SLC2A1/GLUT1 expression in mural nodules of intraductal papillary mucinous neoplasm of the pancreas.

In intraductal papillary mucinous neoplasms (IPMNs), the presence of a mural nodule showing a papillary or nodular proliferation of tumor cells in the dilated pancreatic duct is an indication for resection of IPMN. Solute carrier family 2, facilitated glucose transporter member 1, known as glucose transporter type 1 (SLC2A1/GLUT1) mediates cellular glucose uptake in many carcinomas and is correlated with increased F-fluorodeoxyglucose (F-FDG) uptake. We examined SLC2A1/GLUT1 expression in the mural nodules of 180 IPMN specimens to distinguish malignant/benign tumors. A mural nodule was detected in 80 (44.4%) of the IPMNs, and was detected in 18.6% (13/70) of the IPMN-low (dysplasia) specimens, 36.1% (13/36) of the IPMN-int, 93.3% (28/30) of the IPMN-high, and 59.1% (26/44) of the IPMN-inv (with an associated invasive carcinoma) specimens. The sensitivity for detecting mural nodules was 81.7% by endoscopic ultrasonography, 70% by contrast-enhanced computed tomography and 54% by endoscopic retrograde cholangiopancreatography. SLC2A1/GLUT1 expression in the mural nodules was recognized in the basal and basolateral cytomembrane of tumor cells and was expressed in 15.4% (2/13) of the IPMN-low, 15.4% (2/13) of the IPMN-int, 71.4% (20/28) of the IPMN-high and 84.6% (22/26) of the IPMN-inv groups. The SLC2A1/GLUT1 expression was significantly higher in the IPMN-high and IPMN-inv mural nodules than in those of the IPMN-low and IPMN-int groups. Our findings suggest that SLC2A1/GLUT1 is expressed late in the adenoma-carcinoma sequence during carcinogenesis in IPMN, and SLC2A1/GLUT1 act as therapeutic target for malignant IPMN.