Effects of Instrument-Assisted Constant-Speed Injection Versus Manual Injection on Pain From Large-Volume Subcutaneous Injection of Pertuzumab and Trastuzumab in Breast Cancer: A Randomized, Self-Controlled Study

Inclusion Criteria

• •1. Female breast cancer patients histologically confirmed as HER2-positive.
• •2. Have completed at least one subcutaneous injection of Phesgo, with at least three planned injections remaining.
• •3. No history of acute allergic reactions (e.g., Grade 1-2 allergic reactions) during previous Phesgo injections.
• •4. Aged between 18 and 70 years (inclusive).
• •5. No use of pain medications, pain patches, or pain pumps for pain management within 3 days prior to injection.
• •6. Normal activity level (ECOG score 0-2), no limb paralysis, and able to clearly express personal feelings.
• •7. Signed informed consent form and voluntarily agreed to participate in this study.