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 ClinicalTrials.gov record.
1. Trial at a Glance
ToGA was a completed, randomized, open-label phase 3 trial evaluating trastuzumab in combination with fluoropyrimidine and cisplatin chemotherapy versus fluoropyrimidine/cisplatin alone in patients with HER2-positive advanced gastric cancer. The registry reports 584 participants, two treatment arms, two registered primary endpoints, and seven posted statistical analyses.
| Feature | ToGA |
|---|---|
| Phase | Phase 3 |
| Condition | Gastric Cancer |
| Population | Patients with HER2-positive advanced gastric cancer |
| Design | Randomized, parallel-group, open-label |
| Allocation | Randomized |
| Primary purpose | Treatment |
| Primary endpoints | Overall Survival (OS) - Percentage of Participants With an Event; Overall Survival - Time to Event |
| Primary endpoint type | Time-to-event |
| Hypothesis type | Superiority |
| Enrollment | 584.0 |
| Trial status | Completed |
| Start | 2005-09 |
| Primary completion | 2010-06 |
| Lead sponsor | Hoffmann-La Roche |
| Sponsor type | Industry |
| ClinicalTrials.gov | NCT01041404 |
2. Clinical Question
The central statistical question was whether adding trastuzumab to fluoropyrimidine/cisplatin chemotherapy changed overall survival compared with fluoropyrimidine/cisplatin alone in patients with HER2-positive advanced gastric cancer.
Population
Patients with HER2-positive advanced gastric cancer, as identified in the trial's condition and brief title.
Intervention
Trastuzumab combined with fluoropyrimidine/cisplatin chemotherapy.
Comparator
Fluoropyrimidine/cisplatin chemotherapy alone.
Primary question
Does adding trastuzumab change overall survival relative to fluoropyrimidine/cisplatin alone?
3. Trial Design
Fluoropyrimidine/Cisplatin
- Fluoropyrimidine
- Cisplatin
- Abbreviated in the registry as FP
Trastuzumab + Fluoropyrimidine/Cisplatin
- Trastuzumab
- Fluoropyrimidine
- Cisplatin
- Abbreviated in the registry as FP + H
4. Registered Primary Endpoints
The registry contains two primary endpoints, both concerning overall survival. One is expressed as the percentage of participants with an event; the other is the time to an OS event. The posted formal statistical analysis is for the time-to-event endpoint.
| Endpoint | Registered definition | Time frame | Formal analysis posted |
|---|---|---|---|
| Overall Survival (OS) - Percentage of Participants With an Event | OS was defined as the time from the date of randomization to the date of death due to any cause. Participants were censored at the last date of tumor measurement, the last date in the study drug log, or the date of last follow-up. | Baseline (BL), Days 1, 8, 15, 22, 43, 64, 85, 106, 127, and every 21 days until the end of study, 1 year after the cut-off date for the 2nd interim efficacy analysis | No formal statistical analysis is posted for this specific endpoint in the ClinicalTrials.gov record. |
| Overall Survival - Time to Event | The median time, in months, from the date of randomization to the date of an OS event. Participants were censored at the last date tumor measurement, the last date in the study drug log, or the date of last follow-up. | BL, Days 1, 8, 15, 22, 43, 64, 85, 106, 127, and every 21 days until the end of study, 1 year after the cut-off date for the 2nd interim efficacy analysis | Yes |
Why the two primary endpoint formulations matter
The registry distinguishes an event-based OS endpoint from an OS time-to-event endpoint. For a time-to-event endpoint, patients can contribute information even when they have not experienced death by the end of their observed follow-up, because their observations are censored rather than discarded.
The ClinicalTrials.gov record does not provide a separate effect estimate, confidence interval, or p-value for the primary endpoint labelled "Overall Survival (OS) - Percentage of Participants With an Event." The formal primary statistical result available in the ClinicalTrials.gov record is therefore the OS time-to-event analysis.
5. Endpoints
The registered and posted outcomes cover time-to-event, binary response, and clinical-benefit measures. The registry's statistical methods include log-rank testing for time-to-event outcomes and chi-squared testing for binary outcomes.
| Endpoint | Type | Analysis population | Reported method |
|---|---|---|---|
| Overall Survival - Time to Event | Time-to-event | FAS | Log-rank |
| Progression-Free Survival - Time to Event | Time-to-event | FAS | Log-rank |
| Time to Progression - Time to Event | Time-to-event | FAS | Log-rank |
| Percentage With Confirmed Complete Response or Partial Response | Binary | FAS | Chi-squared |
| Duration of Response | Time-to-event | FAS; only participants with a CR or PR included | Log-rank |
| Percentage With Clinical Benefit | Binary | FAS | Chi-squared for one posted analysis |
| Percentage With Clinical Benefit | Binary | FAS | Odds ratio posted; method not reported |
6. Statistical Methodology
Log-rank testing for time-to-event outcomes
The registry reports the log-rank test for overall survival, progression-free survival, time to progression, and duration of response. The log-rank test compares the observed pattern of event occurrence between randomized groups over follow-up while accounting for censored observations.
The log-rank test is not a measure of effect size. The hazard ratio provides a separate estimate describing the relative event hazard under the corresponding time-to-event analysis.
Hazard ratio
The primary OS analysis reports a hazard ratio of 0.74 comparing FP with trastuzumab + FP as the registry lists the groups. A hazard ratio below 1 indicates a lower estimated instantaneous event rate for the first-listed group relative to the second-listed group under the fitted time-to-event comparison.
An HR of 0.74 corresponds to an estimated instantaneous hazard about 26% lower in the FP group relative to the FP + H group if interpreted directly from that group ordering. This is a relative hazard statement, not a statement that 26% of patients benefit or that survival probability is 26% higher.
Chi-squared testing for binary outcomes
The percentage of participants with confirmed complete response or partial response was analyzed using a chi-squared test. The same method was reported for one analysis of clinical benefit.
For a binary endpoint, the treatment comparison is based on the distribution of participants between outcome categories. The reported difference in response rates provides an absolute contrast, while an odds ratio provides a relative comparison on the odds scale.
Analysis population
The posted analyses identify the Full Analysis Set (FAS) as the analysis population. For duration of response, the registry adds an important qualification: only participants with a complete response or partial response were included in that analysis.
Confidence intervals
The posted effect estimates use two-sided 95% confidence intervals. For the OS hazard ratio, the interval is 0.60 to 0.91. For binary response and clinical-benefit differences, the registry also reports two-sided 95% confidence intervals.
7. Primary Result: Overall Survival
The formal primary statistical analysis posted for ToGA is the overall-survival time-to-event comparison. It used the Full Analysis Set and a two-sided log-rank test under a superiority hypothesis.
Overall Survival Hazard Ratio
95% CI: 0.60–0.91 · P = 0.0046
Analysis population: FAS · Method: log-rank test
| Primary OS analysis | FP | Trastuzumab + FP |
|---|---|---|
| Comparison | Fluoropyrimidine/Cisplatin versus Trastuzumab + Fluoropyrimidine/Cisplatin | |
| Effect measure | Hazard ratio | |
| Estimate | 0.74 | |
| 95% CI | 0.60–0.91 | |
| P-value | 0.0046 | |
| Hypothesis | Superiority | |
The reported hazard ratio of 0.74 is a relative time-to-event measure. Because the registry lists FP first and FP + H second, the estimate corresponds to the estimated event hazard for FP relative to trastuzumab + FP. Numerically, 0.74 is 26% below 1, so under that group ordering it represents an estimated 26% lower instantaneous event hazard for the first-listed group relative to the second-listed group.
The estimate does not mean that 26% of patients survived, that 26% of patients benefited, or that every participant experienced exactly a 26% reduction in risk. It also does not directly give an absolute survival probability or an absolute difference in survival time.
The 95% confidence interval of 0.60 to 0.91 describes the statistical uncertainty around the hazard-ratio estimate under the analysis framework. Its width provides information about precision; it is not a range describing individual patient outcomes.
The P-value of 0.0046 quantifies how incompatible the observed comparison is with the null hypothesis used for the test under the specified statistical framework. It does not measure the magnitude of the treatment effect, the probability that the treatment works, or the probability that the null hypothesis is true.
As with other hazard-ratio analyses, interpretation of a single HR requires care if the relative hazards change substantially over time. The ClinicalTrials.gov record does not report a separate assessment of the proportional-hazards assumption, so that assumption should not be treated as independently verified here.
The other registered primary endpoint
The registry also lists "Overall Survival (OS) - Percentage of Participants With an Event" as a primary endpoint. Its definition is based on death from any cause, with censoring at the last tumor measurement, last date in the study drug log, or last follow-up. The ClinicalTrials.gov record does not contain a formal statistical analysis with an estimate, confidence interval, or p-value for this endpoint, so no separate comparative result is presented here.
8. Secondary Result: Progression-Free Survival
Progression-free survival was analyzed in the Full Analysis Set using a two-sided log-rank test. The registry reports a hazard ratio as the effect measure.
Progression-Free Survival Hazard Ratio
95% CI: 0.59–0.85 · P = 0.0002
Analysis population: FAS · Method: log-rank test
| Secondary PFS analysis | Reported result |
|---|---|
| Groups | Fluoropyrimidine/Cisplatin versus Trastuzumab + Fluoropyrimidine/Cisplatin |
| Effect measure | Hazard ratio |
| Estimate | 0.71 |
| 95% CI | 0.59–0.85 |
| P-value | 0.0002 |
| Hypothesis | Superiority |
| Time frame | BL, Days 43, 85, and 127, and every 21 days thereafter until disease progression or the end of study, 1 year after the cut-off date for the 2nd interim efficacy analysis |
The reported PFS hazard ratio is 0.71, with the same FP-versus-FP + H group ordering shown in the registry. On that scale, the estimated instantaneous hazard of the PFS event is 29% lower for FP than for FP + H. This is a relative hazard interpretation and should not be converted into a statement about the percentage of patients who are progression-free at a particular time.
The 95% CI of 0.59 to 0.85 indicates uncertainty around the estimated hazard ratio. The interval is narrower than the corresponding OS interval of 0.60 to 0.91, although the two endpoints concern different event definitions and should not be compared simply by interval width.
The P-value of 0.0002 is evidence against the specified null hypothesis under the reported test. It is not a measure of how large the effect is. The effect magnitude is described by the HR and its confidence interval.
The PFS time frame begins at baseline and includes scheduled assessments on Days 43, 85, and 127 and every 21 days thereafter until disease progression or the end of study, according to the registry wording reported here.
9. Secondary Result: Time to Progression
Time to progression was another time-to-event endpoint analyzed in the Full Analysis Set using a log-rank test.
Time to Progression Hazard Ratio
95% CI: 0.58–0.85 · P = 0.0003
Analysis population: FAS · Method: log-rank test
The HR of 0.70 represents a 30% lower estimated instantaneous hazard for the first-listed FP group relative to the second-listed FP + H group under the registry's group ordering. This is a model-based relative event measure, not an absolute reduction in the probability of progression.
The 95% CI of 0.58 to 0.85 provides the uncertainty interval reported by the registry. The P-value of 0.0003 concerns the hypothesis test; it does not quantify clinical importance or effect size.
Because time to progression and progression-free survival are distinct registered endpoints, their numerical estimates should not be treated as interchangeable even though both are time-to-event outcomes.
10. Secondary Result: Confirmed Complete or Partial Response
The registry reports a binary endpoint measuring the percentage of participants with confirmed complete response or partial response determined by RECIST. The comparison used a chi-squared test in the Full Analysis Set.
Difference in Response Rates
95% CI: 4.7–20.9 · P = 0.0017
Effect measure: Difference in Response Rates · Method: chi-squared test
The reported effect measure is an absolute difference in response rates, not a hazard ratio. The registry reports an estimate of 12.80, with a two-sided 95% CI of 4.7 to 20.9.
This means the response-rate comparison is expressed on an absolute percentage-point scale. It should not be interpreted as a 12.80-fold increase or as a 12.80% relative increase unless the underlying rates are explicitly used to define that different measure.
The confidence interval quantifies uncertainty around the reported difference. The P-value of 0.0017 addresses the statistical test for the categorical comparison; it does not describe the magnitude of the response-rate difference.
The registry identifies the endpoint as confirmed complete response or partial response determined by RECIST. It does not provide the two arm-specific response percentages in the ClinicalTrials.gov record, so they are not reconstructed here.
11. Secondary Result: Duration of Response
Duration of response was analyzed as a time-to-event endpoint using a log-rank test. Importantly, the registry specifies that only participants with a complete response or partial response were included in this analysis.
Duration of Response Hazard Ratio
95% CI: 0.40–0.73 · P < 0.0001
Analysis population: FAS; only participants with a CR or PR included
The duration-of-response HR of 0.54 corresponds to a 46% lower estimated instantaneous event hazard for the first-listed FP group relative to the FP + H group under the registry's stated group ordering.
The important analytical qualification is the population: this analysis includes only participants who achieved a complete or partial response. It therefore answers a different question from the primary OS analysis, which uses the Full Analysis Set.
The 95% CI of 0.40 to 0.73 describes uncertainty around the response-duration hazard ratio. The P-value of < 0.0001 concerns the statistical evidence under the reported log-rank test and does not itself measure the duration difference or its clinical magnitude.
12. Secondary Results: Clinical Benefit
The registry contains two posted analyses for the percentage of participants with clinical benefit. Both use the Full Analysis Set and compare fluoropyrimidine/cisplatin with trastuzumab plus fluoropyrimidine/cisplatin.
| Clinical-benefit analysis | Estimate | 95% CI | P-value | Method |
|---|---|---|---|---|
| Difference in Clinical Benefit Rate | 9.60 | 2.4–16.9 | 0.0081 | Chi-squared test |
| Odds Ratio | 1.66 | 1.14–2.41 | Not reported | Not reported |
The first analysis expresses the treatment contrast as a difference in clinical benefit rate of 9.60, with a 95% CI of 2.4 to 16.9 and P = 0.0081 from a chi-squared test. This is an absolute difference measure.
The second analysis reports an odds ratio of 1.66, with a 95% CI of 1.14 to 2.41. The registry does not report the formal method for this particular analysis in the ClinicalTrials.gov record, and it does not provide a p-value for it. The odds ratio should therefore be kept conceptually separate from the difference in rates.
An odds ratio of 1.66 does not mean that the probability of clinical benefit was 66% higher. Odds and probabilities are different quantities. Converting an odds ratio to a risk ratio requires the underlying event rates.
13. Statistical Results at a Glance
| Endpoint | Role | Effect | 95% CI | P-value | Method |
|---|---|---|---|---|---|
| Overall Survival - Time to Event | Primary | HR 0.74 | 0.60–0.91 | 0.0046 | Log-rank |
| Progression-Free Survival - Time to Event | Secondary | HR 0.71 | 0.59–0.85 | 0.0002 | Log-rank |
| Time to Progression - Time to Event | Secondary | HR 0.70 | 0.58–0.85 | 0.0003 | Log-rank |
| Confirmed CR or PR | Secondary | Difference 12.80 | 4.7–20.9 | 0.0017 | Chi-squared |
| Duration of Response | Secondary | HR 0.54 | 0.40–0.73 | <0.0001 | Log-rank |
| Clinical Benefit | Secondary | Difference 9.60 | 2.4–16.9 | 0.0081 | Chi-squared |
| Clinical Benefit | Secondary | OR 1.66 | 1.14–2.41 | Not reported | Not reported |
14. Safety Results
The ClinicalTrials.gov record reports serious adverse events by treatment arm. The figures are presented as affected participants divided by participants at risk.
| Serious adverse events | Affected / at risk |
|---|---|
| Fluoropyrimidine/Cisplatin (FP) | 81 / 290 |
| Trastuzumab + Fluoropyrimidine/Cisplatin | 106 / 294 |
15. Statistical Methods Explained
Why was a log-rank test used for overall survival?
Overall survival is a time-to-event endpoint: the outcome is not simply whether death occurred, but the time from randomization to death, with censoring for participants who remain under observation without a recorded event. The log-rank test is designed to compare the survival experience of two groups across follow-up while incorporating censored observations.
What does an OS hazard ratio of 0.74 mean?
With FP listed first and FP + H second, the reported HR of 0.74 represents the estimated instantaneous event hazard for FP relative to FP + H. Numerically, it is 26% below 1. It does not mean that 26% more people survived, that survival time increased by 26%, or that each individual had exactly a 26% reduction in risk.
Why is the confidence interval important?
The point estimate is only one summary of the treatment comparison. The 95% CI of 0.60 to 0.91 shows the statistical uncertainty surrounding the OS HR under the reported analysis. A confidence interval also helps distinguish a precise estimate from a highly uncertain one; it should be interpreted alongside the effect estimate rather than replaced by the P-value.
Why doesn't the P-value measure effect size?
The OS P-value of 0.0046 addresses the compatibility of the observed data with the null hypothesis under the specified test. It is affected by both the size of the observed difference and the amount of information available. The HR and confidence interval are the quantities that describe the estimated relative effect and its uncertainty.
Why was a chi-squared test used for response?
Confirmed complete response or partial response is a binary outcome. Each participant falls into an outcome category, and the chi-squared test provides a way to compare the distribution of those categories between treatment groups. The corresponding effect measure in the registry is a difference in response rates.
Why is duration of response analyzed in responders?
The registry explicitly defines the duration-of-response analysis population as the FAS with only participants who achieved a complete response or partial response included. Conceptually, duration of response begins with achievement of a qualifying response, so it addresses how long those responses persist rather than whether patients respond in the first place.
How should the clinical-benefit odds ratio be interpreted?
An odds ratio of 1.66 compares the odds of clinical benefit between the groups in the registry's reported analysis. Odds are not probabilities. An OR of 1.66 therefore cannot be read as a 66% increase in the probability of benefit without knowing the underlying event rates.
16. Understanding the Time-to-Event Framework
Several of the ToGA outcomes are time-to-event endpoints. This is important because conventional methods for comparing simple proportions do not fully use the information available when patients are followed for different lengths of time.
Event
For overall survival, the registered event is death due to any cause.
Censoring
For OS, participants were censored at the last tumor measurement, last date in the study drug log, or last follow-up, according to the registry definition.
Analysis
The registry reports log-rank testing for the time-to-event comparisons.
Effect measure
The main time-to-event effect measure posted for these analyses is the hazard ratio.
The distinction between an event and censoring is central to survival analysis. A participant who has not experienced the event by the end of observed follow-up is not treated as though the event could never occur. Instead, the participant contributes information up to the censoring time.
Here, di represents events at a particular event time and ni represents participants at risk immediately before that time. The registry-reported ToGA registry data do not contain the event-level information required to calculate a trial-specific Kaplan-Meier curve.
17. Interpreting the Direction of the Hazard Ratios
A particularly important statistical detail on this page is the ordering of the groups. The registry lists the comparisons as "Fluoropyrimidine/Cisplatin (FP) vs Trastuzumab + Fluoropyrimidine/Cisplatin (FP + H)" for the primary OS analysis, and uses similar ordering for several secondary endpoints.
| Endpoint | Group ordering in the ClinicalTrials.gov record | HR | Direct numerical interpretation |
|---|---|---|---|
| Overall Survival | FP vs FP + H | 0.74 | FP has an estimated instantaneous event hazard 26% lower than FP + H under this ordering. |
| Progression-Free Survival | FP vs FP + H | 0.71 | FP has an estimated instantaneous event hazard 29% lower than FP + H under this ordering. |
| Time to Progression | FP vs FP + H | 0.70 | FP has an estimated instantaneous event hazard 30% lower than FP + H under this ordering. |
| Duration of Response | FP vs FP + H | 0.54 | FP has an estimated instantaneous event hazard 46% lower than FP + H among the response-analysis population under this ordering. |
18. P-values, Confidence Intervals, and Effect Measures
ToGA provides a useful illustration of why statistical interpretation should use several quantities together rather than relying on a single number.
Effect estimate
The HR, odds ratio, or rate difference describes the estimated magnitude of the comparison on its particular scale.
Confidence interval
The 95% CI describes statistical uncertainty around the corresponding estimate under the reported framework.
P-value
The P-value addresses evidence against a specified null hypothesis. It is not an effect-size measure.
Endpoint definition
The meaning of an estimate depends on the event definition, time frame, and analysis population.
For example, the OS analysis has HR 0.74, 95% CI 0.60–0.91, and P = 0.0046. The PFS analysis has HR 0.71, 95% CI 0.59–0.85, and P = 0.0002. These values should not be interpreted as three interchangeable measures of the same quantity: OS and PFS have different event definitions.
Likewise, the response-rate difference of 12.80 and the clinical-benefit odds ratio of 1.66 are on different scales. An absolute difference and an odds ratio cannot be compared numerically as though they were the same type of effect measure.
19. Trial Timeline
Trial start
The registry identifies September 2005 as the study start.
Randomized treatment comparison
The completed phase 3 trial used randomized, parallel allocation to two treatment arms without masking.
Primary completion
The registry identifies June 2010 as the primary completion date.
Results posted
The registry reports results posted, with 19 outcome measures and 7 statistical analyses in the ClinicalTrials.gov record.
20. Limitations
- Registry-level reporting: this analysis is limited to the numerical and methodological information contained in the ClinicalTrials.gov record. The registry does not provide every detail that could appear in a full statistical analysis plan.
- Primary-endpoint detail: two primary endpoints are registered, but the ClinicalTrials.gov record provides a formal estimate, confidence interval, and P-value only for the OS time-to-event analysis.
- No arm-specific response percentages in the registry-reported analysis: the response endpoint provides a difference in response rates, but the ClinicalTrials.gov record does not provide the underlying response percentages.
- Open-label design: the registry identifies masking as none. The statistical implications of an unmasked design depend on the endpoint and how outcome assessment was conducted; the ClinicalTrials.gov record does not provide further details.
- Hazard-ratio assumptions: a single HR summarizes relative event hazards over the analyzed follow-up. The ClinicalTrials.gov record does not report a separate assessment of proportional hazards.
- Different analysis populations: most posted analyses use the FAS, while duration of response is restricted to participants with a CR or PR. These results therefore address different populations.
- Multiple posted analyses: the registry contains seven statistical analyses spanning primary and secondary endpoints. The ClinicalTrials.gov record does not specify a multiplicity-adjustment procedure for interpreting all of these tests as one family.
- Safety interpretation: serious-adverse-event counts are reported by arm, but the ClinicalTrials.gov record does not include a formal comparative test or confidence interval for that safety endpoint.
21. Why This Trial Matters Statistically
ToGA is a useful teaching case because it combines randomized treatment assignment with multiple types of statistical endpoints. The primary outcome is a time-to-event endpoint analyzed with a log-rank test and summarized using a hazard ratio, while several secondary outcomes demonstrate categorical-data analysis and response-duration analysis.
| Concept | How it appears in ToGA |
|---|---|
| Randomization | The registry identifies a randomized, parallel-group phase 3 design. |
| Open-label design | Masking is listed as none. |
| Time-to-event analysis | OS, PFS, time to progression, and duration of response are time-to-event endpoints. |
| Log-rank test | Used for the posted OS, PFS, time-to-progression, and duration-of-response analyses. |
| Hazard ratio | Used for the primary OS analysis and several secondary time-to-event analyses. |
| Confidence intervals | Two-sided 95% intervals accompany the reported effect estimates. |
| Chi-squared test | Used for the confirmed CR/PR endpoint and one clinical-benefit analysis. |
| Odds ratio | Posted as an effect measure for a clinical-benefit analysis. |
| Analysis populations | Most posted analyses use FAS; duration of response restricts the population to CR/PR responders. |
| Superiority hypothesis | The posted analyses identify superiority as the hypothesis type. |
22. Overall Statistical Interpretation
The ClinicalTrials.gov record reports a primary OS hazard ratio of 0.74 with a two-sided 95% CI of 0.60 to 0.91 and P = 0.0046, based on a log-rank analysis in the FAS. The registry also reports secondary hazard-ratio analyses for PFS, time to progression, and duration of response, together with categorical analyses for confirmed response and clinical benefit.
These summary statistics do not establish individual patient benefit, do not provide the complete distribution of survival times, and do not permit reconstruction of a Kaplan-Meier curve. They also do not provide the underlying arm-specific response rates for the reported response-rate difference or a formal comparative safety test.
The OS hazard ratio describes relative time-to-event experience; the response-rate difference describes an absolute categorical contrast; the clinical-benefit odds ratio describes an odds-scale comparison. Each answers a different statistical question. A careful interpretation therefore preserves the endpoint definition, effect measure, confidence interval, P-value, and analysis population rather than reducing the trial to a single number.
23. Related Tutorials
Learn more about the methods used in this trial:
24. Related Calculators
25. Sources
- ClinicalTrials.gov: NCT01041404 — ToGA.
- PubMed: PMID 25038874.
- PubMed: PMID 24951609.
- PubMed: PMID 22116464.
- PubMed: PMID 20728210.
Continue through the Clinical Biostats statistical pathway
Explore the statistical concepts behind randomized clinical trials, survival analysis, categorical endpoints, effect measures, and confidence intervals.
26. Record Summary
The ToGA registry record provides a compact example of how a randomized phase 3 oncology trial can be represented statistically across several endpoint types. The principal formal analysis is an OS time-to-event comparison using a log-rank test, with a reported hazard ratio of 0.74, 95% CI 0.60–0.91, and P = 0.0046. Secondary analyses extend the statistical framework to PFS, time to progression, duration of response, confirmed response, and clinical benefit.
The most important interpretive discipline is to keep each estimate attached to its endpoint definition and analysis population. Hazard ratios describe relative time-to-event hazards; rate differences describe absolute categorical contrasts; odds ratios describe relative odds. Confidence intervals quantify uncertainty around those estimates, while P-values address the corresponding hypothesis tests rather than effect magnitude.