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Breast Cancer Phase 2/3 Neoadjuvant Therapy NCT01426880

GeparSixto: Complete Statistical Analysis of Carboplatin in Early Breast Cancer

An independent statistical review of the randomized GeparSixto trial evaluating addition of carboplatin to neoadjuvant therapy for triple-negative and HER2-positive early breast cancer.

ClinicalTrials.gov record: NCT01426880
Scope of this record

This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record.

1. Trial at a Glance

GeparSixto was a randomized phase 2/3 trial evaluating the addition of carboplatin to neoadjuvant therapy for patients with early breast cancer.

595
Enrollment
2
Arms
2011-08
Start Date
2013-05
Primary Completion
FeatureGeparSixto
Phase2/3
AllocationRandomized
Design modelParallel
MaskingNone
Primary purposeTreatment
Lead sponsorGBG Forschungs GmbH
InterventionsCarboplatin and background treatment

2. Clinical Question

Population

Patients with conditions including triple-negative and HER2-positive early breast cancer as recorded in the registry.

Intervention

Addition of carboplatin to neoadjuvant therapy.

Comparator

Background treatment without the additional carboplatin intervention.

Primary question

Does adding carboplatin influence pathological complete response of breast and lymph nodes?

3. Trial Design

Randomize
595 patients
Parallel
2 arms
Neoadjuvant
Therapy
Surgery
Assessment
Primary
Endpoint

4. Endpoints

EndpointTime FrameDescription
Pathological complete response of breast and lymph nodes (ypT0 ypN0; primary endpoint)24 weeks (time window -3 weeks)Pathological response assessed considering all removed breast and lymphatic tissues from surgeries. No microscopic evidence of residual viable tumor cells in breast and axilla meets the endpoint.

5. Planned Analysis

The registry identifies pathological complete response of breast and lymph nodes as the primary endpoint. For a binary pathological response endpoint, the statistical analysis would typically compare the proportion of patients achieving complete response between randomized groups using an appropriate two-group comparison method.

Registry reporting status. Results and formal statistical analyses were not posted on ClinicalTrials.gov for this record.

6. Statistical Methodology

The design uses random allocation in a parallel-group treatment comparison. Randomization provides the framework for comparing treatment groups while reducing the influence of measured and unmeasured baseline differences.

Binary endpoint analysis

Pathological complete response is a categorical outcome: each patient either meets the prespecified pathological definition or does not. Analyses of such endpoints commonly focus on differences in response proportions, confidence intervals, and hypothesis testing.

Conceptual framework

Response rate = patients meeting the pathological complete response definition ÷ analyzed patients

7. Statistical Methods Explained

Why is pathological complete response suitable as an endpoint?

A pathological complete response endpoint directly measures absence of residual viable tumor cells in specified surgical specimens after neoadjuvant therapy.

Why does randomization matter?

Randomization creates treatment groups intended to be comparable at baseline, supporting causal interpretation of differences between groups.

Why are proportions used for this endpoint?

The outcome is whether a prespecified pathological event occurred, making it naturally summarized as a proportion of patients.

What does a confidence interval add?

A confidence interval describes uncertainty around an estimated treatment difference or effect measure rather than simply indicating whether a threshold was crossed.

8. Limitations

9. Why This Trial Matters Statistically

ConceptHow it appears in GeparSixto
RandomizationRandomized parallel-group treatment comparison
Binary endpointPathological complete response
Neoadjuvant assessmentOutcome measured after systemic therapy and surgery
Clinical trial methodologyPhase 2/3 randomized evaluation

10. Sources