The Role of 18F-FDG PET/CT in Predicting the Neoadjuvant Treatment Response in Patients with Locally Advanced Breast Cancer

Sabin Goktas Aydin; Ahmet Bilici; Omer Fatih Olmez; Basak B Oven; Ozgur Acikgoz; Tansel Cakir; Pelin Basim; Asli Cakir; Yasin Kutlu; Jamshid Hamdard

doi:10.1159/000524446

The Role of 18F-FDG PET/CT in Predicting the Neoadjuvant Treatment Response in Patients with Locally Advanced Breast Cancer

Breast Care (Basel). 2022 Oct;17(5):470-479. doi: 10.1159/000524446. Epub 2022 May 3.

Authors

Affiliations

¹ aDepartment of Medical Oncology, Medical Faculty, Istanbul Medipol University, Istanbul, Turkey.
² bDepartment of Medical Oncology, Medical Faculty, Bahcesehir University, Istanbul, Turkey.
³ cDepartment of Nuclear Medicine, Medical Faculty, Istanbul Medipol University, Istanbul, Turkey.
⁴ dDepartment of Surgery, Medical Faculty, Istanbul Medipol University, Istanbul, Turkey.
⁵ eDepartment of Pathology, Medical Faculty, Istanbul Medipol University, Istanbul, Turkey.

Abstract

Purpose: Patients with locally advanced breast cancer (LABC) should be treated with neoadjuvant chemotherapy (NAC). Pathological complete response (pCR) is related to better disease-free survival (DFS). The best strategy for assessing the efficacy of NAC has not been established yet, but several studies have shown that 18F-FDG PET/CT is a potential imaging tool for assessing pCR. The aim of this study is to investigate the merits of 18F-FDG PET/CT imaging in predicting pCR in both axillary and breast tissue and to establish a threshold maximum standard uptake value (SUVmax) for predicting the response after completion of NAC.

Methods: A total of 186 LABC patients, treated with an NAC regimen according to tumor subtype, were retrospectively analyzed in this study. All patients underwent 18F-FDG PET/CT imaging before and after completion of NAC. PET parameters were measured in the most FDG avid breast tissue and axillary lymph nodes. We analyzed the correlation between the tumor SUVmax of the PET/CT response and the pCR after surgery. DFS was also evaluated with respect to pCR.

Results: Higher pCR rates were significantly associated with a higher tumor grade, an initial Ki-67 ≥20% (p = 0.03 and p = 0.003, respectively), a triple-negative subtype (32.9%), and a human epidermal growth factor receptor 2 (HER-2)-positive subtype (24.7%) (p < 0.001). There was a significant correlation between the pCR and a complete response in 18F-FDG PET/CT (p < 0.001). The overall sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of 18F-FDG PET/CT to determine the pCR after NAC were 100%, 72.2%, 85%, 75.2%, and 100%, respectively. We demonstrated a 1.1 cutoff SUVmax for breast tumors after NAC (OR: 3.94, 95% CI: 1.14-5.05, p = 0.004), the 18F-FDG PET/CT response to NAC (OR: 0.50, 95% CI: 0.25-0.99, p = 0.003), and the molecular subtype of breast tumors (OR: 0.58, 95% CI: 0.38-0.88, p = 0.011).

Conclusion: Our results confirm that 18F-FDG PET/CT is a useful method for predicting the NAC response in LABC.

Keywords: 18F-FDG PET/CT; Breast cancer; Neoadjuvant chemotherapy; Prognostic factors; Survival.

Grants and funding

There have been no financial or other relationships. There was no funding.