Statement: the primary trial administers letrozole for 28 days, whereas the secondary trial administers is intervention over 4 cycles of 21 days.
Primary_evidence: INTERVENTION 1:    Post-menopausal Women Using Adjuvant Letrozole   Part A Routine Care Letrozole; Part B Double Dose Letrozole in overweight/obese participants   Letrozole: Part A Monitor standard of care letrozole use for 28 days; measure blood levels of estrogens and vitamin D at start and end of period. Part B In overweight/obese participants who completed Part A, provide a double dose of letrozole and monitor use for 28 days; measure blood levels of estrogens and vitamin D at start and end of period.
Secondary_evidence: INTERVENTION 1:    Neratinib 40 mg Neratinb 40 mg qd INTERVENTION 2:    Neratinib 80 mg Neratinib 80 mg qd