Page 171 - Haematologica Vol. 110 - January 2025

ARTICLE - Plasma Cell Disorders
Risk of infections in multiple myeloma. A population- based study on 8,672 multiple myeloma patients diagnosed 2008-2021 from the Swedish Myeloma Registry
Cecilie Hveding Blimark,1,2 Kristina Carlson,3 Christopher Day,2 Sigrun Einarsdottir,2 Gunnar Juliusson,4 Moshtak Karma,5 Dorota Knut-Bojanowska,6,1 Gunnar Larfors,3 Ingemar Turesson,7 Mariana Villegas-Scivetti2 and Ingigerdur Sverrisdóttir2,8
1Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; 2Sahlgrenska University Hospital, Gothenburg, Sweden; 3Uppsala University Hospital, Uppsala, Sweden; 4Lund University and Department of Hematology, Skåne University Hospital, Lund, Sweden; 5Södra Älvsborg Hospital, Borås, Sweden; 6Uddevalla Hospital, Uddevalla, Sweden; 7Department of Hematology, Skåne University Hospital Malmö, Malmö, Sweden and 8Department of Medicine, University of Iceland, Reykjavik, Iceland
Abstract
In multiple myeloma (MM), advancements in treatments and toxicity management have enhanced survival rates. This, coupled with shifting age demographics in MM, necessitates an updated assessment of infection risks in MM patients compared to the general population. Using Swedish population-based registries, we investigated the incidence of infec- tions in 8,672 Swedish symptomatic MM patients diagnosed 2008-2021 and 34,561 matched controls. Overall, MM patients had a 5-fold risk (hazard ratio [HR] =5.30; 95% confidence interval [CI]: 5.14-5.47) of developing a clinically significant infection compared to matched controls. Bacterial infections represented a 5-fold (HR=4.88; 95% CI: 4.70-5.07) increased risk, viral and fungal infections 7-fold compared to controls. The first year after MM diagnosis the risk of infections com- pared to controls was 7-fold (HR=6.95; 95% CI: 6.61-7.30) and remained elevated up to 5 years after the myeloma diag- nosis. The risk of infection compared to controls remained 5-fold in MM patients with follow-up till 2022. Preceding MM diagnosis, the risk compared to matched controls was significantly increased up to 4 years before MM diagnosis (HR=1.16; 95% CI: 1.05-1.28). Among MM patients, 8% had died within 2 months of diagnosis and infection contributed to 32% of all deaths. After 1 year, 20% MM patients had died, and infection-related mortality was 27%. Our data constitute the largest population-based study to date on the risk of infections compared to the normal population in the era of modern MM therapies and confirms that infections still represent a major threat to patients and underscores importance of preven- tive strategies.
Introduction
In multiple myeloma (MM), new treatments and improved management of toxicities have contributed to improved survival and transformed MM into a chronic disease.1,2 Managing the complications of the disease and its treat- ment, such as infections, thrombosis and neuropathy, has therefore become an important clinical issue.
Infections are a significant cause of morbidity and a lead- ing cause of death in patients with MM.3 In studies mainly from the chemotherapy era, infections contribute to an early death in 14-45% of patients.4,5 In a nationwide study of over 9,000 Swedish MM patients from the Swedish Cancer Register diagnosed from 1988 to 2004, in patients mostly treated with chemotherapy, cortisone and thalidomide, the
risk of infection was 7-fold in MM patients compared to an age-matched healthy population, and the infection-related mortality was 22% the first year after diagnosis.6
In the last 20 years, the treatment of MM has changed substantially towards immunomodulatory drugs (IMiD), pro- teasome inhibitors (PI) and monoclonal antibodies (MoAb) as backbones in MM therapy and this has created a need for an update on basic facts to both evaluate and report the current risk of infections in MM.
We therefore performed a large population-based study on the incidence of infections overall and of specific in- fections among Swedish symptomatic MM patients diag- nosed from 2008 to 2021 compared to matched controls. We also studied the risk of infection over time and the infection-related mortality.
Haematologica | 110 January 2025
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Correspondence: C.H. Blimark cecilie.blimark@vgregion.se
Received: Accepted: Early view:
April 12, 2024. July 8, 2024. July 18, 2024.
https://doi.org/10.3324/haematol.2024.285645
©2025 Ferrata Storti Foundation Published under a CC BY-NC license