Characteristics and Clinical Outcomes of Multiple Myeloma in Adolescents and Young Adults.

INTRODUCTION: Though evidence suggests that multiple myeloma (MM) in adolescents and young adults (AYA) (< 50 years) has significant biological differences from that in older individuals (≥ 50 years), the understanding of the disease in this group is limited. We examined the outcomes in AYA hospitalizations with MM. METHODS: Using the National Inpatient Sample database, we examined sociodemographic, hospital-level, and clinical characteristics between AYA and older populations with MM. RESULTS: Among 183 846 non-elective MM hospitalizations, 13 765 (7.5%) were AYA. There was a higher proportion of males in the AYA group compared to the older group (58.6% vs. 54.8%, p < 0.001) but a lower distribution of non-Hispanic Whites (40.6% vs. 56.7%, p < 0.001). The AYA group had lower odds of mortality (aOR: 0.59, p < 0.001) relative to the older adult group. They were more likely to receive autologous stem cell transplantation (aOR: 1.80, p < 0.001) but had similar odds of acute venous thromboembolism (aOR: 0.87; p = 0.24) and severe sepsis (aOR: 0.89; p = 0.52). CONCLUSION: We highlight the unique characteristics and outcomes of AYA-MM, emphasizing the need for their greater representation in clinical research. Additionally, we underscore the importance of further investigation to better understand and optimize survivorship care in AYA patients with MM.