Correlation between 18F-FDG Positron-Emission Tomography 18F-FDG Uptake Levels at Diagnosis and Histopathologic and Immunohistochemical Factors in Patients with Breast Cancer.

Objective: In this study, we aimed to determine the correlation between pretreatment-staging 18F-FDG total body positron-emission tomography/computed tomography (PET/CT) maximum standardized uptake value (SUV_max) levels and histopathologic and immunohistochemical predictive and prognostic factors in patients with breast cancer.

Materials and methods: One hundred thirty-nine women with breast cancer who were treated between 2009 and 2015 at our hospital and who had pretreatment-staging PET/CT were included in the study. SUV_max levels and histopathologic and immunohistochemical results were compared.

Results: The median age was 48 years (range, 29-79 years). The mean tumor diameter was 33.4 mm (range, 7-120 mm). The histology was invasive ductal carcinoma in 80.6% of the patients. In the univariate analysis, SUV_max levels were significantly higher in patients with invasive ductal carcinoma; in patients with a maximum tumor diameter more than 2 cm; patients who were estrogen, progesterone, and combined hormone receptor-negative, triple-negative patients, and in tumors with higher grades (p<0.05). In HER2-positive patients, SUV_max levels were higher even if it was not statistically significant. There was no correlation between lymph node metastases and pathologic stage. In multivariate analysis, tumor diameter was an independent factor.

Conclusion: SUV_max levels are correlated with known histopathologic and immunohistochemical prognostic factors. PET/CT could be useful in preoperative evaluation of patients with breast cancer to predict biologic characteristics of tumors and prognosis.