Multicenter Prospective Observational Study of Cardiotoxicity in Patients Receiving Targeted Cancer Therapies

Inclusion Criteria: 1.Adults (age \> 18 years) with a pathologically confirmed malignant tumor (any type of cancer); 2.Currently receiving or planning to receive chemotherapy (including regimens containing molecular targeted drugs) as adjuvant treatment for cancer; 3.Willing and able to participate in the study with provision of informed consent, and agreeable to provide required clinical data and biological samples. \- Exclusion Criteria: 1. Incomplete basic patient information or medical records (missing key data necessary for the study); 2. Failure to complete the full course of planned chemotherapy at the study center (e.g., patient did not adhere to or finish all cycles of adjuvant chemotherapy at our institution); 3. History of severe acute cardiovascular or cerebrovascular events within 6 months prior to enrollment, including acute heart failure, acute myocardial infarction, acute intracerebral hemorrhage (stroke), malignant arrhythmia, or New York Heart Association (NYHA) Class IV/V heart failure; 4. Missing essential pre- or post-chemotherapy evaluations: patients who did not undergo complete baseline or end-of-treatment assessments (such as blood routine, hepatic/renal function, coagulation profile, cardiac enzymes (troponin T), NT-proBNP (or BNP), 12-lead ECG, and echocardiogram)