Putzer D et al. – Proteasome inhibitor treatment with bortezomib is a promising therapeutic approach in thyroid cancer (TC) patients without an established treatment alternative. The development of a specific therapeutic regimen for the treatment of radioiodine nonavid TC is warranted.Methods
- Seven patients with inoperable, metastasized progressive TC proven to be radioiodine nonavid were included into this pilot study.
- Patients received bortezomib intravenously with a standardized dose of 1.3 mg/m2 on days 1, 4, 8, and 11.
- All patients underwent 3 therapeutic cycles with an interval of 10 days. [18F]2–deoxy–2–fluoro–D–glucose positron emission tomography (18F–FDG PET) and measurements of thyroglobulin levels were performed before, during, and after therapy, with a 6–week interval to post–therapeutic follow–up.
- Stable disease was seen after proteasome inhibitor therapy in 4 of the 7 patients.
- Two of the 7 patients showed decrease of maximum standardized uptake value in both post–therapeutic follow–up investigations, and one of these cases also had decreasing thyroglobulin levels.
- Two patients experienced stable disease during the posttherapeutic follow–up.
- Two patients showing a mixed response had an improvement in their clinical situation.
- One patient had rapidly progressive disease, and died 3 months after the last therapeutic cycle.
- Adverse events included mild polyneuropathy in 2 patients and alterations of the blood count up to WHO (World Health Organization) grade 2 in 5 patients.