Statins as a new therapeutic approach in dedifferentiated thyroid cancer? A case report

Full text: In general differentiated thyroid tumours are removed surgically and afterwards treated with radioiodine. However, still about one third of patients with differentiated tumours, metastasise. Also 30 percent of recurrent thyroid carcinomas do not respond to iodine treatment due to loss of differentiation. Retinoic acid, biological metabolites of vitamin A, are considered to induce re-differentiation of the thyrocyte and thereby induce tumor regression. In follicular carcinoma cells, it also plays an important role in inducing iodine uptake. Retinoids, however, cannot be used in liver disease as they may induce hepatic enzyme increase. In addition 3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) are reported to induce on the one hand cellular apoptosis and on the other hand, in a lower dosage, differentiation in anaplastic thyroid carcinoma cells in vitro. We are presenting a 79 years old female patient with an oxyphilic follicular thyroid carcinoma and histologically verified autoimmune hepatitis. The first post therapeutic scan, showed only focal cervical localized iodine uptake. Also 3 months later no pathologic iodine uptake was recognized on the diagnostic scan, whereas the FDG-PET showed solid uptake of FDG cervical, in both lungs, in the mediastinum, the pelvis and the right hip. Due to contraindication for retinoic acid the patient was treated with usual dose statin for about 4 weeks to induce re-differentiation. Following, the patient was administered 9,25 GBq I-131 again and the post therapeutic scan showed iodine uptake cervical and in the right femur. We conclude that the administration of Statins, at low dose (20 mg/day) even over a short period of time, only may induce re-differentiation as well as an antiproliferative effect in vivo. (author)