Axitinib Before Surgery in Treating Patients With High-Risk Prostate Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Axitinib Before Surgery in Treating Patients With High-Risk Prostate Cancer (NCT01385059), a randomized phase 2 study. The primary outcome is Pre-metastatic Niche Density.

2. Clinical Question

The trial asks whether pre-surgical axitinib is associated with a different pre-metastatic niche density in regional lymph nodes at prostatectomy than surgery alone. The outcome is defined as the average number of VEGFR1 clusters across microscopic fields in those lymph nodes. The registry describes a randomized phase II comparison in patients with high-risk prostate cancer and lists stage III and stage IV prostate cancer among the conditions.

This is a question about a tissue-based measurement in regional lymph nodes, not a direct comparison of survival, recurrence, or patient-reported outcomes. Those outcomes are not reported as primary outcomes in the registry record. The posted result concerns the measured cluster density and its between-group statistical comparison; it does not by itself establish a causal biological explanation for any observed difference.

3. Trial Design

The registry describes a randomized, phase II, parallel-group study with no masking. One group received axitinib before prostatectomy and pelvic lymph node dissection; the other underwent surgery without the listed pre-surgical axitinib course. The enrollment field records 11 participants. The outcome results list 4 participants in the axitinib-followed-by-surgery group and 7 in the surgery group.

In the axitinib group, participants were scheduled to take axitinib by mouth twice daily on days 1-28, followed by prostatectomy and pelvic lymph node dissection. The record says treatment continued in the absence of disease progression or unacceptable toxicity. In the control group, surgery was scheduled 5-6 weeks after biopsy confirmation. The primary endpoint was assessed at the time of prostatectomy, so the comparison concerns a measurement made during surgery rather than a later clinical event.

City of Hope Medical Center is listed as sponsor. The study status is completed. The start date is 2011-12-05, and the primary completion date is 2013-10-09. The registry identifies a single primary outcome measure and one reported analysis. It does not report a masking procedure, which is consistent with the listed masking status of none.

The registry does not report the method used to generate the random sequence, allocation concealment, or additional operational details of randomization. It also does not report the target sample size as a number. It does state that the target sample size needed per arm was not reached. Accordingly, the small arm-level outcome counts and the registry's explicit sample-size caution are important context for interpreting the comparison.

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: Caution should be taken when drawing conclusions from these data as the target sample size needed per arm was not reached.

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 Pre-metastatic Niche Density, measured over At the time of prostatectomy.

The primary endpoint is pre-metastatic niche density, measured in clusters per high-power field at the time of prostatectomy. The registry defines the measure as the average number of VEGF receptor 1 (VEGFR1) clusters in 8 distinct 40X microscopic fields from regional lymph nodes. This is a tissue-based measure intended to characterize a feature of the lymph-node environment in patients undergoing surgery.

In general, a prespecified biological endpoint can give a trial a focused way to compare groups using a measurement related to the study's scientific question. Here, the endpoint is the density of VEGFR1 clusters, rather than a clinical outcome such as survival or recurrence. The registry's description says the comparison is intended to evaluate whether this density differs between participants treated with axitinib before surgery and those in the control arm.

The posted results report a median and full range for each group. The registry's analysis description, however, specifies a two-sample Student's t-test. A t-test is generally used to compare group means, while the posted summaries are medians and ranges. The record does not provide the underlying participant-level measurements or enough summary statistics to reproduce that test. The endpoint's biological meaning and the statistical comparison therefore need to be kept distinct: the former is what was measured, and the latter is the registry's stated method for comparing groups.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry states that the primary endpoint comparison used a two-sided Student's t-test. In general, a two-sample t-test evaluates whether the means of two independent groups differ, relative to the variability of the observations and the amount of information in each group. A two-sided test allows for a difference in either direction. The registry records the result as p > 0.05, but does not provide the test statistic, degrees of freedom, exact p-value, or confidence interval.

What does the p-value say?

General explanation: a p-value is calculated under a statistical model that assumes no group difference and expresses how unusual a result at least as extreme as the observed one would be under that model. It is not the probability that there is no difference, and it does not measure the size or clinical importance of an effect. The registry's notation, p > 0.05, gives only a thresholded result; it does not identify the exact p-value. It should not be interpreted as proof that the groups are equivalent.

Why does the summary format matter?

The outcome summaries are medians with full ranges. In general, the median describes the central observation after values are ordered, while the range reports the smallest and largest observed values. A mean and a standard deviation convey different information. Because the stated t-test compares means, a reader cannot reproduce it from the medians and ranges alone. The participant-level data, or suitable mean and variability summaries, are not reported in the registry record. The record also does not report a confidence interval for the comparison.

In general, a confidence interval gives a range of effect estimates compatible with the data and the assumptions of the analysis. Its width communicates precision: a wide interval indicates that the data are compatible with a broad range of effects. No interval is posted for this comparison, so its precision cannot be assessed from a reported interval. The small listed group sizes and the explicit warning that the per-arm target was not reached reinforce the need for caution, but they do not permit a numerical estimate of precision without further data.

What assumptions are relevant?

General explanation: the usual two-sample t-test relies on independent observations and, for the standard form, assumptions about the distribution of the outcome and its variability across groups. With a small sample, unusual observations or departures from model assumptions can have a larger influence on the result. The record does not report diagnostic checks, a variance assumption, an alternative test, or an adjustment to the t-test. It is therefore not possible to assess those implementation details from the registry entry.

Over-dispersion is a general concern when observed variability exceeds what a simple model expects. In count-like or biological measurements, greater-than-expected variability can make standard errors too small if the model does not account for it. The registry reports ranges but does not provide the raw observations or a model for over-dispersion. It would be inappropriate to infer that over-dispersion was present or to apply a correction without those data.

How should the study size be considered?

The registry states that the target sample size needed per arm was not reached, but the target number and the justification for it are not reported in the registry record. The posted sample-size planning illustrations are not observed power and are not evidence of the probability that the trial detected an effect. In general, planning calculations depend on assumptions about the effect to detect, variability, significance level, allocation, and analysis method. An illustration based on an observed effect does not establish that the original study was designed around that effect.

The assumptions recorded for planning illustrations are a two-sided significance level of 0.05, equal allocation between arms, and a normal approximation, with the effect expressed as a stated fraction of the observed effect. These are planning assumptions, not a description of the trial's actual allocation counts or a substitute for a prespecified design calculation. The registry does not report the original sample-size justification, interim analyses, or a detailed statistical analysis plan.

What can be independently recalculated?

General explanation: a recalculation from summary data can be useful as a check when the necessary statistics are available, but it is not a replacement for the sponsor's analysis. In this record, medians and full ranges are available, while means and standard deviations are not. The record also lacks a confidence interval and participant-level data. The two-arm comparison is therefore not estimable from the posted summaries using the stated t-test. No recalculated p-value or effect estimate should be inferred from the descriptive summaries.

The distinction between a descriptive comparison and an inferential test is important. The medians and ranges describe the observed group results; the t-test p-value is the reported inferential result. Neither supplies information absent from the other. Together, they show the recorded distributions' central values and extremes and the registry's thresholded test result, while leaving the uncertainty around the group contrast unreported.

10. Analyses Reported by the Sponsor

The registry's own analysis is reported as a two-sided t-test with p > 0.05. No test statistic, exact p-value, confidence interval, or adjusted estimate is recorded. The descriptive endpoint summaries are medians and full ranges, whereas the stated t-test ordinarily compares means. Because the record does not include means, standard deviations, or participant-level measurements, the two-arm comparison cannot be independently recalculated from the posted summaries.

The registry marks no discrepancy between the reported analysis and a recalculation. In this case, however, a separate recalculated result is not available: the posted information is insufficient to reproduce the test. The appropriate reading is therefore to report the registry's own p-value and not to substitute a new estimate. The descriptive medians should not be treated as a recalculation of the t-test or as a confidence interval.

The record's warning that the target sample size needed per arm was not reached remains relevant to the interpretation of the sponsor-reported analysis. It does not alter the reported p-value, but it emphasizes that the comparison is based on limited information. The exact sample-size target and its justification are not reported in the registry record.

11. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome measure and one analysis, and it reports no secondary outcomes. This leaves no posted set of multiple endpoint results from which to assess whether several outcomes were tested and whether any adjustment was used. The registry record does not report a multiplicity adjustment, a hierarchy of hypotheses, or a detailed plan for handling multiple analyses. It also does not report whether interim analyses were conducted. Those details should not be assumed from the single analysis listed.

The outcome summaries give a median and full range in each group, but the registry does not report participant-level data, means, standard deviations, or a confidence interval for the group comparison. It does not describe how missing endpoint measurements were handled, whether all randomized participants were included in the analysis, or how analysis populations were defined. The numbers listed for the outcome are the group counts attached to the reported results; they do not, by themselves, establish the exact handling of every randomized participant.

The record also does not state whether the endpoint was analyzed according to randomized assignment, whether any participants were excluded from the primary analysis, or whether the analysis adjusted for baseline characteristics. These omissions limit assessment of the analysis population and the potential effect of missing or unavailable measurements. They do not establish that data were missing or that participants were excluded; those details are simply not reported in the registry record.

In general, multiplicity matters because repeated testing can increase the chance of a nominally significant result when no true effect exists. Missing-data methods matter because results can depend on which observations are available and how absent observations are handled. Those are general statistical concerns, not claims about what occurred in this trial. The posted record does not provide enough detail to determine whether either issue affected the reported endpoint comparison.

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 0% reporting threshold.

Most frequent non-serious adverse event terms

The registry reports serious adverse events for the two groups. In the axitinib-followed-by-surgery group, 0 serious adverse events were reported among 4 participants at risk. In the surgery group, 0 serious adverse events were reported among 7 participants at risk. The registry also records 0 deaths in each group. These are the reported counts for the safety fields and should be read as counts observed in this study, not as proof that the risk of serious events or death is absent.

For other adverse events, the record reports 3 affected participants among 4 at risk in the axitinib group and 5 among 7 at risk in the surgery group. These counts are distinct from the serious adverse-event counts. The registry does not list serious adverse-event terms. It does not provide a detailed account of event type, severity grading, timing, duration, or attribution to treatment in the information recorded for these results.

General explanation: when event counts are small, the observed counts can give an imprecise picture of underlying event rates. A count of zero in a small group does not show that an event cannot occur. These safety figures are descriptive and do not establish a comparative safety profile. They also should not be interpreted as a recommendation about treatment or care.

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

The result establishes what the registry reports for this endpoint: a median of 75.6 clusters per high-power field in the axitinib-followed-by-surgery group and 62.5 in the surgery group, with the listed full ranges, together with a two-sided t-test result of p > 0.05. The record also states that the target sample size needed per arm was not reached. These registry entries support a cautious description of the observed biomarker data and the reported statistical test.

The result does not establish that the groups are equal. A p-value above 0.05 is not an equivalence finding, and the registry does not report an equivalence margin or an interval estimate that would show which differences are compatible with the data. The result also does not quantify the uncertainty around the difference, because a confidence interval is not reported and the available summaries are insufficient to reproduce the stated t-test.

The endpoint is a tissue-based measure recorded at prostatectomy. The registry does not report a primary clinical outcome such as survival or recurrence, and the biomarker comparison cannot be treated as direct evidence about those outcomes. Nor does the result establish the mechanism by which axitinib might affect tumor cells or the lymph-node environment. The study description gives a rationale for studying the treatment, but the posted endpoint result is limited to the cluster-density measurement.

Randomized allocation is recorded, but a randomized design does not remove all uncertainty, especially when the per-arm target was not reached and the group sizes are small. The record does not report enough information to assess the randomization implementation, analysis population, or missing-data handling. Therefore, the registry result should not be extended beyond the population, endpoint, comparison, and analysis it records.

In general, a study can be informative even when it does not produce a statistically significant result: it can document a measurement, reveal practical limitations, and identify information that is needed for a more precise analysis. For this trial, the useful statistical contribution is a small randomized comparison with a clearly defined tissue endpoint and a reported test result, accompanied by substantial limits on precision and independent verification.

14. Why This Trial Matters Statistically

This trial is statistically notable because it combines randomization with a tissue-based endpoint measured at surgery. Randomized comparisons are designed to support a fair comparison between groups, while a biomarker endpoint can address a focused biological question. The registry records both the intended comparison and the measurement definition: average VEGFR1 cluster density across microscopic fields in regional lymph nodes at prostatectomy.

The record also makes the sample-size limitation explicit. It states that the target sample size needed per arm was not reached, and the outcome counts are 4 and 7. This matters because the precision of a comparison depends on the amount of information available as well as on the observed values. The reported p-value above 0.05 should therefore not be mistaken for strong evidence of no difference. At the same time, the absence of a confidence interval prevents a clear view of the range of effects compatible with the analysis.

Another important statistical lesson is the gap between a stated analysis and the published summaries. The registry describes a two-sample t-test but reports medians and full ranges. Those summaries do not permit the test to be reproduced. In general, transparent reporting of the analysis inputs, effect estimate, and uncertainty allows readers to evaluate whether a statistical method aligns with the outcome and whether the result is robust. Those materials are not present in this record.

The trial illustrates why biological measurements and clinical outcomes should be distinguished. A measured change in a tissue marker can be relevant to a biological research question without establishing a change in patient outcomes. The registry's primary result is informative about the recorded endpoint, but not about unreported clinical outcomes.

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 is the registry's statement that the target sample size needed per arm was not reached. The target itself and the sample-size justification are not reported in the registry record. The listed endpoint counts are small, which limits the precision that can be expected from the comparison. No confidence interval is posted to quantify that precision.

The outcome summaries are medians and full ranges, but the stated analysis is a two-sided Student's t-test. Since the record does not report means, standard deviations, test statistics, or participant-level observations, the analysis cannot be reproduced from the posted summaries. The exact p-value is not reported; only p > 0.05 is given. These gaps prevent an independent check of the reported test and its assumptions.

The registry does not report random-sequence generation or allocation concealment. It does not explain how missing endpoint observations were handled, define the analysis population, or report whether the primary analysis followed randomized assignment. It also does not report baseline endpoint values, adjustment variables, model diagnostics, or a detailed analysis plan. These are limitations in what can be assessed from the registry record, not evidence that a particular procedure was or was not used.

The endpoint is a biomarker measurement at surgery rather than a reported clinical outcome. The registry does not report a follow-up comparison for survival or recurrence as a primary result. Finally, the safety fields provide counts but not detailed event descriptions, grading, timing, or attribution. Together, these limitations constrain interpretation to a small, registry-reported comparison of the specified tissue measure.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Axitinib Before Surgery in Treating Patients With High-Risk Prostate Cancer — NCT01385059.
• Registry record last updated 2026-11-03; status last verified 2026-10.
• Results first posted 2023-03-07.
• 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

NCT01385059 is a completed randomized phase II study sponsored by City of Hope Medical Center. It compares axitinib before prostatectomy with surgery alone in patients with high-risk prostate cancer. The registry records enrollment of 11 and lists the study start date as 2011-12-05 and primary completion date as 2013-10-09.

The primary endpoint is pre-metastatic niche density in regional lymph nodes at prostatectomy, defined as average VEGFR1 cluster counts across microscopic fields. The outcome record lists 4 participants in the axitinib-followed-by-surgery group and 7 in the surgery group. The reported analysis is a two-sided t-test with p > 0.05. The registry cautions that the target sample size needed per arm was not reached.

The record provides medians and full ranges but no confidence interval or sufficient summaries to reproduce the stated test. It reports no secondary outcomes and does not describe missing-data handling or analysis populations. The findings therefore describe the posted biomarker comparison, with limited precision and important reporting gaps.