作者详细讨论了结肠直肠癌的5－FU化疗作用机制、疗效、时相和生化调节剂的作用以及联合化疗的效果，并肯定了5－FU的治疗价值。氟尿嘧啶作用机制：5－FU进入体内后转变为5－氟2－脱氧脲苷单磷酸（FdUMP）、脱氧脲苷三磷酸（FdUTP），前者抑制胸腺嘧啶核苷酸合成酶（TS），干扰 The author discussed in detail the role of 5-FU chemotherapy mechanism, efficacy, phase and biochemical modulators of colorectal cancer, and the effect of combined chemotherapy, and affirmed the therapeutic value of 5-FU. Fluorouracil mechanism of action: 5-FU into the body into 5-fluoro-2-deoxyuridine monophosphate (FdUMP), deoxyuridine triphosphate (FdUTP), the former inhibit thymidine nucleotide synthetase (TS), interference