Undifferentiated carcinomas, if operable, may be treated by thyroidectomy and resection of all involved tissue in the neck. 5-10% can apparently be completely resected, and the patient can have a long survival. Prophylactic X-radiation (5,000 rads) should be given postoperatively in most cases. These tumors rarely concentrate 131I, but it is probably useful to study their ability to accumulate the isotope spontaneously or after stimulation with rhTSH, at least on one occasion. If the lesion is obviously inoperable, X-ray therapy can be the initial treatment. In some instances, the rapidly growing tumors melt almost completely for a time after X-ray therapy, giving the patient a gratifying respite from the disease. Some tumors appear to be suppressed by thyroid hormone, and this therapy should be given a trial. These recommendations probably will change in the near future if tyrosine kinase inhibitors are found to be effective.
Some anaplastic tumors have been treated with alkylating agents, and rarely, a rapidly proliferating and highly undifferentiated tumor has responded with a temporary regression. Chemotherapy is discussed below. Kim and Leeper (528) reported encouraging results combining low dose adriamycin (10 mg/m2) and hyperfractionated radiotherapy (160 rads twice daily) to 5760 rads. Time of survival was prolonged and local recurrences largely prevented. There has been no confirmation of this study, unfortunately. A prospective protocol combining surgery, chemotherapy (CT),and hyperfractionated accelerated radiotherapy (RT) was employed by De Crevoisier et al (528a) in anaplastic thyroid carcinoma. The main toxicity was hematologic. High long-term survival was obtained when RT-CT was given after complete surgery. This protocol avoided local tumor progression, and death was mainly caused by distant metastases. The clinical behavior and therapy of anaplastic carcinoma have recently been reviewed by K. Ain 277a
