The correlation between FDG uptake and biological molecular markers in pancreatic cancer patients

We examined whether fluorine-18 fluorodeoxyglucose (FDG) uptake is related to the mammalian target of rapamycin (mTOR) signal pathway and its related proteins in pancreatic cancer patients.

We retrospectively studied 53 pancreatic cancer patients who underwent FDG positron emission tomography (PET) or FDG PET/CT, and complete curative surgical resection. The SUV max, the tumor to nontumor activity of pancreas [T/N (P)] ratio and the T/N of liver [T/N (L)] ratio were calculated. The expressions of glucose transporter-1(Glut-1) and mTOR pathway proteins in pancreas cell lines were examined by immune blots. Excised tumor tissue was analyzed by immunohistochemistry using monoclonal antibodies for Glut-1, epidermal growth factor receptor (EGFR), mTOR, p70S6kinase (p70S6) and S6 ribosomal protein (S6).

The expressions of Glut-1, EGFR and p70S6 were significantly correlated with the SUV max, T/N (P) ratio and T/N (L) ratio. The expressions of mTOR and S6 were not correlated with all parameters. The expression of Glut-1 was positively correlated with the expressions of EGFR and p70S6, but not with mTOR or S6. S6 was positively correlated with p70S6.

Glut-1, EGFR and p70S6 expressions are associated with the FDG uptake mechanism of pancreatic cancer. FDG uptake may predict the levels of EGFR and p70S6 expressions, and FDG uptake reflects glucose metabolism and cancer progression.