131I therapy in differentiated thyroid carcinoma: M. D. Anderson Hospital experience.

The therapeutic response and survival rates of 352 patients with differentiated thyroid carcinoma who had received radioactive iodine therapy since 1951 were studied. Of these patients, 72% had metastases to the cervical lymph nodes, lungs, bone, or other viscera. Of all patients, 70% showed complete remission, and 30% showed partial response or recurrence of disease or both. Patients with metastases before therapy had a higher incidence of recurrence than those who had localized thyroid disease (32.4% vs. 15.1%). Of these, 97 patients had recurrent disease. In 24 of these patients, the recurrent tumor failed to take iodine, indicating change in its iodine-concentrating characteristics. Of the 352 patients, 44 (12.5%) died of progressive thyroid carcinoma, and all were over 40 years of age at the time of initial diagnosis. Mean survival of patients with metastatic disease who were over 40 years of age at initial diagnosis was significantly lower than that of patients under 40 years of age (6.2 years vs. 11.5 years). Patients with recurrent metastases unresponsive to surgery or radioactive iodine therapy were treated with palliative radiotherapy or chemotherapy or both. They respond poorly and died within a few months.