A landmark Swedish population-based study has unveiled alarming infection risks for patients with multiple myeloma (MM), demonstrating that they are five times more likely to develop infections compared to healthy individuals. The research, published in Haematologica, analyzed data from 8,672 MM patients diagnosed between 2008 and 2021, providing crucial insights into infection patterns in the pre-immunotherapy era.
Infection Risk Profile and Patient Demographics
The study, drawing from the Swedish Myeloma Registry, matched MM patients with 34,561 healthy controls. The patient cohort comprised 57% males, with 60% aged 70 years or older. Analysis revealed that MM patients faced a significantly higher risk of clinically relevant infections (HR, 5.3; 95% CI, 5.14-5.47) compared to healthy controls.
Particularly concerning was the elevated risk for specific infections:
- Bacterial infections: 5-fold increase (HR, 4.88; 95% CI, 4.70-5.07)
- Fungal infections: 7-fold increase (HR, 6.77; 95% CI, 6.13-7.47)
- Sepsis: 20% risk in MM patients vs. 4% in controls
- Pneumonia: 18% risk in MM patients vs. 4% in controls
Early Warning Signs and Disease Progression
The research uncovered a notable pattern of increased infection susceptibility even before MM diagnosis. Patients showed significantly higher infection risks three months prior to diagnosis (HR, 1.21; 95% CI, 1.16-1.26; P < .05), with elevated risks detectable up to four years before diagnosis (HR, 1.16; 95% CI, 1.05-1.28; P < .05).
Mortality Impact and Treatment Evolution
The mortality data presents a sobering picture of infection-related outcomes:
- 8% mortality rate in MM patients within three months of diagnosis
- 32% of MM patient deaths were infection-related, compared to 19% in controls
- 75% six-month mortality rate following significant infections
- 27% one-year infection-related mortality rate
Treatment Landscape and Future Implications
The study period witnessed a significant evolution in treatment approaches, with the adoption of modern therapies increasing substantially:
- 2008-2012: 68% received novel therapeutics
- 2013-2017: 90% received novel therapeutics
- 2018-2021: 97% received novel therapeutics
The researchers emphasize that these findings establish a crucial baseline for infection risk in the pre-immunotherapy era, particularly relevant as treatment paradigms shift toward CAR T-cell therapy and T-cell engagers. The data underscores the critical importance of prophylactic measures in managing infection risks during ongoing MM treatment regimens.
