Radiation Therapy of Carcinoma of the Thyroid

Most papers on carcinoma of the thyroid are from centers where great numbers of patients with thyroid disease are treated. The volume of patients seen and operated upon permits the observation and treatment of a large number of early malignant neoplasms. The experience with thyroid carcinoma in a general hospital is quite different. At Bellevue Hospital only 64 cases of thyroid carcinoma have been seen since 1924 in the Radiation Therapy Department. These cases, unlike those seen at centers of thyroid treatment, are for the most part far advanced. Many of the patients were referred from other institutions where surgery had been done but no radiation had been given until recurrence or metastasis occurred. There are many interesting and informative papers on carcinoma of the thyroid. Lahey, Hare, and Warren (8, 15, 16, 27) have written a series of reports on the findings at the Lahey Clinic. In the most recent paper a series of 231 cases is summarized. Another series, that of the Cleveland Clinic, was recently reviewed by Portmann (23, 24), who reported 220 cases seen since 1922. A third extensive series reported by Pemberton and his associates (1, 18, 19, 20, 21, 22) consists of 774 cases seen at the Mayo Clinic between 1907 and 1937. Welti and Huguenin (29) reported 88 cases, and Watson and Pool (28) 167. Many other excellent papers describe the unusual features of from one to hundreds of cases. Incidence From a review of statistics, it might appear that the number of cases of malignant neoplasm of the thyroid is increasing. Authorities are of the opinion, however, that this increase is more apparent than real and that advances in clinical and pathological diagnosis are largely responsible. The proportion of malignant lesions among thyroid tumors has been variously estimated at from 1 to 5 per cent. Lahey, Hare, and Warren found that their 231 cases represented 1.2 per cent of 18,600 thyroids operated upon. Crile and Crile (2, 3) reported 289 carcinomas among 17,021 thyroid patients, or 1.69 per cent. These 289 cases constituted 3 per cent of nodular goiters. Pemberton found the incidence varying from 2 per cent in 1919 to 4.9 per cent in 1937. Welti and Huguenin's estimate is 1.3 per cent. According to Hare, deaths from thyroid cancer represent 0.66 per cent of all carcinoma deaths in the United States. The age incidence varies widely, cases having been reported from early childhood to the nineties. Moreover, it is becoming increasingly recognized that carcinoma has a predilection for the thyroid in childhood. Because of this, it is no longer customary to defer operation in children with thyroid nodules. The incidence is greatest between the ages of forty and seventy, slightly less from thirty to forty and seventy to eighty. The occurrence of thyroid carcinoma in the various decades among our 64 cases is presented graphically in Figure 1. The average age is about fifty years and is slightly lower in females than in males.