title: Factors predicting lapatinib efficacy in HER-2+ metastatic breast carcinoma: Does it work better in different histologic subtypes?
abstract: BACKGROUND
  Introduction of trastuzumab, a recombinant monoclonal antibody against the extracellular domain of HER-2, is a cornerstone in the treatment of HER-2+ breast carcinoma. However, many cancers that have an initial response to trastuzumab will progress some time later. After progression on trastuzumab-based first-line treatment, there are several options. Although TDM-1 (Trastuzumab emtansine) has prolonged progression-free survival (PFS) and overall survival in patients previously treated with trastuzumab and taxane, it is still not available in Turkey. Patients may be switched to lapatinib (an oral tyrosine kinase inhibitor targeting both HER-1 and HER-2), or they may re-challenge with trastuzumab. There is no clear definition of the patients who should be switched to lapatinib.
  
  
  OBJECTIVE
  In this study, we investigated the factors predicting the efficacy of lapatinib.
  
  
  METHODS
  Totally, 94 patients treated with lapatinib for metastatic breast carcinoma was included in our study. Retrospective data including pathology, treatments and treatment results, metastatic sites, and laboratory tests were collected.
  
  
  RESULTS
  Progression-free survival was 9.1 months. Histologic subtypes other than invasive ductal carcinoma and liver metastasis were inversely related with PFS. Overall survival was 22.1 months, and patients with histologic subtypes other than invasive ductal carcinoma and who progress with brain metastasis had a worse prognosis.
  
  
  CONCLUSIONS
  Clinicians should give attention to histologic subtype and metastatic sites when choosing patients for lapatinib treatment.
authors.affiliation: Department of Medical Oncology, Kayseri State Hospital of Research and Education, Kayseri, Turkey.
authors.forename: S S
authors.initials: SS
authors.lastname: Göksu
authors.forename: H
authors.initials: H
authors.lastname: Bozcuk
authors.forename: L
authors.initials: L
authors.lastname: Koral
authors.forename: B
authors.initials: B
authors.lastname: Çakar
authors.forename: S
authors.initials: S
authors.lastname: Gündüz
authors.forename: A M
authors.initials: AM
authors.lastname: Tatlı
authors.forename: D
authors.initials: D
authors.lastname: Arslan
authors.forename: M
authors.initials: M
authors.lastname: Uysal
authors.forename: M
authors.initials: M
authors.lastname: Koçer
authors.forename: M
authors.initials: M
authors.lastname: Artaç
authors.forename: B
authors.initials: B
authors.lastname: Karabulut
authors.forename: H S
authors.initials: HS
authors.lastname: Coşkun
authors.forename: M
authors.initials: M
authors.lastname: Özdoğan
authors.forename: B
authors.initials: B
authors.lastname: Savaş
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D000077341:Lapatinib; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011237:Predictive Value of Tests; D011379:Prognosis; D011799:Quinazolines / Q000627:therapeutic use*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D000077341:Lapatinib; D011799:Quinazolines; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human