555 Background: Recently, novel metabolic parameters in 18F-FDG PET/CT such as total lesion glycolysis (TLG) and metabolic tumor volume (MTV) as well as maximum standardized uptake value (SUVmax) have been reported to be prognostic and be related with genomic aberration. We evaluated the prognostic role of these metabolic parameters and the correlation with clinical features in resected colon cancer. Methods: This study included 212 colon cancer patients who underwent surgical resection of stage II and III disease and conducted pre-treatment 18F-FDG PET/CT between February 2009 and December 2013. TLG, MTV of the primary tumors as well as SUVmax were analyzed according to clinical features including KRAS mutation, pre-treatment carcinoembryonic antigen (CEA) and recurrence free survival (RFS). Results: TLG was significantly higher in patients with right colon cancer than those with left colon cancer ( P = 0.015) and in patients with elevated CEA than those with normal range of CEA ( P = 0.034), while MTV and SUVmax were not correlated with cancer location and CEA level. KRAS mutation analysis using peptide nucleic acid-mediated real-time polymerase chain reaction clamping was conducted in 94 patients and forty-one (43.6%) patients showed KRAS mutation in tumor tissues. TLG was significantly higher in patients with mutated KRAS compared with in those with wild KRAS ( P = 0.021). CEA was significantly higher in patients with mutated KRAS than those with wild KRAS ( P-value = 0.024). CEA and TLG could predict KRAS mutation showing odds ratio 1.07 and 1.02 in the multivariate logistic analysis ( P-value = 0.024, 0.048). There was no difference of RFS between in patients with high TLG and in those with low TLG. Conclusions: Based on the result that TLG had a predictive role for KRAS mutation and was related with tumor location and CEA value, we suggested that TLG might reflect genomic alteration and other clinical features as well as tumor burden. It could be useful for differentiating different population of colon cancer and further study is clinically warranted.
A CASE OF SIGMOID COLON CANCER WITH URINARY BLADDER INFILTRATION, WHICH WAS FALSE-POSITIVE FOR PARA-AORTIC LYMPH NODE INVOLVEMENT ON FDG-PET/CT