Abstract P1-05-13: Clinical impact of whole-body magnetic resonance imaging on subsequent management in luminal/HER2-negative breast cancer patients

Abstract

Abstract Background: Routine imaging can be inaccurate, especially in metastatic breast cancer (MBC) with bone-only disease or mainly bone disease. This analysis investigates how the use of whole-body magnetic resonance imaging (WB-MRI), in addition to routine computed tomography (CT) and bone scintigraphy (BS), can influence treatment decisions in patients with known MBC. Methods: In a prospective observational study, in our Institute, we performed WB-MRI as baseline and follow-up examination in addition to routine imaging (CT, BS) in luminal/HER2-negative BC patients with prevalence of bone disease potentially candidate to CDK 4/6 inhibitors. All examinations were interpreted by two experienced radiology specialists. Using the results of the examination, a multidisciplinary oncology committee (MOC) reported on the treatment strategy. A positive impact on clinical management was considered if the examination determined a modification in the treatment strategy compared to the MOC decision before WB-MRI. Results: Thirty consecutive luminal breast cancer patients in a metastatic setting at standard imaging were recruited. All these patients underwent CT and BS followed by WB-MRI study. At standard imaging, fourteen patients (46.7%) presented with bone-only disease, while eight patients (26.6%) did not show bone lesions. In 18 of 30 cases (60%) WB-MRI led to a modification of the therapeutic approach. Due to the detection of new metastatic lesions or progression of known metastatic sites, reported on WB-MRI alone, the therapeutic decision changed in 6 (20%) and 3 (10%) patients, respectively. In one patient (3%) the therapeutic decision changed because of both findings. Nine patients (30%) started a new therapeutic line due to evidence of progressive disease on WB-MRI, while 4 patients (13.3%) underwent radiotherapy and 1 patient received orthopaedic counselling for high risk WB-MRI-assessed bone lesions. In 8 patients (26.6%) the disease was re-classified as early breast cancer based on WB-MRI assessment. Conclusions: WB-MRI could play a role in the clinical assessment of luminal MBC. Further studies are needed to better address the potential use of WB-MRI in the assessment and monitoring of bone only/bone predominant luminal MBC and/or in equivocal cases. Citation Format: Filippo Merloni, Michela Palleschi, Alice Rossi, Andrea Prochowski Iamurri, Caterina Gianni, Samanta Sarti, Francesca Mannozzi, Federica Fiori, Giandomenico Di Menna, Lorenzo Cecconetto, Marianna Sirico, Chiara Casadei, Sara Bleve, Lorenzo Gasperoni, Roberto Casadei, Luca Tontini, Antonino Romeo, Domenico Barone, Ugo De Giorgi. Clinical impact of whole-body magnetic resonance imaging on subsequent management in luminal/HER2-negative breast cancer patients [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-05-13.