Many lymphoma treatments are known to affect the immune system, so researchers assessed whether survivors of diffuse large B-cell lymphoma (DLBCL) have an altered risk of developing autoimmune and infectious diseases compared to other cancer survivors. Tanaya Shree, MD, PhD, at Stanford University Medical Center in California, discussed the findings at the ASH Annual Meeting.
In this large, population-based study, researchers used the California Cancer Registry to identify 21,690 adults (aged 18 years or older) with newly diagnosed DLBCL who survived a minimum of one year from diagnosis without any evidence of HIV/AIDS. Patients were excluded if they had autoimmune or infectious diseases prior to or within one year of their cancer diagnosis.
The patients were identified between 1991 and 2012 and followed in California hospital, emergency department, and ambulatory surgery discharge databases through 2014. Outcomes were compared to a cohort of female breast and male prostate cancer survivors who were alive 1–10 years after diagnosis.
Most patients with DLBCL had at least one hospitalization prior to or within one year of diagnosis (67.9%) and between 1 to 10 years of diagnosis (78.6%).
The cohort with female breast (8.2 years) and male prostate (8.3 years) survivors had a longer median follow-up than the DLBCL cohort (female = 6.3 years; male = 5.9 years).
DLBCL survivors had a higher cumulative incidence of autoimmune or infectious disease diagnoses than the breast and prostate cancer cohort. After adjusting for demographic characteristics, the researchers found that DLBCL survivors had a more than two-fold higher incidence of (p < 0.0001 for all):
- Fungal pneumonia (incidence rate ratio [IRR] = 6.2 versus breast cancer; IRR = 8.2 versus prostate cancer)
- Viral pneumonia (IRR = 3.4 versus breast cancer; IRR = 4.5 versus prostate cancer)
- Bacteremia (IRR = 2.6 versus breast cancer; IRR = 3.1 versus prostate cancer)
- Central nervous system infections (IRR = 2.6 versus breast cancer; IRR = 3.2 versus prostate cancer)
Compared to prostate cancer survivors, male DLBCL survivors had a higher incidence of liver abscesses (IRR = 3.0), empyema (IRR = 2.4), bacterial pneumonias (IRR = 2.1), and infections of implanted devices (IRR = 2.1).
DLBCL survivors also had a higher incidence of (p < 0.0001 for all):
- Autoimmune hemolytic anemia (IRR = 10.1 versus breast cancer; IRR = 8.7 versus prostate cancer)
- Immune thrombocytopenia (IRR = 3.1 versus breast cancer; IRR = 4.7 versus prostate cancer)
- Diffuse connective tissue diseases (IRR = 2.1 versus breast cancer; IRR = 2.5 versus prostate cancer)
The researchers also found that male DLBCL survivors had an increase in acquired coagulation factor deficiencies (IRR = 2.1), caused by autoimmunity against clotting factors, compared to male prostate cancer survivors. DLBCL survivors had a markedly increased incidence of being diagnosed with impaired humoral immunity (IRR = 16 versus breast cancer; IRR = 14 versus prostate cancer), which could be a reflection of persistent hypogammaglobulinemia, the researchers suggested.
“These findings suggest that, compared to survivors of other common cancers, DLBCL survivors experience excess immune-related conditions, some expected (such as autoimmune hemolytic anemia and thrombocytopenia) and others unexpected (such as fungal and viral pneumonias and diffuse connective tissue diseases),” the researchers concluded. Further research is needed to examine the immune function in DLBCL survivors.