Preoperative evaluation of prognosis in breast cancer patients by [ 18 F]2-Deoxy-2-fluoro-D-glucose-positron emission tomography

Abstract

[¹⁸F]2-Deoxy-2-fluoro-D-glucose (FDG)-positron emission tomography (PET) was applied to breast cancer patients for the purpose of preoperative evaluation of patient prognosis with more accuracy than conventional TNM staging. FDG-PET was performed preoperatively in 81 patients with breast cancer, and the maximum standardized uptake value (SUVmax) of tumors as well as the focal accumulation of FDG in the axillary region (PET-N status) were investigated in their association with patient prognosis. The SUVmax high group (n=40) showed a significantly (P=0.011) poorer prognosis than the SUVmax low group (n=41) (5-year disease-free survival (DFS) rates; 75.0% vs 95.1%). FDG-PET was more accurate in the diagnosis of axillary lymph node status than physical examination, i.e., diagnostic accuracy was 80% and 70% for FDG-PET and physical examination, respectively. The combination of high SUVmax and positive PET-N (+) was shown to be a highly significant risk factor being independent of the clinical T and N factors, i.e., patients with high SUVmax and positive PET-N (+) showed a significantly (P<0.001) poorer prognosis than the other patients (5-year DFS rates; 44.4% vs 96.8%). These results suggest that FDG-PET is useful in the preoperative evaluation of prognosis in breast cancer patients with more accuracy than conventional TNM staging. It is expected that the indication of neoadjuvant chemotherapy can be decided more precisely by the preoperative evaluation of patient prognosis with FDG-PET due to a possible elimination of overtreatment for those who have good prognosis and, thus, need not to be treated with chemotherapy.