# Surveillance of Smoldering Myeloma Patients Who Progress to Active Disease Is Associated with Favorable Outcomes

## TL;DR

Monitoring patients with early myeloma before it becomes active leads to better health outcomes and fewer complications.

## Contribution

This study demonstrates that surveillance of smoldering myeloma reduces disease severity and improves survival compared to newly diagnosed myeloma.

## Key findings

- Surveillance patients had fewer irreversible complications like kidney failure and bone fractures.
- Three-year survival rates were significantly higher in the surveillance group.
- Surveillance was linked to reduced disease burden and better progression-free survival.

## Abstract

Smoldering multiple myeloma (SMM) is an asymptomatic precursor to active multiple myeloma (MM). Standard management involves surveillance to detect progression before severe organ damage occurs. We compared clinical outcomes between 57 patients who progressed from monitored SMM and 57 matched patients diagnosed with de novo MM. Patients previously under surveillance presented with lower disease burden and fewer irreversible complications, such as renal failure and bone fractures (44% vs. 72%), compared to the de novo group. Furthermore, the surveillance cohort showed superior 3-year progression-free survival (59% vs. 30%) and overall survival (92% vs. 76%). These findings suggest that diagnosis via clinical surveillance is linked to reduced disease severity and favorable survival outcomes. However, since organ damage still occurred in monitored patients, follow-up strategies require optimization to better prevent complications.

Introduction: Smoldering multiple myeloma (SMM) is a precursor condition to active multiple myeloma (MM). While surveillance is standard, data on its effectiveness in preventing irreversible complications is limited. Methods: We conducted a two-center matched retrospective cohort study comparing 57 patients who progressed from SMM (pSMM) with 57 de novo MM (dnMM) patients, matched by age and diagnosis year. Primary endpoints were end-organ damage and progression-free survival (PFS). Results: Median surveillance prior to progression in pSMM was 40 months. At active MM diagnosis, irreversible renal/bone complications were observed in 44% of pSMM patients compared with 72% of dnMM (p = 0.002). dnMM patients presented more frequently with hypercalcemia (12.3% vs. 1.8%, p = 0.03), lytic lesions (67% vs. 45%, p = 0.02), pathological fractures (31% vs. 10%, p = 0.008), and detrimental bone disease (58% vs. 25%, p < 0.001). ISS and R-ISS stages were higher in dnMM, while treatment patterns were similar. At 3 years, PFS was significantly higher in pSMM (59% vs. 30%, p = 0.01), as was overall survival (OS; 92% vs. 76%, p = 0.01). Clinical surveillance was associated with reduced disease burden, fewer irreversible complications, and improved PFS and OS compared with dnMM. Conclusion: These findings support surveillance effectiveness and highlight the need to optimize follow-up strategies.