REDIFFERENTIATION THERAPY OF DIFFERENTIATED THYROID-CARCINOMA WITH RETINOIC ACID - BASICS AND FIRST CLINICAL-RESULTS

Retinoic acids (RA) regulate growth and differentiation of normal epit helial tissue. They have been employed in anticancer treatment and sho wed positive effects in hematopoetic and various epithelial tumors. Ex perimental data with follicular thyroid tumor cells showed strong evid ence of induction of differentiated cell function and antiproliferativ e effects. Based on these data a consecutive series of 10 patients wit h advanced thyroid carcinoma were treated with 13-cis-retinoic acid (R oaccutan(R)) 1.5 mg/kg body weight for six weeks. Follow-up demonstrat ed renewed uptake of radioiodine in 4 of 10 patients allowing performa nce of further radioiodine therapy. Reduction in tumor size due to ant iproliferative effects of RA could not yet be verified.