Baseline and early 18F-FDG PET/CT evaluations as predictors of progression-free survival in metastatic breast cancer patients treated with targeted anti-CDK therapy

• Published in: Cancer imaging Vol. 24; no. 1; pp. 90 - 9
• Main Authors: Lasnon, Charline, Morel, Adeline, Aide, Nicolas, Silva, Angélique Da, Emile, George
• Format: Journal Article
• Language: English
• Published: London BioMed Central Ltd 09.07.2024; BioMed Central; BMC
• Subjects: Breast cancer; Cancer patients; Care and treatment; Cyclin-dependent kinase inhibitor; Development and progression; FDG; Hormone therapy; Medical examination; Methods; PET; PET imaging; Targeted therapy; France
• ISSN: 1470-7330; 1740-5025; 1470-7330
• DOI: 10.1186/s40644-024-00727-2

Background Exploring the value of baseline and early .sup.18F-FDG PET/CT evaluations in prediction PFS in ER+/HER2- metastatic breast cancer patients treated with a cyclin-dependent kinase inhibitor in combination with an endocrine therapy. Methods Sixty-six consecutive breast cancer patients who underwent a pre-therapeutic .sup.18F-FDG PET/CT and a second PET/CT within the first 6 months of treatment were retrospectively included. Metabolic tumour volume (MTV) and total lesion glycolysis (TLG) and D.sub.max, which represents tumour dissemination and is defined as the distance between the two most distant lesions, were computed. The variation in these parameters between baseline and early evaluation PET as well as therapeutic evaluation using PERCIST were assessed as prognosticators of PFS at 18 months. Results The median follow-up was equal to 22.5 months. Thirty progressions occurred (45.4%). The average time to event was 17.8 [+ or -] 10.4 months. At baseline, D.sub.max was the only predictive metabolic parameter. Patients with a baseline D.sub.max [less than or equal to] 18.10 cm had a significantly better 18 m-PFS survival than the others: 69.2% (7.7%) versus 36.7% (8.8%), p = 0.017. There was no association between PERCIST evaluation and 18 m-PFS status (p = 0.149) and there was no difference in 18 m-PFS status between patients classified as complete, partial metabolic responders or having stable metabolic disease. Conclusion Disease spread at baseline PET, as assessed by D.sub.max, is predictive of an event occurring within 18 months. In the absence of early metabolic progression, which occurs in 15% of patients, treatment should be continued regardless of the quality of the initial response to treatment. Keywords: Breast cancer, Targeted therapy, Cyclin-dependent kinase inhibitor, FDG, PET