Relationship of thyroid disease to renal cell carcinoma. An epidemiologic study.

Thyroid hormone participates in numerous cellular functions besides thermogenesis and metabolism. Several studies, including the recent identification of the product of an oncogene, c-erb-A, as a thyroid-hormone receptor, have shown possible involvement of thyroid hormone in the process of carcinogenesis. A recent anecdotal observation of an unusually high incidence of thyroid dysfunction in women with renal cell carcinoma led to a retrospective review of the incidence and distribution of thyroid disorders in women with renal cell carcinoma compared with a control group of women with transitional cell carcinoma of the renal pelvis, ureter, bladder, or urethra. Women with renal cell carcinoma had a statistically significantly higher percentage of hypothyroidism, thyroid disease in general, and the use of thyroid-hormone supplements as compared with the control group (P = 0.033, P = 0.005, P = 0.041, respectively). The nature of the relationship, however, could not be determined. These findings add a new dimension to renal cell carcinoma, and prospective studies are encouraged to define the contribution of thyroid hormone to renal cell carcinogenesis.