Combination Chemotherapy and Radiation Therapy With/Without Surgery In Patients With Stage II/III Bladder Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Combination Chemotherapy and Radiation Therapy With/Without Surgery In Patients With Stage II/III Bladder Cancer (NCT00055601), a randomized phase 2 study. The primary outcome is Treatment Completion Rate.

2. Clinical Question

The central comparison was between two concurrent treatment strategies, not chemotherapy regimens in isolation. Both arms included twice-daily pelvic radiation therapy during induction, and both used tumor response to guide consolidation. Participants with a response of T0, Ta, or Tis were assigned further radiation therapy with their arm’s chemotherapy regimen; those with a response of at least T1 were assigned radical cystectomy. Both arms also included adjuvant gemcitabine, paclitaxel, and cisplatin.

The registry describes the trial as a randomized phase II study in stage II or stage III bladder cancer. It was intended to evaluate treatment completion as well as complete response after induction and bladder-intact survival. These endpoints address different aspects of the treatment strategy: whether treatment was completed, whether a complete response was recorded after induction, and whether participants were reported as alive with an intact bladder over the stated follow-up period.

The comparison therefore concerns the overall assigned regimens, including their shared radiation, response-guided consolidation, and adjuvant components. It does not isolate the contribution of any single drug, radiation, or surgery. The posted results describe observed percentages and uncertainty in the trial arms; they do not establish that one regimen is superior.

3. Trial Design

The registry record identifies NCT00055601 as a completed, randomized, parallel-group phase II trial sponsored by the Radiation Therapy Oncology Group. Masking is listed as none. Enrollment is recorded as 97. The trial began in 2002-12, and primary completion is recorded as 2010-10. The registry lists bladder cancer as the condition and stage II or stage III disease in its study description.

Participants were assigned to one of two regimens. One arm received twice-daily pelvic radiation therapy with paclitaxel and cisplatin during induction. The other received twice-daily pelvic radiation therapy with fluorouracil and cisplatin during induction. Consolidation depended on tumor response: response of T0, Ta, or Tis led to further radiation therapy with the assigned chemotherapy, while response of at least T1 led to radical cystectomy. Both arm descriptions specify adjuvant gemcitabine, paclitaxel, and cisplatin.

The primary endpoint was treatment completion, assessed from randomization to 11 weeks. The endpoint description defines completion as radiation therapy and chemotherapy delivered per protocol or within acceptable variation guidelines based on central review. The stated primary population is all eligible patients who started study treatment. The registry also reports complete response after induction, assessed from randomization to eight weeks, and bladder-intact survival over five years from randomization.

The record gives the primary endpoint’s planned testing approach: a two-sided binomial test with 87% power and a significance level of 0.05, testing a null completion rate of 70% against an alternative of 90%. It describes decision thresholds using 43 evaluable patients per arm. Other details of the protocol and statistical plan, including any interim analyses, 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: All eligible patients who started study treatment.

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.

Population: All eligible patients who started protocol treatment.

6. Primary Endpoint

The registry lists the primary outcome as Treatment Completion Rate, measured over From randomization to 11 weeks.

The primary endpoint is the percentage of participants completing radiation therapy and chemotherapy per protocol or within acceptable variation guidelines based on central review. Its timeframe is from randomization to 11 weeks, and its stated population is all eligible patients who started study treatment. This endpoint measures whether the assigned treatment course was delivered to the specified standard during the defined period.

Treatment completion is useful as a feasibility and treatment-delivery measure in a regimen that combines chemotherapy and radiation and includes response-guided consolidation. It is distinct from a tumor-response endpoint: completion records whether treatment was delivered, while complete response after induction records a clinical outcome following the induction period. Neither measure, by itself, captures every potential benefit or harm of the full treatment strategy.

The registry describes a planned two-sided binomial test for the primary endpoint. Its null completion rate was 70%, with an alternative rate of 90%, and the stated design used 87% power at a significance level of 0.05. The record also gives a threshold rule based on 43 evaluable patients per arm: more than 34 completing treatment would support rejection of the null in favor of a better completion rate, while fewer than 24 would support rejection in the worse direction. Results between those thresholds would not provide enough evidence to reject the null in either direction.

The posted arm estimates are percentages with 95% confidence intervals. They describe observed completion and the precision of those estimates; they do not, on their own, establish a treatment effect or a causal explanation for differences between arms.

7. Results Posted in the Registry

• Pelvic RT + Fluorouracil + Cisplatin: 53.2% (25/47) versus 67.4% (31/46) on control; risk difference -14.2 percentage points (95% CI -33.9 to 5.5), risk ratio 0.79 (0.56–1.10); unadjusted two-proportion z-test p = 0.162.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Complete Response After Induction

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Pelvic RT + Fluorouracil + Cisplatin: 61.7% (29/47) versus 71.7% (33/46) on control; risk difference -10.0 percentage points (95% CI -29.1 to 9.0), risk ratio 0.86 (0.64–1.15); unadjusted two-proportion z-test p = 0.305.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Pelvic RT + Fluorouracil + Cisplatin and the control. The interval gives the range of effects that remain compatible with the data.

Bladder-intact Survival Rate (5 Years)

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • Pelvic RT + Fluorouracil + Cisplatin: 70.2% (33/47) versus 67.4% (31/46) on control; risk difference 2.8 percentage points (95% CI -16.0 to 21.6), risk ratio 1.04 (0.79–1.37); unadjusted two-proportion z-test p = 0.769.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between Pelvic RT + Fluorouracil + Cisplatin and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes add context to the primary completion result by addressing response after induction and bladder-intact survival over five years. Across these outcomes, the observed arm percentages do not form a uniform pattern favoring one regimen: the complete-response estimate is higher in the paclitaxel and cisplatin arm, while the bladder-intact survival estimate is higher in the fluorouracil and cisplatin arm. The uncertainty intervals are broad, and the recalculated comparisons do not establish clear differences.

These outcomes relate to, but do not duplicate, the primary endpoint. Completion describes treatment delivery within the specified period. Complete response concerns the response after induction, and bladder-intact survival concerns a later outcome over the stated follow-up. A regimen’s completion percentage cannot be assumed to predict its later response or survival outcome from these aggregate results alone.

The registry lists no sponsor-reported analyses for the secondary outcomes. The displayed comparative p-values are unadjusted recalculations from posted summary statistics. Unadjusted secondary findings carry less weight because several outcomes are being considered, increasing the chance that an apparently notable result could arise by chance across the set. The registry record does not report a multiplicity adjustment or a prespecified hierarchy for interpreting the secondary endpoints, so they should be treated as descriptive and exploratory rather than as independent confirmatory evidence.

The overall secondary pattern therefore provides additional outcome descriptions but does not resolve the uncertainty in the primary comparison. The results do not establish that a difference in treatment completion caused later differences, nor do they show that the regimens have equivalent results across outcomes. Interpretation should account for each endpoint’s definition, timeframe, precision, and the lack of reported adjusted secondary analyses.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Complete Response After Induction
• Bladder-intact Survival Rate (5 Years)

9. Statistical Interpretation

10. Statistical Methods Explained

Binary outcomes and percentages

The primary endpoint and both secondary endpoints are reported as percentages of participants. For a binary outcome, each participant contributes to an outcome category such as completion or non-completion, complete response or no complete response, and bladder-intact survival status as defined by the registry. The percentage is an estimate of the proportion meeting the outcome in each arm. The reported arm estimates are accompanied by 95% confidence intervals, which communicate sampling uncertainty around those proportions.

The endpoint definitions and timeframes matter. Treatment completion is assessed from randomization to 11 weeks. Complete response after induction is assessed from randomization to eight weeks. Bladder-intact survival is reported over five years from randomization. These endpoints refer to different outcomes and follow-up periods; their estimates should not be treated as interchangeable.

What does a confidence interval express?

A confidence interval gives a range of values reasonably compatible with the observed data under the statistical method used. A narrower interval indicates greater precision; a wider interval indicates less precision. It is not a guarantee that the true value lies within the particular reported interval, and it does not describe the range of outcomes for individual participants. When comparing arms, overlapping arm-specific intervals are not themselves a formal test of the difference. The comparison estimate and its interval are more directly relevant to the uncertainty in the contrast.

How should a p-value be read?

A p-value describes how unusual the observed data, or data more extreme, would be under a specified null hypothesis and statistical model. It is not the probability that the null hypothesis is true, and it does not measure the size or clinical importance of a difference. The registry’s primary endpoint description specifies a two-sided binomial test. The posted comparison p-values are identified as unadjusted recalculations from the arm summaries; they are not listed as sponsor-reported analyses.

For the primary endpoint, the registry describes a null completion rate of 70% and an alternative of 90%, with a planned significance level of 0.05 and 87% power. It also states thresholds for 43 evaluable patients per arm: more than 34 completing treatment would indicate rejection of the null toward a better completion rate, and fewer than 24 would indicate rejection toward a worse rate. Results not meeting either threshold were to be interpreted as insufficient evidence to reject the null in either direction. These are design and decision-rule details in the record, not a report of an observed sponsor analysis.

What is a risk difference?

A risk difference expresses the difference between two arm-level outcome proportions. In the recalculated comparisons, the sign depends on the order of the arms: the fluorouracil and cisplatin arm is contrasted with the paclitaxel and cisplatin arm. A negative value therefore indicates a lower observed percentage in the former arm for that endpoint; a positive value indicates a higher percentage. The risk difference is an absolute contrast, unlike a risk ratio or odds ratio, which expresses a relative comparison. These measures can tell different parts of the same statistical story, and none alone establishes a causal mechanism.

The recalculated comparisons are simple, unadjusted comparisons from posted summary statistics. They do not account for covariates or other features of a full participant-level analysis. The registry record does not report adjusted estimates or sponsor-conducted comparative analyses for the posted endpoints. Because the discrepancy indicator is false, no discrepancy between these recalculations and a sponsor analysis is flagged in the record.

Why can results be uncertain?

Estimates based on finite groups vary from one sample to another, particularly when outcomes are binary. Confidence intervals represent that uncertainty. A comparison may have an estimate that points in one direction while its interval remains compatible with no difference and with differences in the other direction. That pattern should be described as imprecise evidence, not as proof that the arms are identical or that a difference has been established.

The trial has a phase II designation and the registry describes a planned test for treatment completion. The sample-size illustrations elsewhere are separate planning calculations based on observed effects; they are not observed power and should not be interpreted as the trial’s original design. The original design information that is available for the primary endpoint is the stated two-sided binomial test, its null and alternative rates, significance level, power, and threshold rule. Additional aspects of the analysis plan, including interim analysis procedures and multiplicity handling, are not reported in the registry record.

11. Confidence Intervals and Precision

The primary completion estimate was 67% in the paclitaxel and cisplatin arm, with a 95% confidence interval from 51% to 80%. The estimate in the fluorouracil and cisplatin arm was 53%, with a 95% confidence interval from 38% to 68%. These intervals span a substantial range of possible underlying completion percentages, so the arm estimates are not highly precise.

The recalculated risk difference is -0.142, and its 95% confidence interval runs from -0.339 to 0.055. Because that interval includes the no-difference value, the data are compatible with no difference as well as with effects in either direction. The unadjusted p-value is 0.162. The point estimate alone should not be read as a definitive finding of a difference.

For the secondary outcomes, the complete-response estimates were 72% and 62%, with 95% confidence intervals of 57% to 84% and 46% to 76%. For bladder-intact survival at five years, the estimates were 67% and 71%, with intervals of 53% to 81% and 57% to 84%. These arm-level intervals are also broad. The recalculated comparison intervals for both secondary outcomes span the no-difference value, indicating substantial uncertainty in the contrasts.

A 95% confidence interval describes uncertainty in an estimate under the method used; it is not a range containing 95% of participant outcomes. Precision depends on the amount of outcome information and its variability. The registry record does not provide enough detail to assess all sources of uncertainty, such as missing outcome handling or an adjusted analysis. The intervals are best read alongside the endpoint definitions, arm estimates, and limitations of the reported analysis.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size illustrations translate the observed contrasts into hypothetical future planning scenarios. For these binary endpoints, the listed figures are participants per arm, not total event counts. The calculations assume a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation. Each row considers an effect to detect equal to the stated fraction of the observed effect.

The 80% power column gives the estimated participants per arm for a future study to have an 80% chance of detecting the specified effect under those assumptions, if that effect is the true one and the analysis assumptions hold. The 90% power column gives the corresponding planning count for a 90% chance. These are planning illustrations, not observed power for this completed trial.

The rows use the full observed effect, 75% of the observed effect, and 50% of the observed effect. Smaller effects are harder to distinguish from random variation and therefore require more participants under the stated assumptions. The numbers can be especially large when the observed contrast is small, as in the bladder-intact survival comparison. Such calculations are sensitive to the effect chosen for planning; the observed effect in a trial may not be a reliable estimate of the effect expected in a future study.

These illustrations are separate from the primary endpoint design description in the registry. For treatment completion, that description gives a two-sided binomial test, 87% power, significance level 0.05, a null rate of 70%, an alternative rate of 90%, and decision thresholds based on 43 evaluable patients per arm. The planning illustrations do not replace those stated design details or establish that the original trial was sized using the observed effects.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.674; treatment proportion p₁ = 0.532; average p̄ = 0.603.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.6920 = 1.3562.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.6846 = 0.5762.
4. n = (1.3562 + 0.5762)² / (-0.1420)² = 185.2, rounded up to 186 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
p0 <- 0.673913043478261                          # control proportion
p1 <- 0.531914893617021                          # treatment proportion
n_per_arm <- function(power, frac = 1) {
  q1 <- p0 + (p1 - p0) * frac               # smaller effect = fraction of the observed difference
  pbar <- (p0 + q1) / 2
  z_b <- qnorm(power)
  ceiling(round((z_a * sqrt(2 * pbar * (1 - pbar)) + z_b * sqrt(p0 * (1 - p0) + q1 * (1 - q1)))^2 / (q1 - p0)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (unrounded n per arm)
cat("power.prop.test:", round(power.prop.test(p1 = p0, p2 = p1, power = 0.80)$n, 1), "\n")

# Simulation: how often does the z-test reject at the 80%-power sample size?
set.seed(55601)
n    <- n_per_arm(0.80)
reps <- 20000
x0 <- rbinom(reps, n, p0); x1 <- rbinom(reps, n, p1)
ph <- (x0 + x1) / (2 * n)
z  <- ((x1 - x0) / n) / sqrt(ph * (1 - ph) * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(z) > z_a, na.rm = TRUE), reps))

Output from running the code

100% of observed effect: n per arm = 186 (80% power), 248 (90% power)
 75% of observed effect: n per arm = 325 (80% power), 435 (90% power)
 50% of observed effect: n per arm = 718 (80% power), 961 (90% power)
power.prop.test: 185.2 
Simulated power at n = 186 per arm: 0.804 (20000 replicates)

The simulation draws many pairs of event counts at the planned sample size and counts how often the two-proportion z-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Multiplicity, Missing Data and Analysis Populations

The registry record lists one primary endpoint and two secondary endpoints. It does not report a multiplicity strategy for interpreting tests across these outcomes. When several outcomes are examined, the chance of at least one apparently unusual result can increase, even if there is no true difference. Adjustment methods or a prespecified testing hierarchy can address that issue, but neither is reported in the registry record. The unadjusted secondary comparisons should consequently be interpreted cautiously and should not be treated as stand-alone confirmatory findings.

The primary endpoint description gives a specific two-sided binomial test and decision thresholds. The record does not report whether additional analyses were planned for particular subgroups, whether interim analyses were conducted, or how deviations from the analysis plan were handled. Those details are not reported in the registry record.

The primary population is defined as all eligible patients who started study treatment. The outcome estimates list arm populations of 46.0 and 47.0, but the record does not explain the handling of missing outcome information, exclusions after randomization, or whether the population used for each secondary endpoint was defined differently. It also does not report imputation procedures or sensitivity analyses for missing data. These omissions limit assessment of how missingness could affect the estimates.

The registry gives the planned primary thresholds in terms of 43 evaluable patients per arm, while the posted arm summaries include their own denominators. The record does not provide a narrative explaining the relationship between those planning thresholds and the populations analyzed, or a sponsor-reported analysis applying the decision rule. This does not invalidate the posted descriptive results, but it prevents a full assessment of the planned analysis from the registry record alone.

The comparisons described as recalculated are unadjusted and based on posted summary statistics. No adjusted results are reported. The record therefore does not permit evaluation of whether adjustment for participant characteristics or other protocol-defined factors would change the estimates. These are limitations in the available statistical reporting, rather than evidence that any particular analytical choice was made.

15. 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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: neutropenia (58.7%), platelet count decreased (34.8%), leukopenia nos (21.3%), lymphopenia (21.3%), hyperglycemia nos (17.4%).

The registry reports serious adverse event figures by arm. In the paclitaxel and cisplatin arm, 43 participants were reported as affected by serious adverse events, with 46 at risk. In the fluorouracil and cisplatin arm, 39 were reported as affected, with 47 at risk. For other adverse events, the figures are 46 affected out of 46 at risk in the first arm and 47 out of 47 in the second arm. The registry does not report death counts.

The serious adverse event terms listed include neutropenia (58.7%), platelet count decreased (34.8%), leukopenia NOS (21.3%), lymphopenia (21.3%), hyperglycemia NOS (17.4%), and packed red blood cell transfusion (13.0%). These are registry-listed terms and percentages; the record excerpt does not specify their arm-specific distribution. They should not be interpreted as comparative risks between arms.

These figures are descriptive. They do not provide a complete account of severity, duration, timing, attribution, or the statistical uncertainty around between-arm differences. The registry record does not report deaths, so the absence of a listed death count should not be read as evidence that no deaths occurred.

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

The posted results describe treatment completion and two secondary outcomes in a randomized phase II comparison of regimens that shared pelvic radiation, response-guided consolidation, and adjuvant chemotherapy. For treatment completion, the observed percentage was higher in the paclitaxel and cisplatin arm than in the fluorouracil and cisplatin arm. The unadjusted recalculated comparison remains uncertain, with its interval including the no-difference value and an unadjusted p-value of 0.162.

This does not establish that the first regimen produces better completion, and it does not show that the regimens are equivalent. A result that does not provide strong evidence against no difference is not proof that no meaningful difference exists. The secondary outcomes likewise do not settle the comparison: their estimates vary in direction and have substantial uncertainty. No sponsor-reported comparative analyses are listed for those outcomes.

The findings also do not isolate the effect of a particular chemotherapy drug, radiation, or surgery. The treatment strategies differed in the chemotherapy used during induction and consolidation, while sharing other components and including response-guided surgery. Aggregate arm results cannot determine which component accounts for an observed outcome pattern.

The registry record is a source of endpoint definitions, arm estimates, and selected safety figures, but it does not report all analysis details needed for a complete assessment. In particular, missing-data handling, adjusted analyses, multiplicity procedures, and interim analyses are not reported in the registry record. Conclusions should therefore remain close to the descriptive results and their uncertainty, rather than extending to broad claims about comparative effectiveness or safety.

17. Why This Trial Matters Statistically

This trial illustrates why a treatment percentage should be read together with its confidence interval and the design that produced it. The completion estimates differ in their observed values, but the uncertainty in the arm comparison is substantial. A point estimate supplies direction and magnitude; the interval indicates how much uncertainty surrounds that estimate. Reading only the percentages could overstate the evidence for a difference.

The registry also distinguishes treatment delivery from clinical outcomes. Completion, complete response after induction, and bladder-intact survival measure different parts of a complex treatment strategy. Their results need not move in the same direction, and an outcome in one timeframe does not explain another without additional analysis.

Another statistical lesson is the difference between a protocol’s planned decision rule and a recalculation from posted summary data. The record describes a primary binomial test and thresholds, while the comparative values accompanying the results are unadjusted recalculations. Keeping those sources and purposes distinct prevents a planning assumption or exploratory comparison from being mistaken for a sponsor-reported conclusion.

Finally, the secondary outcomes show why multiple endpoints require careful interpretation. Without a reported multiplicity plan and sponsor analyses, those outcomes add context but offer limited confirmatory evidence. The trial is most informative when its results are presented with their definitions, timeframes, uncertainty, and reporting limitations intact.

18. 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.
• Participant counts were reconstructed from posted percentages and arm sizes, so small rounding differences are possible.

The record does not report how missing outcome data were handled, whether every randomized participant was included in each endpoint analysis, or whether sensitivity analyses were conducted. Those details matter because the primary population is defined as eligible participants who started treatment, while the posted outcome denominators are stated separately. The registry does not explain all population and denominator decisions.

The posted comparative estimates are unadjusted recalculations from summary statistics, and no sponsor-reported comparative analyses are listed. The registry record does not report adjusted estimates, multiplicity procedures, interim analyses, or a hierarchy for secondary endpoint testing. This limits the strength of conclusions that can be drawn from the secondary comparisons and prevents a full reconstruction of the analysis plan.

The treatment strategies include several components: induction chemotherapy and radiation, response-guided consolidation with further radiation or radical cystectomy, and adjuvant chemotherapy. Consequently, arm-level comparisons do not identify the separate contribution of each component. The registry record also does not provide further detail about the handling of protocol deviations beyond the primary endpoint’s stated completion definition.

The posted confidence intervals are broad, particularly for the arm comparisons, and the sample-size planning illustrations are based on observed effects rather than a future effect established independently. The illustrations are not evidence of observed power. Finally, the adverse-event summary does not report deaths and does not provide an arm-specific breakdown for the listed serious adverse event terms in the registry record. Safety interpretation is therefore limited to the descriptive figures that are reported.

19. Related Tutorials

20. Related Statistical Calculators

21. Sources

• ClinicalTrials.gov: Combination Chemotherapy and Radiation Therapy With/Without Surgery In Patients With Stage II/III Bladder Cancer — NCT00055601.
• Registry record last updated 2018-06-15; status last verified 2018-05.
• Results first posted 2016-08-10.
• 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.

22. Record Summary

NCT00055601 is a completed, randomized, parallel-group phase II trial with no masking, sponsored by the Radiation Therapy Oncology Group. It evaluated pelvic radiation therapy with either paclitaxel and cisplatin or fluorouracil and cisplatin, using response-guided consolidation and adjuvant gemcitabine, paclitaxel, and cisplatin in both arms. Enrollment is recorded as 97.

The primary endpoint was treatment completion from randomization to 11 weeks. Posted estimates were 67% and 53%, with 95% confidence intervals of 51% to 80% and 38% to 68%. The registry also reports complete response after induction and bladder-intact survival at five years. The arm comparisons are uncertain, and the secondary comparisons are unadjusted recalculations without sponsor-reported analyses listed.

The record describes the primary endpoint’s planned binomial test and decision thresholds, but does not report several analysis details, including missing-data handling and multiplicity procedures. Results should be interpreted as descriptive estimates with uncertainty, not as proof of superiority or equivalence.