Pegylated liposomal doxorubicin (PLD) was an anthracycline nanomedicine to be approved for advanced breast cancer and other solid tumor therapy and showed a good disease control rate (57%). PLD could induce hypersensitivity reaction (HSR). There are about 9-25% patients got infusion reaction or HSR. Severe HSR could lead to allergic shock even presyncope or threat to life. To our knowledge, there were no sensitivity biomarker to predict the PLD induced HSR. And the mechanism of PLD induced HSR is unknown yet. Therefore, to analyze and discuss the biomarkers and mechanism of PLD induced HSR in advanced breast cancer, we design this prospective, observational, biomarker study.

Inclusion Criteria:

• ≥18 years old; Breast cancer confirmed with histological or molecular diagnosis; Advanced breast cancer diagnosis according to American Joint Committee on cancer eighth edition cancer staging manual; Treatment with liposomal doxorubicin; No pregnancy plan and voluntary use of effective contraceptive measures during treatment

Exclusion Criteria:

• Subjects who discontinued treatment due to previous severe adverse reactions to liposomal doxorubicin or doxorubicin; poor compliance.

Advanced breast cancer patients who recieve liposomal doxorubicin treatment.

If we found a significant, sensitive biomarker of liposomal doxorubicin induced hypersensitivity, we will share the protocol and results with other scientists or clinical researchers.