This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for S0008: Chemotherapy Plus Biological Therapy in Treating Patients With Melanoma (NCT00006237), a randomized phase 3 study. The primary outcome is 5-year Overall Survival.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT00006237 |
| Phase | Phase 3 |
| Condition | Melanoma (Skin) |
| Allocation | Randomized |
| Design model | Parallel |
| Masking | None (open label) |
| Enrollment | 432 |
| Arms in the primary outcome | 2 |
| Lead sponsor | SWOG Cancer Research Network |
| Results posted | Yes |
2. Clinical Question
Population
Patients with high-risk melanoma, as described in the trial title and summary. More detailed eligibility criteria are not reported in the registry record.
Intervention
Biochemotherapy: cisplatin, vinblastine, dacarbazine, interleukin-2, and interferon alfa, with filgrastim also listed as an intervention. The registry's description of the filgrastim schedule is incomplete.
Comparator
Interferon alfa alone, given intravenously during weeks 1-4 and subcutaneously during weeks 5-52, subject to disease progression or unacceptable toxicity.
Primary question
How did 5-year overall survival compare between the interferon arm and the biochemotherapy arm? The reported endpoint is a percentage of the population, and the registry gives a log-rank comparison.
The trial was a randomized phase III comparison of two treatment strategies for melanoma. The record's summary describes the underlying question as whether interferon alfa, with or without combination chemotherapy and interleukin-2, differed in effectiveness. For the primary outcome, the record defines overall survival from registration until death from any cause, with observations censored at last contact for patients last known to be alive.
The posted 5-year overall-survival value is 56.0 for each arm. The reported log-rank p-value is 0.49. These entries describe the registry's recorded outcome and comparison; they do not establish that the strategies are equivalent, nor do they determine how an individual patient would fare. The record does not report a confidence interval for the arm values or a treatment-effect estimate from the log-rank analysis.
The registry identifies melanoma of the skin as the condition and describes the population as having high-risk melanoma. Further clinical eligibility details, such as the precise definition of high risk, are not reported in the registry record. The trial's stated purpose and listed treatment schedules frame the comparison, but the registry entry does not include enough detail to reconstruct every treatment-delivery or eligibility decision.
3. Trial Design
This was a randomized, parallel-arm phase III trial with no masking reported. The registry lists an enrollment of 432. The posted arm entries list 203 for interferon and 199 for biochemotherapy; these arm figures are the values recorded for the outcome, and they should not be treated as a reconciliation of all enrolled participants. The record does not explain any difference between the enrollment figure and the outcome-arm entries.
The interferon arm received interferon alfa intravenously on days 1-5 of weeks 1-4, followed by subcutaneous interferon alfa on days 1, 3, and 5 of weeks 5-52, unless disease progression or unacceptable toxicity occurred. The biochemotherapy description lists intravenous cisplatin followed by vinblastine on days 1-4; dacarbazine on day 1; interleukin-2 over 96 hours on days 1-4; and subcutaneous interferon alfa on specified days. Filgrastim is also listed, but the registry's arm description ends before its schedule is complete. The complete dosing schedule for that component is therefore not reported in the registry record.
The study started in 2000-08, had primary completion in 2012-07, and is recorded as completed. The sponsor is SWOG Cancer Research Network. Overall survival was the primary outcome described in the record. Toxicity is listed as a secondary outcome. The registry gives a timeframe for assessing the primary outcome, but it does not report a full analysis protocol, allocation concealment procedures, or detailed follow-up procedures beyond the outcome description.
Randomization supports a comparative interpretation by assigning participants to treatment strategies rather than letting treatment choice alone determine the comparison. General statistical context: randomization can reduce systematic differences between groups at assignment, but it does not guarantee that every measured or unmeasured characteristic is balanced. The registry record does not provide baseline characteristics or enough detail to assess balance directly. Because the study is unmasked, knowledge of assigned treatment may have been available during trial conduct; the record does not describe how that possibility was managed for outcome assessment or other decisions.
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
| Stage | Interferon | Biochemotherapy |
|---|---|---|
| STARTED | 212 | 220 |
| Eligible | 203 | 200 |
| Eligible and Treated | 203 | 199 |
| COMPLETED | 87 | 159 |
| NOT COMPLETED | 125 | 61 |
Reasons for not completing this period:
| Reason | Interferon | Biochemotherapy |
|---|---|---|
| Adverse Event | 39 | 29 |
| Death | 1 | 0 |
| Refusal unrelated to adverse effects | 8 | 4 |
| Progression/relapse | 54 | 2 |
| Not eligible | 9 | 20 |
| Withdrawal by Subject | 0 | 1 |
| Not protocol specified | 14 | 5 |
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.
| Characteristic | Unit | Interferon | Biochemotherapy | Total |
|---|---|---|---|---|
| Participants analysed | 203 | 199 | 402 | |
| Age, Continuous | years | 47 (12 to 73) | 46 (10 to 74) | 47 (10 to 74) |
| Sex: Female, Male: Female | Participants | 62 | 58 | 120 |
| Sex: Female, Male: Male | Participants | 141 | 141 | 282 |
| Region of Enrollment: United States | participants | 203 | 199 | 402 |
6. Primary Endpoint
The registry lists the primary outcome as 5-year Overall Survival, measured over Every three months for a year, every six months for years 2-5, annual for years 5-10.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Percent of population |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is 5-year overall survival, recorded as a percent of the population. The registry defines overall survival as the time from registration to death from any cause. For participants last known to be alive, the observation is censored at the date of last contact. The stated assessment schedule is every three months for a year, every six months for years 2-5, and annually for years 5-10.
Overall survival is used in clinical trials because it captures death from any cause and has a clear event definition. It does not depend on deciding whether a death was caused by the disease or treatment. General statistical explanation: time-to-event outcomes can incorporate the timing of events and censoring, rather than treating every participant as if the outcome were observed for an identical duration. Censoring records that an event was not observed by the last known contact; it does not mean that the participant remained alive indefinitely.
The posted 5-year value is 56.0 in each arm. The registry does not provide confidence intervals for those values, so their precision cannot be read from the percentages alone. Nor does the record give a hazard ratio or another numerical effect estimate for the between-arm comparison. The log-rank test result is reported separately.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry reports a 5-year overall-survival value of 56.0 for the interferon arm and 56.0 for the biochemotherapy arm. It also reports a log-rank p-value of 0.49 for the comparison. The equal displayed percentages are the recorded point values, while the p-value summarizes a test comparing time-to-event information over follow-up. Neither entry, by itself, establishes that the treatments have identical outcomes.
General statistical explanation: a p-value measures how compatible the observed data are with a specified statistical null model, under the assumptions of the test. It is not the probability that the null hypothesis is true, and it does not quantify the size or clinical importance of a difference. A p-value of 0.49 is not conventionally described as strong evidence against the null model, but it also cannot prove that the treatments are equivalent or that a meaningful difference is absent. The registry does not report an equivalence or non-inferiority margin.
The precision of the comparison is difficult to judge from the posted results because the record does not report a confidence interval or a treatment-effect estimate. General statistical explanation: a confidence interval describes a range of effect values compatible with the data and the method used, and can help show whether estimates are precise or uncertain. Without such an interval, the equal rounded arm values should not be taken to mean that uncertainty is negligible. The record also does not provide a numerical estimate of the relative survival experience between arms.
The overall-survival definition includes deaths from any cause and censors participants at last contact if they were last known to be alive. This makes the result dependent on follow-up as well as events. The record does not report the amount of follow-up available by arm, the number of deaths, or details about losses to follow-up. It is therefore not possible to assess the completeness of follow-up from the posted outcome figures alone.
The endpoint is described as 5-year overall survival, but the listed assessment timeframe extends beyond that point. The registry gives the schedule in broad terms, not a detailed account of how survival estimates were constructed or how participants with incomplete follow-up contributed. The analysis method listed for the arm comparison is the log-rank test. No adjusted analysis or additional primary-endpoint model is described in the record.
The interpretation should remain tied to the registered comparison: two treatment strategies in a randomized phase III study of high-risk melanoma. The record does not provide subgroup findings, baseline characteristics, or details sufficient to evaluate whether any subgroup had a different pattern. It also does not provide a basis for translating these aggregate results into advice for an individual. The posted data describe the comparison and its statistical test, not a definitive claim of equal effects or a guarantee of outcome.
9. Statistical Methods Explained
What does the log-rank test compare?
The registry identifies the log-rank test as the method for comparing the two arms on overall survival. General statistical explanation: the log-rank test is designed for time-to-event outcomes. Rather than comparing only the proportion alive at one selected time, it uses the timing of observed deaths and the number of participants still under observation at event times. Censoring is incorporated by recognizing that a censored participant was observed without a recorded death up to the censoring time, while not treating that person as observed indefinitely.
The test produces evidence about whether the observed event-time patterns differ under its null model. The record reports p = 0.49. This is not an estimate of the size of a treatment effect. A p-value does not say how many months or years of survival might be gained or lost, and it is not an individual-level prediction. Since the registry does not report the test statistic, a hazard ratio, or a confidence interval, the magnitude and precision of the between-arm contrast are not available from the reported analysis.
What does censoring mean in this record?
The endpoint definition says that overall survival runs from registration until death from any cause. For patients last known to be alive, observations are censored at the date of last contact. General statistical explanation: censoring is a way to use partial follow-up without claiming that the event occurred or that it will never occur. Standard time-to-event methods rely on assumptions about the relationship between censoring and the chance of the event. The registry does not describe diagnostics or analyses addressing those assumptions, nor does it report how many observations were censored.
The stated follow-up schedule is every three months for a year, every six months for years 2-5, and annually for years 5-10. This tells readers the intended timing of assessments as recorded, but not how closely actual follow-up followed that schedule. Details about missed visits, follow-up completeness, or the handling of particular missing observations are not reported in the registry record.
How should the 5-year percentages be read?
The outcome is recorded as a percentage of the population, and the posted value is 56.0 in each arm. General statistical explanation: a survival percentage at a specified time is an estimate of the proportion surviving to that time under the method used. It is not the same thing as a direct count of people alive at that time unless the study's analysis and follow-up support that interpretation. Time-to-event estimates can use partial follow-up and censoring; the registry does not describe the estimator used to generate the posted percentages.
A point estimate alone does not show its sampling uncertainty. Confidence intervals are commonly used to express the range of values compatible with the data under a statistical method. The record does not report confidence limits for the arm percentages. The equality of the displayed values therefore should not be read as proof of exact equality in the underlying populations.
What can and cannot be inferred from the p-value?
General statistical explanation: a p-value is calculated under a null hypothesis and model assumptions. It reflects how unusual the observed test result, or a more extreme one, would be if that null model held. It does not give the probability that treatment has no effect, and a large p-value does not demonstrate equivalence. Establishing equivalence would require a specified margin and an analysis designed to assess whether plausible effects fall within that margin. Such a margin is not reported in the registry record.
The reported p-value of 0.49 is the only numerical inferential result given for the primary comparison. The record does not state whether the reported test was adjusted for any covariates, nor does it give an adjusted estimate. The entry identifies a log-rank method, but the broader statistical analysis plan, including any choices about stratification or additional modeling, is not reported in the registry record.
What does the sample-size context establish?
General statistical explanation: sample-size planning asks how much information a study may need to detect a specified effect under assumptions about variability, event rates, allocation, and error rates. A planning illustration based on an observed effect is not the trial's original design justification and is not observed power. The registry record does not report the trial's sample-size justification, its target effect, or its design assumptions. No sample-size planning result should be treated as an observed trial outcome.
The record lists enrollment and separate arm counts associated with the posted outcome. Those entries do not, on their own, explain the analysis population, exclusions, or how many participants contributed to each part of the time-to-event analysis. The registry does not report whether the primary analysis followed intention-to-treat principles or another population definition. These omissions limit how fully the reported test can be reconstructed.
10. Analyses Reported by the Sponsor
| Method | Estimate | 95% CI | P-value |
|---|---|---|---|
| Log Rank | not reported | 0.490 |
The registry reports a log-rank analysis with p = 0.49. It does not provide a numerical treatment-effect estimate or confidence interval from that analysis. The primary outcome values recorded for the arms are both 56.0, but they are not a substitute for an effect estimate with uncertainty.
No separate recalculated inferential result is available for this count-other endpoint in the registry record. The posted outcome does not provide the summary statistics needed to reconstruct a two-arm comparison beyond the analysis already reported. Accordingly, there is no recalculated estimate to contrast with the registry's log-rank result. The discrepancy flag is false, so there is no recorded disagreement between a sponsor analysis and a recalculation.
For interpretation, the reported log-rank analysis is the relevant inferential result in the registry. The p-value should be read as a test result, not as a measure of the size or precision of any difference. The missing confidence interval and effect estimate mean that the degree of uncertainty around the comparison is not fully characterized in the posted record.
11. Multiplicity, Missing Data and Analysis Populations
The registry lists three outcome measures and two analyses. It identifies 5-year overall survival as the primary outcome and toxicity as a secondary outcome; one secondary outcome is posted. Details for any other outcome measures are not reported in the registry record. The record does not state how the outcomes were prioritized beyond identifying the primary endpoint.
Multiplicity arises when a study makes several statistical comparisons or evaluates several outcomes. General statistical explanation: as the number of tests increases, the chance of obtaining at least one apparently notable result by chance can increase. Researchers may address this through prespecified hierarchies or adjustments, but the registry does not report a multiplicity strategy. It also does not report whether interim analyses were planned or conducted, or whether any interim-analysis rules affected the final test.
The primary outcome description specifies censoring at the date of last contact for patients last known to be alive. This gives one part of the missing-data and follow-up approach for overall survival. The record does not report the number of censored observations, loss-to-follow-up details, missing-data procedures for other outcomes, or sensitivity analyses. Such information would help readers assess the extent and potential influence of incomplete observation.
The analysis population is not specified. The registry does not say whether the primary comparison included everyone as randomized, whether participants were excluded after randomization, or how treatment discontinuation was handled analytically. The outcome entries list arm counts, but those figures alone do not establish the rules used to select the analysis population.
The registry provides an endpoint schedule and a log-rank method, but it does not report a complete statistical analysis plan. Specifics about stratification, covariate adjustment, handling of protocol deviations, and prespecification of analyses are not reported in the registry record. These gaps do not invalidate the posted result, but they constrain independent assessment of the analysis choices and the possible effects of missingness or multiple testing.
12. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Interferon | 2 | 193 | 1.0% |
| Biochemotherapy | 4 | 185 | 2.2% |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 5% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Interferon | 132 of 193 |
| Biochemotherapy | 144 of 185 |
Most frequent serious adverse event terms
| Event term | Organ system | Interferon | Biochemotherapy |
|---|---|---|---|
| Platelet transfusion | Blood and lymphatic system disorders | 0 of 193 | 1 of 185 |
| Colitis | Gastrointestinal disorders | 0 of 193 | 1 of 185 |
| Reportable adverse event, NOS | General disorders | 1 of 193 | 0 of 185 |
| Respiratory infect w/ neutrop | Infections and infestations | 0 of 193 | 1 of 185 |
| Cerebrovascular ischemia | Nervous system disorders | 1 of 193 | 0 of 185 |
| Depression | Psychiatric disorders | 0 of 193 | 1 of 185 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Interferon | Biochemotherapy |
|---|---|---|---|
| Fatigue/malaise/lethargy | General disorders | 79 of 193 | 27 of 185 |
| Nausea | Gastrointestinal disorders | 37 of 193 | 67 of 185 |
| Neutropenia/granulocytopenia | Investigations | 38 of 193 | 65 of 185 |
| Vomiting | Gastrointestinal disorders | 23 of 193 | 52 of 185 |
| SGPT (ALT) increase | Investigations | 53 of 193 | 20 of 185 |
| Thrombocytopenia | Investigations | 15 of 193 | 58 of 185 |
| Leukopenia | Investigations | 30 of 193 | 42 of 185 |
| SGOT (AST) increase | Investigations | 42 of 193 | 20 of 185 |
| Fever without neutropenia | General disorders | 23 of 193 | 24 of 185 |
| Anemia | Blood and lymphatic system disorders | 15 of 193 | 27 of 185 |
Serious events with the highest arm-level rate: platelet transfusion (0.5%), colitis (0.5%), respiratory infect w/ neutrop (0.5%), depression (0.5%), reportable adverse event, nos (0.5%).
The registry reports serious adverse-event counts of 2 in the interferon group and 4 in the biochemotherapy group, with at-risk counts of 193 and 185, respectively. It also reports other adverse-event counts of 132 and 144, with the same corresponding at-risk counts. These are registry entries, not a complete description of event timing, severity grading, or whether events were considered related to treatment. The record does not report deaths in the adverse-event listing.
Six serious adverse-event terms are listed, each with a reported frequency of 0.5%: platelet transfusion, colitis, respiratory infect w/ neutrop, depression, reportable adverse event, NOS, and cerebrovascular ischemia. The record does not provide further descriptions of these terms in the adverse-event summary.
General statistical explanation: an at-risk denominator identifies the group against which an event count is reported, but interpretation also depends on how events were defined, collected, and summarized. Counts alone do not describe duration of exposure or account for differences in follow-up. They also should not be treated as direct evidence that one regimen is safer than the other. The registry does not provide enough detail to evaluate comparative safety beyond the posted counts and terms.
13. What the Result Does, and Does Not, Mean
The record describes a randomized phase III comparison of interferon alfa alone with a biochemotherapy regimen that included chemotherapy, interleukin-2, and interferon alfa. For the primary outcome, the posted 5-year overall-survival values are 56.0 in both arms. The reported log-rank p-value is 0.49. These figures summarize the registry's recorded result; they do not establish that the treatments have identical effects.
A p-value of 0.49 does not establish equivalence, and the registry does not report an equivalence margin. The absence of a reported confidence interval or treatment-effect estimate also means that the precision and plausible range of the comparative effect cannot be assessed from this entry. Equal displayed percentages may reflect rounding and do not by themselves prove equality of the underlying survival experience.
The result applies to the trial comparison and its recorded population, not automatically to other populations, treatment settings, or individual decisions. The registry describes the participants as having high-risk melanoma but does not give detailed eligibility criteria. Baseline characteristics, subgroup results, and a clearly defined analysis population are not reported in the registry record.
The outcome is overall survival from registration to death from any cause, with censoring at last contact for those last known alive. That definition is direct and clinically interpretable, but the posted entry does not supply death counts, censoring counts, confidence limits, or detailed follow-up completeness. Those omissions limit assessment of how much information supports the estimates.
The adverse-event entries report serious and other event counts and several serious-event terms. They do not provide enough detail about exposure time, event attribution, or collection methods for a complete comparative safety assessment. In short, the record supports a description of the recorded endpoints and test result, while leaving important questions about precision, analysis populations, and follow-up unanswered.
14. Why This Trial Matters Statistically
This trial illustrates why a reported endpoint value and a statistical test answer different questions. The arm entries give the 5-year overall-survival value, while the log-rank p-value summarizes a comparison of time-to-event patterns. Neither item alone provides the size and precision of a treatment contrast. Reading both in context avoids treating a p-value as an effect estimate or treating matching rounded percentages as proof of equal outcomes.
It also highlights the importance of censoring in survival analysis. The registry defines death as the event and last contact as the censoring point for patients last known alive. General statistical explanation: time-to-event methods make use of follow-up that ends before an event is observed, but conclusions depend on follow-up and censoring assumptions. Reporting the censoring definition is useful; counts and further follow-up details would make the analysis easier to evaluate.
The record offers a practical example of the limits of registry-level statistical reporting. It identifies randomization, parallel arms, the primary endpoint, the log-rank method, and selected adverse-event figures. However, it does not provide a confidence interval or treatment-effect estimate, a detailed analysis population, or the full statistical plan. The result is therefore interpretable at a basic level but cannot be independently reconstructed in detail from the registry entry alone.
Finally, the comparison demonstrates why a non-significant test is not the same as evidence of equivalence. Equivalence requires a prespecified margin and an analysis suited to that question; neither is reported. Statistical interpretation should distinguish the question the trial tested from conclusions that would require additional design information or estimates. That distinction matters when reading clinical trial results in any disease area.
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.
Several trial-specific limitations of interpretation follow directly from the registry entry. The record reports the same 5-year overall-survival value, 56.0, for both arms and a log-rank p-value of 0.49, but gives no confidence interval or numerical treatment-effect estimate. Without those quantities, readers cannot assess the precision of the comparison or the range of effects compatible with the analysis.
The registry defines the endpoint and its censoring rule but does not report the number of deaths, the number of censored observations, or detailed follow-up completeness. Although an assessment schedule is listed, actual follow-up patterns are not described. These omissions make it difficult to judge how much information was available at the 5-year endpoint or how censoring may have affected the estimates.
The record does not provide detailed eligibility criteria, baseline characteristics, or a specified analysis population. It therefore does not permit assessment of group balance or of which participants were included in the primary analysis. The enrollment entry and outcome-arm entries are recorded separately, but the registry does not explain their relationship.
The biochemotherapy arm description is incomplete for filgrastim, and the registry does not provide a complete statistical analysis plan. Details about allocation concealment, interim analyses, multiplicity, covariate adjustment, and handling of protocol deviations are not reported in the registry record. The adverse-event summary also lacks information about event attribution, exposure duration, and collection procedures. These are limits on what can be inferred from this record, rather than evidence that any particular procedure was or was not used.
16. Related Tutorials
17. Related Statistical Calculators
18. Sources
- ClinicalTrials.gov: S0008: Chemotherapy Plus Biological Therapy in Treating Patients With Melanoma — NCT00006237.
- Registry record last updated 2015-03-25; status last verified 2015-03.
- Results first posted 2012-09-19.
- 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.
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19. Record Summary
The registry record describes a completed randomized, parallel-arm phase III trial of treatment strategies for high-risk melanoma. The comparison was interferon alfa versus biochemotherapy comprising cisplatin, vinblastine, dacarbazine, interleukin-2, and interferon alfa; filgrastim is also listed. The registry reports no masking.
The primary endpoint was 5-year overall survival, defined from registration until death from any cause, with censoring at last contact for patients last known alive. The posted value is 56.0 for each arm. The reported log-rank p-value is 0.49. Confidence intervals and a numerical comparative effect estimate are not reported.
Toxicity is listed as a secondary outcome. The record reports selected serious and other adverse-event counts and serious-event terms. Further details about analysis populations, missing data, multiplicity, and the statistical plan are not reported in the registry record.