This study is a prospective, multicenter, single-arm, exploratory study. A total of 90 patients with early/later-stage triple-positive breast cancer who were scheduled to receive neoadjuvant therapy were recruited. They received neoadjuvant treatment with trastuzumab, pertuzumab, palbociclib, and exemestane in combination. The aim of this study is to evaluate the efficacy and safety of the neoadjuvant treatment regimen of trastuzumab-pertuzumab combined with palbociclib and exemestane in triple-positive breast cancer.

Inclusion Criteria:

• The patient must meet all of the following criteria to be included in the study:

  1. The tumor stage must be in accordance with the 8th edition of the AJCC standard, being stage II-III for the initial diagnosis;
  2. Pre-menopausal or perimenopausal patients (if this is the case, combined with OFS, which includes bilateral oophorectomy or GnRHa drugs), or post-menopausal patients;
  3. All patients must have been pathologically confirmed as HR+/HER2 receptor positive. The estrogen receptor (ER) is positive (>10%), the progesterone receptor (PR) is positive (>1%), and the HER2 receptor is positive. Follow the 2018 ASCO-CAP HER2 positive interpretation guideline standards. The immunohistochemistry (IHC) score is 3+ or 2+ and the in situ hybridization (ISH) test is positive (ISH amplification rate ≥ 2.0);
  4. Age 18-75 years (inclusive of 18 and 75), female;
  5. ECOG score 0-1;
  6. Expected survival time ≥ 12 weeks;
  7. According to the RECIST 1.1 standard, there must be at least one measurable lesion;
  8. The functional level of organs must meet the following requirements: (a) Blood routine: ANC ≥ 1.5×109/L; PLT ≥ 90×109/L; Hb ≥ 90g/L; (b) Blood biochemistry: TBIL ≤ 1.5×ULN; ALT and AST ≤ 3×ULN; BUN and Cr ≤ 1.5×ULN and creatinine clearance rate ≥ 50 mL/min; (c) Cardiac echocardiography: Left ventricular ejection fraction ≥ 50%:
  9. The subject voluntarily joins this study, signs the informed consent, has good compliance and is willing to cooperate with follow-up.

Exclusion Criteria:

• If the patient meets any of the following conditions, they will not be eligible:

  1. Has received any form of anti-tumor treatment (chemotherapy, radiotherapy, molecular targeted therapy, endocrine therapy, etc.);
  2. Is concurrently receiving other anti-tumor drug treatments;
  3. Stage IV breast cancer;
  4. Breast cancer without pathological tissue diagnosis;
  5. Has had other malignant tumors within the past 5 years, except for cured cervical carcinoma in situ, basal cell carcinoma of the skin, or squamous cell carcinoma of the skin;
  6. Patients with severe dysfunction of important organs such as heart, liver, and kidney;
  7. Unable to swallow, chronic diarrhea and intestinal obstruction, with multiple factors affecting the administration and absorption of the drugs;
  8. Participated in other drug clinical trials within 4 weeks before enrollment;
  9. Has a history of immunodeficiency diseases, including positive HIV test, HCV, active viral hepatitis or other acquired or congenital immune deficiency diseases, or a history of organ transplantation;
  10. Has a known history of allergic reaction to the components of this drug regimen;
  11. Has had any heart diseases, including: requiring drug treatment or clinically significant arrhythmia; myocardial infarction; heart failure; any other heart diseases judged by the researcher as unsuitable for participation in this trial;
  12. Pregnant or lactating female patients, female patients with reproductive capacity and positive baseline pregnancy test results;
  13. According to the investigator's judgment, there are serious accompanying diseases that endanger the patient's safety or affect the patient's completion of the study (including but not limited to severe hypertension that cannot be controlled by drugs, severe diabetes, active infection, etc.);
  14. Has a clear history of neurological or mental disorders, including epilepsy or dementia;
  15. The investigator considers that the patient is not suitable for participating in this study in any other circumstances.