The Real World Study of Pyrotinib in the Treatment of Advanced Breast Cancer With HER2 Positive

Research object：Planned to receive pyrrolidine for HER2 positive first-line breast cancer patients Research purpose: Main research objectives: To observe the efficacy and safety of pyrrolidine in the treatment of HER2 positive advanced first-line breast cancer. Secondary research objectives: 1. Evaluate the correlation between patient characteristics in the late stage of treatment and specific treatment plans and clinical outcomes Sex (including safety outcomes) 2. Evaluate whether and how previous anti HER2 therapy affects the efficacy of subsequent pyrrolitinib treatment 3. To observe the efficacy of pyrrolitinib in patients with brain metastasis of HER2 positive breast cancer Research endpoint: Main research endpoint: Progression free survival (rwPFS) Secondary study endpoint: Efficacy endpoints: objective response rate (rwORR), disease control rate (rwDCR), until treatment failure Time to Flight (TTF), Total Survival (OS), Security