Triptorelin With Either Exemestane or Tamoxifen in Treating Premenopausal Women With Hormone-Responsive Breast Cancer: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Triptorelin With Either Exemestane or Tamoxifen in Treating Premenopausal Women With Hormone-Responsive Breast Cancer (NCT00066703), a randomized phase 3 study. The primary outcome is Disease-free Survival.

2. Clinical Question

3. Trial Design

This was a randomized, phase III, parallel-group trial with no masking. It compared two endocrine-treatment regimens, both combining ovarian function suppression with triptorelin and either exemestane or tamoxifen. The registry lists 2672 participants enrolled. The primary outcome is identified as disease-free survival, and the stated analysis population is intention-to-treat.

The regimen descriptions specify triptorelin 3.75mg by intramuscular injection every 28 days for 5 years in both groups. One group received exemestane 25mg orally daily for 5 years; the other received tamoxifen 20mg orally daily for 5 years. Each oral drug began after completion of adjuvant chemotherapy if it was given, or approximately 6-8 weeks after triptorelin was initiated.

The primary outcome is a 5-year estimate reported at a median follow-up of 72 months. The posted arm estimates use 1328 participants for T+OFS and 1332 for E+OFS. The registry also reports breast cancer-free interval and distant recurrence-free interval estimates at 5 years, and overall survival estimates at 8 years, reported at a median follow-up of 9 years.

The registry record lists the trial as completed. Its own original sample-size justification, detailed allocation procedure, and any stratification factors are not reported in the registry record. The record identifies the study as unmasked but does not describe further implementation details of randomization or treatment administration.

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: Intention-to-treat

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.

Population: Intention-to-treat population excludes 12 patients who immediately withdrew consent, were at a non-adherent center, or had inadequate documentation of informed consent.

6. Primary Endpoint

The registry lists the primary outcome as Disease-free Survival, measured over 5-year estimate reported at a median follow-up of 72 months.

The primary endpoint is disease-free survival, expressed as the estimated percentage of participants alive and disease-free at 5 years from randomization. The registry definition includes time to invasive breast cancer recurrence at a local, regional, or distant site; invasive cancer in the opposite breast; a second invasive cancer other than breast cancer; or death without a cancer event. Participants are censored at the date of last follow-up if no qualifying event has been recorded.

A time-to-event endpoint uses both whether an event occurred and when it occurred. This is useful when follow-up duration varies between participants or some participants have no recorded event by their last observation. Censoring allows those participants to contribute information up to their last known follow-up rather than treating their later outcome as known.

The 5-year percentage is an estimated survival probability, not simply a count of participants who were observed continuously for exactly 5 years. The registry reports the estimate with a 95% confidence interval and gives median follow-up of 72 months. The endpoint definition is broad: it includes several cancer events as well as death without a cancer event. The registry record does not report further detail about how each component was adjudicated.

7. Results Posted in the Registry

• E+OFS: 91.1% (1213/1332) versus 87.3% (1159/1328) on control; risk difference 3.8 percentage points (95% CI 1.4 to 6.1), risk ratio 1.04 (1.02–1.07); unadjusted two-proportion z-test p = 0.002.

8. Secondary Efficacy Endpoints

The registry also posts results for secondary outcomes. For each outcome below, the endpoint type, the test applied to the posted summary statistics, the result and its interpretation are given in turn. Secondary endpoints are usually not adjusted for multiple testing, so they support rather than confirm the primary finding.

Breast Cancer-free Interval

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • E+OFS: 92.8% (1236/1332) versus 88.8% (1179/1328) on control; risk difference 4.0 percentage points (95% CI 1.8 to 6.2), risk ratio 1.05 (1.02–1.07); unadjusted two-proportion z-test p = <0.001.
• Interpretation:
  • The 95% confidence interval excludes no difference, so the proportion with the event is statistically higher for E+OFS than for the control. This is an unadjusted, secondary comparison, so it is suggestive rather than confirmatory.

Distant Recurrence-free Interval

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • E+OFS: 93.8% (1249/1332) versus 92.0% (1222/1328) on control; risk difference 1.8 percentage points (95% CI -0.2 to 3.7), risk ratio 1.02 (1.00–1.04); unadjusted two-proportion z-test p = 0.079.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between E+OFS and the control. The interval gives the range of effects that remain compatible with the data.

Overall Survival

• Endpoint type: Binary: the percentage of participants with the event (counts rebuilt from the posted percentages and group sizes).
• Test: Unadjusted two-proportion z-test, with a Wald 95% confidence interval for the risk difference.
• Result:
  • E+OFS: 93.4% (1244/1332) versus 93.3% (1239/1328) on control; risk difference 0.1 percentage points (95% CI -1.8 to 2.0), risk ratio 1.00 (0.98–1.02); unadjusted two-proportion z-test p = 0.922.
• Interpretation:
  • The 95% confidence interval includes no difference, so these data do not show a statistically significant difference between E+OFS and the control. The interval gives the range of effects that remain compatible with the data.

The secondary outcomes extend the primary comparison to other cancer-related intervals and overall survival. In broad terms, the breast cancer-free interval results follow the primary endpoint's direction, while the distant recurrence-free interval comparison is less consistent across the sponsor analysis and the unadjusted recalculation. Overall survival estimates are close, and the posted analyses do not indicate a clear difference. These outcomes provide context rather than replacing the primary endpoint.

Secondary endpoints differ in what events count and in follow-up period. Breast cancer-free and distant recurrence-free intervals focus on particular cancer outcomes, whereas overall survival concerns death from any cause. Their estimates therefore should not be treated as alternate measurements of the same outcome. The registry reports 5-year estimates for the two recurrence-related outcomes and 8-year estimates for overall survival, with median follow-up of 72 months for the former and 9 years for the latter.

Multiple outcomes create multiplicity: when many hypotheses are tested, the chance of at least one apparently notable result can increase. The registry record does not report an adjustment for multiple comparisons or identify a hierarchy for interpreting secondary outcomes. Their unadjusted results therefore carry less weight than a prespecified primary analysis, particularly when results vary across endpoints or methods. The posted pattern is useful for describing the breadth and consistency of findings, but it should not be read as a set of independent confirmations.

Detailed analysis plans, including whether secondary endpoints were prespecified in a particular order, are not reported in the registry record. The secondary results should consequently be interpreted as supportive context, with attention to their definitions, follow-up, and statistical uncertainty.

Secondary outcomes registered for this trial, for reference (only those above were recalculated):

• Breast Cancer-free Interval
• Distant Recurrence-free Interval
• Overall Survival

9. Statistical Interpretation

10. Statistical Methods Explained

What do the arm estimates represent?

The primary endpoint is a time-to-event outcome, but the registry presents the primary arm results as estimated percentages at 5 years. Each percentage estimates the share of the group alive and disease-free at that time point. A confidence interval conveys uncertainty in that estimated percentage. It is not a range containing a specified proportion of individual participant outcomes.

The arm estimates are based on the intention-to-treat population. In general, intention-to-treat analysis keeps participants in their randomized groups for analysis, regardless of treatment received or later changes, helping preserve the comparison created by randomization. The registry identifies this analysis population for the primary endpoint, but detailed handling of treatment changes and missing observations is not reported in the registry record.

What does the risk difference add?

The recalculated risk difference is an unadjusted comparison of the estimated 5-year percentages between E+OFS and T+OFS. A positive value means the estimate is higher in E+OFS. The posted risk difference is 0.038, with a 95% confidence interval from 0.014 to 0.061. Because the interval does not include zero, the estimate is inconsistent with no difference at the confidence level represented by this interval, under the recalculation's assumptions.

The recalculated comparison is based on posted summary statistics and is not the same analysis as the sponsor's time-to-event model. It does not adjust for covariates, account for the timing of individual events in the same way as a survival analysis, or replace the registry's reported log-rank result. Its purpose is to give a simple comparison of the posted estimates.

How does the log-rank result differ?

The registry reports a log-rank analysis with a hazard ratio. A log-rank test compares event-time patterns across groups over follow-up, rather than restricting comparison to a single fixed time point. The hazard ratio describes the relative event hazard under the analysis. A value below 1 for the listed E+OFS versus T+OFS comparison is in the direction of fewer events over time in E+OFS, given the ordering reported in the registry.

The hazard ratio is 0.717, with a 95% confidence interval from 0.602 to 0.855 and p = .0002. These statistics quantify the reported time-to-event comparison. The registry record does not report additional model specifications, adjustment variables, or checks of assumptions, so interpretation should remain tied to the stated log-rank method and posted estimate.

What does a p-value say?

A p-value describes how unusual results at least as inconsistent with a specified null hypothesis would be if that null hypothesis and the test assumptions were true. It is not the probability that the null hypothesis is true, and it does not measure the clinical importance of a result. The reported p-values relate to their respective analyses; the recalculated unadjusted p-value should not be treated as a replacement for the sponsor's reported test.

Confidence intervals and p-values give related but distinct information. An interval indicates a range of estimates reasonably compatible with the data and method, while a p-value summarizes evidence against a null value under a test. Their interpretation depends on the analysis and on whether multiple outcomes or comparisons were considered. The registry record does not report a multiplicity adjustment.

Why can different analyses give different values?

A survival analysis uses event timing and censoring, while a fixed-time estimate and its risk difference focus on the estimated outcome at a specified time. These methods can therefore produce different numerical summaries even when based on the same trial groups. The posted recalculation is explicitly unadjusted; the sponsor's log-rank analysis is the registry's reported time-to-event analysis. Neither statistic should be translated directly into the other.

General statistical context: censoring is common in time-to-event analysis when follow-up ends before an event is observed. The method uses known follow-up time but relies on assumptions about censoring and the analysis process. The registry says participants were censored at last follow-up in the endpoint definition, but detailed censoring patterns and diagnostics are not reported in the registry record.

11. Confidence Intervals and Precision

The primary arm estimates have 95% confidence intervals: 85.7% to 88.7% for T+OFS and 89.7% to 92.3% for E+OFS. The recalculated risk difference has a 95% confidence interval from 0.014 to 0.061. The sponsor's hazard ratio has a 95% confidence interval from 0.602 to 0.855. Each interval describes uncertainty for a different quantity; the risk difference interval is an absolute comparison of the 5-year estimates, while the hazard ratio interval concerns the relative event hazard over follow-up.

In general, a confidence interval is a range generated by a statistical method that reflects the uncertainty in an estimate. A narrower interval indicates greater precision for that particular estimate, while a wider interval indicates less precision. A 95% interval does not mean that 95% of individual participants have outcomes inside it, and it does not include all uncertainty about the study's design or analysis.

The arm intervals and comparison interval should not be interpreted as if they were the same calculation. A comparison can have its own uncertainty, which is why the risk difference interval is relevant to the contrast. The sponsor's time-to-event interval also incorporates a different analysis target. Follow-up duration, censoring, and the number and timing of events can influence precision, but detailed event-time data are not reported in the registry record.

Precision is not the same as clinical importance. The posted estimates provide information about statistical uncertainty, but the registry record does not report a threshold defining a clinically important difference. The comparison therefore needs to be read alongside the endpoint definition, secondary outcomes, and limitations in the available analysis details.

12. Planning a Similar Trial: Sample Size

This is a planning illustration, not a re-evaluation of the original trial. It asks: if a new study wanted to detect a difference like the one observed, or a smaller one, how large would it need to be? It is deliberately not “observed power” of the finished trial, which is not a meaningful quantity.

The sample-size illustrations describe planning under assumptions based on the observed effect; they are not the trial's original design calculations. For binary outcomes, the listed figures are participants per arm. For time-to-event outcomes, the figures represent total events. The planning assumptions are a two-sided significance level of 0.05, equal allocation between the two arms, and a normal approximation; the effect to detect is the stated fraction of the observed effect.

The 80% power column gives the number of participants per arm, or total events for time-to-event outcomes, associated with an 80% chance of detecting the assumed effect under those planning assumptions, if that effect and the assumptions hold. The 90% power column gives the corresponding planning amount for a 90% chance. These are design illustrations, not a guarantee that a future study will achieve that power.

Rows that plan for 75% or 50% of the observed effect represent smaller effects than a row planning for 100% of the observed effect. Smaller effects are harder to detect and therefore require more participants or events under otherwise comparable assumptions. The original trial's sample-size assumptions and justification are not reported in the registry record. These illustrations are not observed power.

13. How the Sample Size Is Derived

Power is the probability that a study of a given size rejects the null hypothesis when a specific true effect exists. It depends on four things: the effect to detect, the variability of the outcome, the significance level (here a two-sided α of 0.05, so z_1−α/2 = 1.960) and the desired power (z_1−β = 0.842 for 80% and 1.282 for 90%).

Formula

n is the number of participants in each arm, p₀ and p₁ are the control and treatment proportions, and p̄ is their average.

Worked calculation for this trial

1. Control proportion p₀ = 0.873; treatment proportion p₁ = 0.911; average p̄ = 0.892.
2. First term: z_1−α/2 × √[2p̄(1−p̄)] = 1.96 × 0.4395 = 0.8614.
3. Second term: z_1−β × √[p₀(1−p₀) + p₁(1−p₁)] = 0.842 × 0.4387 = 0.3692.
4. n = (0.8614 + 0.3692)² / (0.0379)² = 1,053.1, rounded up to 1,054 participants per arm for 80% power.

The smaller-effect rows in the table above repeat the same calculation with the effect multiplied by 0.75 and 0.5 (for ratios, applied to the logarithm of the ratio).

R code

alpha <- 0.05
z_a   <- qnorm(1 - alpha / 2)          # two-sided
p0 <- 0.872740963855422                          # control proportion
p1 <- 0.910660660660661                          # treatment proportion
n_per_arm <- function(power, frac = 1) {
  q1 <- p0 + (p1 - p0) * frac               # smaller effect = fraction of the observed difference
  pbar <- (p0 + q1) / 2
  z_b <- qnorm(power)
  ceiling(round((z_a * sqrt(2 * pbar * (1 - pbar)) + z_b * sqrt(p0 * (1 - p0) + q1 * (1 - q1)))^2 / (q1 - p0)^2, 6))
}
for (f in c(1, 0.75, 0.5))
  cat(sprintf("%3.0f%% of observed effect: n per arm = %s (80%% power), %s (90%% power)\n", 100 * f,
              format(n_per_arm(0.80, f), big.mark = ","), format(n_per_arm(0.90, f), big.mark = ",")))

# Check against R's built-in function (unrounded n per arm)
cat("power.prop.test:", round(power.prop.test(p1 = p0, p2 = p1, power = 0.80)$n, 1), "\n")

# Simulation: how often does the z-test reject at the 80%-power sample size?
set.seed(66703)
n    <- n_per_arm(0.80)
reps <- 20000
x0 <- rbinom(reps, n, p0); x1 <- rbinom(reps, n, p1)
ph <- (x0 + x1) / (2 * n)
z  <- ((x1 - x0) / n) / sqrt(ph * (1 - ph) * 2 / n)
cat(sprintf("Simulated power at n = %s per arm: %.3f (%d replicates)\n", format(n, big.mark = ","), mean(abs(z) > z_a, na.rm = TRUE), reps))

Output from running the code

100% of observed effect: n per arm = 1,054 (80% power), 1,410 (90% power)
 75% of observed effect: n per arm = 1,945 (80% power), 2,603 (90% power)
 50% of observed effect: n per arm = 4,537 (80% power), 6,073 (90% power)
power.prop.test: 1053.1 
Simulated power at n = 1,054 per arm: 0.802 (20000 replicates)

The simulation draws many pairs of event counts at the planned sample size and counts how often the two-proportion z-test rejects the null. It should land close to the target power; at very small required sample sizes it can fall below it, because the normal approximation is rough there.

14. Analyses Reported by the Sponsor

The sponsor's reported primary analysis uses the log-rank method and reports a hazard ratio of 0.717, with a 95% confidence interval from 0.602 to 0.855 and p = .0002. It evaluates time-to-event patterns across follow-up. The recalculated comparison instead uses the posted 5-year arm estimates to produce an unadjusted risk difference of 0.038, with a 95% confidence interval from 0.014 to 0.061 and p = 0.002.

These results point in the same direction but answer different statistical questions. The hazard ratio summarizes relative event hazards over follow-up; the risk difference compares the 5-year estimates on an absolute scale. Differences in method, use of event timing, and treatment of censoring mean the values and p-values need not match. The registry record does not flag a discrepancy between the posted summary statistics and the sponsor analysis. The sponsor result remains the trial's reported time-to-event analysis, while the recalculation is a simple, unadjusted check based on summary estimates.

Neither result alone determines clinical importance. The registry record does not report a prespecified threshold for an important difference or enough model detail to independently reproduce the sponsor's analysis.

15. Multiplicity, Missing Data and Analysis Populations

The registry identifies disease-free survival as the primary endpoint and lists breast cancer-free interval, distant recurrence-free interval, and overall survival as secondary outcomes. It reports analyses for these endpoints, but multiplicity procedures—such as an adjustment to account for testing several outcomes—are not reported in the registry record. The record also does not report a formal hierarchy specifying how the secondary outcomes were to be tested or interpreted.

Multiplicity matters because separate tests across multiple endpoints can increase the chance of a nominally notable result arising by chance. This does not erase the estimates; it affects how strongly their p-values should be interpreted as confirmatory evidence. Secondary findings are more appropriately treated as contextual unless the analysis plan establishes a controlled testing strategy, which is not reported in the registry record.

The primary endpoint population is identified as intention-to-treat. The registry definition states that participants without a qualifying event are censored at last follow-up. However, the detailed analysis population for each secondary outcome, the number and pattern of missing observations, and methods for handling missing data are not reported in the registry record. The endpoint definition does not specify whether any sensitivity analyses for censoring or missingness were conducted.

The registry record does not report the original sample-size justification, interim analyses, stopping rules, or a complete statistical analysis plan. It also does not provide enough detail to assess whether all planned outcomes and analyses are represented in the posted results. These omissions limit independent evaluation of outcome selection, multiplicity, and analysis choices; they do not by themselves establish that the reported analyses were inappropriate.

16. 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.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: hot flashes/flushes (11.3%), pain - joint (10.6%), hypertension (7.6%), mood alteration - depression (4.5%), insomnia (4.1%).

The registry lists 1321 participants at risk for serious adverse events in T+OFS, with 484 affected, and 1317 at risk in E+OFS, with 496 affected. For other adverse events, it lists 1321 at risk and 1293 affected in T+OFS, and 1317 at risk and 1298 affected in E+OFS. These are group-level registry counts; they do not describe severity, duration, timing, or the number of events per affected participant.

The most frequently listed serious adverse event terms include hot flashes/flushes at 11.3%, pain - joint at 10.6%, hypertension at 7.6%, mood alteration - depression at 4.5%, insomnia at 4.1%, and fatigue (asthenia, lethargy, malaise) at 3.1%. The registry does not explain in this record how these terms were grouped or specify their relationship to the total serious-event counts.

Deaths in the adverse-event record are not reported in the registry record. The posted safety counts should not be interpreted as a complete comparative safety analysis: detailed definitions, exposure-adjusted rates, event timing, and statistical comparisons are not reported.

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

The posted primary estimates show a higher 5-year disease-free survival estimate in E+OFS than in T+OFS, and the reported sponsor log-rank analysis and unadjusted recalculation both favor E+OFS in direction. The estimates are accompanied by confidence intervals that quantify statistical uncertainty for their respective measures. The data therefore describe a difference in this randomized comparison, not a guarantee about what will happen to an individual participant.

The result does not establish that every participant would have the same outcome, nor does it identify which parts of the combined regimens account for the observed comparison. Both arms included triptorelin, while the oral endocrine treatment differed. The registry record does not report a comparison that isolates the effect of triptorelin or estimates the independent effect of either oral treatment.

The endpoint includes specified invasive cancer events and death without a cancer event, and uses censoring at last follow-up. It is not a measure of symptoms, quality of life, or every possible health outcome. The registry record does not report a threshold for clinical importance, detailed missing-data analyses, or a complete analysis plan. Statistical evidence and clinical importance are related but distinct considerations.

The findings also do not establish a clear difference in every secondary outcome. The pattern across secondary endpoints is less uniform, and the record does not report multiplicity adjustment. Overall survival is reported at a later time point than the primary outcome, and the comparison is imprecise. These factors counsel against treating all outcomes as equally conclusive or combining them into a single claim.

18. Why This Trial Matters Statistically

This trial offers a randomized comparison of two regimens that share triptorelin-based ovarian function suppression but differ in the accompanying endocrine therapy. Random allocation can support a fair comparison between groups when carried through analysis, and the intention-to-treat designation indicates that the primary analysis is framed around randomized groups. The registry's unmasked design and incomplete reporting of implementation details remain relevant to interpretation.

Statistically, the result illustrates why more than one measure can be informative. The 5-year disease-free survival estimates and their risk difference describe an absolute contrast at a chosen time point. The sponsor's log-rank hazard ratio uses event timing over follow-up. Agreement in direction across these summaries is reassuring about the broad pattern, but the numerical estimates should not be treated as equivalent.

The secondary outcomes demonstrate the value of distinguishing a consistent signal from a uniform one. Related endpoints may differ in event definition, follow-up, and precision, and the reported secondary findings do not all carry the same evidential weight. Multiplicity and unreported analysis-plan details further matter when interpreting several outcomes together.

The registry also provides a useful example of what results alone cannot answer. Confidence intervals quantify sampling uncertainty for particular estimates, but they do not resolve questions about clinical importance, missing-data mechanisms, or how completely the posted analyses reflect the original plan. Those limits are part of a careful statistical reading, not a reason to disregard the randomized comparison.

19. 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.
• Participant counts were reconstructed from posted percentages and arm sizes, so small rounding differences are possible.

The registry record does not report the original sample-size justification, detailed randomization procedure, allocation concealment, stratification factors, interim analyses, or full statistical analysis plan. It also does not report multiplicity adjustment for the primary and secondary outcomes. These omissions limit assessment of how the posted analyses relate to the trial's original design and testing strategy.

The primary endpoint is time-to-event, and the registry notes censoring at last follow-up. Detailed information on censoring patterns, missing outcome data, treatment adherence, crossovers, and sensitivity analyses is not reported in the registry record. The primary population is identified as intention-to-treat, but comparable population details for each secondary endpoint are not stated in the posted summary.

The sponsor's log-rank analysis is reported with a hazard ratio, but additional model specifications and diagnostics are not reported. The unadjusted recalculation uses summary estimates and cannot reproduce an analysis of individual event times. It is therefore a complementary description, not a substitute for the sponsor's analysis.

Safety reporting is limited in this record. It includes counts of affected participants and selected serious adverse event terms, but deaths are not reported and detailed timing, event duration, exposure-adjusted comparisons, and statistical analyses are not available. These reporting limits mean that the posted safety figures should be read descriptively rather than as a complete comparative assessment.

20. Related Tutorials

21. Related Statistical Calculators

22. Sources

• ClinicalTrials.gov: Triptorelin With Either Exemestane or Tamoxifen in Treating Premenopausal Women With Hormone-Responsive Breast Cancer — NCT00066703.
• Registry record last updated 2026-02-06; status last verified 2026-01.
• Results first posted 2016-04-05.
• 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.

23. Record Summary

This completed randomized phase III trial compared triptorelin plus exemestane with triptorelin plus tamoxifen in premenopausal women with hormone-responsive breast cancer. The registry lists 2672 participants enrolled and identifies disease-free survival as the primary endpoint, analyzed in the intention-to-treat population.

At 5 years, the posted disease-free survival estimates are 91.1% for E+OFS and 87.3% for T+OFS. The sponsor's log-rank analysis reports a hazard ratio of 0.717, with a 95% confidence interval from 0.602 to 0.855 and p = .0002. The unadjusted recalculation of the 5-year estimates points in the same direction but measures a different quantity.

Secondary outcomes provide additional context, with less uniform evidence across endpoints. Multiplicity procedures, detailed missing-data methods, the original sample-size justification, and several elements of the statistical analysis plan are not reported in the registry record.