Limited human epidermal growth factor receptor 2 discordance in metastatic breast cancer patients treated with trastuzumab, a population based study.
Eur J Cancer
; 50(5): 885-91, 2014 Mar.
Article
em En
| MEDLINE
| ID: mdl-24491395
ABSTRACT
BACKGROUND:
Accurate assessment of the human epidermal growth factor receptor 2 (HER2) in breast cancer is essential for proper treatment decisions. HER2 positivity confirmation rates in breast cancer trials by central testing pathology laboratories were reported to be approximately 85%. The aim of our study was to assess in a population based sample concordance of HER2 status in metastatic breast cancer (MBC) patients locally tested HER2 positive and treated with trastuzumab. Moreover cost-effectiveness of in situ hybridisation (ISH) in patients with an immunohistochemical score 3+ (IHC3+) was explored.METHODS:
MBC patients treated between 2005 and 2009 with trastuzumab-based therapy in North East Netherlands were identified by a survey of hospital pharmacies. Primary tumour samples were retested centrally for HER2 status using 1 immunohistochemical (IHC) method and two methods using ISH on tissue micro-arrays. Potential discordant patients were retested on whole tumour slides. HER2 positivity was defined as (1) ISH amplification (according to American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) clinical practice Guideline Update) and (2) when ISH failed an IHC score of 3+. Cost-effectiveness was estimated using potential ISH and treatment costs.RESULTS:
HER2 status could be retested in 174 of 194 (90%) patients. The HER2 concordance rate was 87%. The 21 discordant patients were in the 67% due to primary HER2 testing with only IHC. Overall survival of HER2 discordant and concordant patients was not significantly different (18 versus 25months, p=0.131). Structural ISH in the case of IHC3+ has an estimated potential saving of 87,710 per 100 patients.CONCLUSION:
HER2 concordance in a population based study is comparable to those described in selected populations. Discordance is mostly due to testing with only IHC. ISH in the case of IHC3+ is cost-effective.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias da Mama
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Receptor ErbB-2
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Anticorpos Monoclonais Humanizados
Tipo de estudo:
Clinical_trials
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Guideline
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Prognostic_studies
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Qualitative_research
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Screening_studies
Limite:
Adult
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Aged
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Aged80
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Female
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Humans
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Middle aged
País/Região como assunto:
Europa
Idioma:
En
Revista:
Eur J Cancer
Ano de publicação:
2014
Tipo de documento:
Article