title: Lapatinib plus trastuzumab in pretreated human epidermal growth factor receptor 2-positive metastatic breast cancer.
abstract: BACKGROUND
  Dual human epidermal growth factor receptor 2 (HER2) blockade has been preclinically and clinically assessed in HER2-overexpressing metastatic breast cancer (mBC) with encouraging results.
  
  
  METHODS
  This is a descriptive retrospective study of trastuzumab plus lapatinib activity in patients with HER2-overexpressing mBC from two centers. The primary endpoints were to assess objective response rate (ORR) and toxicity. The secondary endpoints were to assess progression-free survival (PFS) and overall survival.
  
  
  RESULTS
  A total of 23 HER2-positive mBC patients previously treated with trastuzumab received a trastuzumab plus lapatinib based therapy. Chemotherapy (CT) was added to the dual HER2 blockade treatment in 13 patients (56%), whereas hormonotherapy (HT) was added in 8 patients (35%) and 2 patients (9%) received lapatinib plus trastuzumab without any other agent. ORR was 22% (5/23) and 39% (9/23) of patients had stable disease. PFS in the overall population was 4 months. PFS in patients with CT was 5 months, whereas PFS in patients with HT was 2 months. Grade≥3 adverse events were diarrhea (26%) and hand-and-foot syndrome (9%).
  
  
  CONCLUSIONS
  These findings suggest that dual HER2 blockade in combination with CT is feasible in pretreated HER2-positive mBC patients.
authors.affiliation: Department of Medical Oncology, Hospital Universitario Clínico San Carlos, Spain.
authors.forename: Miguel J
authors.initials: MJ
authors.lastname: Sotelo
authors.forename: Jose Angel
authors.initials: JA
authors.lastname: García-Sáenz
authors.forename: Luis
authors.initials: L
authors.lastname: Manso
authors.forename: Fernando
authors.initials: F
authors.lastname: Moreno
authors.forename: Eva
authors.initials: E
authors.lastname: Ciruelos
authors.forename: Hector R
authors.initials: HR
authors.lastname: Callata
authors.forename: Cesar
authors.initials: C
authors.lastname: Mendiola
authors.forename: Santiago
authors.initials: S
authors.lastname: Cabezas
authors.forename: Ismael
authors.initials: I
authors.lastname: Ghanem
authors.forename: Eduardo
authors.initials: E
authors.lastname: Díaz-Rubio
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D018572:Disease-Free Survival; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D000077341:Lapatinib; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011799:Quinazolines / Q000008:administration & dosage* / Q000009:adverse effects; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D012189:Retrospective Studies; D000068878:Trastuzumab / Q000008:administration & dosage* / Q000009:adverse effects; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D000077341:Lapatinib; D011799:Quinazolines; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab; C508053:ERBB2 protein, human