Extramedullary extraosseous disease (EME) patients showed significantly inferior progression-free survival compared with non-EMD and extramedullary bone-related disease (EMB) patients, and EME 'appears to represent a clinically aggressive disease phenotype whose adverse prognosis is closely intertwined with high-risk clinical and cytogenetic characteristics rather than being entirely independent.'
Extramedullary disease (EMD) was present in 21.2% of newly diagnosed multiple myeloma (NDMM) patients screened.
The overall response rate in EMD patients was significantly lower than in non-EMD patients with novel agents-based induction therapy.
EME patients showed significantly inferior progression-free survival compared with both non-EMD and EMB patients.
Patients with EME and high-risk cytogenetic abnormalities (HRCAs) experienced the most unfavorable survival outcomes.
Achieving stringent complete remission or complete remission (sCR/CR) was associated with significantly prolonged PFS and overall survival.
Autologous stem cell transplantation (ASCT) was associated with improved survival in EMD patients.
This research suggests that when multiple myeloma spreads outside of the bone marrow (called extramedullary disease, or EMD), it behaves differently depending on where it spreads. When the disease spreads to soft tissues away from bones (extramedullary extraosseous disease, EME), outcomes are significantly worse than when it spreads to areas directly adjacent to bones (EMB) or stays within the bone marrow. Among 443 newly diagnosed myeloma patients in China, about 1 in 5 had extramedullary disease, and those with the soft-tissue form had a median time before disease progression of only 20 months, compared to 32 months for bone-adjacent spread and 39 months for patients without extramedullary disease. Importantly, this research suggests that the worse outcomes seen in soft-tissue extramedullary disease are not simply due to the location of disease on its own, but are closely tied to other high-risk features like dangerous chromosomal abnormalities. Patients who achieved deep responses to treatment — meaning their myeloma became nearly or completely undetectable — had much better outcomes, as did patients who received stem cell transplantation. Even with modern drug combinations, patients with soft-tissue extramedullary disease were less likely to achieve these deep responses. This research matters because it helps clarify which myeloma patients face the greatest challenges and why. It suggests that soft-tissue extramedullary disease is a marker of overall disease aggressiveness rather than a completely separate condition, and that achieving the deepest possible remission with treatment is especially important for these patients. The authors call for larger studies across multiple centers to confirm these findings and develop better treatment strategies for this high-risk group.
Xu X, Wang Y, Zhang W, Liu X, Wang L, Peng J, et al.. (2026). Prognosis of Extramedullary Disease in Chinese Newly Diagnosed Multiple Myeloma Patients Treated With Novel Agents-Based Induction Therapy.. Cancer medicine. https://doi.org/10.1002/cam4.72210