ESR1 amplification in breast cancer by optimized RNase FISH: Frequent but low-level and heterogeneous

Cathy B. Moelans, Frederik Holst, Olaf Hellwinke, Ronald Simon, Paul J. Van Diest

Research output: Contribution to journalArticle


Prevalence of ESR1 amplification in breast cancer is highly disputed and discrepancies have been related to different technical protocols and different scoring approaches. In addition, pre-mRNA artifacts have been proposed to influence outcome of ESR1 FISH analysis. We analyzed ESR1 gene copy number status combining an improved RNase FISH protocol with multiplex ligation-dependent probe amplification (MLPA) after laser microdissection. FISH showed a high prevalence of ESR1 gains and amplifications despite RNase treatment but MLPA did not confirm ESR1 copy number increases detected by FISH in more than half of cases. We suggest that the combination of the ESR1-specific intra-tumor heterogeneity and low-level copy number increase accounts for these discrepancies.

Original languageEnglish (US)
Article numbere84189
JournalPloS one
Issue number12
StatePublished - Dec 18 2013


ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)
  • General

Cite this