Neoadjuvant Dalpiciclib Plus Aromatase Inhibitors in Luminal B/HER2-negative Breast Cancer (DANCER)

Inclusion Criteria: * Patient is ≥ 18 years-old at the time of consent to participate this trial * Famale stage I-III breast cancer patients * HR-positive（ER≥10%）, HER2-negtive invasive breast cancer, either Ki67≥20% and/or PgR\<20% * No prior anti-cancer treatment * ECOG 0-1 Exclusion Criteria: * Known to have other aggressive malignant tumor in the past 5 years. * Bilateral breast cancer; Inflammatory breast cancer; Occult breast cancer; Distant metastasis confirmed by pathology. * There are other concomitant diseases that seriously threaten the patient's safety or affect the patient's completion of the study, such as serious infection, liver disease, cardiovascular disease, kidney disease, respiratory disease or uncontrolled diabetes or dyslipidemia. * Female patients during pregnancy or lactation. * The investigator determines that subjects are not appropriate to participate in the study due to other factors.