TY - GEN
T1 - Monitoring treatment response in metastatic breast cancer
T2 - impact of FDG-PET/CT on survival and costs
AU - Naghavi-Behzad, Mohammad
PY - 2023/8/23
Y1 - 2023/8/23
N2 - Background: Various diagnostic modalities are being used for staging metastatic disease in breast cancer patients since international guidelines do not yet provide clear recommendations on the modality of choice for this indication. Evidence has confirmed that 18F-fluorodeoxyglucose-positron emission tomography with integrated computed tomography (FDG-PET/CT) has a perfect sensitivity for the diagnosis of distant metastases in this patient group. FDG-PET/CT may therefore also have the potential to improve monitoring of treatment response in patients with metastatic breast cancer, but research in this field has been scarce. We aimed to compare 1) response categories and their clinical impact, 2) survival times, and 3) cost-effectiveness of FDG-PET/CT versus contrast-enhanced computed tomography (CECT) for response monitoring in patients with metastatic breast cancer. Methods: In this observational registry-based study, we included 300 biopsy-verified metastatic breast cancer patients, diagnosed and treated between 2004 and 2018 at the Department of Oncology at Odense University Hospital, Denmark. The response monitoring modalities used in the clinic varied mainly between CE-CT and FDG-PET/CT with the choice of the modality made by the oncologist. The patients were categorized into three groups: a CE-CT group (n=144), a FDG-PET/CT group (n=83), and a combined group (n=73). In the combined group, patients were monitored alternately with CE-CT and FDGPET/CT, having a minimum of two scans of each modality, while only one of the opposite scan types was accepted in the CE-CT and FDG-PET/CT groups. The clinical and health-related cost information was gathered from patients’ medical records, and the patients were followed until August 2019 for survival and cost-efficacy analyses. We analyzed the response categories and their impact on clinical decision making for subgroups of patients in the CE-CT (n=34, 286 scans) and the FDG-PET/CT groups (n=31, 189 scans). The overall survival time was defined as the time from confirmation of metastasis until death, using the end of the study period as the censoring event. The time to the first progression was defined to be from the baseline scan to the first progression that led to the patient’s treatment change in the clinic. The Kaplan-Meier curve was used to estimate the survival function within the study groups. Cox regression model was restricted to the CE-CT group (set as reference) and the FDGPET/CT group.Results: The median (range) follow-up time was 33.0 (3.6-130.6) months. The groups were mostly comparable regarding the baseline characteristics, while a few characteristics with significant difference were not in favor of any of the groups. A statistically significant difference (PConclusions: Metastatic breast cancer patients who were response monitored with FDG-PET/CT alone or in combination with CE-CT had an improved overall survival of 14-24 months compared to patients monitored with CE-CT alone. FDG-PET/CT detected changes in response (regression/progression) more frequently than CE-CT, and CE-CT reported stable disease more often. FDG-PET/CT seems to be a more sensitive and cost-effective modality than CE-CT for monitoring treatment response in metastatic breast cancer, while confirmation of these results are warranted in prospective multi-center randomized trials.
AB - Background: Various diagnostic modalities are being used for staging metastatic disease in breast cancer patients since international guidelines do not yet provide clear recommendations on the modality of choice for this indication. Evidence has confirmed that 18F-fluorodeoxyglucose-positron emission tomography with integrated computed tomography (FDG-PET/CT) has a perfect sensitivity for the diagnosis of distant metastases in this patient group. FDG-PET/CT may therefore also have the potential to improve monitoring of treatment response in patients with metastatic breast cancer, but research in this field has been scarce. We aimed to compare 1) response categories and their clinical impact, 2) survival times, and 3) cost-effectiveness of FDG-PET/CT versus contrast-enhanced computed tomography (CECT) for response monitoring in patients with metastatic breast cancer. Methods: In this observational registry-based study, we included 300 biopsy-verified metastatic breast cancer patients, diagnosed and treated between 2004 and 2018 at the Department of Oncology at Odense University Hospital, Denmark. The response monitoring modalities used in the clinic varied mainly between CE-CT and FDG-PET/CT with the choice of the modality made by the oncologist. The patients were categorized into three groups: a CE-CT group (n=144), a FDG-PET/CT group (n=83), and a combined group (n=73). In the combined group, patients were monitored alternately with CE-CT and FDGPET/CT, having a minimum of two scans of each modality, while only one of the opposite scan types was accepted in the CE-CT and FDG-PET/CT groups. The clinical and health-related cost information was gathered from patients’ medical records, and the patients were followed until August 2019 for survival and cost-efficacy analyses. We analyzed the response categories and their impact on clinical decision making for subgroups of patients in the CE-CT (n=34, 286 scans) and the FDG-PET/CT groups (n=31, 189 scans). The overall survival time was defined as the time from confirmation of metastasis until death, using the end of the study period as the censoring event. The time to the first progression was defined to be from the baseline scan to the first progression that led to the patient’s treatment change in the clinic. The Kaplan-Meier curve was used to estimate the survival function within the study groups. Cox regression model was restricted to the CE-CT group (set as reference) and the FDGPET/CT group.Results: The median (range) follow-up time was 33.0 (3.6-130.6) months. The groups were mostly comparable regarding the baseline characteristics, while a few characteristics with significant difference were not in favor of any of the groups. A statistically significant difference (PConclusions: Metastatic breast cancer patients who were response monitored with FDG-PET/CT alone or in combination with CE-CT had an improved overall survival of 14-24 months compared to patients monitored with CE-CT alone. FDG-PET/CT detected changes in response (regression/progression) more frequently than CE-CT, and CE-CT reported stable disease more often. FDG-PET/CT seems to be a more sensitive and cost-effective modality than CE-CT for monitoring treatment response in metastatic breast cancer, while confirmation of these results are warranted in prospective multi-center randomized trials.
U2 - 10.21996/rb7b-hp46
DO - 10.21996/rb7b-hp46
M3 - Ph.D. thesis
PB - Syddansk Universitet. Det Sundhedsvidenskabelige Fakultet
ER -