MS MAY INCREASE CANCER RISK

 Compared with the general population, patients with multiple sclerosis (MS) have a higher risk of developing cancer, particularly of the respiratory and central nervous systems, a large and lengthy new Norwegian study suggests"We want to get the message out about clinical awareness," study author Nina Grytten Torkildsen, PhD, researcher at Norwegian Multiple Sclerosis Competence Centre, Haukeland University Hospital, Bergen, Norway, told Medscape Medical News.

"It's easy for clinicians treating MS patients not to have cancer symptoms in mind, but they shouldn't interpret every single symptom that these patients have as part of their MS," Grytten Torkildsen said.

She added that delays in cancer diagnosis in MS patients can affect treatment outcomes, including survival.

Interestingly, the study showed that patients with MS had a slightly lower risk of overall cancer compared with their siblings, due to these siblings having a higher rate of hematological cancers.

The findings were presented here at the Congress of the European Academy of Neurology (EAN) 2019.

14% Higher Risk

Using prevalence studies and the Norwegian MS Registry, the researchers gathered data on patients with MS born between 1930 and 1979. They obtained cancer information from the Norwegian Cancer Registry.

The study included 6883 patients, 8918 of their siblings, and 37,919 individuals from the general Norwegian population who acted as "healthy controls."

Over a 65-year follow-up period (from 1952 when the Cancer Registry was established, to 2017), the overall cancer risk among patients with MS was 14% higher than in non-MS population controls (hazard ratio [HR], 1.14; 95% confidence interval [CI], 1.05 - 1.23).

This higher rate was particularly evident for cancers of the respiratory system, including lymphomas and leukemia (HR, 1.66; 95% CI, 1.26 - 2.19), urinary organs (HR, 1.51; 95% CI, 1.12 - 2.04), and the central nervous system (CNS) including the meninges (HR, 1.52; 95% CI, 1.11 - 2.09).

The association was significant in women, but not in men. However, Grytten Torkildsen said she believes this is because of the small number of male study subjects with MS.

The researchers note that smoking may help explain some of the increased cancer risk in MS patients.

"Previous studies from Norway have shown that MS patients are more excessive smokers compared to the Norwegian population, so maybe that can explain the respiratory and urinary cancers," said Grytten Torkildsen.