Cancer Diagnosis and Prognosis After Guillain-Barré Syndrome: A Population-Based Cohort Study.

INTRODUCTION

It is unclear whether Guillain-Barré syndrome (GBS) can be a marker of a paraneoplastic syndrome. We examined whether GBS is associated with cancer and whether the prognosis of GBS patients with cancer differs from that of other cancer patients.

MATERIALS AND METHODS

We conducted a population-based cohort study of patients diagnosed with GBS between 1978 and 2017 using Danish registry-data. Main outcome measures were cancer incidence and mortality after cancer diagnosis. We calculated absolute risks of a cancer diagnosis, treating death as competing risk, and standardized incidence ratios (SIRs) as measures of relative risk. We matched each GBS cancer patient with up to 10 cancer patients without a GBS diagnosis and examined the six-month survival after cancer diagnosis using Cox regression analysis.

RESULTS

We identified 7897 patients (58% male, median age 57 years) with GBS. During a median follow-up of 9.5 years, the one-year risk of cancer was 2.7% (95% confidence interval (CI), 2.4-3.1). The SIR was increased throughout follow-up, but most noticeably during the first year after diagnosis (SIR: 3.35, 2.92-3.83). SIRs were particularly elevated for hematologic cancers (SIR: 8.67, 6.49-11.34), smoking-related cancers (SIR: 3.57, 2.81-4.47), and cancers of neurological origin (SIR: 8.60, 5.01-13.77). Lung cancer was the main contributor to the overall excess risk, which persisted after 36 months of follow-up (SIR: 1.17, 1.09-1.25). The mortality rate ratio comparing patients diagnosed with any cancer within one year of their GBS diagnosis and matched GBS-free cancer cohort members was 1.56 (95% CI, 1.27-1.90).

CONCLUSION

GBS patients had a three-fold increased risk of cancer diagnosis in the first year of follow-up. The absolute cancer risk was almost 3.0%. A GBS diagnosis was an adverse prognostic marker for survival following cancer diagnosis. Clinicians should consider occult cancer in patients hospitalized with GBS.