Bengt Glimelius, Department of Radiology, Oncology and Radiation Science, Uppsala University, SE-751 85, Sweden.
World J Gastroenterol. 2013 Dec 14;19(46):8489-501. doi: 10.3748/wjg.v19.i46.8489.
In rectal cancer treatment, attention has focused on the local primary tumour and the regional tumour cell deposits to diminish the risk of a loco-regional recurrence. Several large randomized trials have also shown that combinations of surgery, radiotherapy and chemotherapy have markedly reduced the risk of a loco-regional recurrence, but this has not yet had any major influence on overall survival. The best results have been achieved when the radiotherapy has been given preoperatively. Preoperative radiotherapy improves loco-regional control even when surgery has been optimized to improve lateral clearance, i.e., when a total mesorectal excision has been performed. The relative reduction is then 50%-70%. The value of radiotherapy has not been tested in combination with more extensive surgery including lateral lymph node clearance, as practised in some Asian countries. Many details about how the radiotherapy is performed are still open for discussion, and practice varies between countries. A highly fractionated radiation schedule (5 Gy × 5), proven efficacious in many trials, has gained much popularity in some countries, whereas a conventionally fractionated regimen (1.8-2.0 Gy × 25-28), often combined with chemotherapy, is used in other countries. The additional therapy adds morbidity to the morbidity that surgery causes, and should therefore be administered only when the risk of loco-regional recurrence is sufficiently high. The best integration of the weakest modality, to date the drugs (conventional cytotoxics and biologicals) is not known. A new generation of trials exploring the best sequence of treatments is required. Furthermore, there is a great need to develop predictors of response, so that treatment can be further individualized and not solely based upon clinical factors and anatomic imaging.
在直肠癌治疗中，人们关注的重点是局部原发性肿瘤和区域肿瘤细胞沉积，以降低局部区域复发的风险。几项大型随机试验还表明，手术、放疗和化疗的联合应用显著降低了局部区域复发的风险，但这尚未对总生存率产生任何重大影响。当放疗在术前进行时，效果最佳。术前放疗改善了局部区域控制，即使手术已经优化以改善侧向清除，即进行全直肠系膜切除术时也是如此。相对减少了 50%-70%。在与包括侧方淋巴结清扫术在内的更广泛的手术相结合的情况下，尚未测试放疗的价值，而侧方淋巴结清扫术在一些亚洲国家已经得到应用。关于如何进行放疗的许多细节仍在讨论中，各国的实践也存在差异。一种高分割放疗方案（5 Gy×5）在许多试验中已被证明有效，在一些国家已得到广泛应用，而传统分割方案（1.8-2.0 Gy×25-28），常与化疗联合应用，在其他国家使用。附加治疗会增加手术引起的发病率，因此，只有当局部区域复发的风险足够高时，才应进行附加治疗。到目前为止，还不知道如何将疗效最差的治疗方式（传统细胞毒药物和生物制剂）最佳地整合在一起。需要开展新一代的探索最佳治疗顺序的试验。此外，迫切需要开发反应预测因子，以便能够进一步对治疗进行个体化，而不仅仅基于临床因素和解剖成像。
