title: Relationship between thymidylate synthase and p53 and response to FEC versus taxane adjuvant chemotherapy for breast carcinoma.
abstract: Many drugs can be used for adjuvant therapy of breast cancer, including anthracyclines, cyclophosphamide, 5-fluorouracil (5-fU) and, recently, taxanes (TXT) have shown promising results. 5-FU blocks thymidylate synthase (TS) which cross-links p53 mRNA, inhibiting its synthesis. TS overexpression is one of the main mechanisms involved in 5-FU drug resistance. Enough p53 mutations can confer resistance to chemotherapy using anthracyclines and 5-FU, while are associated with improved responses to TXT. The aim of this study was to examine the TS and p53 levels in tumor samples and to compare the efficacy of FEC (5-FU, epirubicin, cyclophosphamide) and TXT chemotherapy in a group of patients with differing TS and p53 status. We examined 84 breast tumor samples using immunohistochemistry. TS and p53 levels were inversely related, and TS and p53 positivity was significantly associated with the failure of FEC treatment and with a good response to TXT therapy (p <0.001). This confirms the predictive role of these two markers, which should be considered when choosing the appropriate adjuvant therapy for breast cancer.
authors.affiliation: Department of Health Promotion, G. D'Alessandro, University of Palermo, Italy. calascibettaanna@libero.it
authors.forename: A
authors.initials: A
authors.lastname: Calascibetta
authors.forename: A
authors.initials: A
authors.lastname: Martorana
authors.forename: D
authors.initials: D
authors.lastname: Cabibi
authors.forename: F
authors.initials: F
authors.lastname: Aragona
authors.forename: R
authors.initials: R
authors.lastname: Sanguedolce
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D001952:Bridged-Ring Compounds / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant; D003520:Cyclophosphamide / Q000008:administration & dosage; D015251:Epirubicin / Q000008:administration & dosage; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D007150:Immunohistochemistry; D009367:Neoplasm Staging; D011379:Prognosis; D043823:Taxoids / Q000627:therapeutic use*; D013940:Thymidylate Synthase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D001952:Bridged-Ring Compounds; C495901:TP53 protein, human; D043823:Taxoids; D016159:Tumor Suppressor Protein p53; C080625:taxane; D015251:Epirubicin; D003520:Cyclophosphamide; D013940:Thymidylate Synthase; D005472:Fluorouracil