title: EGFR gene copy number in adenocarcinoma of the lung by FISH analysis: investigation of significantly related factors on CT, FDG-PET, and histopathology.
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.
authors.affiliation: Department of Radiology, Seoul National University Hospital, 28 Yeongeon-dong, Chongno-gu, Seoul 110-744, Republic of Korea.
authors.forename: Eun-Ah
authors.initials: EA
authors.lastname: Park
authors.forename: Hyun Ju
authors.initials: HJ
authors.lastname: Lee
authors.forename: Young Tae
authors.initials: YT
authors.lastname: Kim
authors.forename: Chang Hyun
authors.initials: CH
authors.lastname: Kang
authors.forename: Keon Wook
authors.initials: KW
authors.lastname: Kang
authors.forename: Yoon Kyung
authors.initials: YK
authors.lastname: Jeon
authors.forename: Jin Mo
authors.initials: JM
authors.lastname: Goo
authors.forename: Chang Hyun
authors.initials: CH
authors.lastname: Lee
authors.forename: Chang Min
authors.initials: CM
authors.lastname: Park
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000235:genetics*; D000328:Adult; D000368:Aged; D066246:ErbB Receptors / Q000235:genetics*; D005260:Female; D019788:Fluorodeoxyglucose F18; D018628:Gene Dosage; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D017404:In Situ Hybridization, Fluorescence; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D066246:ErbB Receptors