Several angiogenesis inhibitors are currently used in the clinic for treatment of cancer. While anti-angiogenesis treatment can improve treatment outcome, the overall benefit on patient survival is still rather limited. This is partially explained by intrinsic or acquired resistance of tumor cells to angiostatic drugs. In addition, it has become evident that extrinsic mechanisms are also involved in resistance to angiostatic therapy. Most of these extrinsic mechanisms reside in the tumor stroma, which is composed of different cell types, including endothelial (progenitor) cells, smooth muscle cells, pericytes, (myo)fibroblasts, immune cells and platelets. In the current review, we describe the role of these stromal cells in the resistance to anti-angiogenic drugs and discuss possible strategies to overcome resistance and enhance the efficacy of angiostatic therapy.

目前在临床中使用几种血管生成抑制剂来治疗癌症。尽管抗血管生成治疗可以改善治疗效果，但对患者生存的总体益处仍然相当有限。这部分由肿瘤细胞对血管抑制药物的固有或获得的抗性解释。另外，已经明显的是，外在机制也参与了对血管抑制疗法的抗性。这些外在机制大多数位于肿瘤基质中，肿瘤基质由不同的细胞类型组成，包括内皮细胞（祖细胞），平滑肌细胞，周细胞，（肌）成纤维细胞，免疫细胞和血小板。在目前的评论中，