Safety and Feasibility Study of Combination of State of Art Chemoimmunotherapy, Intensive Central Nervous System Prophylaxis and Scrotal Irradiation to Treat Primary Diffuse Large B-cell Lymphoma of Testis: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Safety and Feasibility Study of Combination of State of Art Chemoimmunotherapy, Intensive Central Nervous System Prophylaxis and Scrotal Irradiation to Treat Primary Diffuse Large B-cell Lymphoma of Testis (NCT00945724), a na phase 2 study. The primary outcome is Adverse Events Assessment.

2. Clinical Question

The clinical question is therefore about whether this treatment program could be delivered and what adverse events were recorded, rather than whether it outperformed another regimen. The posted safety counts describe participants with serious and other adverse events in the listed treatment groups. They do not establish that a specific treatment component caused an event, nor do they provide a controlled estimate of treatment benefit.

Secondary outcomes included five-year cumulative incidence of progression, five-year progression-free survival, and five-year overall survival. The registry record does not report numerical results for those outcomes in the registry record for this analysis. The adverse-event counts should therefore be read as safety descriptions, not as a complete account of the study’s longer-term disease outcomes.

3. Trial Design

This was a phase II, single-group, non-comparative study sponsored by the International Extranodal Lymphoma Study Group. The registry record marks the study completed and lists an enrollment of 54. The recorded start date is 2009-09-27, and primary completion is listed as 2019-06. The record does not describe a randomized allocation; allocation is marked not applicable.

The treatment program combined R-CHOP with central nervous system prophylaxis and radiotherapy. The registry describes R-CHOP treatment during weeks 1–15, intrathecal liposomal cytarabine on day 0 of cycles 2, 3, 4 and 5, and high-dose methotrexate during weeks 18–22. The brief summary describes loco-regional radiotherapy after the drug regimen, with radiotherapy starting from week 25. These protocol descriptions indicate treatment components delivered at different times, not separate randomized interventions assigned for comparison.

The primary outcome is adverse-event assessment, with the stated measure being the number of patients who withdrew treatment due to an adverse event. Its timeframe varies by treatment group and treatment period: up to week 22 for the R-CHOP, Depocyte, methotrexate group; up to 15 weeks for the R-CHOP plus liposomal cytarabine group; and weeks 18–22 for the high-dose methotrexate group. The record does not give a separate withdrawal result in the listed safety counts.

Three secondary outcomes are named: five-year cumulative incidence of progression, five-year progression-free survival, and five-year overall survival. Naming an outcome does not itself establish that a result was posted. Numerical estimates and analyses for these outcomes are not reported in the registry record. The listed safety groups may overlap as participants moved through treatment, so their counts should not be interpreted as independent comparison arms.

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:

Analysis population for the primary outcome, as defined in the registry: Weeks 1 -15 All patients treated with 6 cycles of R-CHOP (CHOP21) on days 0/1 to 5, to be repeated every 21 days Intratecal (IT) Chemotherapy: liposomal cytarabine on day 0 of cycles 2, 3, 4 and 5 of R-CHOP Weeks 18 - 22 High Dose (HD) Methotrexate (MTX) Days 0 - 4 of two 14 days cycles From Week 25 Scrotal prophylactic radio therapy (RT) to the contralateral testis.

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 Adverse Events Assessment, measured over From treatment start until the last drug administration, up to week 22 for the 'R-CHOP, Depocyte, Methotrexate' Group, up to 15 weeks (Weeks 1-15) for the 'R-CHOP + Lyposomal Cytarabine' Group, and from week 18-22 for the 'HD-MTX' Group.

The primary outcome is titled “Adverse Events Assessment.” Its stated measure is the number of patients who withdrew treatment due to an adverse event, with participants as the unit. This is a count-based, binary outcome at the participant level: a participant either meets the specified withdrawal criterion or does not. It is not a count of every adverse event experienced, and it is not the same as a severity score or an estimate of treatment efficacy.

A withdrawal endpoint can be useful in a feasibility and toxicity study because it captures an adverse event serious enough, in the context of the study, to lead to stopping treatment. It addresses treatment delivery as well as safety: a complex regimen may be difficult to complete even when the study also records events that do not result in withdrawal. That general distinction is important when interpreting this record, which includes separate counts for participants with serious and other adverse events.

The registry describes different assessment periods for the listed treatment groups, extending up to week 22, up to 15 weeks, or weeks 18–22. Comparisons of withdrawal counts across periods would need to account for these different observation windows and the treatment sequence. The registry record does not report a distinct withdrawal count among the safety figures. Those figures therefore cannot be substituted for the primary endpoint result, and the primary outcome’s numerical result is not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does a participant count represent?

A participant-level event count records how many participants met a defined event criterion. It differs from an event count, because a participant can experience more than one event. The registry identifies the outcome type as participants with an event and gives counts at risk and affected for the safety group entries. The serious-event and other-event figures should therefore be read as participant counts, not as totals of all episodes.

The primary endpoint has a narrower definition than the general adverse-event counts: it is the number of patients who withdrew treatment due to an adverse event. A participant with an adverse event does not necessarily meet that withdrawal definition. The withdrawal result is not separately reported in the registry record. It would be inappropriate to treat the serious-event counts, other-event counts, or death count as a substitute for that endpoint.

Why does the study design matter?

A single-group, non-comparative study can describe what occurred among participants receiving the regimen, but it does not provide a randomized control group for estimating what would have happened under another treatment. In a randomized comparison, treatment assignment helps make groups comparable in expectation. That protection is absent. The registry explicitly notes that the listed arms are not a like-for-like control comparison.

The named groups correspond to treatment components or periods within the regimen. The R-CHOP plus liposomal cytarabine and high-dose methotrexate counts should not be treated as independent groups that started follow-up under the same conditions. Participants may have proceeded from earlier treatment to later treatment, and the record lists different numbers at risk for the relevant periods. A descriptive contrast between these counts cannot isolate the effect of a drug or component.

What does uncertainty mean?

In general, a confidence interval expresses the range of estimates compatible with a statistical model and the observed data, reflecting sampling uncertainty. It is not a guarantee that the true value lies inside a particular interval. No confidence intervals are reported in the registry information. Without them, the precision of the posted event counts as estimates for a wider population is not quantified.

A p-value is, in general, a measure of how incompatible data are with a specified statistical null model, under that model’s assumptions. It is not a measure of the probability that a treatment works or that a result occurred by chance. No p-values or inferential analysis estimates are reported in the registry record. Because there is no randomized comparator, a p-value would not by itself resolve the design’s limitations or establish causation.

How should event percentages be read?

The serious-event terms are reported with percentages, including febrile neutropenia at 7.4% and pneumonia at 3.7%. Each percentage is a registry-reported value for a named term. Without a term-specific denominator or an explanation of the calculation in the record, it should be quoted as reported rather than reverse-engineered into a participant count. Percentages for separate terms cannot be added to obtain the proportion with any serious event, because participants may have experienced multiple terms.

In general, adverse-event reporting can distinguish event severity, frequency, relatedness, and whether an event led to treatment discontinuation. These are different attributes. The record lists serious and other affected-participant counts, named serious-event terms, and a primary endpoint defined by treatment withdrawal. It does not provide enough detail in the registry entries to equate those categories or to infer relatedness for individual events.

What can planning illustrations tell readers?

In general, a sample-size illustration describes how many participants might be needed under stated assumptions to detect a specified effect with a chosen significance level and power. Such an illustration is planning information, not an observed property of a completed study. It is not “observed power,” and it cannot replace uncertainty intervals or a prespecified analysis.

The registry record describes its planning illustrations as recalculations based on the observed effect, using a two-sided significance level of 0.05, equal allocation, and a normal approximation. It states that the target effect is a specified fraction of the observed effect. For time-to-event outcomes, the illustration concerns the total number of events; for other outcomes, it concerns participants per arm. These assumptions are not reported as the trial’s own design justification. The registry record does not report the sample-size justification used when the trial was planned, so the illustrations should not be presented as evidence that the study had adequate power.

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("R-CHOP, Depocyte, Methotrexate", "R-CHOP + Lyposomal Cytarabine", "HD-MTX")
n      <- c(54, 54, 48)
events <- c(6, 3, 3)
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  R-CHOP, Depocyte, Methotrexate  54  6  11.1  4.2  22.6  5.2  22.2  5.3  22.2
ARM  R-CHOP + Lyposomal Cytarabine  54  3  5.6  1.2  15.4  1.9  15.1  2.0  15.1
ARM  HD-MTX  48  3  6.2  1.3  17.2  2.1  16.8  2.3  16.9

11. Multiplicity, Missing Data and Analysis Populations

The registry names several outcomes: the primary adverse-event assessment and secondary outcomes for five-year cumulative incidence of progression, five-year progression-free survival, and five-year overall survival. When a study assesses multiple outcomes, the chance of at least one apparently notable result can increase if many statistical tests are conducted without an appropriate plan. In general, multiplicity methods can address this issue, but their selection depends on the prespecified hypotheses and analysis strategy.

The registry record reports no analysis estimates for these outcomes. A multiplicity adjustment, testing hierarchy, or other approach for controlling false-positive findings is not reported in the registry record. The statistical analysis plan, including any planned interim analyses, is also not reported in the registry record. No conclusions about whether these procedures were used should be inferred from the absence of posted analysis estimates.

Missing-data handling is not reported in the registry record. The available information does not explain how participants with incomplete follow-up, missing outcome measurements, or treatment discontinuation were handled in analyses. The treatment-withdrawal endpoint is specifically about stopping treatment because of an adverse event, but the record does not provide a separate withdrawal count. Treatment discontinuation and missing outcome data are not interchangeable concepts; each requires its own definition and analysis approach.

The analysis populations are not fully described beyond the safety population and the participant counts at risk for the listed groups. The record does not explain in the registry entries how the safety population was defined or how participants were included in analyses of the named secondary outcomes. It also does not describe an intention-to-treat population or a per-protocol population. These omissions limit assessment of how the analyzed participants relate to enrollment and to the treatment sequence.

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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: febrile neutropenia (7.4%), pneumonia (3.7%), intracranial hemorrhage (2.1%), mucositis (2.1%), renal failure (2.1%).

The safety population lists 54 participants at risk, with 19 affected in the serious-event field and 47 affected in the other-event field. The R-CHOP plus liposomal cytarabine entry lists 54 at risk, with 17 affected for serious events and 47 for other events. The high-dose methotrexate entry lists 48 at risk, with 3 affected for serious events and 17 for other events. The record also lists 12 deaths in the safety population.

These counts are descriptive. The group entries concern components or periods within a treatment program and are not independent randomized arms. The safety information does not establish that a particular treatment caused an event or death. The record does not state that the deaths were treatment-related.

The listed serious-event percentages are event-term figures, not a complete summary of all safety outcomes. Febrile neutropenia is listed at 7.4%, pneumonia at 3.7%, intracranial hemorrhage, mucositis, and renal failure at 2.1% each, and “Increase of neutrophilis” at 1.9%. The record does not report the term-specific denominators in the registry record. These percentages should not be converted into counts, summed, or interpreted as the proportion with any serious event.

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

The registry record documents a phase II study of a combined treatment program and provides participant counts for serious and other adverse events. It also lists serious-event terms with percentages. These are useful descriptive observations about the safety information recorded for the study population and treatment periods. They do not, on their own, quantify a causal effect of the regimen or any individual component.

The study is explicitly non-comparative and single-group, with no randomized control group. As a result, the record cannot support a direct estimate of how safety or outcomes would differ under an alternative treatment. The entries for R-CHOP with liposomal cytarabine and high-dose methotrexate are not like-for-like comparison groups. Apparent differences in their counts should not be presented as evidence that one component is safer or more harmful.

The primary endpoint is defined as treatment withdrawal due to an adverse event, but its numerical result is not reported in the registry record. The listed serious and other adverse-event counts do not answer that specific question. The named longer-term outcomes—cumulative incidence of progression, progression-free survival, and overall survival—also have no numerical estimates reported in the registry information.

The record therefore supports a limited conclusion: adverse events were recorded in the treatment program, with participant counts and selected serious-event percentages reported. It does not establish comparative benefit, comparative safety, or treatment-related causation. It also does not supply the inferential estimates needed to characterize statistical precision. Readers should keep the distinction between a descriptive safety record and an estimate of treatment effect in view.

14. Why This Trial Matters Statistically

This study raises a statistical question common to complex treatment programs: how to describe safety when participants receive multiple components in sequence. The registry lists R-CHOP, intrathecal liposomal cytarabine, high-dose methotrexate, and loco-regional radiotherapy as parts of the treatment program. Adverse events recorded during different components can be clinically important, but assigning an event to a particular component requires information and an analysis that the posted counts do not provide.

The non-comparative design also clarifies what phase II safety data can and cannot answer. Participant counts can show what was recorded among those treated, while the absence of a randomized comparator prevents a controlled estimate of differences from another regimen. The treatment-period entries are not substitutes for randomized arms. This distinction is especially important when readers encounter counts with different numbers at risk across the listed periods.

Endpoint definition matters as well. The primary outcome concerns withdrawal because of an adverse event, whereas the safety entries summarize participants affected by serious and other events. Those measures answer different questions. Without a separately reported withdrawal result, the stated primary safety question cannot be resolved from the counts alone.

Finally, the registry names longer-term outcomes but does not report their numerical estimates in the information. A clear separation between outcomes listed, outcomes measured, and results posted is essential for interpreting clinical-trial records. The study is statistically informative as a description of a complex regimen’s recorded safety experience, but the available record does not support comparative or causal conclusions.

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 central limitation is the absence of a randomized comparison. The study is described as a single-group, non-comparative phase II study, and the registry warns that the listed arms are not a like-for-like control comparison. Consequently, the safety counts cannot isolate the contribution of R-CHOP, liposomal cytarabine, methotrexate, or radiotherapy, and they cannot estimate a comparative treatment effect.

The treatment groups represent different components or periods, with different numbers at risk and different assessment windows. Participants could move through the treatment sequence, so the entries should not be treated as mutually exclusive groups. The record does not explain further how participants were assigned to each safety entry or how exposure time was handled.

The primary endpoint is defined as withdrawal due to an adverse event, but its result is not separately reported in the registry information. The serious and other adverse-event counts do not replace that endpoint. The registry also lists three secondary outcomes but does not report numerical estimates for them in the registry entries.

Details needed to assess the statistical analysis are not reported in the registry record: the analysis plan, missing-data methods, analysis populations beyond the listed safety counts, and any multiplicity approach. Term-specific denominators for the serious-event percentages are also not reported in the registry entries. The reported death count is not accompanied by attribution or a stated follow-up window. These limitations restrict interpretation of precision, completeness, and causal meaning.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Safety and Feasibility Study of Combination of State of Art Chemoimmunotherapy, Intensive Central Nervous System Prophylaxis and Scrotal Irradiation to Treat Primary Diffuse Large B-cell Lymphoma of Testis — NCT00945724.
• Registry record last updated 2025-05-30; status last verified 2025-05.
• Results first posted 2025-05-30.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

The registry record describes a completed phase II, single-group, non-comparative study sponsored by the International Extranodal Lymphoma Study Group. Enrollment was 54. The study evaluated R-CHOP with intensive central nervous system prophylaxis and scrotal irradiation in primary testicular diffuse large B-cell lymphoma.

The primary outcome was adverse-event assessment, defined as the number of patients who withdrew treatment due to an adverse event. The record lists participant counts affected by serious and other adverse events for the safety population and treatment-period groups, as well as selected serious-event terms and percentages. It also records 12 deaths in the safety population.

The primary withdrawal result and numerical estimates for the named secondary outcomes are not reported in the registry information. The listed groups are not randomized comparators, and the safety counts support descriptive interpretation only, not a causal or comparative conclusion.