This is a prospective, single-arm, single-center, open, exploratory clinical study.. Screening for histopathologically confirmed recurrent or metastatic ER-Low positive (1%-10%) and HER2-negative breast cancer patients who meet the inclusion criteria and have not previously received any systemic anticancer therapy for advanced disease, He was treated with albumin-bound paclitaxel in combination with Dalpiciclib and AI.
Postmenopausal or premenopausal/perimenopausal women ≥18 years old and ≤75 years old, meeting one of the following criteria: a) prior bilateral oophorectomy, or ≥60 years old; Or b) age <60, natural postmenopausal status (defined as spontaneous cessation of regular menstruation for at least 12 consecutive months without other pathological or physiological causes), E2 and FSH at postmenopausal levels; Or c) premenopausal or perimenopausal women may also be enrolled, but must be willing to receive LHRH agonist therapy during the study period.
Female breast cancer patients diagnosed by pathology as ER-Low positive (1%-10%) and HER2-negative have evidence of focal recurrence or metastasis, and are not suitable for surgical resection or radiotherapy for the purpose of cure. a) Low ER expression was defined as: the proportion of tumor cells with positive staining accounted for ≥ 1% and ≤10% of all tumor cells (confirmed by investigators in the study center); b) HER2 negative is defined as a standard immunohistochemical (IHC) test of 0/1+; Or the IHC test is 2+ and the ISH test is negative (reviewed and confirmed by the investigator at the study center).
Have not previously received any systemic anticancer therapy for recurrent or metastatic disease.
The physical status score of the Eastern Cancer Collaboration Group (ECOG) was 0-1.
Previous pathological examination diagnosed HER2-positive breast cancer.
Inflammatory breast cancer.
Disease progression or recurrence during prior adjuvant therapy or within 12 months after completion of adjuvant therapy.
Patients judged unsuitable for chemotherapy by the investigators. This includes symptomatic, advanced patients who have spread to the viscera and are at risk of developing life-threatening complications in the short term (including patients with uncontrolled exudation [thoracic, pericardial, abdominal], pulmonary lymphangitis, and more than 50% liver involvement).