THYROID-DYSFUNCTION FOLLOWING COMBINED THERAPY FOR LARYNGEAL CARCINOMA

The thyroid function of 27 patients who previously had carcinoma of th e larynx treated by total laryngectomy with thyroid lobectomy was stud ied by measuring levels of thyroxine (T4) and thyroid stimulating horm one (TSH). Twenty-two of these patients also received external beam ra diotherapy. Abnormal results were found in 45% (10 patients) of those who received combined therapy. Clinical hypothyroidism developed in tw o patients (9%) and subclinical hypothyroidism (elevated TSH) was seen in eight patients (36%). Eighty-eight per cent of those patients with subclinical hypothyroidism had low or low normal T4 levels. All the p atients treated with surgery only had normal thyroid function. To prev ent hypothyroidism and identify those at risk of developing hypothyroi dism, post-operative testing of thyroid function should be carried out on a routine basis in patients receiving combined therapy for larynge al cancer. In addition we recommend that patients with subclinical hyp othyroidism who have had combined treatment should be treated with thy roxine to prevent the complications of this condition.