18F-FDG PET/CT Metabolic Parameters and HER2 Expression in Colorectal Cancer

Abstract Purpose: The relationship between 18F-FDG uptake and HER2 expression in colorectal cancer has not been investigated yet. This study aimed to investigate the predictive efficiency of preoperative 18F-FDG PET/CT for HER2 expression and prognosis in colorectal cancer.Results: Over all 131 colorectal cancer patients, there were 27 (20.6%) patients were HER2 positive. SUVmax of primary tumor (Mean ± SD) in HER2-positive and HER2-negative group was 18.238 ± 8.912 and 14.455 ± 6.531, respectively. SUVmax in HER2-positive group were higher than in negative group (p = 0.034). When the cutoff was based on 5cm, tumor size demonstrated significant positive correlations with SUVmax (p = 0.012) and HER2 expression (p = 0.014). Multivariate analysis showed that both SUVmax and tumor size had significant correlation with HER2 expression (p = 0.049 vs p = 0.043, respectively). In addition, statistical analysis showed that patients with higher SUVmax had better PFS (p = 0.029). There was no statistical difference of PFS between HER2-positive and HER2-negative group (p = 0.28).Conclusion: 18F-FDG metabolic parameters had significant correlation with HER2 expression in colorectal cancer. SUVmax combined with primary tumor size were better for predicting the HER2 status of colorectal cancer.