Autologous or Donor Stem Cell Transplantation in Treating Patients With Recurrent Non-Hodgkin's Lymphoma (BMT CTN 0202): Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Autologous or Donor Stem Cell Transplantation in Treating Patients With Recurrent Non-Hodgkin's Lymphoma (BMT CTN 0202) (NCT00096460), a non-randomized phase 2, phase 3 study. The primary outcome is Lymphoma Progression-free Survival.

2. Clinical Question

3. Trial Design

The registry describes a Phase II/III, multicenter study comparing autologous with non-myeloablative allogeneic HSCT in patients with chemosensitive follicular non-Hodgkin's lymphoma beyond a first complete or partial response. The listed phases are Phase 2 and Phase 3. The study used a parallel design and had no masking. Its allocation is recorded as non-randomized.

The brief description says participants were biologically assigned to a treatment arm according to the availability of an HLA-matched sibling. That assignment process distinguishes the study from a randomized trial: access to the allogeneic strategy was linked to donor availability rather than a chance allocation process. The registry specifically cautions that the arms are not a like-for-like control comparison. Differences between groups could therefore reflect differences in who entered each arm, as well as differences between treatment strategies. The record does not report enough participant-level information to assess those possible differences.

The enrollment listed in the registry is 30, and the study status is terminated. The record lists a start date of 2004-08 and a primary completion date of 2006-03. It does not report why the study was terminated, whether termination occurred before planned completion, or how many participants completed follow-up. Those details should not be inferred from the status alone.

The autologous arm description includes cyclophosphamide and rituximab, filgrastim conditioning, chemotherapy or radiation before transplant, and rituximab maintenance afterward. The allogeneic arm description includes non-myeloablative conditioning, allogeneic HSCT, and graft-versus-host disease prophylaxis. The registry record does not report a full protocol, adherence, crossover, or treatment deviations. The study's stated primary outcome concerns progression-free survival at three years after HSCT, but numerical outcome results 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

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 Lymphoma Progression-free Survival, measured over Three years post-Hematopoietic Stem Cell Transplant (HSCT).

The primary endpoint is titled “Lymphoma Progression-free Survival” and is specified for participants at three years after hematopoietic stem cell transplantation. Progression-free survival is generally used to describe how long participants remain alive without disease progression; it can capture a clinically important aspect of disease control while incorporating the timing of events. That is a general description, not a definition of how this particular study determined progression or handled deaths.

The registry record identifies the unit as participants and the measure type as a number. It does not define the endpoint’s event criteria, the precise assessment schedule, how an event was confirmed, or how participants without a recorded event were handled. It also does not provide an outcome count or a comparison between the arms. Consequently, the endpoint title and timeframe identify the intended question, but do not establish the observed progression-free survival in either group.

Time-to-event outcomes are useful because participants may experience an event at different times and may have different lengths of observation. A full analysis usually needs to account for event timing and incomplete follow-up, rather than treating every participant as if observed for the same duration. The registry record does not report the method used for this endpoint, the amount of follow-up, or how censoring and missing assessments were handled. These omissions prevent assessment of the precision and robustness of the endpoint result.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods turn participant observations into estimates that can be interpreted in light of uncertainty and study design. For this trial, the registry record gives a primary outcome title and timeframe, but does not report the numerical outcome estimates or the methods used to calculate them. The discussion below explains general concepts relevant to the stated question; it does not describe unreported methods as if they were used in this study.

What does progression-free survival measure?

In general, progression-free survival is a time-to-event outcome. It concerns the time until a defined event, commonly disease progression or death, rather than simply whether a participant had an event at one specified visit. The exact event definition matters: different progression criteria or rules for deaths can change which observations count as events. For this trial, the registry names lymphoma progression-free survival at three years after HSCT but does not report its operational definition. It does not state whether the endpoint was analyzed as a time-to-event measure, as a participant count at the three-year point, or by another method.

When a time-to-event analysis is used, participants who have not experienced the event by their last known assessment may be censored. Censoring means that the event time is not known beyond that observation; it is not the same as confirming that an event never occurred. The validity of common time-to-event methods depends on assumptions about censoring and the collection of follow-up data. The registry record does not report censoring rules, follow-up completeness, or how participants lost to follow-up were handled.

Why does assignment matter for the comparison?

Randomization is a method for assigning treatment by chance. In general, it makes systematic baseline differences less likely on average, though it does not guarantee identical groups. This study is recorded as non-randomized. The brief description says assignment depended on availability of an HLA-matched sibling. As a result, any comparison between the transplant groups may reflect both the transplant strategies and differences connected to donor availability or participant characteristics. Statistical adjustment can sometimes address measured differences, but cannot automatically eliminate unmeasured confounding. The registry record does not report baseline characteristics, adjustment variables, or a statistical model for the primary comparison.

A confidence interval is a range of values that expresses uncertainty around an estimate under the assumptions of the analysis. A narrow interval generally indicates greater precision than a wide interval, while an interval that includes values consistent with different conclusions may leave the comparison uncertain. No confidence interval for progression-free survival is reported in the registry record. Therefore, the precision of the primary comparison cannot be evaluated.

What do event counts say about safety?

For adverse events, the registry reports counts of participants affected and counts at risk. These are descriptive counts, not a complete account of event timing, severity beyond the serious-event classification, or repeated events in an individual. A participant count also differs from an event count: one participant can experience more than one event, but the posted affected-participant fields do not express the total number of events. The record reports no serious-event terms and lists zero participants affected by serious events in either group. It lists one participant affected by other events in the allogeneic group and none in the autologous group. The record does not provide detailed event descriptions or a broader safety analysis.

When comparing event counts between groups, denominators and follow-up time matter. Counts alone do not account for differences in the amount of observation or establish that one strategy has a different underlying risk. Here, the adverse-event groups list 20 at risk for autologous HSCT and 7 at risk for allogeneic HSCT. No rate calculation is needed to read those reported counts, and the registry does not provide an analysis comparing safety between arms.

How should planning illustrations be understood?

Sample-size planning asks how many participants may be needed to detect an effect under specified assumptions. The registry record describes a planning illustration based on the observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. It says the effect to detect is a stated fraction of the observed effect. These are planning assumptions, not a description of the trial’s original design or evidence that the trial had a particular probability of detecting an effect.

A planning calculation based on an observed effect is especially sensitive to uncertainty in that observed effect. If the observed estimate is imprecise, calculations using it can also be unstable. Such illustrations can show how assumed effect size and design choices influence a required sample size, but they do not constitute observed power and cannot recover an unreported primary result. The registry record does not report the trial’s own sample-size justification or the assumptions used for its original design.

Over-dispersion is a general concern when count data vary more than a model assumes; ignoring it can make uncertainty appear too small. It is not possible to determine whether over-dispersion is relevant to this primary endpoint from the registry record, which does not report a count model or analysis method. More broadly, an analysis should match the endpoint’s structure, the treatment-assignment process, and the available follow-up. Those details are not reported for the primary outcome, so the analysis cannot be independently evaluated from the record.

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("Autologous Hematopoietic Stem Cell Transplant (HSC", "Allogeneic Hematopoietic Stem Cell Transplant (HSC")
n      <- c(20, 7)
events <- c(13, 6)
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  Autologous Hematopoietic Stem Cell Transplant (HSC  20  13  65.0  40.8  84.6  43.3  81.9  43.0  81.9
ARM  Allogeneic Hematopoietic Stem Cell Transplant (HSC  7  6  85.7  42.1  99.6  48.7  97.4  47.3  96.8

11. Multiplicity, Missing Data and Analysis Populations

Multiplicity arises when investigators conduct multiple statistical tests or evaluate multiple outcomes. Repeated testing can increase the chance of finding an apparently noteworthy result by chance, so a prespecified analysis may use a strategy to control that risk. The registry lists one outcome measure and two analyses, but does not report what the analyses were, whether they addressed distinct questions, or whether any multiplicity adjustment was planned or used. A multiplicity strategy is therefore not reported in the registry record.

Missing data can affect interpretation when participants lack outcome assessments or are lost to follow-up. For a time-to-event endpoint, rules for censoring and the assumptions behind them are important; for a fixed-time participant count, the handling of participants with unknown status also matters. The registry record does not report missing-data methods, the number of participants with missing primary outcome information, follow-up completeness, or the handling of incomplete observations. The reason for termination is also not reported in the registry record, and its relation to missingness or outcome availability cannot be inferred.

Analysis populations describe which participants are included in an analysis, such as all assigned participants or only those meeting particular treatment or follow-up criteria. The registry record does not define the analysis population for progression-free survival, explain exclusions, or provide participant flow between enrollment, transplantation, and follow-up. The adverse-event denominators are reported separately, but they do not establish the primary endpoint population. Without these details, it is not possible to assess whether the analysis population matched the intended comparison or how exclusions may have affected the result.

These omissions do not prove that methods were not used; they mean that the methods are not reported in the registry record. Clear reporting of multiplicity, missing-data handling, and analysis populations is necessary to understand how reported estimates were derived and how robust they may be.

12. Safety Results

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

Other (non-serious) adverse events

Participants with at least one non-serious event at or above the registry's 0% reporting threshold.

Most frequent non-serious adverse event terms

The safety record separates serious adverse events from other adverse events and reports the number of participants at risk and affected. In the autologous HSCT group, 20 participants are listed at risk for serious events and none are listed as affected; for other events, 20 are listed at risk and none are listed as affected. In the allogeneic HSCT group, 7 are listed at risk for serious events and none are listed as affected; for other events, 7 are listed at risk and one is listed as affected.

These are participant counts, not a comparison adjusted for observation time or differences between groups. The registry does not report event descriptions for the one other adverse event, and no serious adverse-event terms are listed. Zero affected participants in the posted serious-event counts means no serious event was recorded in those fields; it does not establish that no events occurred outside the reported categories or observation period. The record does not report the safety observation window, repeated-event totals, or a statistical comparison of adverse-event experience. The death fields are not reported in the registry record.

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

The registry record establishes that a non-randomized Phase II/III study was designed to compare two HSCT strategies in patients with recurrent follicular lymphoma and to assess lymphoma progression-free survival three years after transplantation. It also reports that the study was terminated and lists enrollment of 30. These registry entries describe the study and its intended question; they do not provide the primary outcome result.

No numerical progression-free survival estimates or comparative effect are reported in the registry record. There is therefore no basis in these data for stating which group had better or worse progression-free survival, how large any difference was, or how precisely it was estimated. The absence of a reported result is not evidence of equal outcomes, and it is not evidence that either strategy did or did not affect the endpoint.

The safety counts show zero participants affected by serious adverse events in each listed group, and one participant affected by other adverse events in the allogeneic group compared with none in the autologous group. These descriptive counts should be read alongside the reported group denominators and the missing detail about observation and event definitions. They are not a complete account of safety and do not answer the primary efficacy question.

The non-randomized assignment process is also central to interpretation. Since treatment allocation depended on matched-sibling availability, differences between groups could arise from factors associated with that availability rather than from the transplant strategy alone. Without reported baseline characteristics, analysis methods, and outcome estimates, the registry record cannot resolve that concern. The study's terminated status does not explain why it ended or what conclusions investigators reached.

Accordingly, the record supports a description of the intended comparison and limited posted safety counts, but not a quantitative conclusion about comparative progression-free survival or a causal treatment effect. Any stronger interpretation would require information not reported in the registry record.

14. Why This Trial Matters Statistically

This study is statistically instructive because it asks a comparative question while using non-random treatment assignment. The registry says treatment depended on availability of an HLA-matched sibling. That design feature makes it important to distinguish an observed difference between groups from an effect attributable to the transplant strategy. In general, a comparison can be clinically relevant while still being vulnerable to confounding when allocation is not randomized.

The study also illustrates why an endpoint name and assessment time are not enough to interpret an outcome. “Lymphoma Progression-free Survival” at three years identifies the broad target, but the registry record does not report the event definition, analysis method, result, or uncertainty. Statistical interpretation depends on those details, especially for outcomes involving event timing and incomplete follow-up.

Its safety reporting further shows the limits of small descriptive counts. The listed groups include 20 participants at risk in the autologous arm and 7 in the allogeneic arm. Zero serious-event participants and one participant with another event in the allogeneic group are useful as posted counts, but cannot by themselves establish comparative safety. Denominators, observation periods, event definitions, and repeated-event information all matter.

Finally, the record lists a terminated status without a reason and does not report the primary outcome estimates. This creates a practical lesson in registry interpretation: planned questions, posted counts, and analyzed results are distinct kinds of information. A study’s stated objective should not be mistaken for an observed finding, and a missing result should not be converted into a conclusion. Careful reading separates what the record documents from what remains uncertain.

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 principal limitation for interpreting this specific trial is that the registry record does not report numerical results for its primary endpoint. Without arm-specific progression-free survival estimates or a comparative estimate and its uncertainty, the central question cannot be quantified. The endpoint is described at three years after HSCT, but the record does not provide its operational definition or analysis method.

The non-randomized allocation is another important limitation. The brief description links assignment to availability of an HLA-matched sibling, and the record cautions that the arms are not a like-for-like control comparison. No baseline characteristics or adjustment methods are reported, so the extent to which the groups differed cannot be assessed. A causal interpretation would be especially uncertain without those details.

The registry lists enrollment of 30, while the adverse-event denominators are 20 for autologous HSCT and 7 for allogeneic HSCT. The participant flow and relationship between these counts are not reported. The record also does not report the number completing follow-up, missing outcome assessments, reasons for exclusion, or how outcomes were handled when follow-up was incomplete.

The study status is terminated, but the reason for termination is not reported. The record does not explain whether the planned enrollment or follow-up was completed, or how termination affected the availability of outcome data. It lists two analyses without reporting their methods or results, and it does not report a sample-size justification for the original trial. The planning assumptions described in the record are not evidence of the original design plan or observed power.

Finally, safety reporting is limited to participant counts, with no serious-event terms listed and no detail about the one other event. The observation window, event narratives, and broader safety analysis are not reported. These limitations leave both the primary comparison and the scope of the safety findings difficult to assess.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Autologous or Donor Stem Cell Transplantation in Treating Patients With Recurrent Non-Hodgkin's Lymphoma (BMT CTN 0202) — NCT00096460.
• Registry record last updated 2023-01-05; status last verified 2022-12.
• Results first posted 2012-09-17.
• 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 describes a non-randomized, parallel Phase II/III study comparing autologous and non-myeloablative allogeneic HSCT for chemosensitive follicular non-Hodgkin's lymphoma beyond a first complete or partial response. Assignment was described as depending on the availability of an HLA-matched sibling. The record lists enrollment of 30, a start date of 2004-08, a primary completion date of 2006-03, and a terminated status.

The primary outcome is lymphoma progression-free survival three years after HSCT. Numerical outcome results and details of the primary analysis are not reported in the registry record. Serious adverse-event counts list zero affected participants in both groups; other adverse-event counts list none in the autologous group and one in the allogeneic group. The record does not report the reason for termination, the primary analysis population, or the methods for missing data and multiplicity.