Clinical profile of long-term survivors of breast or thyroid cancer with metastatic spinal tumours

Spinal metastases due to thyroid carcinoma: an analysis of 202 patients

BACKGROUND

Spinal metastases (SMs) due to thyroid cancer (TC) are associated with significantly reduced quality of life. The goal of this study is to analyze the clinical manifestations, presentation, and treatments of TC SMs, and to describe specific features of SMs associated with different TC types.

PATIENTS AND METHODS

A retrospective analysis of 202 TC SM patients treated at Medstar Washington Hospital Center (37) and collected from the literature (165) was performed.

RESULTS

The mean age of patients with SMs was 56.9±14.7 years, and the female-to-male ratio was 2.1:1. Of all patients, 29% (28% of follicular thyroid cancer [FTC] and 37% of papillary thyroid cancer [PTC]) had SMs only. Twenty-nine percent of all patients and 54% of patients with single-site SMs had neither bone non-SMs nor solid organ metastases at the time of presentation. Thirty-five percent of patients had SMs as an initial presentation of TC. TC patients presenting with SMs had a lower rate of other bone and visceral involvement compared with patients whose SMs were diagnosed at the time of thyroid surgery or during follow-up (p<0.05). SMs were more often the initial manifestation of FTC (41% vs. 24%), while PTC SMs were more commonly diagnosed after TC diagnosis (76% vs. 59%; p<0.05). PTC SMs were more frequently diagnosed as synchronous (63% vs. 36% in FTC) versus FTC SMs that developed as metachronous metastases (64% vs. 37% in PTC; p<0.01). All FTC SMs developed within 82 (0-372) months and all PTC SMs within 35 (0-144) months (p<0.01). In FTC SMs as TC manifestation, solid organ metastases involvement was less common than in FTC SMs that were found after TC diagnosis (34% vs. 67%; p<0.01); multisite FTC SMs compared to solitary FTC SMs were associated with the development of other bone nonspinal metastases (82% vs. 30%; p<0.01) and solitary organ metastases (65% vs. 41%; p<0.01). These correlations were not observed in PTC SMs. FTC patients often had neural structure compression (myelopathy/radiculopathy; 72% vs. 36% in PTC), while PTC patients frequently were asymptomatic (38% vs. 5% in FTC; p<0.01). FTC SMs more commonly were (131)I-avid (p<0.01). FTC patients required surgery more frequently (72% vs. 55% in PTC; p<0.05).

CONCLUSIONS

Our study reveals that a significant part of TC SMs patients have solitary spinal involvement at the time of presentation and may be considered for aggressive treatment with the intention to improve quality of life and survival. FTC SMs and PTC SMs appear to have distinct presentations, behavior, and treatment modalities, and should be categorized separately for treatment and follow-up planning.

Multidisciplinary treatment and survival of patients with vertebral metastases from thyroid carcinoma

BACKGROUND

Distant metastases from differentiated thyroid carcinoma occur in up to 20% of cases and represent the most frequent cause of thyroid cancer-related death. Metastatic disease to the spine has the potential to cause severe morbidity, including pain, neurological deficit, and paraplegia.

SUMMARY

We present a case series of eight consecutive patients with symptomatic spinal metastases due to thyroid carcinoma treated by our multidisciplinary team consisting of spinal surgeons, oncologists, and radiologists, with management of each case determined by our surgical algorithm. Four patients underwent surgical decompression and stabilization for spinal metastases causing instability, spinal cord compression, neurological deficit, or intractable pain. Three patients underwent vertebroplasty for focal mechanical pain due to osteolytic metastases in the absence of significant spinal cord compression or spinal instability; one of these patients required subsequent surgical decompression for spinal cord compression. One patient was nonoperatively treated. All patients underwent total thyroidectomy for the primary cancer and adjuvant radioiodine-131 treatment. The only patient with poorly differentiated thyroid cancer, which was refractory to radioiodine-131 died at 6 months after vertebroplasty procedures for symptomatic spinal metastases. One patient with medullary thyroid carcinoma died at 18 months after vertebroplasty. All remaining six patients who had well-differentiated papillary or follicular thyroid carcinoma were alive at an average of 50 months (range: 17-96 months) after diagnosis and treatment of symptomatic spinal metastases and were ambulant, independent, and able to perform activities of daily living and had no significant pain or neurologic symptoms.

CONCLUSION

The potential for long-term survival of several years following development of spinal metastases should be considered during the counseling and decision-making process for patients with thyroid cancer.

Standard and emerging therapies for metastatic differentiated thyroid cancer

Differentiated thyroid cancer accounts for >90% of cases of thyroid cancer, with most patients having an excellent prognosis. Distant metastases occur in 10%-15% of patients, decreasing the overall 10-year survival rate in this group to 40%. Radioactive iodine has been the mainstay of treatment for distant metastases, with good results when lesions retain the ability to take up iodine. For patients with metastatic disease resistant to radioactive iodine, treatment options are few and survival is poor. Chemotherapy and external beam radiotherapy have been used in these patients, but with disappointing results. In recent years, our understanding of the molecular pathways involved in thyroid cancer has increased and a number of molecular targets have been identified. These targets include the proto-oncogenes BRAF and RET, known to be common mutations in thyroid cancer; vascular endothelial growth factor receptor and platelet-derived growth factor receptor, associated with angiogenesis; and the sodium-iodide symporter, with the aim of restoring its expression and hence radioactive iodine uptake. There are now multiple trials of tyrosine kinase inhibitors, angiogenesis inhibitors, and other novel agents available to patients with metastatic thyroid cancer. This review discusses both traditional and novel treatments for metastatic differentiated thyroid cancer with a particular focus on emerging treatments for patients with radioactive iodine-refractory disease.