Relationship Between FDG Uptake and Neutrophil/Lymphocyte Ratio in Patients with Invasive Ductal Breast Cancer

Background: F-18-Fluorodeoxyglucose-positron-emission tomography (FDG-PET) is used to evaluate the glucose metabolic rates of tumors. Several studies have reported that high FDG uptake is predictive of poor prognosis and aggressive features in patients with breast cancer. FDG uptake is influenced by many factors, including inflammation. In this study, the relationship between FDG uptake and neutrophil/lymphocyte ratio (NLR), which is an indicator of systemic inflammation, was investigated. Patients and Methods: A retrospective investigation of the cases of 143 consecutive patients with invasive ductal carcinoma who had undergone surgery and FDG-PET preoperatively. PET was evaluated using standardized uptake value max (SUVmax). The median SUVmax was 2.5 (range=0-10.5). The cases were divided into two groups based on the value of SUVmax: low (< 2.5) and high (>= 2.5). The relationships between SUVmax and clinicopathological features, including NLR, were investigated. Results: Among the 143 patients, 73 (51.0%) had high SUVmax in the primary tumor. The analysis revealed that large tumor size (p<0.001), high nuclear grade (p<0.001), the presence of lymphovascular invasion (p<0.001), high C-reactive protein (p=0.046) and high NLR (p<0.001) were significantly associated with high SUVmax in the primary tumor. SUVmax and NLR were significantly positively correlated (r=0.323, p<0.001). Among the 70 cases with low SUVmax, there was no recurrent disease, while out of the 73 cases with high SUVmax had disease recurrence. It is interesting to note that the group with high SUVmax and low NLR had no recurrent disease. Conclusion: The present study demonstrated that the finding of high preoperative FDG uptake in breast cancer may be reflective of poor prognosis and that a high NLR may be predictive of aggressive features among patients with breast cancer. On the other hand, among patients with breast cancer with high SUVmax in the primary tumor, it will be useful to identify those with a low NLR in order to improve prognostic accuracy.