Variable 18F-fluorodeoxyglucose uptake in gastric cancer is associated with different levels of GLUT-1 expression.
OBJECTIVE
Detection rates of gastric cancer in F-fluorodeoxyglucose (FDG)-PET depend on the histopathological characteristics of the primary tumor. To clarify this observation, FDG uptake in gastric carcinoma was analyzed by focusing on histopathology and on the expression of the glucose transporter (GLUT-1) in the primary tumor.


METHODS
Thirty-five patients with the diagnosis of gastric cancer underwent FDG-PET with visual image analysis and measurement of maximum standardized uptake value (SUV(max)) before surgical treatment. Resected tumor samples were categorized according to Union internationale contre le cancer, WHO, and Laurén classification and tumor differentiation. GLUT-1 expression was graded semiquantitatively by immunohistochemistry. Statistical analysis was done for the correlation of histology, different classifications, and tumor grading with SUV(max) and GLUT-1 expression.


RESULTS
SUV(max) significantly correlated with histopathological classifications according to the WHO (P=0.009) and Laurén classification (P=0.034). Signet-ring cell carcinoma had a median SUV(max) of only 3.0 (range, 1.0-11.5). Median SUV(max) for papillary and tubular carcinoma was 7.8 (range, 1.8-14.4). In 21 (60%) cases, GLUT-1 expression in the primary tumor was positive. GLUT-1 expression correlated significantly with tumor differentiation (P=0.018) and the classification according to Laurén (P=0.023) and WHO (P<0.001). Thirteen (76%) of 17 signet-ring cell carcinoma cases did not show any GLUT-1 expression. SUV(max) in relation to GLUT-1 expression showed a significant correlation (P=0.002). For cases with detectable GLUT-1 expression the median SUV(max) was 6.9 (range, 2.3-14.1) versus a median of 3.1 (range, 1-8.8) for cases without GLUT-1 expression.


CONCLUSIONS
FDG uptake in gastric cancer depends on GLUT-1 expression. One major reason for low FDG uptake in signet-ring cell carcinoma is the low GLUT-1 expression in this histological subtype of gastric cancer.
Alakus
Hakan
H
Department of General, Visceral and Cancer Surgery, University Hospital of Cologne, Cologne, Germany.
Batur
Mert
M
Schmidt
Matthias
M
Drebber
Uta
U
Baldus
Stephan E
SE
Vallböhmer
Daniel
D
Prenzel
Klaus L
KL
Metzger
Ralf
R
Bollschweiler
Elfriede
E
Hölscher
Arnulf H
AH
Mönig
Stefan P
SP
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001692:Biological Transport; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D051272:Glucose Transporter Type 1 / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology
D051272:Glucose Transporter Type 1; D019788:Fluorodeoxyglucose F18