Older adults in the United States with some autoimmune conditions may be more likely to develop primary central nervous system lymphoma (PCNSL), according to study results reported in the British Journal of Haematology.
Researchers used the large cohort of older adults (65 years of age and older) included in the Surveillance, Epidemiology, and End Results (SEER)-Medicare database to test for associations between autoimmune conditions and PCNSL using a case-control study design.
The researchers included 1727 cases of PCNSL that were first malignant cancers classified as non-Hodgkin lymphoma and diagnosed between 1992 and 2015. Most PCNSL cases were diffuse large B-cell lymphoma (69.3%) and occurred in the brain (82.5%). The researchers also randomly selected a control group of 200,000 individuals from a random sample of Medicare participants who were alive and cancer-free. Cases and controls were matched for age, sex, race/ethnicity, and calendar year of diagnosis.
Autoimmune conditions were more prevalent among patients with PCNSL compared with control participants (21.1% vs 17.3%; adjusted odds ratio [aOR], 1.24; 95% CI, 1.09-1.40; P =.0007). PCNSL was significantly associated with systemic lupus erythematosus (aOR, 1.96; 95% CI, 1.31-2.92), polyarteritis nodusa (aOR, 3.99; 95% CI, 1.62-9.81), autoimmune hepatitis (aOR, 6.31; 95% CI, 1.50-26.57), myasthenia gravis (aOR, 3.40; 95% CI, 1.90-6.07), uveitis (aOR, 3.86; 95% C,: 2.64-5.64), and psoriasis (aOR, 1.29; 95% CI, 0.99-1.68).
After a Bonferroni correction for multiple testing, the associations between PCNSL and systemic lupus erythematosus, myasthenia gravis, and uveitis remained significant.
The researchers suggested that further research is necessary to determine whether higher treatment doses or intensity lead to increased risk for PCNSL. They also noted that despite these novel associations, “immunosuppressive treatment for these conditions cannot plausibly explain the increasing PCNSL rates over time among immunocompetent older individuals, given their very low prevalence. Further studies of the etiology of PCNSL in older adults are needed to explain this trend.”
1. Mahale P, Herr MM, Engels EA, Pfeiffer RM, Shiels MS. Autoimmune conditions and primary central nervous system lymphoma risk among older adults [published online October 17, 2019]. Br J Haematol. doi:10.1111/bjh.16222