乳腺癌是女性最常见的癌症，也是全世界最致命的癌症之一。根据肿瘤组织的分布，乳腺癌可分为侵袭性乳腺癌和非侵袭性乳腺癌。浸润性乳腺癌中的癌细胞穿过乳腺，通过免疫系统或体循环到达身体的不同部位，形成转移性乳腺癌。耐药性和远处转移是乳腺癌死亡的主要原因。乳腺癌的研究引起了研究者的广泛关注。利用组织工程方法体外构建肿瘤模型是研究癌症机制和抗癌药物筛选的常用工具。肿瘤微环境由癌细胞和各种类型的基质细胞组成，包括成纤维细胞、内皮细胞、间充质细胞和嵌入细胞外基质的免疫细胞。细胞外基质含有纤维蛋白（如 I、II、III、IV、VI 和 X 型胶原蛋白和弹性蛋白）和糖蛋白（如蛋白聚糖、层粘连蛋白和纤连蛋白），参与细胞信号传导和生长因子的结合。目前传统的二维（2D）肿瘤模型受到生长环境的限制，往往无法准确再现体内肿瘤组织的异质性和复杂性。因此，近年来，对三维（3D）肿瘤模型的研究逐渐增多，特别是高精度、可重复性的3D生物打印模型。与2D模型相比，3D环境可以更好地模拟肿瘤微环境中复杂的细胞外基质成分和结构。三维模型通常用作二维细胞水平实验和动物实验之间的桥梁。脱细胞基质、明胶、海藻酸钠等天然材料因其优异的生物相容性和非免疫排斥性而被广泛应用于肿瘤模型的构建。在此，我们综述了3D组织工程肿瘤模型中涉及的各种天然支架材料和构建方法，为乳腺癌领域的研究提供参考。

Breast cancer is the most common cancer in women and one of the deadliest cancers worldwide. According to the distribution of tumor tissue, breast cancer can be divided into invasive and non-invasive forms. The cancer cells in invasive breast cancer pass through the breast and through the immune system or systemic circulation to different parts of the body, forming metastatic breast cancer. Drug resistance and distant metastasis are the main causes of death from breast cancer. Research on breast cancer has attracted extensive attention from researchers. In vitro construction of tumor models by tissue engineering methods is a common tool for studying cancer mechanisms and anticancer drug screening. The tumor microenvironment consists of cancer cells and various types of stromal cells, including fibroblasts, endothelial cells, mesenchymal cells, and immune cells embedded in the extracellular matrix. The extracellular matrix contains fibrin proteins (such as types I, II, III, IV, VI, and X collagen and elastin) and glycoproteins (such as proteoglycan, laminin, and fibronectin), which are involved in cell signaling and binding of growth factors. The current traditional two-dimensional (2D) tumor models are limited by the growth environment and often cannot accurately reproduce the heterogeneity and complexity of tumor tissues in vivo. Therefore, in recent years, research on three-dimensional (3D) tumor models has gradually increased, especially 3D bioprinting models with high precision and repeatability. Compared with a 2D model, the 3D environment can better simulate the complex extracellular matrix components and structures in the tumor microenvironment. Three-dimensional models are often used as a bridge between 2D cellular level experiments and animal experiments. Acellular matrix, gelatin, sodium alginate, and other natural materials are widely used in the construction of tumor models because of their excellent biocompatibility and non-immune rejection. Here, we review various natural scaffold materials and construction methods involved in 3D tissue-engineered tumor models, as a reference for research in the field of breast cancer.