Statement: the findings from the primary clinical trial's cohorts show a significant difference
Primary_evidence: Outcome Measurement:    Event-free Survival   Event free survival, the primary endpoint of this study, is defined as the time from randomization to the time of documented locoregional or distant recurrence, new primary breast cancer, or death from any cause.   Time frame: 5 years Results 1:    Arm/Group Title: Exemestane   Arm/Group Description: Patients receive oral exemestane (25 mg) once daily for 5 years.   exemestane: Given orally   Overall Number of Participants Analyzed: 3789   Measure Type: Number   Unit of Measure: percentage of participants  88        (87 to 89) Results 2:    Arm/Group Title: Anastrozole   Arm/Group Description: Patients receive oral anastrozole (1 mg) once daily for 5 years.   anastrozole: Given orally   Overall Number of Participants Analyzed: 3787   Measure Type: Number   Unit of Measure: percentage of participants  89        (88 to 90)