传统肿瘤生物学常聚焦于局部病灶的病理特征与演变。然而，随着研究深入，实体肿瘤应被重新定义为一个始于局部、但系统性影响的全身性疾病。本论文系统阐述这一概念的核心内涵：肿瘤的发生与发展是一个涉及全身信号网络重塑的动态过程。从癌前病变阶段起，病变细胞释放的生物标志物即可在循环中被检测；癌变组织持续播散单个癌细胞，但大多被免疫系统有效清除；只有当具备更强生存与转移潜能的细胞微球体(如循环肿瘤细胞团)成功逃逸并定植，才可能实现远端转移。基于此，肿瘤治疗的本质应是局部病灶清除与全身抗癌机制(尤其是免疫监视)的协同启动。而对于进展期癌，则需整合局部切除、化疗、放疗与靶向治疗以及全身抗癌免疫机制的重建与增强，形成多模式联合治疗策略。这一系统性概念为肿瘤的预防、早期诊断、治疗及预后评估提供了新的理论框架。

Traditional tumor biology has predominantly focused on the pathological characteristics and evolution of localized lesions. However, with the deepening of research, solid tumors should be redefined as a systemic disease entity that originates locally but exerts systemic influence.This paper systematically elaborates the core connotation of this concept: the occurrence and development of a tumor is a dynamic process involving the remodeling of systemic signaling networks. From the precancerous lesion stage, biomarkers released by dysplastic cells can be detected in the circulation.Neoplastic tissues continuously disseminate individual cancer cells, most of which are effectively cleared by the immune system; only when cell microspheres (e.g., circulating tumor cell clusters) with stronger survival and metastatic potential successfully escape and colonize, can distant metastasis occur. Based on this, the essence of cancer therapy should be the synergistic initiation of local lesion eradication and systemic anti-cancer mechanisms, especially immune surveillance.For advanced cancers, it is necessary to integrate local resection, chemotherapy, targeted therapy, and the rebuilding and enhancement of systemic anti-cancer immunity to form a multimodal combination therapy strategy.This systemic concept provides a new theoretical framework for cancer prevention, early diagnosis, treatment, and prognosis evaluation.