Endocrine Abstracts

Aim: Progressive medullary (MTC) or iodine-negative papillary (PTC) or follicular (FTC) thyroid carcinomas present a challenge due to limited treatment options. The aim of this study was to evaluate the response to chemotherapy with doxorubicin.

Methods: 22 patients (12 female, 10 male, mean 61 years) with PTC or FTC received chemotherapy with doxorubicin. Tumors were histologically classified as follicular in 14 (64%) patients, including 6 (27%) oncocytary tumors, and papillary in 8 (36%) patients, including 1 (5%) papillary-oncocytary and 1 (5%) poorly differentiated tumor. In addition, 9 patients (5 female, 4 male, mean 51 years) with MTC received doxorubicin. Treatment consisted of either 8 cycles 15 mg/m² weekly or 3 cycles 60 mg/m² every 3 weeks, repeated once depending on response and side effects. Prior to chemotherapy, progressive disease was established during follow-up over 7.0±5.6 (X±S.D., range 1–23) months. Effect of therapy was evaluated by radiographic imaging, ¹⁸FDG-PET, and bone scans. Treatment response was defined according to WHO criteria.

Results: In patients with PTC or FTC, 5.3% had a partial regress over 6 months, followed by stable disease >16 months (until today), 42.1% had stable disease for 8.8±5.9 (3–22) months, and 52.5% had continuous progression established over 4.3±2.8 (1–8) months. Three patients died before completing chemotherapy. In patients with MTC, 11.1% had a partial regress for 6 months, followed by stable disease for 2 months, 11.1% had stable disease over 7 months, and 77.8% demonstrated progressive disease, established over 6±3.3 (2–12) months.

Conclusions: Whereas nearly half of the patients with PTC or FTC and established progressive disease had some benefit of chemotherapy with doxorubicin, most patients with MTC did not respond to such treatment. Due to the lack of alternatives, doxorubicin may be used as a palliative option in the treatment of patients with progressive PTC or FTC.