Radiation Therapy and Concurrent Cisplatin Chemotherapy for Locally Advanced or Metastatic Malignant Melanoma: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Radiation Therapy and Concurrent Cisplatin Chemotherapy for Locally Advanced or Metastatic Malignant Melanoma (NCT00707161), a na phase 2 study. The primary outcome is Response Rate of Melanoma Lesions.

2. Clinical Question

The question concerns lesion response following combined radiation and cisplatin, in a population selected because treating physicians considered radiation appropriate for local control or palliation. This is a clinical activity question rather than a direct comparison of two treatment strategies: the record describes one group and does not identify a control arm.

In general, a response endpoint can describe whether treated disease meets defined criteria for shrinkage or other response. The particular criteria and how lesion-level findings would be combined into a response rate are not reported in the registry record. Consequently, the registered question is identifiable, but its precise measurement rules and the result are not.

3. Trial Design

The registry describes a prospective phase II study at the University of Utah. Its official title identifies radiation therapy with concurrent cisplatin chemotherapy for locally advanced or metastatic malignant melanoma. The design is listed as single group, with no masking and allocation marked as not applicable. There is no like-for-like control group in the record.

Enrollment was 6. The study started in 2005-09, had a primary completion date of 2010-02, and is listed as terminated. The registry does not report why the study was terminated. These dates describe the record's study milestones; they do not establish when each participant entered, completed treatment, or had outcome assessment.

The brief description states that patients would receive radiation therapy in 20 treatments of 2.5 Gy, for a total of 50 Gy, concurrent with cisplatin chemotherapy. It says eligibility included pathologically confirmed melanoma and that participants were considered to require radiation by their treating physicians for local control or palliation. The timing and dosing details for cisplatin are not reported in the registry record.

Radiation Therapy, Cisplatin, and Surgical resection appear in the intervention listing. The record does not explain whether surgical resection was planned, optional, or received by any participant. The all-participants arm has no further description, so participant-level treatment details cannot be established from the registry entry.

The record lists one primary outcome measure, response rate of melanoma lesions, and gives 2005-2010 as its timeframe. It also states that the study was terminated and analysis was not conducted. Protocol details such as a planned sample-size justification, eligibility exclusions, treatment adherence rules, follow-up schedule, and statistical analysis plan 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: Study terminated. Analysis not conducted.

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 Response Rate of Melanoma Lesions, measured over 2005-2010.

The primary endpoint is titled “Response Rate of Melanoma Lesions.” The registry describes it as the response rate of lesions measured after treatment with the trial agent and gives 2005-2010 as the timeframe. It does not provide a unit, a response definition, or a numerical result. The population note states that the study was terminated and analysis was not conducted.

In general, response rate is used to describe the share of assessed disease meeting a specified response definition. It can provide an indication of antitumor activity over an assessment period, but interpretation depends on how response is defined, which lesions are assessed, how missing or unevaluable assessments are handled, and whether response must be confirmed. Those details are not reported in the registry record.

The endpoint is described at the lesion level, while enrollment is reported for participants. If participants can contribute more than one lesion, the analysis needs to specify how lesion-level findings are combined and whether dependence among lesions from the same participant is addressed. That method is not reported. Without the analysis and its rules, neither a response rate nor its precision can be recovered from the registry entry.

Because no response analysis was conducted, the record does not show whether lesions responded, remained unchanged, or progressed. The endpoint's intended purpose can be described, but it cannot be treated as an observed study result.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

What does the design permit? The registry describes a prospective, single-group phase II study with no masking. In general, a single-group study can describe outcomes among enrolled participants, provided outcomes are collected and analyzed according to defined rules. It does not provide a concurrent control group for estimating what would have happened under a different treatment. This distinction matters even when an endpoint is clearly named: a response proportion in one group is descriptive unless a suitable comparison and analysis support a broader causal interpretation.

Here, the registry does not report an outcome analysis. The stated endpoint is response rate of melanoma lesions, but no lesion response counts, participant response counts, or estimate are reported. Statistical methods that would usually accompany a completed estimate—such as an uncertainty interval or a test against a prespecified benchmark—are not reported in the registry record. It is therefore not possible to reproduce or assess an efficacy analysis from the entry.

What would a response-rate analysis require? In general, an analysis first needs an operational response definition and a rule for identifying the cases eligible for assessment. It also needs to specify the denominator: for example, whether the unit is participants or lesions and how participants with no evaluable assessment are treated. Those choices can change what a response proportion means. The registry does not report these rules, so it is not possible to identify the intended numerator and denominator or determine how the endpoint would have been calculated.

The endpoint title refers to lesions, while enrollment counts participants. If several lesions could be assessed for one participant, their outcomes may be related rather than statistically independent. In general, treating related lesion observations as independent can make an analysis overstate the amount of information. A valid approach would need to specify whether lesion results were combined within participants or analyzed with a method that accounts for clustering. The registry does not report the number of lesions or the planned handling of multiple lesions.

How should uncertainty be understood? In general, a confidence interval describes the range of values reasonably compatible with an estimate under the chosen statistical model and assumptions. It reflects sampling uncertainty, not all possible sources of bias or measurement error. A narrow interval does not correct a poorly defined endpoint, incomplete follow-up, or the lack of a comparison group. A wide interval can indicate that the data are compatible with a broad range of effects. No response estimate or confidence interval is reported for this study, so uncertainty about the endpoint cannot be quantified from the registry entry.

A p-value, in general, measures how incompatible data are with a stated null hypothesis under a specified model; it does not measure the probability that a treatment works, nor does it describe the size or clinical importance of an effect. A p-value requires an analysis and a defined statistical question. No p-value or primary endpoint analysis is reported. It would be inappropriate to infer statistical significance or lack of significance from the fact that the study was terminated.

What does the planning illustration represent? The stated assumptions describe a planning illustration using a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation, with the target effect expressed as a fraction of an observed effect. In general, such calculations explore the sample size associated with a specified effect and assumptions; they do not describe the number of participants actually analyzed. The assumptions also describe two arms, unlike this trial's registered single-group design. They are not the trial's own design justification, which is not reported in the registry record, and they should not be interpreted as observed power.

For a planning illustration based on an observed effect to be meaningful, the underlying effect estimate and its analysis must be clear. The registry record says the primary analysis was not conducted and supplies no response estimate. Accordingly, a planning illustration cannot fill the gap in clinical outcome reporting or establish what the trial observed. The registry does not report an original protocol-based sample-size rationale, target effect, or power calculation.

Why can over-dispersion matter? In general, over-dispersion occurs when outcome variation is greater than a statistical model assumes. For count outcomes, it can make standard errors too small if the model does not accommodate the extra variability. This trial's registered primary endpoint is a response rate, not a reported count analysis, and the registry does not identify an over-dispersion model or any other fitted model. The concept is relevant only as a general reminder that analysis assumptions must match the outcome and data structure; it is not evidence that over-dispersion occurred in this study.

More broadly, a statistical analysis plan should state the analysis population, endpoint definition, treatment of missing assessments, model or estimator, and any planned sensitivity analyses. These features allow readers to understand which observations contribute to an estimate and how robust it is to assumptions. Such details are not reported in the registry record. Since the analysis was not conducted, there are no posted estimates whose methods can be evaluated or recalculated.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists one primary outcome measure, response rate of melanoma lesions. It does not report other outcome measures in the registry record, but that does not establish that no additional outcomes were planned or assessed. The number and handling of secondary or exploratory outcomes are not reported in the registry record.

In general, multiplicity arises when several outcomes, time points, subgroups, or statistical tests are considered. Conducting many tests can increase the chance of at least one apparently notable result by chance. A protocol may address this with a prespecified hierarchy, adjustment, or a clear distinction between confirmatory and exploratory analyses. No multiplicity strategy is reported. Because no primary analysis was conducted, the record contains no inferential results to interpret in light of multiplicity.

Missing-data methods and analysis populations are also not reported. The registry's statement that analysis was not conducted does not tell readers whether outcome assessments were missing, whether participants stopped treatment, or whether any participants had evaluable lesions. Those details should not be inferred. The record does not describe an intention-to-treat population, a per-protocol population, an evaluable population, or rules for including participants in an endpoint analysis.

In general, missing outcome data can affect both the denominator and the interpretation of an estimate. The impact depends on why assessments are missing and on the assumptions used to handle them. A complete-case analysis, imputation, or another approach would require explicit methods and supporting information; none is reported. With no response analysis and no stated missing-data plan, the registry cannot establish how missingness would have influenced the endpoint.

11. 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 0% reporting threshold.

The registry's treatment-arm safety entry lists six participants at risk for serious adverse events and zero affected. It also lists six at risk for other adverse events and zero affected. These figures describe the counts recorded in the registry; they should not be read as proof that no event occurred outside the recorded definitions or observation period.

The record does not report the definitions used for serious or other adverse events, the length or completeness of safety follow-up, or how events were assessed for relationship to treatment. No top serious-event terms are listed. The death count is not reported in the registry record, so a value should not be inferred from the blank entry.

In general, zero recorded events in a small group do not establish that an event is impossible or that a treatment has no risk. A safety count is most interpretable when its denominator, follow-up period, event definitions, and reporting completeness are clear. The registry provides the at-risk count and recorded affected count but does not report the additional details needed for a broader safety assessment.

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

The registry record establishes that a prospective phase II study was registered to examine radiation therapy concurrent with cisplatin in locally advanced or metastatic melanoma. It reports six enrolled participants, a single-group design, and a primary endpoint concerning response rate of melanoma lesions. It also states that the study was terminated and that the primary analysis was not conducted. These are the limits of what can be concluded from the posted outcome information.

No response rate is reported. This means readers cannot tell from the registry whether lesions met the intended response criteria, how many participants or lesions were evaluable, or how precise any potential estimate would have been. It does not mean that the response rate was zero, nor does it establish a lack of treatment effect. The reason for termination is not reported, and the study's status cannot be used to infer the reason or the outcome.

The design does not include a registered control group. Even if a within-group response estimate had been reported, it would describe outcomes in the enrolled group and would not, on its own, establish what outcomes would have been under an alternative treatment. Comparisons with other studies would also require care because participant selection, endpoint definitions, assessment schedules, and other study features may differ; those comparative details are not reported.

The safety entry records zero affected among six at risk for both serious and other adverse events, but the registry does not provide key information about definitions and follow-up. Those counts therefore describe the recorded entries, not a complete characterization of safety. The death count is not reported in the registry record.

In general, an incomplete outcome record limits both positive and negative conclusions. The study's registered question remains identifiable, but without an analysis and adequate endpoint detail, neither effectiveness nor absence of effectiveness can be determined from this record. The findings should be described as unavailable, rather than interpreted as a favorable or unfavorable result.

13. Why This Trial Matters Statistically

This study illustrates an important distinction between a registered clinical question and an analyzed clinical result. The registry gives a clearly named primary endpoint and an intended treatment approach, but it also states that analysis was not conducted. A trial's title, design, and enrollment do not substitute for outcome data. Statistical interpretation begins with the observations and the rules used to analyze them; neither an endpoint estimate nor its uncertainty is available.

The single-group structure also highlights the difference between describing an outcome and estimating a comparative treatment effect. A treated-group response rate, if measured and analyzed, could summarize what happened among participants. A control group is needed for a direct concurrent comparison, and even that comparison depends on appropriate design and analysis. The registered study has no separate comparator group, so causal claims would require evidence beyond the design described in the record.

The endpoint's lesion-level wording raises a further general issue: the observational unit and the analysis unit may differ. Participants can be the unit of enrollment while lesions are the unit named by an endpoint. When observations are clustered within people, valid uncertainty estimates depend on handling that dependence. The registry does not state how the lesion endpoint would be analyzed, making this a limitation in interpretability as well as a missing-result issue.

Finally, the safety counts show why denominators and context matter. A recorded count of zero affected among six at risk is a specific entry, but its meaning depends on event definitions, follow-up, and reporting completeness. The registry does not report those details. Taken together, the record is a useful example of why design descriptions, outcome results, and analysis methods must be distinguished rather than treated as interchangeable evidence.

14. 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 is that the registry explicitly reports that the study was terminated and the primary analysis was not conducted. No lesion response estimate, uncertainty interval, or inferential result is available. The reason for termination is not reported in the registry record, so no explanation should be assigned to the missing analysis.

Enrollment was 6, and the study has a single-group design without a control arm. Even if outcomes had been analyzed, the absence of a concurrent comparator would limit direct estimation of a treatment effect relative to another strategy. The small enrollment also means the record offers limited information about the range of possible outcomes, but no precision measure can be calculated without endpoint data.

The response endpoint is not operationally defined in the registry entry. Criteria for response, lesion selection, assessment timing, confirmation, denominator, and handling of unevaluable assessments are not reported. The record also does not explain how results from multiple lesions within a participant would be combined or analyzed. These omissions prevent readers from judging the intended estimand or reproducing a response analysis.

Other protocol and analysis details are not reported, including a sample-size justification, analysis populations, missing-data methods, multiplicity strategy, and the specific statistical model. The registry lists surgical resection as an intervention but does not explain its role or whether any participant received it. The cisplatin dosing details and safety follow-up information are also not reported.

Safety entries list zero affected among six at risk for serious and other adverse events, but event definitions and follow-up completeness are not reported; the death count is not reported in the registry record. These limitations mean the counts should not be interpreted as comprehensive evidence about safety. The limitations concern what can be established from this registry record and do not explain why the study ended.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Radiation Therapy and Concurrent Cisplatin Chemotherapy for Locally Advanced or Metastatic Malignant Melanoma — NCT00707161.
• Registry record last updated 2017-03-31; status last verified 2017-03.
• Results first posted 2012-04-04.
• 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.

18. Record Summary

The registry describes a prospective phase II, single-group study sponsored by the University of Utah, investigating radiation therapy concurrent with cisplatin for locally advanced or metastatic melanoma. It lists six participants, no masking, and allocation as not applicable. The treatment description specifies radiation therapy in 20 treatments of 2.5 Gy for a total of 50 Gy.

The primary outcome is response rate of melanoma lesions, with a stated timeframe of 2005-2010. The record says the study was terminated and analysis was not conducted, so it reports no response estimate. Safety entries list zero affected among six at risk for serious adverse events and zero affected among six at risk for other adverse events. The death count is not reported in the registry record. The reason for termination and the detailed statistical plan are not reported.