Oncology News Updates
Hypothyroidism Often Follows Laryngeal Carcinoma Treatment
Elsevier Global Medical News
Aug 25, 2008
Undiagnosed hypothyroidism occurred in 28% of patients treated for a laryngeal carcinoma in a retrospective study of 156 patients who underwent surgery and/or radiotherapy. Of the patients with undiagnosed hypothyroidism, the condition was subclinical in 66% and clinical in 34%.
Weight gain and dry skin were significantly more common in the patients with hypothyroidism, so the presence of these symptoms may prove useful in identifying other patients who become hypothyroid after treatment for head and neck cancers.
Annalisa M. Lo Galbo of Vrije University Medical Center, Amsterdam, and her colleagues presented their findings in a poster session at the Seventh International Conference on Head and Neck Cancer.
The investigators defined clinical hypothyroidism as high levels of thyroid-stimulating hormone (TSH) accompanied by low levels of free T4 (FT4). Patients with high TSH and normal FT4 were deemed to have subclinical hypothyroidism.
After conducting a multivariate analysis that controlled for confounding variables, the investigators determined that the combination of surgery and radiotherapy was associated with a significantly increased risk of hypothyroidism, as was hemithyroidectomy, they said at the meeting, sponsored by the American Head and Neck Society.
The investigators also found a significant association between hypothyroidism and high levels of circulating antithyroperoxidase and antithyroglobulin. They were unable to establish whether radiation treatment induced development of those autoantibodies or whether the patients who already had the autoantibodies were predisposed to developing hypothyroidism after radiotherapy.
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