Metastasis is not the result of a random event, as cancer cells can sustain and proliferate actively only in a suitable tissue microenvironment and then form metastases. Since Dr. Stephen Paget in the United Kingdom proposed the seed and soil hypothesis of cancer metastasis based on the analogy that plant seeds germinate and grow only in appropriate soil, considerable attention has focused on both extracellular environmental factors that affect the growth of cancer cells and the tissue structure that influences the microenvironment. Malignant tumor tissues consist of not only cancer cells but also a wide variety of other cells responsible for the inflammatory response, formation of blood vessels, immune response, and support of the tumor tissue architecture, forming a complex cellular society. It is also known that the amounts of oxygen and nutrients supplied to each cell differ depending on the distance from tumor blood vessels in tumor tissue. Here, we provide an overview of the tumor microenvironment and characteristics of tumor tissues, both of which affect the malignant phenotypes and radioresistance of cancer cells, focusing on the following keywords: diversity of oxygen and nutrient microenvironment in tumor tissue, inflammation, immunity, and tumor vasculature.

转移不是随机事件的结果，因为癌细胞只有在合适的组织微环境中才能维持和活跃增殖，然后形成转移。自英国Stephen Paget博士根据植物种子只能在适宜的土壤中发芽和生长的类比提出癌症转移的种子和土壤假说以来，相当多的注意力集中在影响癌细胞生长的细胞外环境因素和影响微环境的组织结构。恶性肿瘤组织不仅包括癌细胞，还包括负责炎症反应、血管形成、免疫反应和肿瘤组织结构支持的多种其他细胞，形成一个复杂的细胞社会。还已知提供给每个细胞的氧和营养物的量根据与肿瘤组织中的肿瘤血管的距离而不同。在这里，我们概述了肿瘤微环境和肿瘤组织的特征，两者都影响癌细胞的恶性表型和放射抗性，重点关注以下关键词：肿瘤组织中氧气和营养微环境的多样性、炎症、免疫和肿瘤脉管系统。