Anaplastic thyroid carcinoma: comparison of conventional radiotherapy and hyperfractionation chemoradiotherapy in two groups.

Anaplastic thyroid carcinoma (ATC) is a highly aggressive neoplasm with a poor prognosis. Curative management of these tumors has been difficult secondary to delayed diagnosis and advanced disease at presentation. Treatment modalities including surgery and fractionated radiotherapy have had limited success in controlling these tumors. Median survival time is often measured in months. A review of all patients treated between 1952 and 1999 identified 32 patients with anaplastic or poorly differentiated thyroid carcinoma. Patients were divided into two groups: those treated between 1952 to 1980 (9 patients, group 1) and those treated between 1981 and 1999 (23 patients, group 2). Most group 1 patients received once-daily radiotherapy and most group 2 patients received twice-daily radiotherapy with concurrent chemotherapy. A variety of radiotherapy techniques were used. Chemotherapy consisted of doxorubicin, paclitaxel, vincristine, or cisplatin. Eleven patients presented with lymph node metastasis and two patients had distant metastases at diagnosis. The most common clinical presentation was a neck mass in 17 patients. In group 1, one patient was treated with surgery only, four with surgery and radiotherapy and four with radiotherapy alone. In group 2, 1 patient was treated with surgery only; 3 with surgery and radiotherapy; 10 with radiotherapy and chemotherapy; 5 with surgery, radiotherapy, and chemotherapy; and 5 with radiotherapy alone. Overall 2-year survival rates were 44% for group 1 and 52% for group 2. Two-year progression-free survival (PFS) was 53% for group 1 and 38% for group 2. Five (16%) patients died within 60 days of diagnosis. Severe side effects included skin sequelae (one patient) and osteoradionecrosis of the mandible (one patient). There were 10 (52%) long-term survivors (>2 years). Clinicopathologic features associated with extended survival were limited extent of disease and inclusion in group 2. Among patients with ATC surgery, hyperfractionated radiotherapy in conjunction with chemotherapy is associated with better survival but not PFS compared to conventional radiotherapy.