Disease heterogeneity
Breast cancer is not a single analytical story. Biological subtype, treatment pathway and disease context can reshape how signals appear in the data. A pattern that looks consistent in a top-line summary may behave differently once clinically meaningful subgroups are considered.
For trial teams, this affects endpoint strategy, stratification logic, subgroup planning and interpretation. It also changes how results should be communicated: an overall estimate is important, but it does not always tell the whole story.