Fluorine-18-fluorodeoxyglucose uptake of bone marrow on PET/CT can predict prognosis in patients with colorectal cancer after curative surgical resection.

OBJECTIVE: This study investigated the relationship of fluorine-18-fluorodeoxyglucose (F-FDG) uptake of bone marrow (BM) on PET/computed tomography (PET/CT) with clinicopathologic factors and survival in patients with colorectal cancer.

PATIENTS AND METHODS: The study retrospectively included 226 patients with colorectal cancer who underwent F-FDG PET/CT for staging workup and treated with curative surgical resection. The maximum F-FDG uptake of primary cancer (Tmax) and mean F-FDG uptake of BM [BM standardized uptake value (SUV)] were derived from PET/CT images. The relationships between BM SUV and clinicopathologic factors and prognostic value of BM SUV for predicting recurrence-free survival (RFS) were assessed.

RESULTS: Patients with T3-T4 stage and hepatic metastases had significantly higher values of BM SUV than those with T1-T2 stage and no distant metastases (P<0.05). BM SUV showed significant positive correlation with Tmax, tumor size, serum C-reactive protein level, white blood cell count, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio (P<0.05). Univariate survival analysis revealed that N stage, M stage, tumor involvement of resection margin, lymphatic invasion, and BM SUV were significant predictors for RFS (P<0.05), whereas Tmax failed to show significance. In multivariate analysis, N stage (P=0.012 for N1 stage and P=0.020 for N2 stage), tumor involvement of resection margin (P=0.009), and BM SUV (P=0.005) were significantly associated with RFS.

CONCLUSION: Increased BM SUV was observed in patients with advanced stage and increased serum inflammatory markers. BM SUV was an independent predictor for RFS in colorectal cancer.