title: Trastuzumab-based Retreatment after Lapatinib in Heavily Pretreated HER2 Positive Metastatic Breast Cancer: an Anatolian Society of Medical Oncology Study.
abstract: BACKGROUND
  For HER2 positive metastatic breast cancer (MBC), continuing anti-HER2 therapy beyond progression is associated with improved outcome. However retreatment with trastuzumab after lapatinib progression is controversial. We retrospectively analyzed the efficacy of trastuzumab-based chemotherapy in HER2+ metastatic breast cancer patients whose disease progressed after lapatinib.
  
  
  METHODS
  Between October 2010 and May 2013, 54 patients whose disease progressed after lapatinib were retreated with trastuzumab-based chemotherapy. Efficacy and toxicity results were evaluated retrospectively.
  
  
  RESULTS
  The median age of patients was 46 (range 27-67). Fourteen patients (26%) had metastases at the time of diagnosis. All of the patients had received trastuzumab in an adjuvant or metastatic setting, while 16 (30%) had received two lines of trastuzumab. All patients had received lapatinib plus capecitabine. The median chemotherapy line for the metastatic setting was 2 (range 1-7). Cranial metastases were identified in 27 (50%) patients. 53 patients received trastuzumab-based chemotherapy following lapatinib progression while one patient received trastuzumab monotherapy. Combination chemotherapy consisted of navelbin (n=33), taxane (n=10), gemcitabine (n=2), platinum (n=2) and platinum with taxane (n=6). The median treatment cycle was 5 (range 1-44). Among 49 patients assessed for response 2 (4%) showed CR, 12 (25%) PR, 11 (22%) SD and 24 (49%) disease progression. Asymptomatic cardiotoxicity was reported in 2 (4%) of the patients. At a median follow-up of 9 months (1-39), median progression-free survival was 5 months (95% CI 4.1-5.9) and median overall survival was 10 months (95% CI 6.9-13.0). PFS and OS were not affected by the absence/presence of cranial metastases.
  
  
  CONCLUSIONS
  Retreatment with trastuzumab-based therapy after lapatinib progression showed efficacy in heavily treated MBC patients.
authors.affiliation: Departments of Medical Oncology, Education and Research Hospitals, Ankara, Turkey E-mail : doganuncu@yahoo.com.
authors.forename: Dogan
authors.initials: D
authors.lastname: Uncu
authors.forename: Ibrahim Vedat
authors.initials: IV
authors.lastname: Bayoglu
authors.forename: Ulku Yalcintas
authors.initials: UY
authors.lastname: Arslan
authors.forename: Mehmet
authors.initials: M
authors.lastname: Kucukoner
authors.forename: Mehmet
authors.initials: M
authors.lastname: Artac
authors.forename: Dogan
authors.initials: D
authors.lastname: Koca
authors.forename: Arzu
authors.initials: A
authors.lastname: Oguz
authors.forename: Umut
authors.initials: U
authors.lastname: Demirci
authors.forename: Erkan
authors.initials: E
authors.lastname: Arpaci
authors.forename: Mutlu
authors.initials: M
authors.lastname: Dogan
authors.forename: Yuksel
authors.initials: Y
authors.lastname: Kucukzeybek
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Turker
authors.forename: Abdurrahman
authors.initials: A
authors.lastname: Isikdogan
authors.forename: Tunc
authors.initials: T
authors.lastname: Guler
authors.forename: Nurullah
authors.initials: N
authors.lastname: Zengin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000556:secondary; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D000069287:Capecitabine / Q000008:administration & dosage; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D000077341:Lapatinib; D008875:Middle Aged; D060787:Neoplasm Grading; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D011379:Prognosis; D011799:Quinazolines / Q000008:administration & dosage; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D019233:Retreatment; D012189:Retrospective Studies; D015996:Survival Rate; D000068878:Trastuzumab / Q000008:administration & dosage; D055815:Young Adult
chemical_list: D000069287:Capecitabine; D000077341:Lapatinib; D011799:Quinazolines; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab; C508053:ERBB2 protein, human