Introduction:

Skeletal-related events (SREs) in spinal metastases dramatically affect the activities of daily living and qualities of life. Prophylactic administrations of bone modified agents including denosumab are recommended for patients with bone metastases. The aim of this study was to evaluate the efficacy of prophylactic administrations of denosumab for advanced cancer patients with spinal metastases.

Methods:

We retrospectively reviewed medical records of patients who treated with denosumab for spinal metastases between January 2012 and December 2020 in our institution. Exclusion criteria were defined as switching from zoledronic acid, usage for hematologic disease and bone/soft tissue tumor, and less than three months follow-up. The rates of SREs excluding irradiation under denosumab treatment and surgeries for spinal metastases were evaluated. Moreover, spinal instability neoplastic scores (SINS) were analyzed between patients with SRE and those who with Non-SRE.

Results:

Two hundred twenty-two patients including 138 men and 84 women were eligible for this study. The median age was 62.8 years old. The median follow-up period was 35.1 months. Cancer origins consisted of lung (27.0%), prostate (12.1%), breast (10.9%), colorectal (9.0%), and kidney (8.4%) mainly. Thirteen patients (5.9%) developed SREs even under denosumab treatment. Of 13 patients, eight patients (3.6%) underwent palliative surgery for SREs. Regarding SINS, Patients with SREs had significantly higher points, averaged 10.7±3.8 compared to 7.4±3.8 in those who with non-SRE (p<0.01).

Discussion:

Prophylactic administration of denosumab could achieve favorable clinical outcomes. However, prophylactic surgery may need for patients with spinal metastases who have more than 10 points in SINS even under denosumab treatment.