Alping P, Askling J, Burman J, et al. - Researchers conducted this nationwide register-based cohort study to compare the risk of cancer in a large population of multiple sclerosis (MS) patients treated with rituximab, fingolimod, or natalizumab. Data were linked from the Swedish MS register to the Swedish Cancer Register and other national healthcare and census registers. They involved 4,187 first-ever initiations of rituximab, 1,620 of fingolimod, and 1,670 of natalizumab, in 6,136 MS patients, age-sex-and-location matched to 37,801 non-MS general population individuals. Data reported that the general population incidence rate was 31.0. There was no increased risk of invasive cancer with rituximab and natalizumab vs the general population in this first, large, comparative study of three highly effective MS disease-modifying therapies. However, in comparison with the general population and rituximab, there was a borderline-significant increased risk with fingolimod. This increased risk was not attributable to any specific type of cancer and further studies are warranted to validate these findings.