Relationship between 18F-FDG uptake and heat shock protein 90α expression in colorectal cancer.

OBJECTIVE We investigated whether heat shock protein 90α (HSP90α) expression is associated with fluorine-18-labeled fluoro-2-deoxy-D-glucose (18F-FDG) uptake and whether 18F-FDG positron emission tomography/computed tomography (PET/CT) can be used to predict the status of HSP90α expression in colorectal cancer (CRC). SUBJECTS AND METHODS The medical records and preoperative 18F-FDG PET/CT studies of 51 patients with newly diagnosed CRC who underwent surgical treatment were retrospectively reviewed. The maximum standardized uptake value (SUVmax) of the primary tumor was calculated from the level of 18F-FDG uptake. HSP90α expression was determined by immunohistochemistry. The relationship between SUVmax and HSP90α expression was analyzed. RESULTS Colorectal cancer with high HSP90α expression had significantly higher SUVmax than CRC with low HSP90α expression (18.88±10.06 vs. 12.38±5.04, P=0.003). There was a significant correlation between HSP90α expression and 18F-FDG uptake (r=0.354, P=0.011). The highest accuracy for determining HSP90α status (68.6%) was obtained with a SUVmax cut-off of 15.4. Maximum SUV was the only predictor of HSP90α expression on multivariate logistic regression analysis (Odds Ratio=5.384, P=0.016). CONCLUSION The expression status of HSP90α was significantly related to 18F-FDG uptake in CRC.