Cancer occurrence following azathioprine treatment in myasthenia gravis patients: A systematic review and meta-analysis

•Azathioprine is the first-line immunotherapy in myasthenia gravis patients.•The safety of azathioprine raises concern in other autoimmune disease like Crohn's disease.•Azathioprine will not increase overall cancer risk in myasthenia gravis patients.•Clinicians should regularly monitor side effects of azathioprine in the long term.