# High rate of progression to symptomatic multiple myeloma in patients with smoldering myeloma and isolated osteoporotic vertebral fracture

## TL;DR

Patients with smoldering myeloma and osteoporotic vertebral fractures are at high risk of progressing to symptomatic multiple myeloma within 18 months.

## Contribution

Identifies a rare but high-risk group of smoldering myeloma patients with osteoporotic vertebral fractures who rapidly progress to symptomatic disease.

## Key findings

- 12 out of 13 patients with smoldering myeloma and osteoporotic vertebral fractures progressed to symptomatic multiple myeloma.
- Half of the patients progressed within 18 months of vertebral fracture diagnosis.
- Early progressors had higher serum calcium levels and more vertebral fractures at diagnosis.

## Abstract

Multiple myeloma (MM) frequently causes vertebral fractures (VF). Some are lytic lesions and others have the aspect of benign osteoporotic fractures not requiring anti-myeloma treatment. We explored outcome of these patients with smoldering myeloma (SM) and osteoporotic VF.

In this retrospective bi-centric study, patients were identified using a systematic keyword search on electronic medical records. Patients with SM and isolated VF of osteoporotic aspect without indications for myeloma-specific therapy were included.

Overall, 13 (7 %) of the 184 identified patients had SM and VF confirmed to be osteoporotic (median number of VF was 3). During follow-up, 12 (92 %) patients evolved to symptomatic MM, 7 (54 %) of them within 18 months (early progressors). Myeloma defining events were new lytic bone lesions in 7 patients (53.8 %). The serum calcium level was significantly higher in the early progressor group (median 2.35 IQR [2.31–2.38] and 2.28 IQR [2.21–2.29] respectively, p = 0.003). Early progressors had a higher number of VF at diagnosis (3.0 [2.0–5.5] vs 1.0 [1.0–2.5], p = 0.18) and more frequently evolved to symptomatic MM because of lytic bone lesions (5 [71 %] vs 2 [33 %], p = 0.13) compared to late progressors.

VF of osteoporotic appearance in the context of SM is a rare situation but at high risk of rapid progression to symptomatic MM, suggesting that they may represent bone fragility linked to MM infiltration rather than solely osteoporotic fractures. Further studies are needed to assess if earlier treatment might be beneficial in this population.

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•Progression is frequent in patients with vertebral fractures and smoldering myeloma•Half of them progress within 18 months after vertebral fracture diagnosis•Prospective studies are needed to determine the prognosis of these patients

Progression is frequent in patients with vertebral fractures and smoldering myeloma

Half of them progress within 18 months after vertebral fracture diagnosis

Prospective studies are needed to determine the prognosis of these patients