This study is an open, multicenter, randomized controlled clinical trial for patients with newly diagnosed primary invasive breast cancer and clinical stage of T2 or above. The main purpose of this study is to evaluate the efficacy of dose-dense nab-paclitaxel compared with dose-dense docetaxel followed by anthracycline and cyclophosphamide in the treatment of HR positive and HER-2 negative breast cancer. The effectiveness and safety of the treatment.

Inclusion Criteria:

• 1) age: 18-70 years old, female;

  2) patients with primary breast cancer, T2 or above, diagnosed by histopathology;

  3) HR was positive and HER-2 was negative by IHC;

  4) according to the RECIST 1.1 standard, there should be at least one measurable objective focus with tumor diameter > 2cm;

  5) ECoG physical fitness score 0-1;

  6) LVEF≥55%；

  7) bone marrow function: neutrophil ≥ 1.5 × 109 / L, platelet ≥ 100 × 109 / L, hemoglobin ≥ 90g / L;

  8) liver and kidney function: serum creatinine ≤ 1.5 times the upper limit of normal value; AST and alt ≤ 2.5 times the upper limit of normal value; total bilirubin ≤ 1.5 times the upper limit of normal value, or patients with Gilbert's syndrome ≤ 2.5 times the upper limit of normal value;

  9) patients have good compliance with the planned treatment, can understand the research process of this study and sign the written informed consent

Exclusion Criteria:

• 1) previously received cytotoxic chemotherapy, endocrine therapy, biological therapy or radiotherapy for any reason;

  2) patients with stage IV metastasis at the initial diagnosis;

  2) New York Heart Association (NYHA) rating of patients with heart disease above grade II (including grade II);

  3) patients with serious systemic infection or other serious diseases;

  4) patients who are known to be allergic or intolerant to chemotherapy drugs or their adjuvants;

  5) in the past 5 years, there have been other malignant tumors, except the cured carcinoma in situ of cervix and skin cancer without melanoma;

  6) pregnancy or lactation, as well as childbearing age patients who refuse to take appropriate contraceptive measures during the trial;

  7) participated in other experimental studies within 30 days before the administration of the first study drug;

  8) patients not suitable for the study were judged by the researchers.