Moulder J E, Rockwell S
Cancer Metastasis Rev. 1987;5(4):313-41. doi: 10.1007/BF00055376.
The presence of radiation resistant cells in solid human tumors is believed to be a major reason why radiotherapy fails to eradicate some such neoplasms. The presence of unperfused regions containing hypoxic cells may also contribute to resistance to some chemotherapeutic agents. This paper reviews the evidence that radiation resistant hypoxic cells exist in solid tumors, the assumptions and results of the methods used to detect hypoxic cells, and the causes and nature of tumor hypoxia. Evidence that radiation resistant hypoxic cells exist in the vast majority of transplanted rodent tumors and xenografted human tumors is direct and convincing, but problems with the current methodology make quantitative statements about the magnitude of the hypoxic fractions problematic. Evidence that radiation resistant hypoxic cells exist in human tumors is considerably more indirect than the evidence for their existence in transplanted tumors, but it is convincing. However, evidence that hypoxic cells are a significant cause of local failure after optimal clinical radiotherapy or chemotherapy regimens is limited and less definitive. The nature and causes of tumor hypoxia are not definitively known. In particular, it is not certain whether hypoxia is a chronic or a transient state, whether hypoxic cells are proliferating or quiescent, or whether hypoxic cells have the same repair capacity as aerobic cells. A number of new methods for assessing hypoxia are reviewed. While there are still problems with all of the new techniques, some of them have the potential of allowing the assessment of hypoxia in individual human tumors.
实体人类肿瘤中存在抗辐射细胞被认为是放射治疗未能根除某些此类肿瘤的主要原因。含有缺氧细胞的未灌注区域的存在也可能导致对某些化疗药物产生耐药性。本文综述了实体瘤中存在抗辐射缺氧细胞的证据、用于检测缺氧细胞的方法的假设和结果，以及肿瘤缺氧的原因和性质。绝大多数移植的啮齿动物肿瘤和异种移植的人类肿瘤中存在抗辐射缺氧细胞的证据是直接且令人信服的，但当前方法存在的问题使得对缺氧分数大小进行定量表述存在困难。人类肿瘤中存在抗辐射缺氧细胞的证据比其在移植肿瘤中存在的证据要间接得多，但也令人信服。然而，缺氧细胞是最佳临床放疗或化疗方案后局部治疗失败的重要原因的证据有限且不太明确。肿瘤缺氧的性质和原因尚未明确知晓。特别是，尚不确定缺氧是一种慢性还是短暂状态，缺氧细胞是在增殖还是静止，或者缺氧细胞是否具有与有氧细胞相同的修复能力。本文综述了一些评估缺氧的新方法。虽然所有这些新技术仍然存在问题，但其中一些有潜力用于评估个体人类肿瘤中的缺氧情况。
