title: Efficacy of weekly paclitaxel in patients with docetaxel-resistant metastatic breast cancer.
abstract: BACKGROUND
  Partial cross-resistance to paclitaxel and docetaxel has been demonstrated in pre-clinical studies.
  
  
  METHODS
  We retrospectively evaluated the efficacy of weekly paclitaxel 80 mg/m(2) in 82 patients with docetaxel-resisitant metastatic breast cancer. Docetaxel resistance was classified into primary resistance, defined as progressive disease while receiving docetaxel, and secondary resistance, defined as progression after achievement of a documented clinical response to docetaxel. Secondary resistance was subclassified according to the interval between the final infusion of docetaxel and the start of weekly paclitaxel into: (1) short interval, < or =120 days, and (2) long interval, >120 days.
  
  
  RESULTS
  The response rate of the 82 patients was 19.5% (95% confidence interval, 10.8-27.9%). The response rate according to the docetaxel resistance category was: primary resistance (n = 24), 8.3%; secondary resistance (n = 58), 24.1% (short interval [n = 39], 17.9%, and long interval, [n = 19], 36.8%). The differences in response rates among the three categories were statistically significant (p = 0.0247, Cochran-Mantel-Haenszel test). The interval between from the final docetaxel infusion and disease progression were predictors for response of weekly paclitaxel.
  
  
  CONCLUSIONS
  Weekly paclitaxel is modestly effective and safe in docetaxel-resistant metastatic breast cancer patients. However, weekly paclitaxel should not be recommended for primary resistance patients with docetaxel.
authors.affiliation: Breast and Medical Oncology Division, Department of Medical Oncology, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
authors.forename: Kan
authors.initials: K
authors.lastname: Yonemori
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Katsumata
authors.forename: Hajime
authors.initials: H
authors.lastname: Uno
authors.forename: Koji
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Kouno
authors.forename: Shinya
authors.initials: S
authors.lastname: Tokunaga
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yamanaka
authors.forename: Chikako
authors.initials: C
authors.lastname: Shimizu
authors.forename: Masashi
authors.initials: M
authors.lastname: Ando
authors.forename: Masahiro
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Fujiwara
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000627:therapeutic use*; D001859:Bone Neoplasms / Q000188:drug therapy / Q000556:secondary; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D018450:Disease Progression; D000077143:Docetaxel; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy / Q000556:secondary; D008175:Lung Neoplasms / Q000188:drug therapy / Q000556:secondary; D008207:Lymphatic Metastasis / Q000473:pathology; D008875:Middle Aged; D017239:Paclitaxel / Q000627:therapeutic use*; D012189:Retrospective Studies; D016879:Salvage Therapy; D043823:Taxoids / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D043823:Taxoids; D000077143:Docetaxel; D017239:Paclitaxel