title: CYP3A4 expression to predict treatment response to docetaxel for metastasis and recurrence of primary breast cancer.
abstract: OBJECTIVE
  Tumors expressing high levels of CYP3A4 are likely to have a poor treatment response to docetaxel (DOC), which is metabolized by CYP3A4. Tissue samples of recurrent breast cancer are sometimes hard to obtain just before treatment because the tumor is often difficult to access. Using immunohistochemistry, we measured CYP3A4 expression in primary lesions and compared their treatment responses to DOC with those of recurrent breast cancer lesions.
  
  
  METHODS
  The subjects of this study were 42 patients who had undergone surgery for breast cancer, and had metastasis or recurrence treated by DOC (60 mg/m(2) every 3 weeks). Tumor samples resected at surgery were immunostained for CYP3A4 and its expression levels were compared with the response rate to ongoing DOC treatment.
  
  
  RESULTS
  Patients with CYP3A4-negative tumors (n = 19) showed a significantly higher response rate (63.2%) to DOC treatment than did those with CYP3A4-positive tumors (n = 23) (26.1%). The predictive value, negative predictive value, and diagnostic accuracy of CYP3A4 expression in the prediction response to DOC were 63.2%, 73.9%, and 68.6%, respectively.
  
  
  CONCLUSIONS
  Measuring CYP3A4 expression immunohistochemically in the primary breast cancer lesion was useful for predicting the treatment response to DOC of tumors that recurred after a long interval.
authors.affiliation: Division of Breast and Endocrine Surgery, Department of Surgery, Nihon University School of Medicine, 30-1 Oyaguchi-kamimachi, Itabashi-ku, Tokyo, 173-8610, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sakurai
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Enomoto
authors.forename: Sadanori
authors.initials: S
authors.lastname: Matsuo
authors.forename: Sadao
authors.initials: S
authors.lastname: Amano
authors.forename: Motomi
authors.initials: M
authors.lastname: Shiono
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D002277:Carcinoma / Q000188:drug therapy / Q000201:enzymology / Q000556:secondary*; D051544:Cytochrome P-450 CYP3A / Q000378:metabolism*; D018450:Disease Progression; D000077143:Docetaxel; D004354:Drug Screening Assays, Antitumor; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D043823:Taxoids / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D043823:Taxoids; D000077143:Docetaxel; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human