PURPOSE: The aim of this study was to determine the long-term incidence and possible predictive factors for posttreatment hypothyroidism in nasopharyngeal carcinoma (NPC) patients after radiotherapy. METHODS AND MATERIALS: Four hundred and eight sequential NPC patients who had received regular annual thyroid hormone surveys prospectively after radiotherapy were included in this study. Median patient age was 47.3 years, and 286 patients were male. Thyroid function was prospectively evaluated by measuring thyroid-stimulating hormone (TSH) and serum free thyroxine (FT4) levels. Low FT4 levels indicated clinical hypothyroidism in this study. RESULTS: With a median follow-up of 4.3 years (range, 0.54-19.7 years), the incidence of low FT4 level was 5.3%, 9.0%, and 19.1% at 3, 5, and 10 years after radiotherapy, respectively. Hypothyroidism was more common with early T stage (p = 0.044), female sex (p = 0.037), and three-dimensional conformal therapy with the altered fractionation technique (p = 0.005) after univariate analysis. N stage, chemotherapy, reirradiation, and neck electron boost did not affect the incidence of hypothyroidism. Younger age and conformal therapy were significant factors that determined clinical hypothyroidism after multivariate analysis. Overall, patients presented with a low FT4 level about 1 year after presenting with an elevated TSH level. CONCLUSION: Among our study group of NPC patients, 19.1% experienced clinical hypothyroidism by 10 years after treatment. Younger age and conformal therapy increased the risk of hypothyroidism. We suggest routine evaluation of thyroid function in NPC patients after radiotherapy. The impact of pituitary injury should be also considered. Copyright 2010 Elsevier Inc. All rights reserved.
PURPOSE: The aim of this study was to determine the long-term incidence and possible predictive factors for posttreatment hypothyroidism in nasopharyngeal carcinoma (NPC) patients after radiotherapy. METHODS AND MATERIALS: Four hundred and eight sequential NPCpatients who had received regular annual thyroid hormone surveys prospectively after radiotherapy were included in this study. Median patient age was 47.3 years, and 286 patients were male. Thyroid function was prospectively evaluated by measuring thyroid-stimulating hormone (TSH) and serum free thyroxine (FT4) levels. Low FT4 levels indicated clinical hypothyroidism in this study. RESULTS: With a median follow-up of 4.3 years (range, 0.54-19.7 years), the incidence of low FT4 level was 5.3%, 9.0%, and 19.1% at 3, 5, and 10 years after radiotherapy, respectively. Hypothyroidism was more common with early T stage (p = 0.044), female sex (p = 0.037), and three-dimensional conformal therapy with the altered fractionation technique (p = 0.005) after univariate analysis. N stage, chemotherapy, reirradiation, and neck electron boost did not affect the incidence of hypothyroidism. Younger age and conformal therapy were significant factors that determined clinical hypothyroidism after multivariate analysis. Overall, patients presented with a low FT4 level about 1 year after presenting with an elevated TSH level. CONCLUSION: Among our study group of NPCpatients, 19.1% experienced clinical hypothyroidism by 10 years after treatment. Younger age and conformal therapy increased the risk of hypothyroidism. We suggest routine evaluation of thyroid function in NPCpatients after radiotherapy. The impact of pituitary injury should be also considered. Copyright 2010 Elsevier Inc. All rights reserved.
Authors: Ren Luo; Vincent W C Wu; Binghui He; Xiaoying Gao; Zhenxi Xu; Dandan Wang; Zhining Yang; Mei Li; Zhixiong Lin Journal: BMC Cancer Date: 2018-05-18 Impact factor: 4.430