Neoadjuvant Chemotherapy for Patients With Squamous Cell Carcinoma of the Penis: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Neoadjuvant Chemotherapy for Patients With Squamous Cell Carcinoma of the Penis (NCT00512096), a non-randomized phase 2 study. The primary outcome is Number of Participants With Pathologic Complete Remission (pCR).

2. Clinical Question

3. Trial Design

This was a phase II study of neoadjuvant chemotherapy before extirpative surgery for penile squamous cell carcinoma. The registry records a single-group model, non-randomized allocation and no masking. These design features describe a study in which the listed regimen was evaluated without a randomized control group or masking. The record lists an enrollment of 30 and a completed status. The start is recorded as 1999-08 and primary completion as 2010-08.

The regimen consisted of cisplatin, ifosfamide and paclitaxel. The record describes cisplatin at 25 mg/m^2 intravenously on days 1-3, ifosfamide at 1200 mg/m^2 intravenously on days 1-3, and paclitaxel at 175 mg/m^2 intravenously on day 1. The primary endpoint timeframe refers to restaging with the second and fourth 21-day cycles followed by surgery. The record does not report further details about treatment modifications, the number of cycles received, or the timing of surgery for individual participants.

The stated primary objective was to evaluate the feasibility and efficacy of multimodality treatment. Those aims should be distinguished from what can be assessed using the registry results. A feasibility assessment could require measures such as treatment completion or treatment delivery, while the listed primary endpoint concerns pathologic complete remission. The registry record includes one outcome measure and no analyses. It does not report an endpoint result for the remission outcome, nor does it provide detailed feasibility results.

Because the study had one group and no randomized comparator, outcomes describe participants treated under the study approach rather than an estimated causal contrast between treatment strategies. The design can describe what was observed in the reported population, but it cannot separate the regimen's effect from other explanations using a concurrent randomized comparison. The registry record does not report a protocol, a detailed statistical analysis plan, or the reasons for the study's design choices.

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: Participants who completed chemotherapy without progression then had surgical resection.

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 Pathologic Complete Remission (pCR), measured over restaging with second and fourth 21-day cycles followed by surgery.

The primary endpoint is the number of participants with pathologic complete remission, abbreviated pCR in the outcome title. It is a binary outcome at the participant level: each person either meets the stated remission definition or does not. The record defines complete remission as disappearance of all target lesions, confirmed by histopathologic assessment of the surgical resection. In this study, assessment followed chemotherapy and surgery.

The outcome population is not described simply as everyone listed in the registry's enrollment. It consists of participants who completed chemotherapy without progression and then had surgical resection. That distinction matters because participants who progressed, did not complete chemotherapy, or did not proceed to resection may not enter this endpoint population as described. The registry record does not report how many participants met the population criteria, how many had a pCR, or how participants outside that population were handled in an analysis.

A pathologic endpoint can provide evidence about residual disease in the resected tissue, rather than relying only on clinical or imaging assessment. As a general statistical point, a clearly defined binary endpoint also supports direct reporting of the number meeting the criterion and the denominator assessed. Its interpretation depends on complete ascertainment and transparent definition of the analysis population. Here, the definition and intended population are stated, but the observed count, denominator, and uncertainty are not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The study is recorded as single-group and non-randomized, with no masking. These are design descriptions, not statistical findings. A single-group study can report the outcomes observed among participants who received the study regimen. Randomization, when used, supports a controlled comparison by assigning participants to treatment groups in a way intended to reduce systematic differences. There is no randomized comparison in this study, so the main endpoint cannot be interpreted as a between-group treatment contrast.

What does a binary endpoint mean?

The primary outcome counts participants meeting a yes-or-no criterion: pathologic complete remission. The record defines remission as disappearance of all target lesions confirmed by histopathologic assessment of surgical resection. For a binary outcome, a complete result would ordinarily identify the number who met the criterion and the number assessed in the specified population. The registry record does not report either number for this endpoint. Therefore, no observed proportion or associated uncertainty can be described.

The population definition is important to that calculation. The record specifies participants who completed chemotherapy without progression and then had surgery. This is a post-treatment-defined group. In general, analyses limited to people who reach a later assessment can differ from analyses of everyone who began treatment, because progression, treatment discontinuation, or inability to undergo surgery may affect who is assessed. The registry record does not report the number in each of these circumstances or how they were incorporated into an analysis.

What would a confidence interval convey?

As a general statistical explanation, a confidence interval expresses uncertainty around an estimated quantity under a specified statistical procedure. For a binary endpoint, it can communicate how precisely the observed response proportion is estimated, given the number of participants assessed and the number meeting the endpoint. A narrow interval generally indicates greater precision than a wide interval, while neither width nor position alone establishes clinical importance. No confidence interval or endpoint estimate is reported in this registry record, so no numerical precision statement is possible.

Why does the absence of a comparator matter?

In a randomized comparison, the difference between groups can be used to estimate a treatment contrast, subject to the design and analysis assumptions. In this single-group study, the endpoint result would instead be an observed outcome in the treated cohort. It would not establish what those same participants' outcomes would have been under an alternative approach. General comparisons with historical or external outcomes require careful alignment of eligibility, clinical setting, endpoint definition and follow-up. Such a comparison is not reported in the registry record.

The sample-size assumptions described for planning illustrations are not the study's own design justification. They specify a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. The record does not report the study's sample-size justification. These planning assumptions should not be mistaken for the actual single-group design, an observed power calculation, or evidence that a particular effect was demonstrated. No planning output or observed primary effect is reported in the registry record.

What can be inferred from the analysis listing?

The registry record lists zero analyses. This means the record does not present an analysis entry for the endpoint; it does not establish what analyses may have been conducted outside the registry. No test, model, adjustment method, confidence interval procedure, or prespecified analysis is reported. As a general principle, statistical methods should match the endpoint, design, population and estimand—the precise quantity the analysis aims to estimate. Without the analysis plan and results, it is not possible to determine whether a particular method was used or whether any assumptions were assessed.

For a participant-count endpoint, the number assessed and the handling of participants without an evaluable resection are especially relevant. A complete report would explain whether such participants were excluded, counted as not having pCR, or addressed in another way, and would identify the analysis population. The record does not report those decisions. It also does not report an adjusted analysis. No adjustment should be assumed, and no recalculation from summary statistics is possible because the primary endpoint count and denominator are absent.

How should safety counts be interpreted statistically?

Safety summaries describe participants at risk and participants affected for the listed event categories. Such counts are descriptive unless a comparative analysis and its methods are reported. General interpretation also depends on the definitions used for serious and other events, the observation period, repeated events in the same participant, and the rules for attributing events to treatment. Those details are not reported in the registry record. The percentages attached to the two serious-event terms should be read as posted, not converted into a different measure or treated as evidence of comparative risk.

Multiplicity concerns arise when several outcomes, contrasts, time points or analyses are tested. As a general point, testing multiple hypotheses can increase the chance of at least one apparently notable result unless the analysis plan addresses that issue. The record lists one outcome measure and zero analyses, but it does not report a multiplicity plan or whether additional outcomes or analyses were assessed elsewhere. It is therefore not possible to characterize the study's control of multiplicity.

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("Cisplatin + Ifosfamide + Paclitaxel")
n      <- c(30)
events <- c(3)
for (i in seq_along(n)) {
  ci <- binom.test(events[i], n[i])$conf.int          # Clopper-Pearson exact interval
  cr <- qbeta(c(0.025, 0.975), 1 + events[i], 1 + n[i] - events[i])   # Bayesian, uniform Beta(1,1) prior
  wi <- (function(x, n) { p <- x / n; z <- qnorm(0.975); d <- 1 + z^2 / n
    c((p + z^2 / (2 * n) - z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d, (p + z^2 / (2 * n) + z * sqrt(p * (1 - p) / n + z^2 / (4 * n^2))) / d) })(events[i], n[i])
  cat(sprintf("ARM|%s|%d|%d|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f|%.1f\n", arm[i], n[i], events[i], 100 * events[i] / n[i],
              100 * ci[1], 100 * ci[2], 100 * wi[1], 100 * wi[2], 100 * cr[1], 100 * cr[2]))
}

ARM  Cisplatin + Ifosfamide + Paclitaxel  30  3  10.0  2.1  26.5  3.5  25.6  3.6  25.8

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists one outcome measure and no analyses. It does not report a multiplicity strategy, such as a prespecified hierarchy or adjustment for testing multiple outcomes, time points, or analyses. As a general statistical matter, the interpretation of multiple tests depends on which analyses were planned and how their results were handled. The registry information does not establish whether such testing occurred outside the record.

The primary endpoint population is defined as participants who completed chemotherapy without progression and then had surgical resection. However, the record does not give the size of that population, the number with an evaluable pathology result, or the number with missing endpoint information. It does not describe how participants who progressed, stopped chemotherapy, or did not undergo surgery were handled for the primary analysis. It would therefore be inappropriate to assume that all participants listed under enrollment were included in the endpoint assessment or to infer an endpoint denominator.

The missing-data method is not reported in the registry record. There is no stated approach for incomplete pathology assessments or unavailable outcomes, and no sensitivity analysis is reported. In general, missingness can affect an endpoint estimate if the chance of being assessed is related to disease status, treatment experience, or other participant characteristics. Whether that concern applies, and how it might affect results, cannot be evaluated from the registry information.

The analysis population, analysis plan, and any protocol-defined handling of deviations are also not reported. These omissions limit assessment of whether the analyzed group matched the intended population and whether the endpoint was handled consistently. The absence of a reported analysis does not prove that no analysis was conducted; it means the analysis is not documented 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% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: myocarcial ischemia (8.7%), allergic reaction (4.3%).

The registry lists one treatment group, cisplatin plus ifosfamide plus paclitaxel. For serious adverse events, 30 participants are recorded as at risk and 3 as affected. For other adverse events, 30 are recorded as at risk and 13 as affected. These are counts in the registry summary; they should not be combined or converted into a new measure. The record lists “myocarcial ischemia” at 8.7% and “allergic reaction” at 4.3% among the top serious terms.

The posted terms and counts do not supply a full safety profile. The registry record does not report event-level details such as onset, duration, severity grading, treatment relatedness, recurrence, or whether a participant experienced more than one event. It also does not describe the observation period used for the safety summaries. The term “myocarcial ischemia” is reproduced as recorded; its spelling is not clarified in the registry record.

Deaths are not reported in the registry record. The safety counts are descriptive for a single study group and do not provide a comparison with another regimen or a control group. They can be read as the posted counts of affected participants, but they do not establish comparative risk or by themselves characterize how events relate to treatment.

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

The record describes a completed phase II, single-group study evaluating cisplatin, ifosfamide and paclitaxel before surgery in patients with penile squamous cell carcinoma. It specifies a primary outcome based on histopathologic confirmation of disappearance of all target lesions. It also reports limited safety counts for the treatment group. These features make the study question and endpoint understandable, but the primary outcome result itself is not reported in the registry record.

Without the number of participants with pCR and the number assessed, it is not possible to state how often remission was observed or how precisely it was estimated. The enrollment listing of 30 is not a substitute for the endpoint denominator because the endpoint population is defined by chemotherapy completion without progression followed by surgery. The registry record does not report how many participants met those criteria.

Even if a complete single-group endpoint result were available, it would describe outcomes in that group rather than establish the benefit of the regimen relative to another strategy. The study has no randomized comparator. Differences between this cohort and another cohort could reflect differences in selection, disease, care, assessment, follow-up or other factors. The registry record does not provide a comparative analysis that could address those explanations.

The listed safety counts indicate that adverse events were recorded, including serious events. They do not provide all the details needed to judge event timing, severity, attribution or comparative risk. The record does not report deaths. These limitations argue for careful, descriptive reading rather than a broad conclusion about the overall balance of benefits and risks.

The results available in the registry can therefore establish the study's design, stated objective, regimen, endpoint definition and posted safety summary. They do not establish a primary endpoint effect, its statistical significance, its precision, or a causal treatment effect. The protocol, statistical analysis plan, missing-data methods and sample-size justification are not reported in the registry record. Conclusions beyond the recorded design and descriptive information would require information that is not reported there.

14. Why This Trial Matters Statistically

This study is statistically notable because its endpoint is clinically specific but depends on reaching surgery and obtaining a pathologic assessment. The record makes that population restriction explicit: participants must have completed chemotherapy without progression and then undergone surgical resection. That definition highlights a central interpretive issue in neoadjuvant studies. The patients who can be assessed pathologically may not represent everyone who began treatment, so the endpoint denominator and the handling of those who do not reach surgery are essential to interpretation. Neither is reported for the primary outcome.

The single-group, non-randomized design also clarifies the boundary between describing outcomes and estimating a treatment contrast. A study can document what happened in its treated participants, but without a concurrent comparator it cannot directly show how those outcomes differ from an alternative. This is a design issue, not a defect that can be resolved by a statistical test alone. A complete outcome report would still be descriptive of the cohort unless an appropriate comparison were available.

The record also illustrates why endpoint definitions and analysis populations matter alongside the headline objective. The objective refers to feasibility and efficacy, while the listed outcome measures pathologic complete remission. These are related but not interchangeable concepts. The registry does not report the broader measures or an analysis that connects them. Likewise, the presence of safety counts does not provide the detail needed for a full benefit-risk comparison.

Finally, the registry's lack of a posted endpoint result and analysis prevents assessment of effect size and uncertainty. A completed status and an enrollment listing do not fill that gap. The case underscores the importance of reporting the observed endpoint count, its denominator, analysis population, missing-data handling and uncertainty, especially when the endpoint is assessed only after a sequence of treatment and surgery.

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 primary limitation for trial-specific interpretation is that the registry record does not report the primary endpoint result. Neither the number with pathologic complete remission nor the number assessed is stated. The stated endpoint population includes only participants who completed chemotherapy without progression and then had surgery, but the record does not report how many people reached that point or how others were treated analytically.

The single-group, non-randomized design has no concurrent control arm. It can describe observed outcomes in the study group but does not provide a randomized estimate of the difference between the regimen and another treatment approach. The absence of masking is recorded, but the registry does not describe outcome-assessment procedures beyond histopathologic confirmation or whether any safeguards were used to limit assessment bias.

The official title uses clinical stage TanyN2-3M0, while the brief summary uses TXN2-3M0. The registry record does not explain this difference in notation. It also does not report detailed eligibility criteria, participant characteristics, treatment completion, dose modifications, follow-up, or the number undergoing surgery. These omissions make it difficult to assess the characteristics and clinical course of the population represented in the endpoint.

For safety, the record gives counts and two serious-event terms, but not detailed event definitions, timing, severity, attribution, recurrent-event handling or observation period. Deaths are not reported. The statistical analysis plan, multiplicity strategy, missing-data approach and sample-size justification are not reported in the registry record. With no posted primary analysis or result, the endpoint's magnitude, precision and sensitivity to analytic choices cannot be evaluated.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Neoadjuvant Chemotherapy for Patients With Squamous Cell Carcinoma of the Penis — NCT00512096.
• Registry record last updated 2012-08-01; status last verified 2012-07.
• Results first posted 2010-12-08.
• Data retrieved from ClinicalTrials.gov on 2026-11-09.
• Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.

19. Record Summary

The registry record describes NCT00512096, a completed phase II study sponsored by M.D. Anderson Cancer Center. It is recorded as non-randomized, single-group and unmasked, with an enrollment of 30. The study evaluated cisplatin, ifosfamide and paclitaxel before extirpative surgery for clinical stage TanyN2-3M0 squamous cell carcinoma of the penis; the brief summary uses TXN2-3M0 notation.

The primary outcome was the number of participants with pathologic complete remission, defined as disappearance of all target lesions confirmed by histopathologic assessment of surgical resection. The endpoint population was participants who completed chemotherapy without progression and then had surgery. The registry record does not report the endpoint count, denominator, analysis, or confidence interval.

Safety summaries list 3 affected among 30 at risk for serious adverse events and 13 affected among 30 at risk for other adverse events. The record names “myocarcial ischemia” and “allergic reaction” among the top serious terms. It does not report deaths. The protocol, statistical plan, missing-data handling and sample-size justification are not reported in the registry record.