Early prognostic factors at the time of diagnosis of bone metastasis in patients with bone metastases of differentiated thyroid carcinoma.
OBJECTIVE
Bone is the second most common site of distant metastases from differentiated thyroid cancer (DTC). Patients with bone metastases were associated with poor clinical outcomes; however, their clinical courses are heterogeneous. The aim of this study is to evaluate early prognostic factors of patients with bone metastases from DTC at the time of diagnosis of bone metastasis.


METHODS
This retrospective study included 93 patients with bone metastases from DTC. We defined 'Pre-RAIT group' as patients whose bone metastases were detected before initial RAIT. The 'post-RAIT group' was defined as patients whose bone metastases were detected after initial RAIT or during the follow-up period.


RESULTS
Median age was 55.4years, and 55 patients (59%) had papillary thyroid cancer. Patients in the pre-RAIT group (n=32) demonstrated significantly poorer overall survival (OS) (HR=1.86, P=0.04) than those in the post-RAIT group. There was no significant difference in the OS according to the initial RAI avidity among all patients (P=0.18). RAI-avid bone metastases had better OS only in the pre-RAIT group (HR=0.23, P=0.01) but not in the post-RAIT group. In the post-RAIT group, older age (>45years), elevated serum thyroglobulin (Tg) level (>250ng/mL), and the presence of skeletal-related events (SREs) were significantly associated with poor OS. RAI avidity was not a significant prognostic factor in the post-RAIT group (P=0.33).


CONCLUSIONS
Patients whose bone metastases were diagnosed before initial RAIT demonstrate a poorer prognosis. RAI avidity is an early prognostic indicator in the pre-RAIT group. Old age, higher serum Tg levels, and SRE are associated with poor survival outcomes in the post-RAIT group.
Division of EndocrinologyDepartment of Internal Medicine Department of Internal MedicineHallym University Dongtan Sacred Heart Hospital, Gyeonggi-Do, South Korea.
Yun Mi
YM
Choi
Division of EndocrinologyDepartment of Internal Medicine wongukim@amc.seoul.kr.
Won Gu
WG
Kim
Division of EndocrinologyDepartment of Internal Medicine.
Hyemi
H
Kwon
Division of EndocrinologyDepartment of Internal Medicine.
Min Ji
MJ
Jeon
Department of Nuclear MedicineAsan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
Jong Jin
JJ
Lee
Department of Nuclear MedicineAsan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
Jin-Sook
JS
Ryu
Department of Internal MedicineHallym University Dongtan Sacred Heart Hospital, Gyeonggi-Do, South Korea.
Eun-Gyoung
EG
Hong
Division of EndocrinologyDepartment of Internal Medicine.
Tae Yong
TY
Kim
Division of EndocrinologyDepartment of Internal Medicine.
Young Kee
YK
Shong
Division of EndocrinologyDepartment of Internal Medicine.
Won Bae
WB
Kim
D000328:Adult; D000368:Aged; D015415:Biomarkers; D001859:Bone Neoplasms / Q000097:blood / Q000556:secondary*; D002291:Carcinoma, Papillary / Q000097:blood / Q000556:secondary*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D013954:Thyroglobulin / Q000097:blood; D013964:Thyroid Neoplasms / Q000097:blood / Q000473:pathology*
D015415:Biomarkers; D013954:Thyroglobulin