title: [PTEN loss correlates withthe clinical efficacy of lapatinib in HER2 positive metastatic breast cancer with trastuzumab-resistance].
abstract: OBJECTIVE
  To discuss the indexes related to the efficacy of lapatinib after failure in trastuzumab in HER2-positive metastatic breast cancer (MBC) such as the status of PTEN, p-4EBP1 and clinical features.
  
  
  METHODS
  Sixtymatched patients were included. Immunohistochemical (IHC) test of tissue specimens of metastatic lesions were applied to determine the status of PTEN and p-4EBP1. The correlation betweenclinical efficacy andthestatus of PTEN, p-4EBP1 and clinical features were analysed by long-rank test and Cox regression.
  
  
  RESULTS
  In all patients, themedian progression free survival (PFS), ORR and CBR was 4.6 months, 36.7% and 50.0% respectively.Univariate analysis revealed that lapatinib-treated patients with PTEN loss (P = 0.015) and liver metastasis (P = 0.02) had significantly shorter median PFS. Multivariate analysis revealed that patients with PTEN lossandliver metastasis had higher risk of diseaseprogression (P = 0.005, 0.006, respectively).
  
  
  CONCLUSIONS
  HER2-positive MBC with trastuzumab-resistance could benefit from lapatinib regimen. PTEN statusand liver metastasis couldpredict theclinical efficacyof subsequent lapatinib therapy. The detection ofrelated biomarkers could provide some referenceto optimize the personal treatment with HER2-positive breast cancer.
authors.affiliation: Department of Breast Cancer, Affiliated Hospital, Academy of Military Medical Science, Beijing 100071, China.
authors.forename: Ge
authors.initials: G
authors.lastname: Du
authors.forename: Li
authors.initials: L
authors.lastname: Bian
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Xu
authors.forename: Shaohua
authors.initials: S
authors.lastname: Zhang
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Guo
authors.forename: Jinmei
authors.initials: J
authors.lastname: Zhuo
authors.forename: Santai
authors.initials: S
authors.lastname: Song
authors.affiliation: Email: jiangzf@hotmail.com.
authors.forename: Zefei
authors.initials: Z
authors.lastname: Jiang
mesh_terms: D000970:Antineoplastic Agents; D001943:Breast Neoplasms; D018572:Disease-Free Survival; D019008:Drug Resistance, Neoplasm; D006801:Humans; D007150:Immunohistochemistry; D000077341:Lapatinib; D009362:Neoplasm Metastasis; D051059:PTEN Phosphohydrolase; D011799:Quinazolines; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D000077341:Lapatinib; D051059:PTEN Phosphohydrolase; D011799:Quinazolines; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab; C508053:ERBB2 protein, human; C494929:PTEN protein, human