Liauw Stanley L, Minsky Bruce D
Department of Radiation and Cellular Oncology, University of Chicago Hospitals, Chicago, IL 60637, USA.
Clin Colorectal Cancer. 2008 Mar;7(2):99-104. doi: 10.3816/CCC.2008.n.013.
Locally advanced rectal adenocarcinoma is treated by combined-modality therapy, which consists of surgery, chemotherapy, and radiation therapy. A series of randomized trials established a preferred treatment sequence of preoperative radiation therapy and 5-fluorouracil(5-FU)-based chemotherapy, total mesorectal excision, and adjuvant 5-FU-based chemotherapy for patients with stage II/III disease. Capecitabine is an oral prodrug of 5-FU that has potential advantages compared with intravenous 5-FU, including ease of administration and potentially increased therapeutic effect. Capecitabine is converted by a 3-step enzymatic process; the last step involves the enzyme thymidine phosphorylase, which is overexpressed in tumor tissues and is stimulated by concurrent radiation therapy. Over the past 5 years, several phase I/II trials of capecitabine-based therapy were reported. This review discusses the evolution of combined-modality therapy for rectal cancer with specific attention given to the use of capecitabine in conjunction with radiation therapy.
局部晚期直肠癌采用综合治疗，包括手术、化疗和放疗。一系列随机试验确定了II/III期疾病患者的首选治疗顺序：术前放疗和基于5-氟尿嘧啶（5-FU）的化疗、全直肠系膜切除术以及辅助性基于5-FU的化疗。卡培他滨是5-FU的口服前体药物，与静脉注射5-FU相比具有潜在优势，包括给药方便以及可能增强治疗效果。卡培他滨通过三步酶促过程转化；最后一步涉及胸苷磷酸化酶，该酶在肿瘤组织中过度表达，并受到同步放疗的刺激。在过去5年中，报告了几项基于卡培他滨治疗的I/II期试验。本综述讨论了直肠癌综合治疗的演变，特别关注卡培他滨与放疗联合使用的情况。
