International Journal of Hematology and Oncology 2022, Vol 32, Num 3 Page(s): 150-158
18F FDG PET/CT after Neoadjuvant Chemotherapy and Pathological Responses are Predictive Factors for Disease-Free Survival and Overall Survival in Patients with Locally Advanced Breast Cancer: A Prospective Study

Osman KUPIK1, Murat TUNCEL2, Sercan AKSOY3, Pinar O. KIRATLI2, Meltem G. AKPINAR4, Kadri ALTUNDAG5, Figen B. DEMIRKAZIK4, Belkis ERBAS2

1Sıtkı Koçman University, Faculty of Medicine, Department of Nuclear Medicine, Muğla, TURKIYE
2Hacettepe University, Faculty of Medicine, Department of Nuclear Medicine, Ankara, TURKIYE
3Hacettepe University, Faculty of Medicine, Department of Clinical Oncology, Ankara, TURKIYE
4Hacettepe University, Faculty of Medicine, Department of Radiology, Ankara, TURKIYE
5MKA Breast Cancer Clinic, Ankara, TURKIYE

Keywords: Breast cancer, Neoadjuvant chemotherapy, Fluorodeoxyglucose, PET/CT, Survival
We investigated the prognostic value of interim and post-neoadjuvant chemotherapy (NAC) 18F FDG PET/CT and the complete pathological and metabolical response after NAC for disease-free survival (DFS) and overall survival (OS) in patients with locally advanced breast cancer (LABC) receiving NAC. Patients who were decided to receive NAC were evaluated with baseline (PET1), after 2-3 cycles of chemotherapy (interim-PET2), and after NAC-before surgery (PET3) with 18F FDG PET/CT. The primary tumor SUV and the total metabolic tumor volume (MTV) of the primary tumor+axillary lymph nodes were calculated and defined for PET1-2-3 as SUV1-2-3 and MTV1-2-3. We also calculated Δ%SUV and Δ%MTV for PET1-2 and PET1-3. The relation between parameters and survival was evaluated with Cox regression analysis. Patients were grouped as a complete metabolic response or not (metCR/nonmetCR) according to PET3 and as PCR/non-PCR according to the presence of residual invasive tumor as a result of pathology after NAC. Forty-two patients were analyzed (46.36±10.4 years old). The median follow-up time was 94.3 months. For DFS and OS, only MTV from post-NAC PET/CT was an independent predictor. For MTV3 ≤ 2.1 mL vs. > 2.1 mL, 7-year DFS and OS were 81.3% - 50%, (p= 0.038) and 88.2% and 55.6%, (p= 0.042) respectively. Survival was statistically significantly different in the PCR/non-PCR patient groups. There was no difference in DFS between patients with metCR/non-metCR, only between groups for OS (Log-rank). MTV (≤ 2.1mL vs. > 2.1mL) obtained from 18F FDG PET/CT after NAC-pre-surgery and complete pathological response might distinguish patients with poor prognosis.