Immune checkpoint inhibitors can affect any organ, including the salivary glands. A case of Sjögren's syndrome (SjS) induced by nivolumab for the treatment of gastric cancer is herein presented. Nivolumab treatment caused marked tumor shrinkage, but xerostomia developed after two cycles. It took 3 months after symptom onset to confirm the diagnosis of SjS. Prednisolone and pilocarpine hydrochloride did not relieve the symptoms. SjS is a relatively rare immune-related adverse event that might sometimes be overlooked. Since SjS can severely impair a patient's quality of life, oncologists should not miss any signs of salivary gland hypofunction and cooperate with specialists for SjS.
Keywords: Sjögren's syndrome; immune checkpoint inhibitors; immune-related adverse event.