The Effect of FDG-PET/CT on Clinical Prognostic Staging of Breast Cancer Patients being Planned Neoadjuvant Treatment.

ABSTRACT

OBJECTIVE: To evaluate the effect of FDG-PET/CT in the radiological imaging of breast cancer (BC) patients planned for neoadjuvant treatment (NAT), on the clinical prognostic stage (CPS). STUDY DESIGN: A descriptive study. PLACE AND DURATION OF STUDY Haydarpasa Numune Training and Research Hospital, Istanbul, Turkey, between June 2014 and September 2020. METHODOLOGY: Consecutive patients with stage I-III breast cancer (BC) who were planned for neoadjuvant treatment (NAT). The distribution of CPS detected by both conventional radiological methods (c-CPS) and FDG-PET/CT (PET-CPS) were compared. RESULTS: Significant upstaging on CPS was detected with the addition of FDG-PET/CT to conventional imaging methods in 25/121 (20.7%) patients (p <0.001). In the c-CPS stage, IB, IIA, IIB, IIIA, IIIB patients, the stage change rate was 22.7%, 28.6%, 37.5%, 50%, and 9.1%, respectively. There was no change in patients with c-CPS stage IA and IIIC. There was a significant change in the cN stages (p <0.001), while no significant change was detected in the cT stages of the patients (p = 0.180). Upstaging was detected in 5/16 (6.3%, p=0.034), 14/71 (19.7%, p <0.01), 15 / 30 (50%, p <0.01) of initially cN 0, 1, 2 patients, respectively (p<0.001). CONCLUSION: The change in CPS was due to nodal upstaging. The effectiveness of including FDG-PET/CT in the initial radiological imaging in patients planned for NAT should be evaluated with prospective studies evaluating treatment choices to be used in NAT. Key Words PET scan, Breast cancer, Positron emission tomography, Neoadjuvant treatment, Cancer staging, Staging system, TNM.