The presence of large focal lesions is a strong independent prognostic factor in multiple myeloma

Abstract

Spatial intratumor heterogeneity is frequently seen in multiple myeloma (MM) and poses a significant challenge for risk classifiers, which rely on tumor samples from the iliac crest. Because biopsy-based assessment of multiple skeletal sites is difficult, alternative strategies for risk stratification are required. Recently, the size of focal lesions (FLs) was shown to be a surrogate marker for spatial heterogeneity, suggesting that data from medical imaging could be used to improve risk stratification approaches. Here, we investigated the prognostic value of FL size in 404 transplant-eligible, newly diagnosed MM patients. Using diffusion-weighted magnetic resonance imaging with background suppression, we identified the presence of multiple large FLs as a strong prognostic factor. Patients with at least 3 large FLs with a product of the perpendicular diameters >5 cm were associated with poor progression-free survival (PFS) and overall survival (OS; median, 2.3 and 3.6 years, respectively). This pattern, seen in 13.8% of patients, was independent of the Revised International Staging System (RISS), gene expression profiling (GEP)-based risk score, gain(1q), or extramedullary disease (hazard ratio, 2.7 and 2.2 for PFS and OS in multivariate analysis, respectively). The number of FLs lost its negative impact on outcome after adjusting for FL size. In conclusion, the presence of at least 3 large FL is a feature of high risk, which can be used to refine the diagnosis of this type of disease behavior and as an entry criterion for risk-stratified trials.

Toward personalized treatment in multiple myeloma based on molecular characteristics

“…52,53 Recent studies have shown that the number and size of focal lesions on positron emission tomography computed tomography and magnetic resonance imaging also predict for a poor outcome independent of molecular features. 54…”

1q21 Gain Combined with High-Risk Factors Is a Heterogeneous Prognostic Factor in Newly Diagnosed Multiple Myeloma: A Multicenter Study in China

“…However, the prognostic value of 1q21 gain in MM remains controversial. Several studies have shown that 1q21 gain is a significant and independent factor for poor prognosis , although other studies have failed to confirm this finding . These apparently conflicting results might be explained by the fact that 1q21 gain is frequently accompanied by other classic biological and genetic prognostic factors.…”

Guidelines for Acquisition, Interpretation, and Reporting of Whole-Body MRI in Myeloma: Myeloma Response Assessment and Diagnosis System (MY-RADS)

“…Furthermore, most patients with apparently solitary plasmacytoma at skeletal surveys are upstaged with MRI, which profoundly influences treatment strategies (11,12). The number and sizes of focal lesions at MRI have also been shown to predict outcome (20,21). Fluorodeoxyglucose (FDG) PET/CT can also be used for diagnosis of focal bone lesions; however, MRI is more sensitive for diagnosis and contemporary MRI techniques have increased the advantage (22-25) (sensitivity of diffusion-weighted [DW] imaging has been reported as 77% compared with 47% for FDG PET/ CT) (23).…”