255P Challenges to assess bone metastases in Blinded Independent Central Review (BICR) of breast cancer trials using RECIST 1.1

Abstract

The most common site of metastases in breast cancer patients is bone with reported incidence around 60–80 %. The skeletal metastases are associated with increased morbidity, but studies have noted a better overall survival compared to patients with visceral organ metastases. Imaging plays a key role in the diagnosis and assessment of bone metastases in clinical practice and trials. The commonly used RECIST 1.1 criteria recognize challenges of assessing bone metasteses. Bone lesions are mainly considered unmeasurable and qualitatively assessed, except in the presence of osteolytic lesions with measurable soft tissue component.