Glimelius B
Department of Oncology, Radiology and Clinical Immunology, Section of Oncology, University Hospital, Uppsala, Sweden.
Ann Oncol. 2001 Aug;12(8):1039-45. doi: 10.1023/a:1011628524392.
Chemoradiotherapy is increasingly used in the primary management of rectal cancer. A critical review of present knowledge of whether an optimal combination exists was made for each of the major clinical situations.
As preoperative therapy to reduce local recurrence rates in primarily resectable rectal cancers, radiotherapy has almost exclusively been used as single modality, and combined chemoradiotherapy should remain experimental until further evidence is available. This can only be achieved in randomised trials. Postoperatively, a combination of chemotherapy and radiotherapy appears to be more efficient in reducing local failure rates and improving survival than either modality alone, but the literature-based evidence is partly conflicting. As a reference treatment, a combination of continuous infusion 5-fluorouracil (5-FU) and radiotherapy can be advocated based upon one trial. In primarily irresectable cancer, there is some support that chemoradiotherapy may be more efficient than radiotherapy alone in causing tumour regression allowing radical surgery, but the literature is again conflicting. A great number of phase II studies have been performed in these cancers and in those considered to be locally advanced, revealing promising activity and claims of superiority to radiotherapy alone or other schedules. The studies are, however, inconclusive with respect to antitumour activity, and patient selection may be of greater relevance for the results. Chemoradiation has also increasingly been used to facilitate a sphincter-preserving procedure in low-lying cancers. Again, literature is inconclusive as to whether an optimal combination exists, whether it is superior to radiotherapy alone, or if it actually facilitates sphincter preservation at all. Long-term functional outcome is poorly known. Again, 5-FU has been most extensively used, but many other drugs are presently being tested in various combinations.
An optimal combination of chemoradiotherapy for rectal cancer does not exist. Actually, a critical review of the literature shows that the support for superiority of chemoradiation over radiation alone is weak, or lacking. There is a great need of both more conclusive study designs and a more rational exploration of drug-radiation interactions prior to clinical testing.
化疗联合放疗在直肠癌的初始治疗中应用越来越广泛。针对每种主要临床情况，对是否存在最佳联合方案的现有知识进行了批判性综述。
作为术前治疗以降低可切除直肠癌的局部复发率，放疗几乎仅作为单一模式使用，在有更多证据之前，联合放化疗仍应作为实验性治疗。这只能通过随机试验实现。术后，化疗和放疗联合应用在降低局部失败率和提高生存率方面似乎比单独使用任何一种模式更有效，但基于文献的证据部分相互矛盾。作为参考治疗方案，基于一项试验可推荐持续输注5-氟尿嘧啶（5-FU）与放疗联合应用。在初始不可切除的癌症中，有一些证据支持放化疗在使肿瘤缩小从而允许进行根治性手术方面可能比单纯放疗更有效，但文献同样相互矛盾。针对这些癌症以及被认为局部进展的癌症进行了大量II期研究，显示出有前景的活性，并声称优于单纯放疗或其他方案。然而，这些研究在抗肿瘤活性方面尚无定论，患者选择可能对结果更具相关性。放化疗也越来越多地用于促进低位癌症的保肛手术。同样，关于是否存在最佳联合方案、是否优于单纯放疗或是否真的有助于保肛，文献尚无定论。长期功能结果知之甚少。同样，5-FU使用最为广泛，但目前许多其他药物正在以各种组合进行测试。
不存在用于直肠癌的最佳放化疗联合方案。实际上，对文献的批判性综述表明，支持放化疗优于单纯放疗的证据薄弱或缺乏。在临床测试之前，非常需要更具结论性的研究设计以及对药物与放疗相互作用进行更合理的探索。
