title: Outcome of patients with HER2-positive advanced breast cancer progressing during trastuzumab-based therapy.
abstract: We sought to describe patterns of treatment and clinical outcome in patients with HER2-positive advanced breast cancer progressing on trastuzumab-based therapy. One hundred eighty-four consecutive HER2-positive advanced breast cancer patients received trastuzumab-based therapy between September 1999 and September 2004. Patients were followed up until death or May 2005. For patients progressing on trastuzumab-based therapy, we calculated the response rate (RR) to the first post-progression treatment, overall survival (OS) from the first administration of trastuzumab, time to second progression (TT-SP), and post-progression survival (PPS), according to treatment. At the time of this analysis, 132 patients had progressed on trastuzumab-based therapy, and 89 had died. Of the progressing patients, 21 experienced rapid progression and could not receive additional anticancer treatments;40 patients continued trastuzumab either alone (12 patients with isolated central nervous system progression), with chemotherapy (23 patients), or with endocrine therapy (5 patients); and 71 stopped trastuzumab and received chemotherapy (61 patients) or endocrine therapy (10 patients) as the first post-progression treatment. Excluding patients with rapid progression, clinical outcomes were similar whether trastuzumab was continued or not, in terms of RR (18% and 27%, respectively), OS (31 and 30 months, respectively), TT-SP (6 and 7 months, respectively), and PPS (21 and 19 months, respectively). The clinical outcome of patients with HER2-positive advanced breast cancer progressing during trastuzumab-based therapy might not be influenced by continuing trastuzumab. The optimal therapeutic strategy in this setting of patients needs evaluation in randomized trials.
authors.affiliation: Medical Oncology, Institute for Cancer Research and Treatment, Candiolo, Torino, Italy. fmontemurro@ircc.mauriziano.it
authors.forename: Filippo
authors.initials: F
authors.lastname: Montemurro
authors.forename: Michela
authors.initials: M
authors.lastname: Donadio
authors.forename: Matteo
authors.initials: M
authors.lastname: Clavarezza
authors.forename: Stefania
authors.initials: S
authors.lastname: Redana
authors.forename: Maria Elena
authors.initials: ME
authors.lastname: Jacomuzzi
authors.forename: Giorgio
authors.initials: G
authors.lastname: Valabrega
authors.forename: Saverio
authors.initials: S
authors.lastname: Danese
authors.forename: Guido
authors.initials: G
authors.lastname: Vietti-Ramus
authors.forename: Antonio
authors.initials: A
authors.lastname: Durando
authors.forename: Marco
authors.initials: M
authors.lastname: Venturini
authors.forename: Massimo
authors.initials: M
authors.lastname: Aglietta
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D016543:Central Nervous System Neoplasms / Q000188:drug therapy / Q000556:secondary; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D018734:Genes, erbB-2 / Q000187:drug effects*; D006801:Humans; D008875:Middle Aged; D012189:Retrospective Studies; D016019:Survival Analysis; D000068878:Trastuzumab; D016896:Treatment Outcome
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D000068878:Trastuzumab