This study investigated the relationship of fluorine-18-fluorodeoxyglucose (18F-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 18F-FDG PET/CT for staging workup and treated with curative surgical resection. The maximum 18F-FDG uptake of primary cancer (Tmax) and mean 18F-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.