Bone Metastases from Thyroid Carcinoma of Follicular Origin: A Single Institutional Experience

Abstract

Background/Aims: Overall, 2–13% of patients with thyroid cancer develop bone metastases (BM). In addition to decreased survival, patients with BM may present skeletal-related events (SRE) that impair the quality of life. Our objectives were to characterize clinical features, treatment approaches, and outcomes of patients with thyroid cancer and BM. Material and Methods: We identified patients diagnosed with thyroid carcinoma of follicular origin and BM followed at the Instituto Português de Oncologia de Lisboa Francisco Gentil (IPOLFG), Lisbon, Portugal, from 1991 to 2017. SRE were defined as the need for bone irradiation, bone surgery, spinal cord compression, or pathologic fractures. Results: The final cohort consisted of 86 patients, with a median follow-up time of 54 months (IQR 22.8–82.8), mainly women (67.4%), and a median age of 64 years (IQR 53.6–71.2). BM was the initial presentation of thyroid cancer in 36.0% of the patients. Bone involvement was multiple in 59.3% of the cases. Papillary carcinoma was the most frequent histological type, present in 47.7% of the patients, of which 56.1% presented the follicular variant. SRE were found in 76.7% of the patients. The most frequent SRE was radiotherapy (66.3%). Treatment with bisphosphonates was initiated in 19.8% of the patients. The 5-year specific survival was 60%, whereas the 10-year specific survival decreased to 50%. There were no differences in 5- or 10-year specific survival regarding gender, the occurrence of SRE, or histological type. However, patients with initial radioiodine non-avid lesions had a lower 5- and 10-year specific survival (p = 0.002). Discussion: The high frequency of patients with SRE was notable. The follicular variant of papillary thyroid cancer was the variant most commonly associated with BM, reflecting a more similar behavior to follicular carcinoma than the classic variant.

Bone metastases from differentiated thyroid carcinoma: heterogenous tumor response to radioactive Iodine therapy and overall survival

“…BM were diagnosed radiologically and/or on biopsy and/or on the post-therapy RAI whole-body scan (WBS) images and/or on 18-fluorodeoxyglucose ( 18 FDG) positron emission tomography (PET) computed tomography (CT). BM were considered RAI avid if RAI uptake was observed at the post-therapy WBS, FDG avid if FDG uptake was observed at any 18 FDG PET-CT examination. Diagnosis of BM without RAI uptake was established by a tumour board review (through dynamic monitoring of imaging modalities and serial serum thyroglobulin [Tg] measurements) or confirmed on biopsy in atypical cases (for the exclusion of BM from another primary tumour).…”

“…Tg determination was considered not reliable in the presence of Tg antibodies. Morphologic assessment with one or more of the following techniques: bone scintigraphy, CT, magnetic resonance imaging (MRI) or 18 FDG PET-CT was performed every 3 to 6 months according to a local tumor board decision.…”

“…BM-diagnosis was clinical (accounting for a SRE) in 42.1% of the patients. In the other 68%, BM were detected on post-therapeutic WBS (n = 74) or on cross-sectional or 18 FDG PET-CT imaging (n = 29). Synchronous BM presentation was strongly associated with RAI uptake of BM (p = 3.83 × 10 −13 ).…”

“…The presence of 18 FDG uptake in BM is associated with an absence of C-BM-R and with a poor OS. 18 FDG PET-CT should be performed when BM is suspected.…”

Independent risk factors evaluation for overall survival and cancer-specific survival in thyroid cancer patients with bone metastasis

“…A relevant research showed that the 10-year survival rate even dropped to 14% for patients older than 40 years having TCBM. [ 11 ] In addition, the quality of life is severely affected for TCBM patients. One study showed that 78% of TCBM patients had at least one skeleton-related event (SRE) during a median follow-up period, and 49% had multiple SREs during a 5-year follow-up period, with significantly increased mortality in patients with bone metastasis (BM).…”