Lower Cancer Risk Seen in Multiple Sclerosis Patients
Does not appear to be due to an inherited factor
TUESDAY, March 31 (HealthDay News) -- Patients with multiple sclerosis have an overall lower cancer risk, which does not appear to be due to heredity, according to the results of a study published in the March 31 issue of Neurology.
Shahram Bahmanyar, M.D., Ph.D., from Karolinska Institute in Stockholm, Sweden, and colleagues compared estimated cancer risk in 20,276 patients with multiple sclerosis and 203,951 patients without the disease in Sweden.
After an average follow-up of 35 years, the researchers found that multiple sclerosis patients had a lower overall cancer risk (hazard ratio 0.91), although the risk was higher for cancers such as brain tumors (hazard ratio, 1.44), urinary organ cancers (HR, 1.27) and cancers of the small intestine (HR, 1.63). Cancer risk was even lower in patients diagnosed at an earlier age and in women. Overall cancer risk was similar in parents of multiple sclerosis patients and parents of patients without the disease, the report indicates.
"The reduction in cancer risk in patients with multiple sclerosis may result from behavioral change, treatment, or we speculate that some immunologic characteristics of multiple sclerosis disease activity improve antitumor surveillance," Bahmanyar and colleagues conclude. "The lack of association among parents indicates that a simple inherited characteristic is unlikely to explain the reduced cancer risk among patients with multiple sclerosis."