Hypofractionated Pre-operative Radiation Therapy for Soft Tissue Sarcomas of the Extremity and Chest-wall: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Hypofractionated Pre-operative Radiation Therapy for Soft Tissue Sarcomas of the Extremity and Chest-wall (NCT02634710), a na na study. The primary outcome is Local Disease Control Assessed by Physical Examination.

2. Clinical Question

In statistical terms, this is a pilot question about outcomes observed after a treatment in one group, not a causal comparison between treatment options. The registry also lists secondary outcomes involving the Musculoskeletal Tumor Rating Scale, disease-free survival, overall survival, radiologic and pathologic changes, and treatment-related necrosis and fibrosis. These outcomes broaden the study’s descriptive scope, but their presence in the record does not establish that results were reported for them.

3. Trial Design

The registry identifies this as a nonrandomized Phase II pilot protocol with a single-group model. Allocation is listed as not applicable, and masking as none. The intervention is hypofractionated radiation therapy for soft tissue sarcomas of the extremity and chest wall. Because there is no comparison group, the design describes outcomes among participants receiving the intervention rather than estimating a randomized treatment contrast.

The listed enrollment is 35. The record gives a start date of 2016-02-23, a primary completion date of 2022-05-18, and a status of completed. Those administrative details do not establish how many participants received treatment, completed follow-up, or contributed data to any particular outcome. Those analysis-specific counts are not reported in the registry record.

The stated purpose is to determine feasibility, toxicity, and disease control, including local control, overall survival, and progression-free survival. The primary outcome is local disease control assessed by physical examination, expressed as a count of participants experiencing recurrence of the primary lesion, with a two-year timeframe. Secondary outcomes listed include the Musculoskeletal Tumor Rating Scale score, disease-free survival, overall survival, radiologic changes, pathologic changes, and treatment-related necrosis and fibrosis.

The registry record does not report the specific radiation dose, treatment schedule, eligibility criteria, follow-up procedures, or operational definitions for feasibility. It also does not report a statistical analysis plan, an intended sample-size justification, or details of analysis populations. The designation as a pilot communicates the stated study purpose; it does not, by itself, supply those missing design details. The registry lists eight outcome measures, while the named outcomes do not include result estimates for every measure.

With no randomized control arm, observed outcomes can be described for the treated group, but differences from an external or hypothetical comparator cannot be attributed to treatment on the basis of this design alone. Variation in participants, clinical care, or follow-up could also affect outcomes. The registry record does not report a comparison that would account for such factors.

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 Local Disease Control Assessed by Physical Examination, measured over 2 Years.

The primary endpoint is local disease control assessed by physical examination. More specifically, the measure is the count of participants experiencing recurrence of the primary lesion, with assessment at two years. It is a binary participant-level outcome in the sense that each participant can be classified as having or not having a recorded recurrence for the stated assessment, although the registry describes the measure as a count rather than reporting a rate.

A physical examination offers a clinically direct way to assess whether a local lesion has recurred. For a study focused on local control, a recurrence count can describe how often that event was observed in the treated group during the specified timeframe. A clearly defined assessment time also helps readers understand the window to which the measure refers. These are general reasons such an endpoint may be used; the registry does not report why this particular endpoint was selected or how examinations were standardized.

The endpoint’s interpretation depends on the number assessed, the completeness and duration of follow-up, and the rules for defining recurrence. The registry record does not report those details or the observed recurrence count. It therefore does not permit calculation or interpretation of an event proportion, confidence interval, or time-to-event estimate from the information recorded. Nor does it establish whether every participant had an examination at the stated time point.

The endpoint should not be confused with overall survival, disease-free survival, or the other secondary outcomes. Those are distinct measures, and the registry lists them separately. No results for those measures are reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a single-group design estimate?

General statistical context: a single-group study can describe outcomes observed among participants receiving an intervention. It does not, by itself, estimate the difference between that intervention and a control treatment. A randomized comparison is useful for estimating a treatment contrast because random assignment helps make groups comparable on average. This trial is listed as nonrandomized and single-group, so there is no within-trial control group for that purpose.

For this study, the primary endpoint is a count of participants with recurrence assessed by physical examination at two years. A count is straightforward to understand, but its interpretation depends on the number of participants who were actually assessed. The record lists enrollment as 35 but does not report the endpoint analysis denominator or the recurrence count. Neither an event proportion nor a treatment contrast can therefore be read from the primary endpoint information in the registry record.

What would uncertainty add?

General statistical context: a confidence interval gives a range of values compatible with the data under a specified statistical method. It communicates precision as well as the direction and scale of an estimate. For a binary event outcome, the estimate and interval are informative together: a count without its denominator is incomplete, while an estimate without an interval can conceal substantial uncertainty. No primary endpoint estimate or confidence interval is reported in the registry record.

A p-value answers a narrower question about how unusual the data would be under a specified null hypothesis and model. It does not measure the probability that a treatment works, nor does it describe the size or clinical importance of an effect. The record reports no primary endpoint p-value or inferential analysis. In a single-group study, a p-value would also require a clearly stated reference value or hypothesis; such a statistical plan is not reported in the registry record.

Why does the design matter for interpretation?

General statistical context: randomization supports comparison by reducing systematic differences between groups in expectation. In a single-group study, outcomes may reflect the intervention, participant characteristics, other care, disease course, and follow-up processes. Without a concurrent comparator, those influences cannot be separated using a treatment contrast within the trial. The design remains useful for describing experience in the group studied, but its descriptive reach is different from a randomized efficacy comparison.

The registry lists the allocation as not applicable, the model as single-group, and masking as none. It does not report blinding of outcome assessors or procedures for minimizing assessment differences. For a recurrence endpoint assessed by physical examination, consistent assessment rules can matter. The registry record does not explain those rules, so the extent to which assessment procedures were standardized cannot be evaluated.

What do the planning assumptions mean?

General statistical context: a sample-size calculation is a planning exercise. It asks how much information a proposed design might need under assumed conditions, such as a target effect, variability, significance level, and allocation. It is not a trial result. A calculation based on an observed effect is especially dependent on that estimate and should not be presented as observed power. Power is a pre-study design property under specified assumptions; it does not tell readers the probability that a study finding is true after the data are collected.

The planning assumptions associated with the calculations describe a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the effect framed as a stated fraction of an observed effect. The assumptions also distinguish time-to-event calculations, which use a total event count, from other calculations, which use participants per arm. These are planning conventions, not a description of this trial’s single-group design. The registry record does not report a trial-specific sample-size justification or the primary observed effect needed to evaluate those illustrations.

General statistical context: for count outcomes, the number of events and the population at risk are both important. For time-to-event outcomes, follow-up duration and censoring also matter; participants who have not experienced an event by their last observed time contribute information differently from participants with an event. The registry lists disease-free and overall survival as secondary outcomes, but does not report their estimates, event counts, follow-up distributions, or analysis methods.

What can be said about analyses and model assumptions?

The record lists eight outcome measures and zero analyses. That does not establish that no analysis was conducted; it means that statistical analyses are not reported in the registry record. No model specification, covariate adjustment, handling of repeated observations, or method for time-to-event outcomes is stated. It would be inappropriate to infer any of these choices from the outcome names or the pilot designation.

General statistical context: over-dispersion matters when count data vary more than a chosen model expects. If present and ignored, estimated uncertainty can be too small. This concept does not establish that over-dispersion is relevant to the primary endpoint, which is described as a participant count, or that any particular model was used. The registry record provides no model or dispersion assessment to evaluate.

For a binary endpoint, a useful report would ordinarily identify the number assessed, the number with the event, the method used to estimate uncertainty, and how missing assessments were handled. For survival outcomes, it would also be useful to know the time origin, censoring rules, and analysis population. These are general reporting considerations; the registry record does not provide these details for this trial.

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("Hypofractionated Radiation Therapy")
n      <- c(35)
events <- c(0)
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  Hypofractionated Radiation Therapy  35  0  0.0  0.0  10.0  0.0  9.9  0.1  9.7

11. Multiplicity, Missing Data and Analysis Populations

The registry lists eight outcome measures, including the primary local-control measure and named secondary measures concerning function, survival, imaging, pathology, necrosis, and fibrosis. It reports zero analyses. No multiplicity strategy, hierarchy among secondary outcomes, or adjustment for multiple testing is reported in the registry record.

General statistical context: when researchers test or estimate many outcomes, the chance of at least one apparently notable result can increase if each result is interpreted independently. Prespecifying a primary outcome and distinguishing it from exploratory outcomes helps readers understand which question is central. Adjustment methods or a clear outcome hierarchy may also be relevant, depending on the purpose of the analyses. The registry identifies a primary outcome, but does not report how multiplicity was handled for the additional measures.

Missing-data methods are not reported in the registry record. It does not state how missing physical examinations, incomplete follow-up, or unavailable secondary-outcome assessments were handled. It also does not report the number of participants with data for each outcome. The enrollment figure alone cannot show whether every participant contributed to every analysis.

Analysis populations are likewise not described. The record does not state whether analyses included all enrolled participants, only those who received treatment, or another defined group. These distinctions can affect how an outcome count is interpreted, particularly if participants did not complete the planned assessment. No assumptions about missing outcomes or analysis populations should be inferred from the completed status.

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 0% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: wound infection (11.4%), wound complication (8.6%), wound dehiscence (5.7%), cardiac arrest (2.9%), hyper parathyroidism (2.9%).

For the hypofractionated radiation therapy group, the registry lists 35 participants at risk for serious adverse events and 19 participants affected. For other adverse events, it lists 35 at risk and 20 affected. The record also lists 4 deaths. These figures describe the entries in the registry and do not, on their own, establish that an event was caused by treatment.

The most frequent serious adverse event terms listed are wound infection at 11.4%, wound complication at 8.6%, and wound dehiscence at 5.7%. Cardiac arrest, hyper parathyroidism, and pain are each listed at 2.9%. The registry record does not provide further details about event timing, severity grading, duration, recurrence, or attribution. The percentages should be read as reported rather than converted into participant counts.

General statistical context: adverse-event categories can overlap, because one participant may experience more than one type of event. Therefore, category counts or percentages should not be added to estimate the number of participants affected unless the reporting method explicitly establishes that categories are mutually exclusive. The record does not state whether the listed terms represent unique participants, events, or another counting convention.

The recorded deaths are not identified as treatment-related or otherwise characterized in the registry record. The safety figures do not provide a comparison with another group, so they cannot establish a relative safety difference. They should be interpreted as descriptive safety information within the single intervention group.

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

The registry record establishes that a completed, nonrandomized, single-group pilot was registered to study hypofractionated pre-operative radiation therapy for soft tissue sarcomas of the extremity and chest wall. It identifies local recurrence assessed by physical examination at two years as the primary outcome, and lists additional outcomes and safety counts. These details explain what the study set out to assess and what information the record contains.

The record does not report the observed primary endpoint count, the number assessed at two years, or an estimate with uncertainty. It therefore does not show the observed local-control result. It also does not report estimates for the named secondary outcomes. The absence of posted results is not evidence that no events occurred, and the enrollment figure is not a substitute for an outcome analysis.

The design places an important boundary on what can be inferred. Because there is no control group, the study cannot provide a randomized comparison of treatment outcomes. A descriptive result, if reported, would characterize the participants studied, but would not by itself establish what would have occurred under another treatment or no treatment. Differences from other studies would also need careful interpretation because participant populations and follow-up may differ.

The safety record lists serious adverse events, other adverse events, and deaths in the intervention group. Those data should not be treated as proof that the intervention caused each event. The registry does not report attribution or a comparative safety analysis. Likewise, the planning assumptions associated with sample-size illustrations are not evidence of treatment effect and should not be confused with findings from participants.

In short, the information supports a description of the trial’s structure, goals, primary endpoint definition, and recorded safety counts. It does not support a quantitative conclusion about the primary clinical outcome, a comparative effect, or the precision of any outcome estimate. Those questions require results and analytic details that are not reported in the registry record.

14. Why This Trial Matters Statistically

This trial is statistically instructive because it illustrates the difference between a study’s research question and the evidence its design can directly provide. The stated aim includes feasibility, toxicity, and disease control, while the registered design is a single-group pilot. Such a design can characterize outcomes within the treated group, but it cannot create a randomized estimate of the difference between treatment options.

The choice and definition of the primary endpoint also matter. The registry specifies a count of participants with local recurrence assessed by physical examination at two years. That definition identifies an event and a time horizon, but meaningful interpretation additionally requires the observed count, the number assessed, and an account of missing follow-up. Those results and details are not reported in the registry record. This makes clear why an endpoint description alone is not a result.

The record also distinguishes a planned statistical exercise from a completed analysis. Planning assumptions associated with sample-size illustrations describe hypothetical design conditions, including equal allocation between two arms. The registered study itself has one group. Keeping these ideas separate prevents a planning calculation from being mistaken for evidence about the trial’s observed outcomes or its statistical power.

Finally, the safety counts show why descriptive reporting needs context. Serious and other adverse events are listed alongside deaths, but the registry does not report attribution, timing, or a comparison group. Counts are useful for identifying what was recorded; they are not automatically causal estimates. Taken together, the study’s design and reporting status demonstrate why endpoint results, denominators, uncertainty, analysis populations, and limitations must be considered alongside a trial’s stated purpose.

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 immediate limitation for interpretation is that the registry record does not report the primary endpoint result. The recurrence count at two years, the number assessed, and an uncertainty estimate are absent. The record also does not provide results for the named secondary outcomes, despite listing eight outcome measures.

The single-group, nonrandomized design has no concurrent comparator. Any results reported for the intervention group would be descriptive rather than a randomized estimate of comparative effect. The absence of masking is recorded, but the registry does not explain whether outcome assessors were blinded or how physical examinations were standardized. These omissions prevent assessment of possible measurement or assessment influences.

The registry lists enrollment as 35 but does not report participant characteristics, treatment receipt, completion, follow-up completeness, or outcome-specific analysis denominators. Eligibility criteria and detailed radiation dose and schedule information are also not reported in the registry record. These details would help readers understand which participants the findings represent and how the intervention was implemented.

Statistical methods are not described: the record lists zero analyses and does not specify an analysis population, a missing-data approach, a model, confidence intervals, or a multiplicity strategy. Nor does it report the trial’s sample-size justification. The planning assumptions associated with sample-size illustrations do not resolve these omissions or replace trial-specific analysis methods.

Safety interpretation has its own limits. Counts are reported, but timing, severity grading, event attribution, and the counting convention for event terms are not. The registry does not identify the cause of the 4 deaths. Without comparative data, the safety entries cannot establish a relative difference between treatment options.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Hypofractionated Pre-operative Radiation Therapy for Soft Tissue Sarcomas of the Extremity and Chest-wall — NCT02634710.
• Registry record last updated 2025-12-02; status last verified 2025-11.
• Results first posted 2023-06-13.
• 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.

19. Record Summary

The registry record identifies NCT02634710 as a completed, nonrandomized Phase II pilot of hypofractionated pre-operative radiation therapy for soft tissue sarcomas of the extremity and chest wall. It lists a single-group design, no masking, enrollment of 35, a start date of 2016-02-23, and a primary completion date of 2022-05-18.

The primary outcome is the count of participants experiencing recurrence of the primary lesion assessed by physical examination at two years. Secondary outcomes include functional, survival, radiologic, pathologic, and tissue-change measures. The registry lists eight outcome measures and zero analyses.

For the intervention group, 19 participants are listed as affected by serious adverse events, 20 by other adverse events, and 4 deaths are recorded. The primary endpoint result, analysis denominators, statistical analysis methods, and event attribution are not reported in the registry record. Consequently, the record supports a description of the design and selected safety information, but not an estimate of the primary outcome or a comparative treatment effect.