Letrozole

o The primary endpoint for chemotherapy versus no chemotherapy (R-T) is that the 5-year distant metastasis free survival (DMFS) of 92% will be tested (a one-sided test).

o The primary endpoint for the chemotherapy randomization (R-C) is disease free survival (DFS).

The primary test for the endocrine randomization (R-E) is DFS.

PFS defined as the time from the date of first IMP administration until the date of progression (recurrence) or death by any cause in the absence of progression. Assessment of progression (recurrence) is generally indicated by SYMPTOMS and will be assessed by the investigator most commonly on the basis of CT scans of the pelvis, abdomen and thorax, according to RECIST v1.1 criteria recommended and mostly presented by an elevated CA-125 level. Elevated CA-125 levels alone shouldn't be considered as progression. Progression assessment according to local standard of care, however, is similarly acceptable.

Change in bone mineral density (BMD) measured by dual X-ray absorptiometry (DXA) in lumbar spine (L1-L4). Change calculated by (Month 36 BMD-Baseline BMD)/Baseline BMD\*100.

Bone Mineral Density is measured by dual energy x-ray absorptiometry (DXA) scan. ANCOVA model was used in the analysis where: Variable = Baseline, Center, Treatment BMD = (Month 36 BMD-Baseline BMD)/Baseline BMD\*100.

BMD measured by DXA (dual energy x-ray absorptiometry) at lumbar spine, L1-L4. The T-Score is a comparison of a patient's BMD to that of a healthy 30 year of the same sex and ethnicity. The criteria of the World Health Organization are Normal is a T-Score of 1.0 or higher. Osteopenia is defined as between - 1.0 and -2.5. Osteoporosis is defined as -2.5 or lower, meaning a bone density that is two and half standard deviations below the mean of a 30 year old man/woman.

Bone Mineral Density is measured by dual energy x-ray absorptiometry (DXA). The Z-Score is the number of standard deviations a patient's BMD differs from the average BMD of their age, sex and ethnicity. A Z-score of less than minus -1.5 raises concern of factors other than aging as contributing to osteoporosis.

Disease-free survival was defined as the time from the date of randomization to the date of the first documentation of re-occurrence of invasive breast cancer in local, regional or distant sites, new invasive breast cancer in the contra-lateral breast, or death from any cause.

Lumbar spine (L2-L4) BMD measurements by dual energy X-ray absorptiometry (DXA) were performed after surgery and within 2 weeks prior to randomization and repeated every 6 months for the first 2 years and annually thereafter until 5 years after enrollment. The primary scanning site was the lumbar spine (L2 to L4) and the secondary scanning site was the total hip. All DXA scans were evaluated by a central reader.

This outcome will report the number of patients who experienced a dose-limiting Toxicity (DLT) in Phase I Cohort 1, Phase I Cohort 2, and Phase I Cohort -1. A DLT was defined as: 1. A grade 3 or 4 non-hematologic toxicity except anorexia, alopecia, nausea (which is not refractory to antiemetics), fatigue, and fever without neutropenia; 2. Failure to recover to baseline (except alopecia) after delaying the next dose by more than 14 days; 3. Grade 3 or 4 neutropenia complicated by fever \>38.5°C or infection, or grade 4 neutropenia of ≥7 days duration; or 4. Grade 4 thrombocytopenia, or grade 3 thrombocytopenia complicated by hemorrhage. The maximum tolerated dose (MTD) is defined as the highest dose at which 0 out of the first 3 or 1 out of a total of 6 patients experience DLT during the first cycle of therapy; this dose level will be the recommended phase 2 dose (RP2D) in the Phase II Group.

The highest dose of the drug that does not cause unacceptable side effects. The maximum tolerated dose be testing increasing doses until the highest dose with acceptable side effects is found.