Tamoxifen for Progressive Transitional Cell Carcinoma Following Previous Chemotherapy Treatment: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Tamoxifen for Progressive Transitional Cell Carcinoma Following Previous Chemotherapy Treatment (NCT00710970), a na phase 2 study. The primary outcome is Number of Participants With Freedom From Progression of Cancer at 4 Months.

2. Clinical Question

3. Trial Design

This is a phase II pilot study with a single-group design and no masking. The registry lists allocation as not applicable. The study title identifies progressive transitional cell carcinoma following previous chemotherapy, and the summary describes metastatic bladder cancer as the setting. Tamoxifen is the listed intervention.

The registry summary describes a two-stage minimax design and planned enrollment of 25 subjects: 15 during stage 1 and 10 during stage 2. The registry lists enrollment as 28. These are different record entries: planned enrollment in the summary and the enrollment value recorded for the study. The record does not explain the difference, so the reason for it is not reported in the registry record.

The treatment plan specifies outpatient tamoxifen at 20 mg/day as a single daily oral dose. The arm description instead names 25mg tamoxifen, while the adverse-event group title says 20mg tamoxifen. The record does not reconcile these dose labels. The intervention name and treatment-plan detail are therefore not fully consistent with the arm label.

Clinical assessments were scheduled every 4 weeks, and imaging every 8 weeks or earlier if indicated. The summary says participants were followed monthly for clinical symptoms and signs of progression and underwent radiographic CT scans every 8 weeks to look for progression. The registry lists the study status as completed, with a start date of 2007-01 and a primary completion date of 2011-12. Detailed conduct, deviations from the planned design, and the stage-specific decision rules 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:

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 Number of Participants With Freedom From Progression of Cancer at 4 Months, measured over Estimated from date of starting therapy until 4 months but up to progression or death which ever comes first..

The primary endpoint is the number of participants with freedom from progression of cancer at 4 months. The registry defines freedom from progression as the period from the start of therapy to objective radiologic progression. The timeframe description says assessment is from the start of therapy until 4 months, but only up to progression or death, whichever comes first. The record does not further clarify how death was classified in the endpoint analysis.

The registry summary explains why the investigators selected disease stability rather than response rate as the primary focus. Tamoxifen was expected to act as a cytostatic, rather than cytotoxic, agent, so sustained stable disease was considered the more likely clinically important event. In that rationale, a response-rate endpoint would not capture the principal anticipated pattern of benefit as directly as freedom from progression.

The stated follow-up schedule included clinical assessments every 4 weeks and imaging every 8 weeks or earlier if indicated. Those intervals describe assessment timing, not the observed endpoint result. The registry record identifies the primary measure and its timeframe but does not report the number of participants who were free from progression at 4 months, an estimate of the proportion, or uncertainty around that result.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical interpretation begins with the kind of outcome being measured. The primary endpoint is a count of participants who meet a defined status at a specified assessment time: freedom from progression of cancer at 4 months. For a binary outcome, each participant is classified according to whether the endpoint condition is met. A count can describe how many meet the condition, while a proportion would relate that count to the participants assessed. The registry record reports the endpoint definition but not its observed count, denominator, proportion, or uncertainty estimate.

What does a confidence interval mean?

In general, a confidence interval expresses the uncertainty around an estimate under the assumptions of the statistical method used. A narrower interval indicates greater precision, while a wider interval indicates less precision. It does not remove possible bias from study design, outcome measurement, missing observations, or selection of participants. No confidence interval for the primary outcome is reported in the registry record, so its precision cannot be assessed from the posted results.

Why does the single-group design matter?

The study has one treatment group and no randomized comparator. A single-group outcome can describe what happened among participants receiving the intervention, but it does not directly estimate a contrast against a concurrent control. General differences between groups in a randomized comparison are protected, on average, by the random assignment process; that protection is not available for a comparison with an external expectation or historical experience. No external comparator or comparative result is reported in the registry record.

The registry says the study used a two-stage minimax design. In general, a two-stage design can allow a study to assess early information before proceeding to a later stage, according to prespecified rules. The particular thresholds, decision boundaries, and operating characteristics for this study are not reported in the registry record. The stated enrollment plan of 15 during stage 1 and 10 during stage 2 does not, by itself, reveal whether or how the stage decisions were applied.

What can a planning calculation tell a reader?

In general, sample-size calculations describe how much information a future study might need under specified assumptions about an effect, allocation, statistical significance, and method. They are planning illustrations, not observed power for a completed study. The calculation assumptions associated with this record specify a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; they also describe effects as fractions of the observed effect. Those are assumptions for planning illustrations, not evidence that this single-group trial had two randomized arms. The record does not provide the primary outcome result needed to judge those scenarios, nor does it report a sample-size justification for the trial’s own design.

In general, a normal approximation is a method for estimating the sampling behavior of a statistic using a normal distribution. Its suitability depends on the outcome and the amount of information available. A planning calculation that uses such an approximation may be useful as an illustration, but it does not establish that the completed trial’s endpoint analysis used that method. The statistical analysis plan for the trial is not reported in the registry record.

How do assessment timing and endpoint definition interact?

The registry summary defines progression by objective radiologic progression and describes CT imaging every 8 weeks, with earlier imaging if indicated. Clinical assessments were scheduled every 4 weeks. In general, when an event is detected at scheduled assessments, the recorded event time may reflect the assessment schedule rather than the exact biological time at which change began. This distinction can matter for time-to-event analyses. The registry record describes the assessment schedule but does not report the event-time data, the method used to assign event times, or whether a time-to-event model was used.

The primary measure is presented as a count of participants at 4 months, rather than a reported time-to-event estimate. The timeframe wording also refers to progression or death, whichever comes first, but does not fully describe endpoint classification for death. The analysis rules for participants with incomplete follow-up, missed imaging, or other unevaluable endpoint information are not reported in the registry record. These details are necessary for interpreting how the endpoint count would relate to everyone enrolled.

Finally, statistical significance and clinical importance are different concepts in general. A statistical test addresses compatibility of data with a specified statistical model or null hypothesis; it does not determine whether an outcome matters to patients or whether the result is free from bias. The record does not report a primary endpoint estimate, test, or confidence interval. Consequently, no statement about statistical evidence or the precision of the endpoint result can be made from the posted results.

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("Single Arm Receiving 25mg Tamoxifen")
n      <- c(20)
events <- c(20)
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  Single Arm Receiving 25mg Tamoxifen  20  20  100.0  83.2  100.0  83.9  100.0  83.9  99.9

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome measure and zero analyses. This describes the outcomes and analyses recorded in the registry; it does not establish that no analyses were performed. The statistical analysis plan, the analyses actually conducted, and any additional outcomes assessed are not reported in the registry record.

In general, multiplicity arises when several statistical tests or outcome comparisons are made. Repeated testing can increase the chance of finding an apparently notable result by chance, unless the analysis plan accounts for that testing. A single listed primary measure does not establish that only one statistical test was conducted, particularly when secondary outcomes, subgroup assessments, or stage-specific decisions are not fully described. No multiplicity adjustment or strategy for controlling multiple comparisons is reported in the registry record.

Missing data can affect an endpoint when participants lack an assessment or cannot be classified at the relevant time. General approaches may include defining who is evaluable, using an analysis population based on enrollment or treatment, or applying explicit assumptions about missing outcomes. The choice depends on the design and the reason information is missing. The registry record does not report missing endpoint counts, reasons for missingness, imputation procedures, or sensitivity analyses.

The record also does not identify an analysis population for the primary endpoint, such as whether the analysis included everyone enrolled or only those with an assessment at the relevant time. Without that information and the outcome count, the denominator and handling of incomplete follow-up cannot be evaluated. The planned two-stage design is described, but stage-specific analysis populations and stopping rules are not reported in the registry record.

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 2.8% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: acute renal failure (10.5%).

The registry lists an adverse-event group titled Single Arm Receiving 20mg Tamoxifen. For serious events, it records 19 participants at risk and 2 affected. For other events, it records 19 at risk and 18 affected. Acute Renal Failure appears among the top serious-event terms, with 10.5% recorded. These figures are event-summary entries, not the primary cancer-progression outcome.

The group title identifies the treatment label used for these entries, but the record has an inconsistency: the treatment plan specifies 20 mg/day, while the arm description names 25mg. The adverse-event group itself says 20mg. The record does not explain the discrepancy, so the dose represented by the arm description is uncertain.

In general, an affected-participant count indicates how many participants in the stated risk group were recorded as having an event category; it does not by itself describe event severity beyond the category label, timing, recurrence, or causal relationship to treatment. A serious adverse event is not necessarily an event caused by the intervention. The registry record does not report a causal assessment, event-level details, or an explanation of the denominator used for the 10.5% entry. The figures should therefore be read as recorded safety summaries, not as proof of treatment causation or as a complete account of safety.

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

The record establishes that a completed phase II pilot study evaluated tamoxifen in progressive transitional cell carcinoma following previous chemotherapy, with the primary question framed around freedom from progression at 4 months. It also gives the study’s single-group design, planned two-stage enrollment, treatment-plan dose, assessment schedule, and selected adverse-event figures. These registry entries describe the study’s intent and some registry entries; they do not establish the primary outcome.

The registry does not report how many participants were free from progression at 4 months, the denominator used for that result, or an estimate of uncertainty. Therefore, it is not possible to tell from the posted results how often the endpoint occurred or how precisely it was measured. A completed status does not fill that reporting gap. No conclusion about whether the study met its objective can be drawn from the primary outcome information recorded.

The single-group design also limits what a reported outcome could establish. Without a randomized comparator, an observed outcome would describe participants in the treated group, rather than isolate a treatment effect relative to another option. The design and missing outcome result together mean that the record does not support a comparative efficacy conclusion.

The safety entries should be interpreted separately from the primary endpoint. They list serious and other affected-participant counts and a serious-event term, but do not establish that tamoxifen caused those events. The inconsistency between the dose in the treatment plan and the arm label adds uncertainty to the record’s description of exposure.

In short, the registry provides context for the research question and selected study details, but the key observed result and its statistical precision are not reported in the registry record. The planned study rationale should not be mistaken for a finding, and the safety summaries should not be treated as evidence of causation.

14. Why This Trial Matters Statistically

This trial is statistically notable for the way its endpoint follows its stated biological rationale. The registry summary expected tamoxifen to be cytostatic and therefore emphasized sustained disease stability rather than regression. Choosing freedom from progression at 4 months makes the outcome question align with that stated rationale. The choice is a design decision; it does not indicate that stability was observed.

The study also illustrates the importance of separating a planned design from a reported analysis. The registry describes a two-stage minimax phase II design, including planned stage enrollment, while the posted record lists no analyses and gives no primary endpoint result. Without the stage-specific rules and outcome findings, readers cannot assess how the intended design was implemented or what evidence it generated.

The single-group structure is another key statistical feature. It is appropriate to distinguish descriptive information about an intervention group from a comparative treatment effect. A control group can provide a basis for a direct contrast, while a single-group design cannot make that randomized comparison. This distinction remains important even if an endpoint is clinically meaningful and carefully defined.

Finally, the record illustrates why completeness and internal consistency matter. The dose differs between the treatment-plan description and the arm label, and the endpoint result is not reported. Such gaps do not establish that the study was conducted incorrectly, but they limit what can be interpreted from its registry record. Statistical reasoning depends not only on the endpoint selected, but also on clear reporting of who was analyzed, what was observed, and how uncertainty was assessed.

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 main trial-specific limitation in the registry record is the absence of the observed primary endpoint result. Although the outcome is defined and the study is marked completed, the record does not report the endpoint count, denominator, estimate, or precision. The central study question therefore cannot be answered from the registered results.

The single-group design has no concurrent randomized comparator, so it cannot provide a randomized comparison of tamoxifen with another treatment or with no treatment. This affects the interpretation of any group outcome, even if that outcome were reported. The registry’s two-stage design description does not include the decision boundaries or stage-specific findings needed to understand how the design operated.

There is also a dose-label inconsistency. The treatment plan specifies 20 mg/day; the arm description names 25mg; and the adverse-event group is labelled 20mg. The record does not explain whether the arm wording is an error or reflects a different detail of treatment. That ambiguity should not be resolved by assumption.

Other trial-specific details needed for a full assessment are not reported in the registry record. These include eligibility criteria in sufficient detail, endpoint analysis population, missing-outcome handling, stage-specific analyses, statistical analysis plan, and the handling of death in the primary endpoint beyond the timeframe wording. Biomarker samples and future studies are mentioned in the summary, but corresponding results are not reported in the registry record. These reporting gaps limit assessment of both the endpoint and the study’s conduct.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Tamoxifen for Progressive Transitional Cell Carcinoma Following Previous Chemotherapy Treatment — NCT00710970.
• Registry record last updated 2022-01-24; status last verified 2022-01.
• Results first posted 2013-08-22.
• 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 identifies NCT00710970 as a completed phase II pilot study of tamoxifen for progressive transitional cell carcinoma following previous chemotherapy. It lists a single-group design, no masking, and enrollment of 28. The study summary describes a two-stage minimax plan with planned enrollment of 25, including 15 during stage 1 and 10 during stage 2.

The primary outcome is the number of participants with freedom from progression of cancer at 4 months. The registry summary explains that stability was the focus because the intended action was cytostatic rather than cytotoxic. The treatment plan specifies tamoxifen at 20 mg/day, while the arm description names 25mg. The primary outcome result and its statistical precision are not reported in the registry record.

The adverse-event record lists serious and other affected-participant counts and Acute Renal Failure at 10.5% among the top serious-event terms. These entries do not establish causation. Overall, the registry provides design and endpoint context, but not the primary finding needed to judge the stated research question.