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

Purpose: The relationship between 18 F-FDG uptake and HER2 expression in colorectal cancer has not been investigated yet. This study aimed to investigate the predictive efficiency of preoperative 18 F-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: 18 F-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.