Abstract 255P
Background
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. The aim of this study is to analyze double blinded assessments of advanced breast cancer trials which used RECIST 1.1 and to document the proportion of reader discrepancies on baseline and overall assessment due to bone lesions.
Methods
We analyzed two breast cancer trials that included 355 patients involving 7 radiologists. The readers performed the response assessment according to the RECIST 1.1, based on CT/MRI and bone scintigraphy. The discordance rate of baseline bone metastases selection among the paired readers was analyzed. The impact of the bone lesions on the overall response was investigated.
Results
Bone metastases was indicated on baseline in 218 from 355 patients with advanced breast cancer patients (61,4 %). Considering baseline timepoint, bone metastases were recorded by both readers in 128 and by one reader in 90 patients with the discrepancy rate of 41,3 %. Bone lesion was selected as a target lesion in 19 and as non-target lesions (NTL) in 199 patients. Considering overall response assessment, 5 patients among 16 with baseline bone NTL had progressive disease (PD) due to the progression of the specified bone lesions.
Conclusions
This study assessed the discordance rate of baseline bone lesion selection between the BICR readers and the associated effect on the overall assessment according to RECIST 1.1 in two breast cancer trials. Bone lesions were indicated predominantly by the readers as NTL. High discrepancy in the baseline selection of bone metastases was found, but the follow-up assessments indicated bone metastases not to contribute substantially for the overall assessment.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Median Technologies.
Funding
Has not received any funding.
Disclosure
S. Bodard: Financial Interests, Personal, Advisory Role: Median Technologies. C. Ojango, A. Iannessi, L. Balcells, J. He, Y. Liu: Financial Interests, Personal, Full or part-time Employment: Median Technologies.