NASHVILLE, Tenn. – Recent research into comorbidities in multiple sclerosis – including head-scratching findings about lower cancer rates – is shedding light on the links between the disease and other illnesses, according to an epidemiologist specializing in MS.
“People should be mindful that if they look at having a positive impact on those comorbidities, they may have the ability to benefit patients in context of their MS,” Helen Tremlett, PhD, said in a video interview at the annual meeting of the Consortium of Multiple Sclerosis Centers. She is the Canada Research Chair in Neuroepidemiology and Multiple Sclerosis at the University of British Columbia, Vancouver.
In recent years, research into comorbidities in MS has risen dramatically. Dr. Tremlett found that the number of papers per year in PubMed that address MS and comorbidity has risen from roughly 30 in 2007 to about 80 in 2015, although the numbers dipped to about 50 and 60, respectively, in 2016 and 2017.
A 2015 systematic review of research into MS and comorbidities reported that while “findings were inconsistent overall,” studies suggested that “meningiomas and possibly urinary system cancers, inflammatory bowel disease, irritable bowel syndrome, epilepsy, depression, anxiety, bipolar disorder, early cataracts, and restless legs syndrome were more common than expected in the MS population.” (Mult Scler. 2015 Mar;21[3]:263-81).
Notably, most cancers are missing from this list. In fact, Dr. Tremlett cowrote a 2012 study that found lower risks of all cancers and several specific types of cancer – breast, lung, colorectal, prostate, and melanoma – in MS patients, compared with age- and gender-matched controls (Brain. 2012 Oct;135[Pt 10]:2973-9).
According to Dr. Tremlett, there are several theories about the apparent lower cancer risk in patients with MS. Perhaps their immune systems are hypervigilant, or maybe MS diagnoses inspire healthier lifestyles.