title: Can EGFR mutation status be reliably determined in pre-operative needle biopsies from adenocarcinomas of the lung?
abstract: The identification of EGFR mutations in non-small-cell lung cancer is important for selecting patients, who may benefit from treatment with EGFR tyrosine kinase inhibitors. The analysis is usually performed on cytological aspirates and/or histological needle biopsies, representing a small fraction of the tumour volume. The aim of the present investigation was to evaluate the diagnostic performance of this molecular test. We retrospectively included 201 patients with primary adenocarcinoma of the lung. EGFR mutation status (exon 19 deletions and exon 21 L858R point mutation) was evaluated on both pre-operative biopsies (131 histological and 70 cytological) and on the surgical specimens, using PCR. Samples with low tumour cell fraction were assigned to laser micro-dissection (LMD). We found nine (4.5%) patients with EGFR mutation in the lung tumour resections, but failed to identify mutation in one of the corresponding pre-operative, cytological specimens. Several (18.4%) analyses of the pre-operative biopsies were inconclusive, especially in case of biopsies undergoing LMD and regarding exon 21 analysis. Discrepancy of mutation status in one patient may reflect intra-tumoural heterogeneity or technical issues. Moreover, several inconclusive results in the diagnostic biopsies reveal that attention must be paid on the suitability of pre-operative biopsies for EGFR mutation analysis.
authors.affiliation: Department of Pathology, Vejle Hospital, part of Lillebaelt Hospital, Vejle, Denmark; Department of Pathology, Odense University Hospital, Odense, Denmark.
authors.forename: Kim Hein
authors.initials: KH
authors.lastname: Lindahl
authors.forename: Flemming Brandt
authors.initials: FB
authors.lastname: Sørensen
authors.forename: Søren Peter
authors.initials: SP
authors.lastname: Jonstrup
authors.forename: Karen Ege
authors.initials: KE
authors.lastname: Olsen
authors.forename: Siegfried
authors.initials: S
authors.lastname: Loeschke
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000235:genetics* / Q000601:surgery; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001483:Base Sequence; D001707:Biopsy, Needle / Q000379:methods; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000235:genetics* / Q000601:surgery; D004252:DNA Mutational Analysis; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000235:genetics*; D000069347:Erlotinib Hydrochloride; D005260:Female; D000077156:Gefitinib; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011300:Preoperative Care; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use; D011799:Quinazolines / Q000627:therapeutic use; D012189:Retrospective Studies; D017422:Sequence Analysis, DNA
chemical_list: D000970:Antineoplastic Agents; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D000069347:Erlotinib Hydrochloride; C512478:EGFR protein, human; D066246:ErbB Receptors; D000077156:Gefitinib
keywords: Epidermal growth factor receptor; lung adenocarcinoma; mutation; needle biopsy; tumour heterogeneity