Background: Differentiated thyroid cancer (DTC) is a common primary cancer for spinal metastases (SM). The treatments for DTC spinal metastases (SM) have evolved from simple surgery and radiotherapy to a multidisciplinary comprehensive therapeutic strategy of combined spinal surgery, general surgery, radiotherapy, nuclear medicine and endocrinology. The purpose of this study was to discuss the efficacy and prognosis associated with different surgical treatments of SM patients with DTC.
Methods: A total of 21 consecutive patients with SM of DTC that were treated between 1999 and 2013 were studied. Biopsy was routinely performed to achieve the pathological diagnosis before treatment. Three patients underwent total spondylectomy intralesionally or piecemeally, and 18 had curettage. Postoperative recurrence and survival times were analyzed by the Kaplan-Meier methods.
Results: Nineteen patients (90%) had an average of 42.7 months (range, 7-170 months) follow-up. The median visual analogue scale for pain reduced from 5 points to 1 point (P < 0.01), and the median Karnofsky performance score increased from 70 to 90 points after surgery (P < 0.01). Seventeen patients with neurological deficits attained improvements after surgeries, of at least one level according to the Frankel classification (P < 0.01). Eight patients with curettage had recurrence. Four patients died of DTC, 12 patients lived with disease, and three patients were disease-free. No significant effects on postoperative recurrence or survival were observed between surgery combined with conservative treatment, total spondylectomy, the number of bone metastases and visceral metastasis.
Conclusions: DTC-SM have a relatively favorable prognosis, and curettage and stabilization can effectively relieve the pain and improve the quality of life and neurological status of the patients. For patients with Tomita scores of ≤3, total spondylectomy may have better clinical outcomes. Comprehensive therapeutic strategies including surgery, radioiodine, external beam radiation therapy and embolization should be considered for most patients.