Factors affecting the prognosis of patients with carcinoma of the thyroid.

Of 763 patients with carcinoma of the thyroid who had undergone a primary operation between 1948 and 1970, 705 were observed for more than five years. Included were 545 patients with papillary carcinoma. 123 with follicular carcinoma, 59 with microcancer, 30 with undifferentiated carcinoma and six with medullary carcinoma. The relative survival rate for patients with pure undifferentiated carcinoma one year after operation was 27 per cent and that for those with mixed undifferentiated carcinoma was 24 per cent. For patients with differentiated carcinomas, the most important factors affecting the prognosis were age and sex. The 15 year survival rates for women less than 40 years of age with papillary or follicular carcinoma were 102 and 100 per cent, respectively, while for women more than 40 years with papillary or follicular carcinoma, they were 90 and 84 per cent, respectively. For men more than 40 years of age with papillary carcinoma, the relative survival rate was 67 per cent. The size of the tumor and the types of operation did not affect the prognosis in patients less than 40 years. The presence of chronic thyroiditis also had no effect upon the prognosis. The relative survival rate with tumors up to 99 grams in weight, after 20 years, was almost 100 per cent in women less than 40 years of age, while for women more than 40 years of age the survival rates were 95 per cent with tumors weighing less than 20 grams and 72 per cent with those weighing 20 to 99 grams, an indication that tumor size may affect prognosis in older patients.