A retrospective analysis of clinical and pathological data was conducted on 706 patients (514 females and 192 males) treated for differentiated thyroid carcinoma at The University of Texas M. D. Anderson Hospital and Tumor Institute at Houston from 1951 to 1975 and followed to 1981. The histological diagnoses were mixed papillary/follicular carcinoma (66.7%), papillary carcinoma (14.6%), follicular carcinoma (15.3%), or Hurthle cell carcinoma (3.4%). Patients diagnosed before the age of 40 yr lived significantly longer than those diagnosed over the age of 40 yr, and females lived longer than males. According to survival analyses and disease-free intervals, the order of increasing aggressiveness of the tumors was papillary, mixed, follicular, and Hurthle cell. Total thyroidectomy was associated with longer disease-free intervals and fewer recurrences. The 136 patients who received ablative 131I after surgery had fewer recurrences than a matched group who did not, but the disease-free interval and survival rate showed no significant difference. Further classification showed that patients with follicular and mixed tumors, and those who underwent total thyroidectomy benefited from 131I. There were 78 deaths attributed to thyroid cancer in the whole group. Approximately two thirds occurred in the first 10 yr after diagnosis. In conclusion, total thyroidectomy is recommended, when feasible, for differentiated thyroid cancer, followed by ablative 131I therapy, at least for follicular and mixed varieties.

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.