title: Multiple myeloma and infections: a population-based study on 9253 multiple myeloma patients.
abstract: Infections are a major cause of morbidity and mortality in patients with multiple myeloma. To estimate the risk of bacterial and viral infections in multiple myeloma patients, we used population-based data from Sweden to identify all multiple myeloma patients (n=9253) diagnosed from 1988 to 2004 with follow up to 2007 and 34,931 matched controls. Cox proportional hazard models were used to estimate the risk of infections. Overall, multiple myeloma patients had a 7-fold (hazard ratio =7.1; 95% confidence interval = 6.8-7.4) risk of developing any infection compared to matched controls. The increased risk of developing a bacterial infection was 7-fold (7.1; 6.8-7.4), and for viral infections 10-fold (10.0; 8.9-11.4). Multiple myeloma patients diagnosed in the more recent calendar periods had significantly higher risk of infections compared to controls (P<0.001). At one year of follow up, infection was the underlying cause in 22% of deaths in multiple myeloma patients. Mortality due to infections remained constant during the study period. Our findings confirm that infections represent a major threat to multiple myeloma patients. The effect on infectious complications due to novel drugs introduced in the treatment of multiple myeloma needs to be established and trials on prophylactic measures are needed.
authors.affiliation: Department of Hematology, Sahlgrenska University Hospital and Department of Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden cecilie.blimark@vgregion.se.
authors.forename: Cecilie
authors.initials: C
authors.lastname: Blimark
authors.affiliation: Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sweden.
authors.forename: Erik
authors.initials: E
authors.lastname: Holmberg
authors.affiliation: Department of Hematology, Sahlgrenska University Hospital and Department of Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden.
authors.forename: Ulf-Henrik
authors.initials: UH
authors.lastname: Mellqvist
authors.affiliation: Myeloma Service, Division of Hematology Oncology, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY, USA.
authors.forename: Ola
authors.initials: O
authors.lastname: Landgren
authors.affiliation: Department of Medicine, Division of Hematology, Karolinska University Hospital and Karolinska Institutet, Stockholm, Sweden.
authors.forename: Magnus
authors.initials: M
authors.lastname: Björkholm
authors.affiliation: Department of Medicine, Division of Hematology, Karolinska University Hospital and Karolinska Institutet, Stockholm, Sweden.
authors.forename: Malin
authors.initials: M
authors.lastname: Hultcrantz
authors.affiliation: Department of Medicine, Division of Hematology, Karolinska University Hospital and Karolinska Institutet, Stockholm, Sweden.
authors.forename: Christian
authors.initials: C
authors.lastname: Kjellander
authors.affiliation: Skåne University Hospital Malmö, Malmö, Sweden.
authors.forename: Ingemar
authors.initials: I
authors.lastname: Turesson
authors.affiliation: Department of Medicine, Division of Hematology, Karolinska University Hospital and Karolinska Institutet, Stockholm, Sweden Faculty of Medicine, University of Iceland, Reykjavik, Iceland.
authors.forename: Sigurdur Y
authors.initials: SY
authors.lastname: Kristinsson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001424:Bacterial Infections / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D016022:Case-Control Studies; D003131:Combined Modality Therapy / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000150:complications* / Q000401:mortality / Q000628:therapy; D009367:Neoplasm Staging; D011379:Prognosis; D012042:Registries; D015996:Survival Rate; D013548:Sweden / Q000453:epidemiology; D014777:Virus Diseases / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality