Prognostic Value of SUVmax of <sup>18</sup>F-FDG PET/CT in Early Stage Breast Cancer with No LN Metastasis

Purpose: To investigate the correlation between SUVmax of FDG-PET/CT and pathological findings including prognostic factors in early-stage T1-T2 breast cancer patients with no LN metastasis. Materials and Methods: This retrospective study investigated 75 patients (mean age 58.9 years; age range 30 - 82 years) with invasive breast cancer who underwent FDG-PET/CT for preoperative staging. All patients underwent subsequent surgery without prior neoadjuvant chemotherapy or endocrine therapy, and those who were confirmed to have T1- or T2-stage by histopathology with no LN metastasis were included. Two patients who had no perceptible FDG accumulation on PET/CT scans were excluded. The correlations between the SUVmax of the tumor and the pathological and immunohistochemical data were evaluated. Results: The mean SUVmax for the total 73 tumors was 5.46 ± 4.05. The mean SUVmax was 3.95 ± 3.28 for the T1 stage group (n = 36) and 7.23 ± 4.10 (p < 0.001) for the T2 stage group (n = 37). A high SUVmax was significantly associated with high nuclear grade (p < 0.001), negative hormone receptor status (p < 0.001), positive HER2 status (p = 0.008), and high Ki-67 status (p < 0.001), respectively. Conclusion: In T1-T2 breast cancer with no LN metastasis, the SUVmax of FDG-PET/CT had significant positive relationships with several prognostic parameters of pathological status. Even in early-stage breast cancer patients, pretreatment FDG-PET/CT is useful for predicting malignant behavior and prognosis).