This study is a multicenter, observational real-world study, aiming to observe and evaluate the efficacy and safety of prophylactic application of Mecapegfilgrastim Injection in tumor patients after radiotherapy/chemotherapy/immunotherapy in the real world to prevent neutropenia.The subjects who met the inclusion criteria of the protocol were defined as those who needed radiotherapy/chemotherapy/immunotherapy after being diagnosed with solid malignant tumors. The researchers believed that the subjects needed to use Mecapegfilgrastim Injection for primary/secondary prevention after receiving tumor treatment.