Safety and Efficacy of Umbilical Cord Blood Therapy for Cancer Therapy-Induced Thrombocytopenia (CTIT)

Inclusion Criteria: 1. Aged 12 to 65 years at the time of signing the informed consent, regardless of gender. 2. Meets the diagnostic criteria for cancer treatment-induced thrombocytopenia (CTIT):Peripheral blood platelet count \< 100 × 10⁹/L; Prior definite exposure to a chemotherapy agent (or tumor-targeted therapy, immunotherapy, or other anti-tumor drugs) known to cause thrombocytopenia, with gradual improvement of thrombocytopenia-related symptoms/signs or normalization of platelet count after discontinuation of the offending drug; Presence or absence of bleeding tendency, such as petechiae, purpura, unexplained epistaxis, or even severe organ/tissue hemorrhage; 3. No significant hepatic or renal impairment: ALT and AST ≤ 2.5 × upper limit of normal (ULN), serum creatinine (Cr) and blood urea nitrogen (BUN) ≤ 1.25 × ULN; 4. Karnofsky Performance Status (KPS) score ≥ 60 (see Appendix 1), Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2 (see Appendix 2); 5. Estimated life expectancy of more than 3 months. Exclusion Criteria: 1. Other causes of thrombocytopenia, in particular exclusion of underlying diseases or comorbidities such as aplastic anemia, acute leukemia, radiation sickness, immune thrombocytopenia (ITP), hypersplenism, or bone marrow infiltration by tumor cells; 2. Use of non-anti-tumor medications known to cause thrombocytopenia (including but not limited to sulfonamides and other drugs); 3. Pseudothrombocytopenia induced by ethylenediaminetetraacetic acid (EDTA) anticoagulant; 4. Uncontrolled malignant tumor, hypertension, or diabetes mellitus; 5. Active infection, including but not limited to known HIV positivity, active hepatitis B or C, or syphilis; 6. Poor compliance; 7. Known allergy or hypersensitivity to any component of the study intervention (umbilical cord blood or related products); 8. Participation in another clinical trial within 1 month prior to enrollment or current participation in another clinical trial; 9. Any other condition that, in the investigator's judgment, makes the patient unsuitable for participation in this clinical study.