EGFR gene copy number in adenocarcinoma of the lung by FISH analysis: investigation of significantly related factors on CT, FDG-PET, and histopathology

Lung Cancer. 2009 May;64(2):179-86. doi: 10.1016/j.lungcan.2008.08.003. Epub 2008 Sep 25.

Abstract

It has been suggested that a high EGFR gene copy number may be an indicator of good response to EGFR tyrosine kinase inhibitor therapy and a marker of poor prognosis in NSCLC. However, imaging features related to EGFR gene copy number status in adenocarcinoma are still unknown. We therefore retrospectively analyzed CT, FDG-PET, and histopathologic slides of surgical resected lung adenocarcinoma in 132 patients. Tumor characteristics on preoperative chest-CT, such as, GGO proportions, tumor diameters, and cavitation; FDG-PET SUV(max); and histopathologically determined differentiation degrees and tumor subtypes were evaluated. EGFR gene copy number status was categorized as FISH-positive or -negative. FISH-positivity was found in 53 patients (40.2%) and was significantly more frequent in tumors with a SUV(max)>7.0 (P=0.007). Furthermore, FISH-negativity was found to be more frequent in tumors with a GGO>50% (P=0.023) and diameter <15.5mm (P=0.006) on CT, or a well-differentiated histopathology (P=0.002). Moreover, the frequency of FISH-positivity increased as SUV(max) increased (P=0.0008) and as the proportion of GGO decreased (P=0.01). SUV(max)>7.0 was an independent predictor of FISH-positive results (odds ratio, 3.941; 95% CI, 1.691-9.182; P=0.01). In conclusion, a high SUV(max) on FDG-PET was significantly related to FISH-positive results. A high proportion of GGO, small tumor diameter on CT, and a well-differentiated histopathology were more frequent in FISH-negative adenocarcinomas.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / diagnostic imaging*
  • Adenocarcinoma / genetics*
  • Adult
  • Aged
  • ErbB Receptors / genetics*
  • Female
  • Fluorodeoxyglucose F18
  • Gene Dosage
  • Humans
  • Image Interpretation, Computer-Assisted
  • In Situ Hybridization, Fluorescence
  • Lung Neoplasms / diagnostic imaging*
  • Lung Neoplasms / genetics*
  • Male
  • Middle Aged
  • Positron-Emission Tomography
  • Radiopharmaceuticals
  • Retrospective Studies
  • Tomography, X-Ray Computed

Substances

  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18
  • ErbB Receptors