The Outcomes of Newly Diagnosed Multiple Myeloma Patients With Concurrent or Previous Solid Tumor History

The coexistence of solid tumors and multiple myeloma (MM) presents diagnostic and therapeutic challenges; however, data on clinical outcomes in this population remain limited. This study aimed to evaluate the clinical characteristics and survival outcomes of patients with newly diagnosed multiple myeloma (NDMM) who had synchronous or prior solid tumor malignancies.

A retrospective analysis was conducted on 41 NDMM patients with a documented history of solid tumor, classified as either concurrent (diagnosed within 6 months) or prior. Clinical characteristics, treatment patterns, and outcomes were evaluated. Patients were stratified according to the timing of solid tumor diagnosis.

The median age was 66 years, with a male predominance (58.5%). Breast (24.4%), lung (17.1%), colon, and prostate cancers (9.8% each) were the most common solid tumors. Extramedullary disease was observed only in the synchronous group (100% vs. 0%). Autologous transplantation was performed significantly less frequently in the synchronous group (26.3% vs. 73.7%, P = 0.041). Lenalidomide maintenance therapy was underutilized in patients with synchronous malignancies, reflecting possible clinical hesitation. Myeloma-related mortality occurred in 17.1% of patients, with a median overall survival of 48 months (range: 16-80), and no significant survival difference between synchronous and patient with prior solid tumor history group.

The presence of synchronous solid tumors in NDMM patients is associated with a higher rate of extramedullary disease and may influence clinical decision-making, highlighting the need for multidisciplinary management and individualized treatment strategies. Furthermore, extramedullary involvement in MM should prompt evaluation for a potential coexisting solid malignancy.