A large Swedish study using population-based data to estimate the risk of bacterial and viral infections among 9,610 patients with multiple myeloma (9,253 eligible for analysis) found that the myeloma patients had a 7-fold risk of developing any infection compared to 34,931 matched controls from the Swedish Population Database (hazard ratio [HR] = 7.1; 95% confidence interval [CI] = 6.8–7.4). The increased risk of developing a bacterial infection was 7-fold (HR = 7.1; 95% CI = 6.8–7.4), and for viral infections, 10-fold (HR = 10.0; 95% CI = 8.9–11.4). The risk of specific infections, such as pneumonia and septicemia, was over 10 times higher in myeloma patients than in the controls during the first year of diagnosis. The research was presented at the 54th Annual Meeting of the American Society of Hematology (ASH) in Atlanta.1
The risk of infections was highest during the first year after diagnosis. The risk of bacterial infections was 11-fold, and the risk of viral infections was nearly 18-fold. The risk of infections in multiple myeloma patients increased significantly with time compared to controls. From 1988 and 1993, the risk was 5.7-fold; from 1994 to 1999, the risk was 7-fold; and from 2000 to 2004, the risk was 8.9-fold compared to controls.
Women had a significantly lower risk of developing infections compared to men (P < .001). Increasing age was significantly associated with a higher risk of infections (P < .001). At both 2 months and 1 year after diagnosis, 22% of the multiple myeloma deaths were infection-related.
The exact reason why there has been a rise in infection risk is unclear, Cecilie Bilmark, MD, a hematologist at Sahlgrenska University Hospital in Gothenburg, Sweden, and lead author of the study told conference attendees. However, she commented, the effect of novel drugs on infectious complications in the treatment of multiple myeloma needs to be established. Regardless of the cause, said Dr. Bilmark, clinical trials of prophylactic measures are needed. ■
Disclosure: Dr. Bilmark reported no potential conflicts of interest.
Reference
1. Bilimark C, Mellqvist UH, Landgren O, et al: Multiple myeloma and infections: A population-based study based on 9,610 multiple myeloma patients. 2012 ASH Annual Meeting. Abstract 945. Presented December 11, 2012.
