Role of the pretreatment 18 F-fluorodeoxyglucose positron emission tomography maximal standardized uptake value in predicting outcomes of colon liver metastases and that value's association with Beclin-1 expression.

The current study sought to evaluate the predictive and prognostic performance of the maximum standardized uptake value (SUVmax ) prior to treatment in 43 patients with colon cancer and unresectable liver metastases. Patients with colon cancer who underwent 18 F-FDG-PET/computed tomography (CT) scans for staging before the start of first-line 5-fluorouracil-based chemotherapy were retrospectively analyzed. Expression of Beclin-1 in cancer cells was evaluated in primary tumors using immunohistochemical staining. The pretreatment SUVmax for liver metastases was not able to predict progression-free survival but was significantly associated with poorer overall survival, with a hazard ratio of 2.05 (95 % CI, 1.016-4.155). Moreover, a negative correlation was noted between SUVmax and expression of a marker of autophagy - Beclin-1 (rho = -0.42, p = 0.006). This suggests that the pretreatment SUVmax in 18 F-FDG PET/CT is a useful tool to help predict survival outcome in patients with colon cancer and unresectable liver metastases and may significantly distinguish between patients with low and high levels of Beclin-1 expression (AUC = 0.809, 95% CI: 0.670-0.948, p = 0.001).