BACKGROUND: Radiation is a well-described risk factor for differentiated thyroid carcinoma (DTC). Although the natural history of DTC following nuclear disasters and in healthcare workers with chronic radiation exposure (RE) has been described, little is known about DTC following short-term exposure to therapeutic medical radiation for benign disease. This study compares DTC morphology and outcomes in patients with and without a prior history of therapeutic external RE. METHODS: A retrospective review was performed of patients with DTC treated at The University of Chicago between 1951 and 1987, with a median follow-up of 27 years (range 0.3-60 years). Patients were classified as either having (RE+) or not having (RE-) a history of therapeutic RE. Variables examined included sex, age at RE, dose of RE, indication for RE, DTC histology, and outcome. Morphology was determined by blinded retrospective review of all available histologic slides. Outcomes were assessed using Cox proportional hazards model and Kaplan-Meier curves. RESULTS: Of 257 DTC patients, 165 (64%) were RE- and 92 (36%) were RE+, with males comprising a greater proportion of the RE+ group (43.5% vs. 27.3%; p = 0.01). A total of 94.2% of DTC cases were classic papillary cancers; histology did not differ between RE+ and RE- cohorts (p = 0.73). RE was associated with an increased median overall survival (OS; 43 years vs. 38 years; hazard ratio [HR] = 0.55 [confidence interval (CI) 0.34-0.89]; p = 0.01). Survival for males in the RE- group was significantly worse than it was for RE- females (HR = 1.78 [CI 1.05-3.03]; p = 0.03) or RE+ males (HR = 2.98 [CI 1.39-6.38]; p = 0.01). Recurrence did not differ between the RE+ and RE- groups (HR = 0.85 [CI 0.52-1.41]; p = 0.54), nor did DTC-specific mortality (HR = 0.54 [CI 0.21-1.37]; p = 0.20). CONCLUSIONS: While DTC following RE has historically been considered a more aggressive variant than DTC in the absence of RE, the present data indicate that RE+ DTC is associated with better OS than RE- DTC, especially for males. Additionally, recent reports are confirmed of equivalent rates of thyroid cancer recurrence. These results warrant further investigation into the factors underlying this unexpected finding.
BACKGROUND: Radiation is a well-described risk factor for differentiated thyroid carcinoma (DTC). Although the natural history of DTC following nuclear disasters and in healthcare workers with chronic radiation exposure (RE) has been described, little is known about DTC following short-term exposure to therapeutic medical radiation for benign disease. This study compares DTC morphology and outcomes in patients with and without a prior history of therapeutic external RE. METHODS: A retrospective review was performed of patients with DTC treated at The University of Chicago between 1951 and 1987, with a median follow-up of 27 years (range 0.3-60 years). Patients were classified as either having (RE+) or not having (RE-) a history of therapeutic RE. Variables examined included sex, age at RE, dose of RE, indication for RE, DTC histology, and outcome. Morphology was determined by blinded retrospective review of all available histologic slides. Outcomes were assessed using Cox proportional hazards model and Kaplan-Meier curves. RESULTS: Of 257 DTCpatients, 165 (64%) were RE- and 92 (36%) were RE+, with males comprising a greater proportion of the RE+ group (43.5% vs. 27.3%; p = 0.01). A total of 94.2% of DTC cases were classic papillary cancers; histology did not differ between RE+ and RE- cohorts (p = 0.73). RE was associated with an increased median overall survival (OS; 43 years vs. 38 years; hazard ratio [HR] = 0.55 [confidence interval (CI) 0.34-0.89]; p = 0.01). Survival for males in the RE- group was significantly worse than it was for RE- females (HR = 1.78 [CI 1.05-3.03]; p = 0.03) or RE+ males (HR = 2.98 [CI 1.39-6.38]; p = 0.01). Recurrence did not differ between the RE+ and RE- groups (HR = 0.85 [CI 0.52-1.41]; p = 0.54), nor did DTC-specific mortality (HR = 0.54 [CI 0.21-1.37]; p = 0.20). CONCLUSIONS: While DTC following RE has historically been considered a more aggressive variant than DTC in the absence of RE, the present data indicate that RE+ DTC is associated with better OS than RE- DTC, especially for males. Additionally, recent reports are confirmed of equivalent rates of thyroid cancer recurrence. These results warrant further investigation into the factors underlying this unexpected finding.
Authors: Stephanie Siu; James Ted McDonald; Murali Rajaraman; Jason Franklin; Terri Paul; Irina Rachinsky; Deric Morrison; S Ali Imran; Steven Burrell; Robert Hart; Al Driedger; Mahmoud Badreddine; John Yoo; Martin Corsten; Stan Van Uum Journal: Thyroid Date: 2013-12-13 Impact factor: 6.568
Authors: Bryan R Haugen; Erik K Alexander; Keith C Bible; Gerard M Doherty; Susan J Mandel; Yuri E Nikiforov; Furio Pacini; Gregory W Randolph; Anna M Sawka; Martin Schlumberger; Kathryn G Schuff; Steven I Sherman; Julie Ann Sosa; David L Steward; R Michael Tuttle; Leonard Wartofsky Journal: Thyroid Date: 2016-01 Impact factor: 6.568
Authors: Pavel O Rumyantsev; Vladimir A Saenko; Alexey A Ilyin; Valery F Stepanenko; Ulyana V Rumyantseva; Aleksandr Yu Abrosimov; Evgeny F Lushnikov; Tatiana I Rogounovitch; Yoshisada Shibata; Norisato Mitsutake; Anatoly F Tsyb; Shunichi Yamashita Journal: J Clin Endocrinol Metab Date: 2010-11-17 Impact factor: 5.958
Authors: Theresa H M Keegan; Raymon H Grogan; Helen M Parsons; Li Tao; Michael G White; Kenan Onel; Pamela L Horn-Ross Journal: Thyroid Date: 2015-04-20 Impact factor: 6.568
Authors: Suchitra Acharya; Kyriakie Sarafoglou; Michael LaQuaglia; Skyler Lindsley; William Gerald; Norma Wollner; Charlotte Tan; Charles Sklar Journal: Cancer Date: 2003-05-15 Impact factor: 6.860
Authors: Joan L Warren; K Robin Yabroff; Angela Meekins; Marie Topor; Elizabeth B Lamont; Martin L Brown Journal: J Natl Cancer Inst Date: 2008-06-10 Impact factor: 13.506