is incidence of early adverse skin reactions, expressed as a count of participants. It concerns acute skin toxicity related to radiation therapy, classified using the Modified ONS Criteria for Radiation-Induced Acute Skin Toxicity. The description also specifies RTOG grading: Grade I includes faint or dull erythema and dry desquamation, while Grade II includes tender or bright erythema and patchy, moist desquamation. Grade II is considered the worse outcome.

The stated assessment timeframe is up to 4 weeks post-RT. The description refers to participant reports over a total of 7 visits and says comparative effectiveness will include the number of participants in each arm experiencing Grade I or Grade II radiation dermatitis and moist desquamation. This endpoint is clinically relevant to the trial question because it captures skin reactions arising during radiation therapy and the stated follow-up period. It also distinguishes reaction categories rather than reducing severity to a single numerical score.

The registry record does not provide the number of participants experiencing each category in either arm, nor a single reported effect estimate or comparison. As a result, the endpoint definition can be described, but its observed comparative result cannot be interpreted from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Randomization assigns participants to study groups by chance rather than by a clinician’s choice. In general, random assignment is intended to make the groups comparable on average at the start of a study, including on factors that may not have been measured. It does not guarantee that every characteristic will be balanced in a small trial. The registry identifies this study as randomized, but the random sequence-generation and allocation-concealment procedures are not reported in the registry record.

What does the parallel-group design mean?

In a parallel-group design, participants are assigned to one study group and receive that group’s intervention during the study. Here, the registry describes one group receiving topical keratin and another receiving standard of care until the end of radiation therapy. It lists no masking. In general, masking can reduce the influence of treatment knowledge on assessments or reporting, but the record does not report whether any particular assessment procedure was protected from such influence.

How should a participant-count endpoint be read?

The primary endpoint is a count of participants with early adverse skin reactions. For a binary event, each participant is classified as having or not having the specified event over a defined period. A group count is meaningful alongside its denominator and event definition. Here, the endpoint description involves Grade I and Grade II categories, moist desquamation, and reports across visits. The registry does not state one combined event definition or one analysis that resolves those categories and visits into a single comparison. It also does not report group-specific primary outcome counts.

General statistical interpretation would often compare event proportions between groups using an absolute difference, a relative measure, or both. An absolute difference describes the separation in event proportions; a relative measure describes one group’s event frequency in relation to the other. These are different summaries and answer different interpretive questions. Neither can be calculated or interpreted for this primary endpoint without the relevant outcome counts and denominators. No such estimate is reported in the registry record.

What would an uncertainty interval communicate?

General: a confidence interval expresses the range of estimates reasonably compatible with the observed data under a specified statistical method. A narrow interval indicates greater precision than a wide interval, while an interval spanning values on either side of no difference may be consistent with multiple possible effects. An interval is not a guarantee that the true effect lies within its bounds. The registry record does not report a confidence interval for the primary endpoint, so the precision of any group difference cannot be assessed.

General: statistical tests assess how compatible observed data are with a specified null hypothesis under assumptions of the test. A p-value is not the probability that the null hypothesis is true, nor does it measure the clinical importance of an effect. No primary endpoint test or p-value is reported in the registry record. Therefore, no conclusion about statistical evidence for a group difference can be drawn from the posted primary outcome information.

What do the planning assumptions mean?

The sample-size planning description refers to a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. It describes the effect to detect as a stated fraction of the observed effect. In general, such a calculation estimates how many participants a future study would need under its assumptions to detect a selected effect with a chosen probability. These calculations are planning illustrations, not observed power for this completed trial. They do not demonstrate that the study had adequate power, and they do not replace a reported analysis of observed outcomes. The registry record does not report the trial’s own sample-size justification.

General: over-dispersion occurs when observed variability is greater than expected under a chosen statistical model. Accounting for it can affect uncertainty estimates and tests. It is not a reported feature of this endpoint, and no over-dispersion adjustment or model is reported in the registry record. The primary endpoint is described as participant counts, not as a continuous measure or a time-to-event outcome; the record does not specify a statistical model for its analysis.

The record lists zero analyses. It does not report an analysis population, handling of missing observations, an approach to repeated visits, a multiplicity procedure, or adjusted or unadjusted estimates for the primary outcome. These omissions prevent replication of a primary endpoint analysis from the registry entry alone.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists 4 outcome measures. It does not report a statistical plan describing which outcomes were confirmatory, how they were ordered, or whether any adjustment for multiple comparisons was planned. When a study evaluates several outcomes, categories, or time points, the chance of at least one apparently notable result can increase if many tests are conducted. General approaches to multiplicity include defining a primary comparison in advance or adjusting interpretation across a family of tests. The record does not say whether either approach was used.

The primary endpoint description includes Grade I and Grade II reactions, moist desquamation, and assessments across visits. The analysis information indicates that the outcome has several categories or time points and is not reduced to one comparison. The registry does not identify a single primary contrast, state how repeated reports were combined, or describe a method for accounting for multiple categories or visits. No primary endpoint analyses are listed.

Missing-data procedures are not reported in the registry record. It does not state whether participants with incomplete visits were excluded, whether any imputation was used, or how incomplete outcome records would enter an analysis. The analysis population is also not reported: there is no description of an intention-to-treat population, a per-protocol population, or another defined group for the primary analysis.

Enrollment is listed as 25, whereas the adverse-event risk denominators are 13 and 11. The record does not explain the denominators or report the number of participants included in the primary endpoint analysis. Those details are important for understanding the flow from enrollment to analysis, but cannot be inferred from the figures given.

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 entries list zero serious adverse events among 13 participants at risk in Group I (Topical Keratin), and zero among 11 participants at risk in Group II (Standard of Care). The same entries list zero participants affected by other adverse events in each group and zero deaths in each group. No serious adverse event terms are listed.

These are counts recorded in the registry, with the stated risk denominators. They are not the primary endpoint counts: the primary endpoint concerns early radiation-related skin reactions, while the figures above come from the adverse-event reporting entries. The registry does not provide further detail about adverse-event definitions, ascertainment, duration, or the relationship between the at-risk denominators and total enrollment.

General: observing zero events in a group does not prove that the underlying event risk is zero. With no events recorded, the data offer limited information about the frequency of rare events, especially when the number at risk is limited. The adverse-event figures should therefore be read as the counts reported for this trial, not as proof that no adverse events could occur.

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

The registry record establishes that a randomized, parallel-group pilot trial was conducted to study topical keratin for radiation dermatitis in patients with breast cancer. It describes the intervention, standard-of-care comparator, and intended primary endpoint. It also records adverse-event counts by group. These registry entries support a description of the research question and design.

The posted record does not report the primary endpoint results or a comparative statistical analysis. It therefore cannot show whether the groups differed in skin reactions, how large any difference was, or how uncertain an estimate might be. The absence of reported primary outcome results is not evidence that the groups had the same outcomes, and completion of the trial is not a substitute for those results.

The adverse-event entries report zero serious events and zero other affected participants in the two listed groups, along with zero deaths. Those figures are descriptive and have limited ability to characterize uncommon events in a pilot study. They should not be taken as proof of the absence of risk or as evidence about the primary skin-reaction outcome.

General: a pilot trial can help establish whether study procedures and outcome assessments are feasible and can inform planning for later research. But the registry record does not report feasibility results, a sample-size justification, or a detailed analysis plan. It also does not give enough primary outcome data to estimate an effect. Any claim about benefit, lack of benefit, equivalence, or comparative safety would go beyond the results recorded.

13. Why This Trial Matters Statistically

This trial is statistically notable as a randomized pilot study with a clinically focused endpoint, but the registry record separates the existence of a study from the availability of interpretable results. The design identifies two treatment groups and a stated comparison. The endpoint description gives meaningful clinical categories for radiation-related skin reactions. Yet the comparative counts and analysis are not reported, so the central statistical question cannot be answered from the registry entry.

That distinction matters in clinical research. A well-defined outcome is necessary for analysis, but it is not itself an outcome result. For an endpoint involving severity categories and multiple visits, readers need to know how events were defined for the comparison, which observations were included, and how uncertainty was quantified. Those details are not reported in the registry record. Without them, neither an effect estimate nor its precision can be evaluated.

The adverse-event counts also illustrate why denominators and context matter. The registry gives risk denominators for the two groups and reports zero affected participants, but those entries do not provide the primary efficacy results and do not establish the absence of possible harms. Further, the listed denominators do not match the enrollment figure as a complete accounting, and the reason is not reported.

For statisticians and clinical researchers, the record underscores the value of transparent outcome reporting: group-level counts, clearly defined analysis populations, methods for handling repeated assessments and missing data, and uncertainty estimates. The registry record includes the trial’s broad design and outcome intent, but not the information needed to assess the comparative result. Its statistical importance lies in making that boundary explicit rather than treating design details or event-free entries as evidence of an outcome effect.

14. Limitations

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

The primary limitation for interpretation is that the registry record does not report primary endpoint counts or a comparative estimate. It also lists no analyses. As a result, the planned outcome categories cannot be linked to observed results, and statistical precision cannot be assessed. No conclusion about the direction or magnitude of a group difference is supported by the primary outcome information recorded.

The endpoint description spans Grade I and Grade II reactions, moist desquamation, and multiple visits. The record does not report how those categories or visits were combined, which comparison was primary, or how repeated observations were handled. This makes the intended estimand—the specific treatment-group difference the analysis was intended to estimate—unclear from the registry entry.

The registry does not report the randomization method, allocation concealment, a detailed analysis plan, missing-data procedures, analysis populations, or a sample-size justification. It lists enrollment of 25, while the adverse-event entries give denominators of 13 and 11; the reason those figures differ is not reported. The record also lists 4 outcome measures without explaining any multiplicity strategy.

The trial is described as a pilot, and no masking is listed. The adverse-event entries show zero affected participants, but the registry does not give further detail on ascertainment or follow-up for those entries. These limitations are specific to the information recorded and should not be treated as evidence about unreported procedures or results.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Topical Keratin in Treating Radiation Dermatitis in Patients With Breast Cancer — NCT03374995.
• Registry record last updated 2024-06-11; status last verified 2020-02.
• Results first posted 2020-02-12.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

18. Record Summary

The registry record describes NCT03374995, a completed randomized pilot study sponsored by Wake Forest University Health Sciences. The study evaluates topical keratin against standard of care for radiation dermatitis in patients with breast cancer. Enrollment is listed as 25, and the design is parallel-group with no masking listed.

The primary endpoint is incidence of early adverse skin reactions, measured as participant counts and assessed up to 4 weeks post-RT. The description refers to Modified ONS classification, RTOG Grade I and Grade II reactions, and reports across visits. Primary outcome results and statistical analyses are not reported in the registry record.

The adverse-event entries report zero serious events, zero other affected participants, and zero deaths in each group, with risk denominators of 13 for topical keratin and 11 for standard of care. The reason for the difference between those denominators and total enrollment is not reported.