Chemotherapy of Differentiated (Papillary or Follicular) Thyroid Carcinoma

Abstract

Chemotherapy is employed as a palliative measure in the 25% of recurrent inoperable or metastatic, follicular, or mixed thyroid cancers that do not concentrate ¹³¹I. Doxorubicin, bleomycin, and cisplatin have been the mainstay of treatment. Since advanced thyroid cancer is rare, there are few meaningful clinical trials which compare single and multiple-agent chemotherapy for differences in efficacy and toxicity. The Eastern Cooperative Oncology Group designed and completed the only randomized study of doxorubicin vs doxorubicin plus cisplatin in inoperable, radioiodine-resistant advanced thyroid cancer in chemotherapy naive patients. In this study reported in 1985 (1), 41 patients received doxorubicin alone and 43 patients received the combination. Sixteen patients with differentiated thyroid cancers received single-agent doxorubicin, given at a dose of 60 mg/m² intravenously every 3 weeks. Nineteen comparable patients received the combination of doxorubicin, 60 mg/m² and cisplatin at 40 mg/m² every 3 weeks. Treatment was discontinued when stable disease was achieved after 3 cycles of treatment, disease progressed after 2 cycles of treatment, or when total dose of doxorubicin exceeded 550 mg/m². Suppressive thyroid hormone treatment was continued throughout the treatment in both groups of patients. The overall response rate for all patients was 21%. In the doxorubicin-alone arm, response rate was 17% compared to 26% in the combination arm; however, because of the small number of patients, this difference was not statistically significant. Moreover, neither the time to relapse nor overall survival was found to be statistically different among the two groups.