Prognostic role of metabolic 18F-FDG PET/CT parameters and hematological prognostic indicators in patients with colorectal cancer.

BACKGROUND

The aim of this study is to evaluate the role of preoperative 18F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) parameters, including maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), hematologic prognostic indicators in patients with colorectal cancer (CRC) in terms of predicting prognosis.

METHODS

One hundred and one patients who had undergone 18F-FDG PET/CT for initial staging were evaluated retrospectively. Patient data including pathologic stage at presentation, histology, tumor location, and overall survival (OS) were analyzed. Neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), serum carcinoembryonic antigen (CEA) (ng/mL), CA-125 (cancer antigen 125) (U/mL), and CA19-9 (U/mL) levels, which were obtained within 2 weeks of the PET/CT examination, were used for hematological data.

RESULTS

The TNM Classification of Malignant Tumors stage and PET/CT parameters, including SUVmax, MTV, and TLG, were found to be correlated with survival rate in univariate analysis (P < 0.05). All hematological markers excluding PLR were also significantly associated with survival time. Receiver operating characteristics (ROC) analysis revealed that the optimal SUVmax cutoff value for predicting survival time in patients with CRC was >17.9 (Area under curve (AUC) = 0.625; P < 0.05). The calculated sensitivity and specificity values for this cutoff were 60% and 65.7%, respectively. To predict the survival time in these patients, the optimal MTV cutoff value was >34.29 (AUC = 0.775; P < 0.001; sensitivity = 85%; specificity = 62.3%). The optimal TLG cutoff value for predicting survival time was >270.4 (AUC = 0.790; P < 0.001; sensitivity = 77.5%; specificity = 68.9%).

CONCLUSIONS

FDG PET/CT metabolical parameters are useful for predicting the prognosis in patients with CRC. High preoperative NLR and high tumor markers were also shown to be negative independent prognostic factors in these patients.