Azusa Kitao, Presenter: Nothing to Disclose

Osamu Matsui MD, Abstract Co-Author: Research Consultant, Kowa Company, Ltd Research Consultant, Otsuka Holdings Co, Ltd Research Consultant, Eisai Co, Ltd Speakers Bureau, Bayer AG Speakers Bureau, Eisai Co, Ltd

Toshifumi Gabata MD, Abstract Co-Author: Nothing to Disclose

Norihide Yoneda, Abstract Co-Author: Nothing to Disclose

Kazuto Kozaka MD, Abstract Co-Author: Nothing to Disclose

Satoshi Kobayashi MD, Abstract Co-Author: Nothing to Disclose

Dai Inoue, Abstract Co-Author: Nothing to Disclose

Kotaro Yoshida MD, Abstract Co-Author: Nothing to Disclose

Tetsuya Minami MD, Abstract Co-Author: Nothing to Disclose

Wataru Koda, Abstract Co-Author: Nothing to Disclose

Wnt/β-catenin signaling pathway activation expressed by β-catenin mutation is frequently observed in hepatocellular carcinoma (HCC) at about 30-40%. HCC with β-catenin mutation and expression of its transcriptional product glutamine synthetase (GS) is supposed to be classified into a particular subtype. The purpose of this study is to clarify the imaging and pathological characteristics of this subtype of HCC.

Surgically resected 138 HCCs were subjected. The grade of immunohistochemical expression of β-catenin and GS was evaluated, and then classified into three groups: β-catenin(+)GS(+) group as HCC with β-catenin mutation, β-catenin(-)GS(+) group as intermediate type HCC and β-catenin(-)GS(-) group as HCC without β-catenin mutation. We compared three groups regarding following imaging and pathological findings of HCCs. 1.Precontrast CT value. 2.Enhancement ratio on arterial phase of dynamic CT. 3.Contrast noise ratio (CNR) on T1 weighted image. 4.CNR on T2 weighted image. 5.CNR and ADC value on diffusion weighted image (DWI). 6.CNR and enhancement ratio on hepatobiliary phase of gadoxetic acid enhanced MR imaging. 7.Pathological findings (macroscopic appearance, differentiation grade, proliferation pattern, vessel invasion and bile production). We also evaluated the correlations between immunohistochemical expression of β-catenin, GS and OATP1B3 (uptake transporter of gadoxetic acid).

HCC with β-catenin mutation (n=27) showed low CNR on DWI, high ADC value, high CNR and high enhancement ratio on gadoxetic acid enhanced MR imaging than those of intermediate type HCC (n=23) and HCC without β-catenin mutation (n=84) (P<0.05). Pathologically, β-catenin mutated HCC frequently showed pseudoglandular proliferation and bile production with higher grade of differentiation (P<0.01). There were significant positive correlations between expression of β-catenin, GS and OATP1B3 (P<0.01).

HCCs with β-catenin mutation, which was supposed to be a biologically less aggressive subtype, showed high ADC value and high enhancement ratio on gadoxetic acid enhanced MR imaging.

DWI and gadoxetic acid enhanced MR imaging are useful to diagnose HCCs with β-catenin mutation. Imaging diagnosis of this subtype of HCC will be important for future personalized medicine.

Kitao, A, Matsui, O, Gabata, T, Yoneda, N, Kozaka, K, Kobayashi, S, Inoue, D, Yoshida, K, Minami, T, Koda, W, Imaging and Biological Characteristics of Hepatocellular Carcinoma with β-catenin Mutation.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14005308.html