Hypothyroidism after Treatment for Laryngo-Hypopharyngeal Cancer

Min, Hun Ki; Oh, Jae Kook; Chung, Geun; Kim, Young Min; Rho, Young Soo

Abstract

BACKGROUND AND OBJECTIVES: Hypothyroidism is a well recognized complication of radiotherapy and surgery in the treatment of head and neck cancer, especially laryngo-hypopharyngeal cancer. Several studies were undertaken to determine the thyroid stimulating hormone (TSH) levels in the population of patients with head and neck cancer, to better characterize clinical factors in the eventual elevated TSH levels. We evaluated the incidence and related factors of hypothyroidism following radiotherapy, surgery and combined treatment for laryngeal and hypopharyngeal cancer. MAERIALS AND METHODS: Forty-four patients who had been treated for laryngeal and hypopharyngeal cancer were divided into three groups according to the types of treatment they received: radiotherapy alone, surgery with partial thyroidectomy, surgery with partial thyroidectomy and postoperative radiotherapy. TSH and free thyroxin (T4) level were examined before and after the treatment. We analyzed the differences according to clinical factors and treatment modalities.
RESULTS
The TSH level was higher in hypopharyngeal cancer than in laryngeal cancer (p>0.05). In the advanced stage and during longer follow-up periods, the TSH level were elevated (p<0.05). In patient with combined treatment modalities, the TSH level was higher than in patients who received radiotherapy or surgery alone (p<0.05).
CONCLUSION
We concluded that hypothyroidism frequently develops following treatment for laryngeal and hypopharyngeal cancer even when thyroid resection has not been performed. Patient should be evaluated postoperatively and carefully monitored by means of serial thyoid function test.