Aim: To explore the relationship between basal (18) F-FDG PET/CT information in breast tumours and survival in locally advanced breast cancer (LABC).
Methods: This prospective, multicentre study included 198 women diagnosed with LABC. All patients underwent (18) F-FDG PET/CT prior to treatment. The maximum standardized uptake value (SUVmax) in tumor (T), lymph nodes (N) and the N/T ratio was obtained in all cases. Stage according to PET/CT imaging (metabolic stage) and conventional imaging techniques (clinical stage) was established. During follow-up, patient status was established (disease free status or not). The relationship between all the variables and overall survival (OS) and disease-free survival (DFS) was analysed using the Kaplan-Meier and Cox regression methods. A ROC analysis was performed to obtain a cut-off value of SUVmax that was useful in the prediction of outcome.
Results: The mean SUVmax ± SD values in the primary tumour, lymph nodes and the SUVmax N/T index were 7.40 ± 5.57, 4.17 ± 4.74 and 0.73 ± 1.20, respectively. Higher semiquantitative metabolic values were found in more advanced metabolic and clinical stages. During follow-up, 78.4 % of patients were free of disease. Significant relationships were observed between SUVT and SUVN and patient status. With respect to OS and DFS, significant differences were detected for the metabolic stage. Kaplan-Meier analysis revealed that using the cut-off values, a primary-tumour SUVmax ≥ 6.05 or a nodal SUVmax ≥2.25 were significantly correlated with DFS and OS.
Conclusion: PET imaging with (18) F-FDG offers prognostic information for LABC that can be obtained preoperatively and noninvasively.
Keywords: 18 F-FDG PET/CT; Disease-free status; Disease-free survival; Locally advanced breast cancer; Overall survival; Prognosis.