[The effect of thyroid hormone on the growth of thyroid cancer]

Thyroid cancer is well known to be hormone sensitive as well as breast cancer, prostatic cancer, and endometrial cancer of the uterus. Various experimental results suggest that the growth regulation for thyroid cancer, as well as the normal thyroid gland, appears to depend upon the TSH (Thyroid stimulating hormone) receptor on cell membranes. Differentiated thyroid carcinoma cells possess TSH receptor, although anaplastic carcinoma cells do not; therefore suppression therapy of TSH with thyroid hormone is considered to be effective against differentiated thyroid carcinoma. It has been recognized that some recurrent differentiated thyroid cancers cause regression in size in response to treatment with thyroid hormone. But the administration of the thyroid hormone after the operation for the differentiated thyroid carcinoma does not necessarily enhance the survival rate. To analyze the difference in survival rate is very difficult because of the excellent survival rate of thyroid cancer patients after the operation. It is hoped that further clinical study and laboratory investigation about suppression in adjuvant therapy for differentiated thyroid cancer will give us a conclusive answer.