[Hypothyroidism in patients treated for laryngeal cancer: preliminary results]

The reported incidence of hypothyroidism following surgery and/or irradiation for laryngeal cancer varies widely and the condition often is misdiagnosed. This study examines the incidence of thyroid dysfunction in patients with laryngeal cancer.

Thyroid function tests were carried out in 75 patients with stage III and IV laryngeal carcinoma who were treated in our center with surgery (13 cases), radiotherapy (13 cases), or surgery and radiotherapy (49 cases) at least 18 months earlier. The clinical and histological variables recorded included T4 and TSH concentrations. Univariate and multivariate analysis was carried out with the BMDP program from UCLA (1995 version) to examine the relationship between hypothyroidism and clinical and pathological factors.

Twenty-nine patients (38.6%) had high TSH or low T4 concentrations and were diagnosed as having hypothyroidism. Hypothyroidism was significantly related with date of surgery (before 1993) and the treatment used on the neck. Thyroid function was rarely affected in patients who underwent functional neck dissection, but radical neck dissection and irradiation of the neck always were followed by hypothyroidism.

Thyroid testing should be performed routinely in the follow-up of laryngeal cancer. Many psychological symptoms attributed to total laryngectomy may be due to hypothyroidism, an easily treated condition.