, based on the findings of a retrospective study conducted at the Rambam Health Care Campus, Haifa, Israel.
Although the findings are preliminary, the possible associations should be considered when treating pemphigus patients, the investigators reported in the Journal of the American Academy of Dermatology.
Khalaf Kridin, MD, of the Rambam Health Care Campus department of dermatology and his fellow investigators conducted a cross-sectional, retrospective, controlled study of 11,859 patients gathered from the Clait Health Services computerized database. A total of 1,985 pemphigus patients and 9,874 control patients were included. Patients were 72 years old on average, and most were female (60%) and Jewish (90%).
Dr. Kridin and his colleagues measured the prevalence of acute and chronic leukemia, Hodgkin and non-Hodgkin lymphoma, multiple myeloma, and polycythemia vera.
The pemphigus patients, compared with the control group, had a significantly higher prevalence of chronic leukemia (0.9% vs 0.4% [P = .007]), multiple myeloma (0.8% vs 0.4% [P = .009]), and non-Hodgkin lymphoma (1.8% vs 1.2% [P = .040]).
In a sensitivity analysis, patients with pemphigus were twice as likely to have chronic leukemia (odds ratio = 2.1; 95% confidence interval, 1.2-3.6) and multiple myeloma (OR = 2.2; 95% CI, 1.2-3.9) and were one and a half times as likely to have non-Hodgkin lymphoma (OR = 1.5; 95% CI, 1.0-2.2).
Dr. Kridin and his fellow investigators hypothesized that the risks may be related to some pemphigus treatments.
“Certain immunosuppressive treatments for pemphigus, such as azathioprine, could increase the risk of developing hematologic malignancies,” they wrote. “Controlling for immunosuppressive agents attenuated the association of pemphigus with non-Hodgkin lymphoma and multiple myeloma, hinting that they play a role in the higher prevalence.”
Chronic immune stimulation also may be influencing a higher prevalence of hematologic cancers in pemphigus patients “by randomly introducing pro-oncogenic mutations in rapidly dividing cells,” they said.
Investigators were limited by a lack of data on patients’ immunopathological subtype, clinical features, severity of pemphigus, and precise histological type of leukemia and lymphoma.
Dr. Kridin and his fellow investigators reported no relevant financial disclosures.
SOURCE: Kridin K et al. J Am Acad Dermatol. 2017 Dec 2. doi:10.1016/j.jaad.2017.11.039.