title: Continuing trastuzumab beyond disease progression: outcomes analysis in patients with metastatic breast cancer.
abstract: BACKGROUND
  We performed a retrospective analysis of HER2-overexpressing metastatic breast cancer patients to describe clinical outcomes of those who, despite progression of the disease (PD), maintained trastuzumab for multiple chemotherapy lines. We also compared survival of these patients with that of those who halted trastuzumab at first PD.
  
  
  METHODS
  We identified 101 patients treated between July 2000 and January 2007. Nineteen were still receiving the first-line trastuzumab-based treatment without evidence of PD and were not included in this analysis. Of the remaining 82 patients, 59 retained trastuzumab for one or more additional lines of chemotherapy after PD, according to our institution policy. Twenty-three patients who changed treating institution and stopped trastuzumab at first progression were used as a control group.
  
  
  RESULTS
  For patients retaining trastuzumab, the median follow-up was 39.6 months. Clinical outcomes showed the typical degradation between first and second lines of therapy which we would expect by halting trastuzumab at first progression. Response rates were 35% and 16% and median times to progression were 7.25 and 5.25 months for the first and second lines of trastuzumab therapy, respectively. The median overall survival (OS) rates were 70 months for patients who retained trastuzumab and 56 months for patients who halted the drug (hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.51 to 1.18; P = 0.52). If we consider OS from the start of trastuzumab therapy, the figures are 53.9 and 34.8 months, respectively (HR 0.78, 95% CI 0.58 to 1.32; P = 0.2).
  
  
  CONCLUSIONS
  A nonstatistically significant trend of improved survival for patients retaining trastuzumab is observed. This is in line with most retrospective analyses and recent randomized data. Retaining trastuzumab after progression is a reasonable option, but further randomized data are warranted to better define its role in comparison with other available options.
authors.affiliation: Dipartimento di Endocrinologia ed Oncologia Molecolare e Clinica, Università 'Federico II', via Sergio Pansini, 5, 80131 - Napoli, Italy. giuseppe.cancello@tele2.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Cancello
authors.forename: Emilia
authors.initials: E
authors.lastname: Montagna
authors.forename: Diego
authors.initials: D
authors.lastname: D'Agostino
authors.forename: Mario
authors.initials: M
authors.lastname: Giuliano
authors.forename: Antonio
authors.initials: A
authors.lastname: Giordano
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Di Lorenzo
authors.forename: Monica
authors.initials: M
authors.lastname: Plaitano
authors.forename: Sabino
authors.initials: S
authors.lastname: De Placido
authors.forename: Michele
authors.initials: M
authors.lastname: De Laurentiis
mesh_terms: D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008875:Middle Aged; D009362:Neoplasm Metastasis; D012189:Retrospective Studies; D000068878:Trastuzumab; D016896:Treatment Outcome
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D000068878:Trastuzumab