Cancer, Autoimmune Disorders Linked to Postsurgical Guillain-Barré

Pauline Anderson

November 29, 2016

A new study has shown that pre-existing autoimmune disorders or malignancies are strongly associated with the development of postsurgical Guillain-Barré syndrome (GBS).

Further research is needed on what could be a "unique entity" — patients who develop GBS after a surgical procedure — said Sara E. Hocker, MD, associate professor, neurology, Division of Neuro-critical Care, Mayo Clinic, Rochester, Minnesota.

"It might be reasonable" for clinicians with a patient who develops GBS within 8 weeks of surgery who aren't aware of a malignancy or autoimmune disorder "to consider looking for one," said Dr Hocker, because "in our study, we found these may be predictors."

The researchers found that about 15% of patients who developed GBS had a prior surgical procedure, a figure that is higher than seen in previous research.

The study was published online November 23 in Neurology.

For this analysis, the researchers retrospectively reviewed medical records of patients diagnosed with GBS between January 1995 and June 2014 at the Mayo Clinic.

They included 208 adult patients (median age, 55 years); 58% of patients were men. Of the 208 patients, 22.1% had an underlying malignancy and 9.6% had an autoimmune condition.

Researchers compared those who developed GBS within 8 weeks of a surgery or procedure (15%) with those who had GBS and no prior surgery or procedure.

That 15% of study patients had a prior surgery was "unexpectedly high," according to Dr Hocker. "It's higher compared to previously published literature, but it's still rare."

The reason the rate was higher in this study isn't clear, she said.

"Surgery in most instances does not predispose patients to GBS," she told Medscape Medical News. "Over 50,000 surgical procedures were performed during the study period, and it was very rare for a patient to develop GBS."

In the surgery group, the most common surgery was gastrointestinal (32.1%), followed by colonoscopy with biopsy (12.9%). The most commonly used type of anesthesia was general (52%), followed conscious sedation (41.9%).

No patient developed GBS after a procedure in which they were administered only spinal or local anesthesia.

About 61% of the surgical patients had an associated malignancy, but only 52.6% of these were active malignancies. The most common types of malignancies were gastrointestinal and hematologic, followed by prostate and gynecologic cancers.

Autoimmune conditions were present in 29% of the postsurgical group. Autoimmune disorders included ulcerative colitis, type 1 diabetes, Sjögren syndrome, and rheumatoid arthritis.

GBS Triggers

In addition to surgery, other possible "triggers" included chemotherapy, blood transfusion, trauma, and vaccination. Dr Hocker noted that these were the ones that researchers were able to identify.

"This gets to one of the limitations of a retrospective study; we are reliant upon what doctors or other people documented in the chart."

So, for example, in patients who developed GBS, chemotherapy was a "potential trigger" in 31.3% of cases.

The authors can't say that the chemotherapy triggered the GBS, but chemotherapy is a known potential trigger for GBS, she noted. "These patients happened to have had chemotherapy prior to GBS, so it was a potential trigger."

A univariate analysis showed that significant factors associated with GBS after a surgery or procedure were age (P = .003), malignancy (P < .0001), active malignancy (P = .05), or pre-existing autoimmune disorder (P = .001).

A multivariate logistic regression analysis showed that malignancy (P < .0001), pre-existing autoimmune disorder (P = .004), and, to a lesser extent, age (P = .05), remained significant.

That malignancy and autoimmune disorders are risk factors for GBS after surgery raises the possibility that the surgery "may act as a catalyst" for GBS, said Dr Hocker.

"It may act as a sort of stress event, in the same way that an infection does, or a vaccination can, that triggers GBS, probably because of an autoimmune pathophysiology."

Because this wasn't a prospective study, it's not possible to point to any particular surgical procedure that might increase risks for GBS more than others, said Dr Hocker.

"I listed the types of surgeries that were the most common, but that might just reflect what we were doing the most of, so it's hard to put too much weight on that."

Patients undergoing surgery shouldn't be overly concerned about these new results, said Dr Hocker. "I certainly wouldn't want this to make a patient think twice about having a surgery they need."

The study received no targeted funding. Dr Hocker serves on a scientific advisory board for SAGE Therapeutics; has received speaker honoraria from the American Academy of Neurology and honoraria from Continuum; and serves as an Associate Editor for Frontiers in Neurology Education, on the editorial board of Journal of Stroke and Cerebrovascular Diseases, and as Review Editor for Frontiers in Stroke and Frontiers in Neurocritical and Neurohospitalist Care.

Neurology. Published online November 23, 2016. Abstract

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