Hyun Ju Lee MD, Presenter: Nothing to Disclose

Young Tae Kim, Abstract Co-Author: Nothing to Disclose

Chang Hyun Kang, Abstract Co-Author: Nothing to Disclose

Jin Mo Goo MD, PhD, Abstract Co-Author: Nothing to Disclose

Chang Min Park, Abstract Co-Author: Nothing to Disclose

To determine whether EGFR mutation and EGFR gene copy number status are associated with imaging features in prospectively identified patients with primary adenocarcinomas of the lung

In 154 patients (M:F=73:81; mean age, 63) who underwent curative surgical resection of lung adenocarcinoma between October 2007 and October 2008, chest CT, FDG-PET, and pathologic features were analyzed. Proportion of ground-glass opacity (GGO) in the tumor on CT and SUVmax on PET were evaluated. EGFR gene mutation and gene copy number status were determined by direct DNA sequencing and fluorescent in situ hybridization (FISH), respectively. Imaging and pathologic characteristics were correlated with EGFR mutation and gene copy number status. Chi-square, student-t, one way ANOVA, and Duncan multiple comparison tests were performed. P <0.05 indicated a significant difference.

83 tumors were mutation-positive [EM (+)] (53.9%) and 58 tumors were FISH-positive [FISH (+)] (37.7%). The frequency of EM (-) FISH (-), EM (+) FISH (+), EM (+) FISH (-), and EM (-) FISH (+) tumors was 58 (37.7%), 45 (29.2%), 38 (24.7%), and 13 (8.4%), respectively. EM (+) results were found in 83.3% of pure GGOs, 52.9% of GGOs >50%, 63.9% of GGOs ≤50%, and in 48.4% of pure solid tumors. EM (+) results were significantly more frequent in GGO containing tumors than in pure solid tumors (P=0.01). FISH (+) results were found in 0% of pure GGOs, 11.8% of GGOs >50%, 44.4% of GGOs ≤50%, and in 42.1% of pure solid tumors. FISH (+) results were significantly more rare in GGO containing tumors than in solid tumors (P=0.02). The SUVmax was higher in FISH (+) tumors than in FISH (-) tumors (P=0.003). FISH (+) results were significantly more rare in well-differentiated adenocarcinomas (P=0.004). There was no difference in SUVmax and histologic differentiation between EM (+) and EM (-) tumors (P>0.05). Cancers tended to be more likely to have a higher proportion of GGO and lower SUVmax in order of EM (+) FISH (-), EM (-) FISH (-), EM (+) FISH (+), and EM (-) FISH (+) tumors.

The proportion of GGO, glucose metabolism and histologic differentiation were associated with EGFR mutation and gene copy number status.

Biologic differences may manifest in imaging characteristics, thus, studying the imaging features may help refine current molecular phenotypes of lung adenocarcinomas.

Lee, H, Kim, Y, Kang, C, Goo, J, Park, C, EGFR Gene Mutation and EFGR Gene Copy Number Status: Relationship with Imaging Features in Primary Adenocarcinomas of the Lung.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8014469.html