Monitoring treatment response in metastatic breast cancer: impact of molecular imaging on survival and cost

The target population of this project is patients with metastatic breast cancer (MBC) for whom the therapeutic goal is to prolong survival since there is currently no curative treatment available. We aim to compare molecular imaging (Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT)) with conventional imaging (contrast-enhanced computed tomography (CE-CT)) for monitoring treatment effects in MBC patients.

In the first section of the project (already completed), we found a significant survival benefit of 14-24 months for MBC patients who were response-monitored with FDG-PET/CT compared with patients monitored with CE-CT alone. This may explained by earlier detection of first progression (4.7 months, on average) by FDG-PET/CT, which led to an earlier change in treatment. The study was performed retrospectively on 300 patients with biopsy-verified MBC. These results were supported by a sub-study, in which we compared the response categories within response monitoring scans among 65 MBC patients. According to our results, FDG-PET/CT indicated regression of disease more frequently than CE-CT, while CE-CT indicated stable disease more often. Our results indicate that using FDG-PET/CT for response monitoring of MBC patients may improve clinical decision-making and patient survival.

There is a concern about the higher cost of PET/CT compared to CE-CT, but no previous studies have addressed this issue. We hypothesize that the overall cost of the healthcare system will be decreased when using PET/CT, due to the superiority of PET/CT in detecting treatment failure and hence the opportunity for improved treatment planning that includes termination of ineffective toxic treatment. Therefore, in the second part, we aim to compare the cost-effectiveness of these two response monitoring methods in a large unique dataset of MBC patients. We believe this could be valuable along with our significant results from clinical and survival analyses. We plan to follow up 300 MBC patients for a median of 5 years (after confirmation of metastasis) which will provide an evident conclusion on the cost-efficacy of using FDG-PET/CT in this group of patients. We have received the permission from Region of Southern Denmark to get access to patients’ cost information (DRG codes) and the permission from Danish Patient Safety Authority to access patients’ clinical information.

This project received administrative and financial support from Odense University Hospital (Department of Nuclear Medicine), University of Southern Denmark, GE healthcare company, and Dagmar Marshall's Fund.