RELATIONSHIP BETWEEN THYMIDYLATE SYNTHASE EXPRESSION AND p53 LEVELS WITH THE TREATMENT BY CYCLOPHOSPHAMIDE, 5-FLUOROURACIL CHEMOTHERAPY (CMF) VERSUS DOCETAXEL IN THE LOCALLY ADVANCED CARCINOMA OF THE BREAST.

Relationship between thymidylate synthase expression and p53 levels with the treatment of cyclophsphamide, methotrexate, 5-fluorouracil chemotherapy ( CMF)versus docetaxel ( TXT) in locally advanced carcinoma of the breast

10546 Background: Adjuvant chemotherapy is used in the treatment of breast carcinoma independently of axillar node involvement. Different drug combinations such as CMF, FAC, FEC are still used; recently new drugs such as TXT (NEJM 332:1004,1997) show activity and are used also in adjuvant chemotherapy. 5 Fluorouracil (5Fu), a drug involved in main therapeutic regimens, blocks Thymidylate Synthase (TS), an enzyme involved in the DNA synthesis. TS not only links its own mRNA, but also p53 mRNA, inhibiting post transcriptional p53 protein synthesis. TS protein overexpression (Cancer Res 55:1407,1995), and/or its absence (Cancer Res 61:1421,2001) are some of the main mechanisms of 5-Fu drug re…