The objective of this study is to compare the curative effects in patients under the age of
35 with hormone receptor positive breast cancer and high recurrent risk factors including
large tumor or metastatic lymph nodes randomized to ovarian function suppression (OFS) plus
aromatase inhibitors or OFS plus tamoxifen as adjuvant endocrine therapy, and explore the
differences of curative effects between different subtypes to provide direct evidence for
treatments of young breast cancer patients.