Resumen:
BACKGROUNDMolecular testing to determine gene mutation status is now the recommended standard of care for patients with advanced or metastatic Non-small cell lung cancer (NSCLC). Because the majority of patients with NSCLC present with metastatic disease, minimally invasive procedures are necessary for diagnosis, staging, and molecular analysis. However, the resulting samples have perceived limitations in the oncology community, and most commercially available tests have not been validated for these sample types. The current study was undertaken to assess the feasibility of determining epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation status in fine-needle aspirates (FNAs) and core-needle biopsies (CNBs) after staining with Papanicolaou or hematoxylin and eosin, respectively. METHODSGene mutation status was determined in 140 NSCLC tumor samples with proprietary tests for EGFR and KRAS mutations (cobas tests) followed by Sanger sequencing of exons 18 through 21 of the EGFR gene and exon 2 of the KRAS gene. The results were analyzed based on FNA (n=91) or CNB (n=49) sampling. RESULTSThe cobas tests yielded valid results in the majority of FNA and CNB samples for both EGFR (97.9%) and KRAS (93.6%). Moreover, valid results were obtained for 90% of samples that had DNA concentrations below the values recommended by the manufacturer. For samples with valid results from both cobas testing and Sanger sequencing, 95.7% and 93% agreement were observed for EGFR status and KRAS status, respectively. CONCLUSIONSGene mutation testing can be successfully performed on cytology and CNB samples, expanding the potential of personalized cancer treatment to patients who have limited tissue samples. Cancer (Cancer Cytopathol) 2015;123:230-236. (c) 2014 The Authors. Cancer Cytopathology published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. EGFR or KRAS mutation status can be successfully determined in Papanicolaou-stained fine-needle aspiration samples and hematoxylin and eosin-stained core-needle biopsy samples using polymerase chain reaction-based tests. The findings from this pilot study highlight the feasibility of rapid and accurate mutation testing for patient samples derived from minimally invasive diagnostic procedures or from samples with limited available tissue.
