Paclitaxel in Treating Patients With Ovarian Stromal Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Paclitaxel in Treating Patients With Ovarian Stromal Cancer (NCT00006227), a na phase 2 study. The primary outcome is Probability of Complete Clinical Response.

2. Clinical Question

The study asked whether paclitaxel, given as second-line chemotherapy, was associated with complete clinical responses in participants with measurable malignant ovarian stromal tumors. The primary endpoint was the probability of complete clinical response, expressed as a percentage of participants and assessed using GOG RECIST criteria. The endpoint description specifies eligible and evaluable participants, with a timeframe of up to 5 years.

This setup can describe outcomes among participants receiving the study regimen, but it cannot directly compare those outcomes with a concurrent control group. The registry record does not report the primary response count, the response percentage, or its 80% confidence interval. It therefore does not permit a numerical estimate of the observed complete clinical response probability.

3. Trial Design

This is a phase II, single-group study of paclitaxel for ovarian stromal tumors as second-line therapy. The registry records 31 enrolled participants. It lists no allocation and no masking; the study model is single group. Accordingly, the design does not include a randomized or masked comparison between treatment groups.

Participants received paclitaxel intravenously over 3 hours on day 1. Treatment was scheduled every 21 days while there was no disease progression or unacceptable toxicity. The registry identifies Gynecologic Oncology Group as the sponsor. The recorded study start date is 2000-11-20, and the primary completion date is 2016-07-16. The overall study status is completed.

The primary endpoint population is described as eligible and evaluable. The registry does not report how many of the 31 enrolled participants were eligible and evaluable for this endpoint, or the rules used to determine evaluability. Enrollment and endpoint analysis populations should therefore not be treated as interchangeable.

Progression-free survival and overall survival are listed as secondary outcomes. The record lists 3 outcome measures and 0 analyses. It does not report a comparison group, a detailed statistical analysis plan, or the rationale for the enrollment target. The single-group structure means that the posted outcomes, if available, would describe participants in this study; they would not by themselves establish what would have happened to comparable participants under another treatment or no treatment.

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

Analysis population for the primary outcome, as defined in the registry: Eligible and evaluable

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 Probability of Complete Clinical Response, measured over Up to 5 years.

The primary endpoint is the probability of complete clinical response, reported as a percentage of participants. The registry describes the response as assessed using GOG RECIST criteria in eligible and evaluable participants with measurable malignant ovarian stromal tumors receiving paclitaxel as second-line chemotherapy. Its stated timeframe is up to 5 years.

A response proportion is a binary-outcome summary: each participant is classified according to whether the defined response occurred, and the proportion meeting that definition describes the frequency in the analysis population. General statistical interpretation: a confidence interval conveys uncertainty around an estimated proportion. The registry specifies an 80% confidence interval for this endpoint, but the response estimate and interval are not reported in the registry record.

Using a defined response endpoint makes the clinical outcome more explicit than a general description of improvement. However, the meaning of any response estimate depends on the population assessed, how response was determined, and how missing or unevaluable assessments were handled. The record identifies the criteria and the eligible-and-evaluable population, but does not report the response count, the denominator analyzed, assessment timing details beyond the stated timeframe, or the handling of missing assessments. No observed response rate can therefore be interpreted from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The study's primary endpoint is a percentage, so its outcome type is binary at the participant level: a participant either meets the complete clinical response definition or does not. The registry says that response is assessed using GOG RECIST criteria and that the endpoint population is eligible and evaluable participants. It does not report the participant-level classifications or the resulting response proportion.

What does a confidence interval convey?

General statistical explanation: a confidence interval gives a range of values compatible with an estimate under the method's assumptions. For a response percentage, the interval communicates uncertainty about the underlying response proportion, rather than uncertainty about whether any particular participant responded. Narrower intervals generally indicate greater precision, while wider intervals indicate greater uncertainty. The registry specifies an 80% confidence interval, but does not report its limits or the point estimate. Its width and the precision of the result therefore cannot be evaluated.

The confidence level is distinct from the response percentage. An 80% confidence interval is a statistical description of the interval procedure; it is not an 80% response rate. Nor does the confidence level alone tell readers whether an estimate is clinically important. Interpretation would require the actual estimate, the interval, the endpoint definition, and the analysis population.

Why does the single-group design matter?

General statistical explanation: a single-group study estimates outcomes within the participants who received the study intervention. A randomized comparison can also estimate a difference between groups, subject to its design and analysis. This study has one group and no allocation to a comparator, so there is no concurrent treatment contrast to interpret. A proportion observed in one group cannot by itself show what the outcome would have been under an alternative.

The registry record describes an intervention schedule of paclitaxel intravenously over 3 hours on day 1, repeated every 21 days in the absence of progression or unacceptable toxicity. It records 31 enrolled participants, but does not report the number included in the primary endpoint analysis. That distinction affects the denominator for a proportion and limits what can be inferred from enrollment alone.

What do the planning illustrations represent?

The stated planning assumptions describe illustrations based on the observed effect, not the study's own design. They use a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; the effect to detect is a stated fraction of the observed effect. For non-time-to-event outcomes, the illustrations express participants per arm. These assumptions do not describe this single-group trial, which has no two-arm allocation. They are planning illustrations, not evidence that the trial had a particular probability of detecting an effect, and they are not observed power.

General statistical explanation: sample-size planning asks how many participants would be needed under specified assumptions to target a chosen level of precision or detection capability. It is not a substitute for the observed outcome estimate and does not establish that a study's actual result is precise. Because the primary response estimate is not reported in the registry record, the trial's observed response effect cannot be assessed from the record. No planning illustration should be read as a trial finding.

What can the reported safety counts establish?

The safety display records participants at risk and affected for serious and other adverse events, along with deaths and selected serious-event terms. These are descriptive counts. General statistical explanation: safety counts need a clear population, observation period, event definition, and attribution context to support interpretation. The registry record does not report the timing of events, whether events were judged related to treatment, or additional exposure details. The counts alone cannot establish causation or permit a comparison with another regimen.

Overall, the methods information defines the primary outcome and identifies the intended confidence-interval level, but does not provide the outcome data or the details needed to reproduce its analysis. The analysis population size, missing-data approach, and response calculation are not reported in the registry 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("Treatment (Paclitaxel)")
n      <- c(31)
events <- c(1)
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  Treatment (Paclitaxel)  31  1  3.2  0.1  16.7  0.6  16.2  0.8  16.2

11. Multiplicity, Missing Data and Analysis Populations

The registry lists a primary outcome, probability of complete clinical response, and two secondary outcomes: progression-free survival and overall survival. It also records 3 outcome measures and 0 analyses. The record does not report whether or how statistical testing across multiple outcomes was addressed. No adjustment procedure, testing hierarchy, or interpretation plan for multiple comparisons is reported in the registry record.

General statistical explanation: when several outcomes or hypotheses are examined, the chance of at least one apparently notable finding can increase if each is considered separately. A prespecified testing strategy can help readers understand how multiple results are to be interpreted. Without a reported strategy, the registry does not establish whether the outcomes were intended to be confirmatory, exploratory, or handled in some other way.

The primary endpoint population is eligible and evaluable, while enrollment is 31. The number eligible and evaluable is not reported in the registry record. The record also does not report how missing response assessments, withdrawals, or participants who became unevaluable were handled, or whether an intention-to-treat analysis was used. These omissions prevent assessment of whether the endpoint denominator included all enrolled participants or a subset, and whether the analysis could be affected by missing outcome information.

General statistical explanation: missing outcome data can alter a proportion's interpretation when the likelihood of missingness is related to participants' outcomes or characteristics. Transparent reporting of the number and reasons for missing assessments, together with the analysis rules, helps readers evaluate that risk. The registry record does not provide those details, so no missing-data adjustment or sensitivity analysis can be assessed.

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: neutrophil count decreased (3.2%), white blood cell decreased (3.2%), muscle weakness lower limb (3.2%), hyperglycemia (3.2%), injection site reaction (3.2%).

The registry safety record lists 31 participants at risk for serious adverse events and 1 affected. It lists 31 at risk for other adverse events and 31 affected. It also records 16 deaths. These counts are descriptive; the registry record does not report the timing of the deaths or whether they were attributed to treatment.

The listed serious adverse event terms are neutrophil count decreased, white blood cell decreased, muscle weakness lower limb, hyperglycemia, injection site reaction, and febrile neutropenia. Each term is reported as 3.2%. The record does not give further event-level detail, such as onset, duration, severity grading, recurrence, or treatment attribution. The percentages should therefore be read as registry-reported figures, not as proof that paclitaxel caused the events.

General statistical explanation: an adverse-event count describes what was recorded in the stated safety population; it does not establish causation. A single-group study has no concurrent safety comparator, so these figures do not quantify a difference in risk between treatments. They also do not establish the safety profile beyond the participants and observation information recorded.

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

The registry record establishes that this was a completed phase II, single-group study of paclitaxel as second-line therapy for ovarian stromal tumors, with 31 participants enrolled. It defines complete clinical response as the primary endpoint, specifies GOG RECIST criteria, identifies an eligible-and-evaluable population, and states an 80% confidence interval and a timeframe of up to 5 years.

However, the primary response result is not reported in the registry record. There is no reported response count, percentage, confidence interval, or endpoint denominator. Consequently, the posted information does not show how often complete clinical response occurred or how precise an estimate might be. It also does not provide the results for progression-free survival or overall survival.

The design cannot support a direct comparison with an alternative treatment because it has no comparator group. Outcomes in a single group do not, on their own, estimate a treatment difference or establish that the intervention caused an observed outcome. The registry's safety counts likewise describe recorded events but do not establish their cause.

These limits do not mean that the study had no findings; they mean the registry record does not report the numerical efficacy results needed to evaluate them. A clinical or statistical conclusion about the primary endpoint would require the observed response data, the analyzed population, and the analysis details. In their absence, the appropriate interpretation is limited to the study's design, endpoint definition, and the descriptive safety information recorded.

14. Why This Trial Matters Statistically

This study illustrates why the outcome definition, analysis population, and result estimate need to be read together. The primary outcome is a participant-level response proportion, but the registry describes its population as eligible and evaluable without reporting that population's size. It records 31 enrolled participants, which is not necessarily the denominator used for the endpoint. Without the response count and denominator, the proportion cannot be checked or interpreted.

The record also highlights the distinction between estimating an outcome within one group and estimating a comparative effect. A single-group design can describe outcomes among participants treated under the study regimen, but has no concurrent control group against which to estimate a difference. That limitation shapes the statistical question before any calculation is considered.

The specified 80% confidence interval is another reminder that a point estimate and its precision are separate pieces of information. The registry record names the interval level but does not report the interval or the response estimate. Readers therefore cannot judge how much uncertainty surrounds the primary outcome. A stated analysis method or confidence level does not substitute for reporting the result.

Finally, the contrast between detailed endpoint wording and absent outcome estimates demonstrates the value of complete results reporting. The endpoint criteria and time horizon identify what was intended to be measured, while the missing analysis population and result prevent an assessment of what was observed. These are practical statistical issues in interpreting clinical trial records, not merely technical details.

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 trial-specific limitation is the single-group design. With no comparator, the study cannot directly estimate a difference between paclitaxel and another treatment. The registry records allocation as not applicable and masking as none, so there is no randomized or masked control comparison described.

The registry records 31 enrolled participants, but does not report how many were eligible and evaluable for the primary endpoint. It also does not report the complete clinical response count, percentage, or 80% confidence interval. This prevents assessment of both the observed response frequency and its precision. The results for the listed secondary outcomes, progression-free survival and overall survival, are also not reported in the registry record.

The record does not report the rules for determining endpoint evaluability, the handling of missing response assessments, or the numbers and reasons for exclusions from analysis. Those details matter because the primary endpoint is defined for an eligible-and-evaluable population rather than explicitly for all enrolled participants. A reader cannot determine how the analysis population was formed.

The listed conditions include adult type ovarian granulosa cell tumor, ovarian gynandroblastoma, ovarian Sertoli-Leydig cell tumor, ovarian sex cord tumor with annular tubules, and ovarian steroid cell tumor. The registry does not report subgroup-specific results or enough outcome data to assess whether results differed across these diagnoses. Nor does it report a detailed statistical analysis plan, multiplicity handling, or the rationale for the enrollment target.

Safety interpretation is limited by the absence of event timing, treatment attribution, and further clinical detail in the registry record. The reported counts do not permit a comparative safety assessment or establish causation.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Paclitaxel in Treating Patients With Ovarian Stromal Cancer — NCT00006227.
• Registry record last updated 2020-03-05; status last verified 2020-02.
• Results first posted 2020-03-05.
• 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

This completed phase II study evaluated paclitaxel as second-line therapy for ovarian stromal tumors in a single group. The registry records 31 enrolled participants and a regimen of intravenous paclitaxel over 3 hours on day 1, repeated every 21 days in the absence of progression or unacceptable toxicity.

The primary endpoint was the probability of complete clinical response, assessed using GOG RECIST criteria in eligible and evaluable participants, with an 80% confidence interval and a timeframe of up to 5 years. The response estimate, response count, confidence interval, and endpoint denominator are not reported in the registry record. Progression-free survival and overall survival are listed as secondary outcomes, with results not reported in the registry record.

The safety record lists 1 participant affected by a serious adverse event among 31 at risk, 31 affected by other adverse events among 31 at risk, and 16 deaths. These descriptive figures do not establish treatment causation or comparative risk.