Hypothyroidism after therapy for larynx and pharynx carcinoma

Early detection of local and regional recurrence is the main goal during fo llow-up of patients with larynx and pharynx cancer. Hypothyroidism occurrin g in those patients stays frequently undiagnosed as screening for hypothyro idism is not part of the routine follow-up. This study was performed to ass ess the prevalence of hypothyroidism in these patients. We included 120 pat ients (106 male, 14 female) with larynx or pharynx cancer treated more than 2 months earlier (mean = 41 months) in the study. Cancer treatment consist ed of either surgery (n = 44), radiotherapy (n = 15), or surgery combined w ith postoperative radiotherapy (n = 61). In all patients, thyroid function studies (thyrotropin [TSH], free triiodothyronine [FT3], and free thyroxine [FT4]) were performed. Twenty-six of all patients (22%) were hypothyroid; in two patients hypothyroidism was diagnosed postoperatively and these two patients were on replacement therapy with thyroid hormones. The highest rar e of hypothyroidism (34%) was present in patients treated with surgery comb ined with radiotherapy, whereas among patients treated with surgery only 7% were hypothyroid (p < 0.001). There was no difference in the duration of f ollow-up between therapy and inclusion in the study between those two group s. Two of 15 patients treated only with radiotherapy were diagnosed hypothy roid, but in this group the latency was shorter (p < 0.05). The results ind icate that thyroid function studies should be routinely performed in the fo llow-up of head and neck cancer patients, especially if radiotherapy was pa rt of the treatment.