Capecitabine and tegafur + uracil: new preparations. Metastatic colorectal cancer: two oral fluorouracil precursors, few advantages.
(1) The standard chemotherapy for metastatic colorectal cancer is intravenous fluorouracil combined with calcium folinate. This treatment improves the median survival time by approximately 4-6 months compared with optimal palliative care. (2) Two metabolic precursors of fluorouracil are now available in the European Union for first-line oral treatment of metastatic colorectal cancer, namely capecitabine and tegafur + uracil. According to the licensing terms, only the tegafur-uracil combination must be given with calcium folinate. (3) The evaluation files on each of these two cytotoxic agents contain data from two comparative unblinded trials versus intravenous fluorouracil + calcium folinate (Mayo Clinic protocol). None of these trials showed a difference in survival. (4) Both drugs caused severe diarrhoea in 12% of patients. Severe palmoplantar erythrodysesthesia was more frequent on capecitabine. Longer postmarketing follow-up is available for the tegafur + uracil combination, which has been used in Japan for many years. (5) Patients receiving capecitabine or tegafur + uracil + calcium folinate have to take large numbers of tablets or capsules. (6) In practice, the standard treatment for metastatic colorectal cancer remains the fluorouracil + calcium folinate combination. The tegafur + uracil + calcium folinate combination is only useful for patients who prefer oral administration. Capecitabine has no documented advantage over this latter combination.
D000284:Administration, Oral; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D002986:Clinical Trials as Topic; D015179:Colorectal Neoplasms / Q000188:drug therapy*; D003841:Deoxycytidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D018572:Disease-Free Survival; D017277:Drug Approval; D005062:European Union; D006801:Humans; D002955:Leucovorin; D009367:Neoplasm Staging; D005641:Tegafur / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D014498:Uracil / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*
D000964:Antimetabolites, Antineoplastic; D003841:Deoxycytidine; D005641:Tegafur; D014498:Uracil; D002955:Leucovorin