Multiple Myeloma (MM) is a systemic lymphoproliferative neoplasm characterized by the accumulation of abnormal plasma cells in the bone marrow. The median age at diagnosis is approximately 66–70 years [1]. Since the annual prevalence of MM increases with age (31 in 100,000 for people aged 65–74 years vs 46 in 100,000 for people aged >75 years), the incidence of the disease is expected to rise in the future, owing to population aging [2].

MM is a very heterogenous disease with an overall survival span of more than 10 years. The international Staging system (ISS) is a simple risk stratification algorithm which, based on serum B2-microglobulin and albumin levels, categorizes MM patients into three groups with different prognoses: the ISS stage I, II and III groups with median overall survivals (OS) of 62, 44 and 29 months respectively (p < 0.0001) [3]. The prognostic strength of ISS has been confirmed by multiple studies [3,4].

Spinal involvement is common and affects over 80% of MM patients [5]. Consequently, MM is the most common primary cause of spinal cancer in adults, and yet is often overlooked.

The prognostic factors of spinal metastases (SpM) have been extensively studied in the context of multiple primary tumor types, and appear identical [6]. However, prognostic factors of spinal MM seem to differ from those of secondary SpM, although the data in the literature remains sparse.

Previous studies on MM-associated spinal lesions have failed to investigate spinal involvement in isolation and in large sample sizes [4,[7], [8], [9]]. Thus, the aim of our study, is to identify factors which positively and negatively influence OS in MM patients with spinal lesions.