People who have certain types of cancers may have an increased risk of having new onset Guillain-Barré syndrome (GBS), according to a study published in the March 2, 2022, online issue of Neurology, the medical journal of the American Academy of Neurology. Researchers from Aarhus University Hospital in Denmark found an increased risk in people who had lymphomas and blood cancers, as well as in those who had lung, prostate, or breast cancers.
GBS is an acute inflammatory polyradiculoneuropathy that usually develops after infection. “Recent infections are reported in 40% to 70% of the cases, with a 10- to 20-fold increased risk of subsequent GBS 60 days after hospital-diagnosed infections, and a 3-to-5 fold increased risk of GBS after community-treated infections, compared with no infection exposure,” the authors write. Still, half of all patients with GBS are not preceded by an infection, indicating that other important risk factors may play a triggering role, such as cancer.
While previous studies have suggested a link between cancer and GBS, quantifying that number, as well as the types of cancers associated with the disease, has not been well-studied. “To our knowledge, only two small population-based epidemiological studies have formally evaluated cancer as a GBS risk,” the authors write.
To address those unanswered questions the researchers conducted a nationwide population-based case-control study of all patients with first-time hospital-diagnosed GBS in Denmark between 1987 and 2016. They looked at the population of nearly six million people in Denmark and found that people diagnosed with certain cancer types appear to have a higher risk of developing Guillain-Barré.
Over that 30-year period, the researcher identified 2,414 patients with GBS and 23,909 controls. They then identified the number of people in the study who had a recent cancer diagnosis—either a cancer diagnosis up to six months before or two months after a Guillain-Barré diagnosis.
“In this large nationwide epidemiologic study, cancer was associated with a markedly increased risk of subsequent GBS development,” they write. Researchers found that people recently diagnosed with cancer had over a three-and-a-half times greater risk of developing Guillain-Barré than people without cancer. Of the 2,414 patients with GBS and 23,909 controls, 49 people, or 2.0% had a recent cancer diagnosis. Of those who did not have GBS, 138 controls, or 0.6% had a recent cancer diagnosis, respectively.
“The highest association was found for lymphomas and blood cancers which had a seven times greater risk,” the authors write. People with lung cancer had a 5.6 greater risk, and those with prostate, other male genital organ cancer, and breast cancer had a five times greater risk.
“While the precise mechanisms of GBS development remain unclear, it is conceivable that a tumor might lead to the development of GBS by yet unknown disturbances of the immune system, associated with several different types of cancer,” write the authors.
The researchers suggest two possible immune-based disturbances may be involved. One is that specific onconeural antibodies prompt a misdirected immune response directed against components of the peripheral nerves. Another is that cancer may induce an immunosuppressive state, leading to development of GBS by allowing autoantibodies to promote an attack on peripheral nerves.
