Paclitaxel and Carboplatin or Bleomycin Sulfate, Etoposide Phosphate, and Cisplatin in Treating Patients With Advanced or Recurrent Sex Cord-Ovarian Stromal Tumors: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Paclitaxel and Carboplatin or Bleomycin Sulfate, Etoposide Phosphate, and Cisplatin in Treating Patients With Advanced or Recurrent Sex Cord-Ovarian Stromal Tumors (NCT01042522), a randomized phase 2 study. The primary outcome is Progression-free Survival (PFS).

2. Clinical Question

3. Trial Design

This is a randomized, open-label, parallel-group phase II trial sponsored by the GOG Foundation. The registry records enrollment of 63 participants. The posted primary outcome results include 31.0 participants in the paclitaxel-and-carboplatin arm and 32.0 in the bleomycin, etoposide, and cisplatin arm. No masking was used, so the treatments were not blinded according to the registry record.

The experimental regimens combine chemotherapy drugs. In the paclitaxel-and-carboplatin arm, both drugs are administered on day 1, with treatment repeating every 21 days for 6 courses if there is no disease progression or unacceptable toxicity. In the other arm, bleomycin sulfate is administered on day 1, while etoposide and cisplatin are administered on days 1–5; that regimen repeats every 21 days for 4 courses if there is no disease progression or unacceptable toxicity. These are the registry’s planned schedules; the extent to which participants completed treatment is not reported in the registry record.

The eligible disease group includes newly diagnosed advanced-stage or recurrent chemonaive ovarian sex cord-stromal tumors. The listed tumor types include granulosa cell tumors, Sertoli-Leydig cell tumors, gynandroblastoma, sex cord tumors with annular tubules, and other specified or unspecified sex cord-stromal tumors. The primary outcome population is identified as intent to treat, but details about how that population was defined or handled are not reported in the registry record.

The registry describes a median follow-up time of 48 months for the primary outcome. It also lists overall survival and tumor response rate as secondary outcomes. The registry status is recorded as UNKNOWN. The protocol’s sample-size justification, allocation concealment procedures, and detailed analysis plan 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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Intent to Treat

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 Progression-free Survival (PFS), measured over From start of treatment to time of progression or death, whichever occurs first. Median follow-up time was 48 months..

Progression-free survival measures the time from treatment start until disease progression or death, whichever occurs first. It combines two clinically meaningful events into a time-to-event outcome: a participant experiences an event when progression is identified or when death occurs before a recorded progression. Participants without a recorded event by the end of observation may contribute follow-up without having experienced the endpoint, depending on the analysis approach.

For this trial, tumor progression is assessed using RECIST 1.1. The registry defines progression as at least a 20% increase in the sum of the diameters of target lesions, using the smallest sum on study as the reference. The sum must also increase by at least 5 mm in absolute terms. The appearance of one or more new lesions also counts as progression.

The registry reports median progression-free survival, in months, for each treatment arm and gives a 95% confidence interval for each median. A median describes the time by which half of the relevant group has experienced the event, as estimated by the analysis. A time-to-event endpoint is useful when participants can have different lengths of follow-up and when the timing of progression or death matters, rather than only whether an event occurred by a single fixed time. The registry does not report a hazard ratio or another formal comparative estimate for this primary endpoint.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The main endpoint is time-to-event: the event is progression or death, whichever occurs first. The registry reports medians rather than a hazard ratio. A median time-to-event estimate locates the point at which half of the analyzed group is estimated to have experienced the event. It does not describe every part of the survival curve, and it does not directly quantify how the event rate compares between randomized groups over follow-up.

What does a confidence interval express?

A confidence interval conveys uncertainty in an estimate under the method used to calculate it. A narrower interval indicates greater precision; a wider interval indicates less precision. The primary outcome confidence intervals are broad, so the median estimates should be interpreted with caution. A confidence interval for each arm’s median is not a confidence interval for the difference between medians, and it does not replace a direct between-arm analysis. The registry does not report the method used to calculate these intervals.

Why is a hazard ratio relevant?

For time-to-event outcomes, a hazard ratio is one possible way to compare the event experience of randomized groups across follow-up. It is not the only possible method, and its interpretation depends on assumptions about how the relative event rates behave over time. The registry record does not report a hazard ratio for progression-free survival, its confidence interval, or the analysis method for a comparative estimate. It would therefore be inappropriate to infer such a result from the arm-specific medians. The record explicitly indicates that a two-arm comparison is missing or not estimable for the posted median endpoint.

How should overall survival be read?

Overall survival is defined in the registry as time from treatment start until death or the date of last contact, assessed up to 10 years. The posted values are counts of participants who died, not median survival times or a time-to-event comparison. A count-based contrast does not show when events occurred. In settings with variable follow-up, a time-to-event analysis can use information about event timing and censoring, whereas a simple count comparison does not account for those features in the same way.

The risk difference, confidence interval, and p-value stated for overall survival are recalculated, unadjusted comparisons from the posted summary counts. They are not sponsor-reported estimates. A risk difference expresses the difference between the observed event proportions in the two groups under the calculation used; its confidence interval represents uncertainty in that comparison. The interval includes values on both sides of zero, and the p-value is 0.384. This recalculation is exploratory and does not substitute for a prespecified sponsor analysis. No discrepancy between the posted results and the recalculation is identified in the registry record.

What does over-dispersion mean in general?

In general, over-dispersion occurs when observed variability is greater than a statistical model assumes. If it is ignored, standard errors can be too small and confidence intervals or tests can appear more certain than warranted. Over-dispersion is especially relevant to some count outcomes. The registry does not report an over-dispersion assessment or a count-model analysis for these outcomes, and the posted primary endpoint is time-to-event rather than a count endpoint.

What do the planning illustrations mean?

The overall-survival planning illustration uses the observed effect and states assumptions of a two-sided significance level of 0.05, equal allocation, and a normal approximation. It gives participants per arm for 80% power and participants per arm for 90% power at 100%, 75%, and 50% of the observed effect. These figures are planning illustrations based on the observed effect, not observed power and not evidence that the trial was designed with those assumptions. The trial’s own sample-size assumptions and justification are not reported in the registry record. Planning from an observed effect can be unstable, particularly when the observed estimate is imprecise; smaller assumed effects require larger planning samples. The illustration should not be treated as a retrospective measure of whether the trial could detect a true effect.

10. Multiplicity, Missing Data and Analysis Populations

The registry identifies progression-free survival as the primary outcome and lists overall survival and tumor response rate among secondary outcomes. It does not report how the family of outcomes was handled statistically. In particular, the multiplicity strategy, any hierarchy among secondary outcomes, and any adjustment of significance thresholds or confidence intervals are not reported in the registry record. Without those details, an unadjusted secondary comparison should be treated as exploratory rather than as confirmatory evidence.

The primary outcome population is identified as intent to treat. That label generally refers to analyzing participants according to randomized assignment, but the registry does not describe the exact analysis population, handling of participants who did not begin treatment, or approach to missing outcome data. The number of participants randomized, treated, and included in each analysis is not separately documented beyond the arm denominators posted with the outcome results. Reasons for missing data, withdrawal, loss to follow-up, and any sensitivity analyses are not reported in the registry record.

For time-to-event endpoints, details about censoring are important because they describe how participants without a recorded event contribute information. The registry defines the primary endpoint and gives a median follow-up time of 48 months, but does not report censoring rules, a survival-analysis method, or how incomplete follow-up was handled. It also does not report a formal comparative estimate for progression-free survival.

Randomization is recorded, but the method for sequence generation and allocation concealment is not reported in the registry record. Masking is recorded as none. The protocol’s analysis plan, interim-analysis procedures, sample-size justification, and handling of protocol deviations are not reported. These omissions limit assessment of prespecification, bias protection, and the robustness of the posted findings.

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.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: neutrophil count decreased (21.9%), febrile neutropenia (6.2%), anemia (3.2%), pain (3.2%), death nos (3.2%).

The registry reports serious adverse events among 6 of 31 participants at risk in the paclitaxel-and-carboplatin arm and 11 of 32 participants at risk in the bleomycin, etoposide, and cisplatin arm. It also reports other adverse events among 31 of 31 and 29 of 32 participants at risk, respectively. These are descriptive counts from the registry record. They do not, on their own, establish that a regimen caused an event or quantify comparative risk with an adjusted analysis.

The record lists serious adverse event terms including neutrophil count decreased at 21.9%, febrile neutropenia at 6.2%, anemia at 3.2%, pain at 3.2%, death NOS at 3.2%, and sinus bradycardia at 3.1%. These term-specific percentages should be read as reported; the registry does not give further detail in these figures about event timing, duration, severity grading, or whether a participant could contribute more than one event term. Death counts are also reported separately as 5 and 8 in the two arms. The adverse-event counts are not a substitute for the trial’s efficacy results, and the registry record does not provide an adjusted safety comparison.

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

The posted results describe a randomized comparison of two chemotherapy regimens in patients with advanced-stage or recurrent chemonaive ovarian sex cord-stromal tumors. For the primary outcome, the registry reports an estimated median progression-free survival for each arm and a confidence interval around each estimate. Those values indicate the observed estimates and their uncertainty, but the registry does not report a hazard ratio or another formal comparative analysis for progression-free survival. The medians alone do not establish that one regimen is better, worse, or equivalent.

The overall-survival results are counts of deaths, with an unadjusted recalculation that remains imprecise. They do not provide event timing or a sponsor-reported time-to-event comparison. The registry names tumor response rate as a secondary outcome, but its results are not reported in the registry record. These omissions mean that the posted outcomes do not provide a complete comparative account across all named endpoints.

The record also does not provide the detailed statistical plan, multiplicity approach, missing-data methods, or sample-size justification. Those details matter when judging whether estimates were prespecified, how uncertainty was handled, and how much weight to place on secondary findings. A randomized design helps structure a comparison, but it does not remove uncertainty from limited information or replace transparent reporting of the analysis.

These results are a description of the posted trial record, not medical advice. They do not establish whether either regimen should be chosen for an individual, and they do not determine the comparative clinical value of the regimens beyond what the reported estimates and their limitations support.

13. Why This Trial Matters Statistically

This trial is statistically notable because it compares two multi-drug regimens in a rare tumor group while reporting a time-to-event primary endpoint. In such a setting, the distinction between arm-specific medians and a direct comparative estimate is important. Medians can summarize the timing of events within each group, but without a hazard ratio or another formal comparison, they do not quantify the relative treatment effect across follow-up.

The confidence intervals are central to interpretation. The medians are accompanied by broad intervals, signaling considerable uncertainty in the estimated event times. A reader should not treat the central estimates as precise rankings, or infer a statistical contrast from the apparent difference between them. The absence of a primary comparative estimate further limits the statistical conclusion that can be drawn from the record.

The secondary overall-survival comparison illustrates another important point: a recalculation from posted counts can be informative as a descriptive check, but it is not interchangeable with a prespecified sponsor analysis. Its uncertainty and unadjusted status matter, particularly when multiple outcomes are named. The planning illustrations also demonstrate why an observed effect should not be mistaken for observed power or for the original trial’s design rationale. They are hypothetical planning quantities under stated assumptions.

Finally, interpretation depends on reporting completeness. The record identifies the population and endpoint, but does not describe important analytic choices such as censoring, missing-data handling, multiplicity, or the sample-size justification. Clear reporting of these elements is needed to evaluate precision and potential bias. The trial therefore offers useful descriptive information, while leaving substantial questions about comparative inference unanswered.

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 most direct limitation is that the registry reports arm-specific median progression-free survival but no formal between-arm estimate for the primary endpoint. The record states that a two-arm comparison for the median time endpoint is missing or not estimable. This prevents interpretation of the primary outcome as a quantified treatment contrast.

The primary estimates have broad confidence intervals, so their precision is limited. The median follow-up time is 48 months, but details on censoring and the number of participants remaining under observation over time are not reported in the registry record. Such information would help assess how much follow-up supports the later portions of the time-to-event estimates.

The registry lists tumor response rate as a secondary outcome, but its results are not reported in the registry record. Overall survival is posted as death counts, and the associated recalculation is unadjusted rather than a sponsor-reported time-to-event analysis. The record does not describe multiplicity control, missing-data handling, sensitivity analyses, or the detailed analysis population beyond identifying the primary population as intent to treat.

Additional trial details that could affect interpretation—including allocation concealment, the sample-size justification, interim-analysis procedures, and the statistical analysis plan—are not reported in the registry record. The open-label design is recorded, and the record does not explain how knowledge of treatment assignment was managed during outcome assessment. These limitations do not negate the posted observations, but they constrain the strength of comparative conclusions that can be drawn from them.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Paclitaxel and Carboplatin or Bleomycin Sulfate, Etoposide Phosphate, and Cisplatin in Treating Patients With Advanced or Recurrent Sex Cord-Ovarian Stromal Tumors — NCT01042522.
• Registry record last updated 2022-01-25; status last verified 2021-12.
• Results first posted 2022-01-25.
• 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 NCT01042522, a randomized, open-label, parallel-group phase II trial sponsored by the GOG Foundation. It compares paclitaxel and carboplatin with bleomycin sulfate, etoposide phosphate, and cisplatin in patients with newly diagnosed advanced-stage or recurrent chemonaive ovarian sex cord-stromal tumors. Enrollment is recorded as 63.

The primary outcome is progression-free survival, measured from treatment start to progression or death, whichever occurs first. The registry reports arm-specific median estimates and 95% confidence intervals, but no formal comparative estimate for this endpoint. Overall survival is listed as a secondary outcome and reported as death counts; tumor response rate is also named, but results are not reported in the registry record.

Key analysis details—including the multiplicity strategy, missing-data methods, and sample-size justification—are not reported in the registry record. The trial status is listed as UNKNOWN.