RESUMEN
Hypothyroidism is a well-documented complication after treatment of laryngeal cancer and is particularly significant among patients undergoing laryngectomy. We investigated the frequency of hypothyroidism in patients treated with total laryngectomy for laryngeal cancer. We also evaluated the effect of neck radiotherapy on thyroid function after total laryngectomy for laryngeal cancer. In a cross-sectional study, we evaluated 31 patients with laryngeal squamous cell carcinoma [mean age 53.6 years]. Among these patients, 14 were treated with surgery only and 17 were treated with surgery plus radiotherapy. Laboratory evaluation included levels of thyroid stimulating hormone [TSH], free T4, free T3, and antithyroid antibodies both preoperatively and postoperatively at the first day, as well as one and six months after surgery. All patients had normal thyroid function before treatment; however, after 6 months, five patients [16.1%] were hypothyroid. Of these, three patients [9.6%] had subclinical symptoms, including elevated thyroid-stimulating hormone with normal free T4, and two patients [6.5%] showed clinical symptoms of hypothyroidism. Radiotherapy and neck dissection were significantly associated with higher incidences of hypothyroidism. Our data suggest that hypothyroidism occurs in a substantial proportion of patients undergoing surgery for laryngeal cancer. The results indicate that thyroid function studies should be routinely performed in the follow-up care of laryngeal cancer patients, especially if radiotherapy and neck dissection were part of the treatment. We suggest that this approach will improve the patient's quality of life and diminish the co-morbidity associated with this kind of surgery